Start porting over some of the random generation stuff.

Cargo.toml

@@ -9,7 +9,13 @@ license-file = "LICENSE"
 repository = "https://github.com/acw/simple_crypto"
 
 [dependencies]
+byteorder   = "^1.2.1"
+digest      = "^0.7.1"
+num         = "^0.1.39"
 rand        = "^0.3"
+sha-1       = "^0.7.0"
+sha2        = "^0.7.0"
+simple_asn1 = "^0.1.0"
 
 [dev-dependencies]
 quickcheck = "^0.4.1"

src/cryptonum/arithmetic_traits.rs

@@ -0,0 +1,70 @@
+macro_rules! define_arithmetic {
+    ($type: ident, $asncl: ident, $asnfn: ident,
+                   $cl: ident, $clfn: ident,
+                   $self: ident, $o: ident, $body: block) =>
+    {
+        build_assign_operator!($type, $asncl, $asnfn, $self, $o, $body);
+        derive_arithmetic_operators!($type, $cl, $clfn, $asncl, $asnfn);
+    }
+}
+
+macro_rules! build_assign_operator {
+    ($type: ident, $asncl: ident, $asnfn: ident, $self: ident,
+                   $o: ident, $body: block) =>
+    {
+        impl<'a> $asncl<&'a $type> for $type {
+            fn $asnfn(&mut $self, $o: &$type) $body
+        }
+    }
+}
+
+macro_rules! derive_arithmetic_operators
+{
+    ($type: ident, $cl: ident, $fn: ident, $asncl: ident, $asnfn: ident) => {
+        impl $asncl for $type {
+            fn $asnfn(&mut self, other: $type) {
+                self.$asnfn(&other)
+            }
+        }
+
+        impl $cl for $type {
+            type Output = $type;
+
+            fn $fn(self, other: $type) -> $type {
+                let mut res = self.clone();
+                res.$asnfn(&other);
+                res
+            }
+        }
+
+        impl<'a> $cl<&'a $type> for $type {
+            type Output = $type;
+
+            fn $fn(self, other: &$type) -> $type {
+                let mut res = self.clone();
+                res.$asnfn(other);
+                res
+            }
+        }
+
+        impl<'a> $cl<$type> for &'a $type {
+            type Output = $type;
+
+            fn $fn(self, other: $type) -> $type {
+                let mut res = self.clone();
+                res.$asnfn(&other);
+                res
+            }
+        }
+
+        impl<'a,'b> $cl<&'a $type> for &'b $type {
+            type Output = $type;
+
+            fn $fn(self, other: &$type) -> $type {
+                let mut res = self.clone();
+                res.$asnfn(other);
+                res
+            }
+        }
+    }
+}

src/cryptonum/barrett.rs

@@ -0,0 +1,112 @@
+macro_rules! derive_barrett
+{
+    ($type: ident, $barrett: ident, $count: expr) => {
+        impl CryptoNumFastMod for $type {
+            type BarrettMu = $barrett;
+
+            fn barrett_mu(&self) -> Option<$barrett> {
+                // Step #0: Don't divide by 0.
+                if self.is_zero() {
+                    return None
+                }
+                // Step #1: Compute k.
+                let mut k = $count;
+                while self.contents[k - 1] == 0 { k -= 1 };
+                // Step #2: The algorithm below only works if x has at most 2k
+                // digits, so if k*2 < count, abort this whole process.
+                if (k * 2) < $count {
+                    return None
+                }
+                // Step #2: Compute floor(b^2k / m), where m is this value.
+                let mut widebody_b2k  = [0; ($count * 2) + 1];
+                let mut widebody_self = [0; ($count * 2) + 1];
+                let mut quotient      = [0; ($count * 2) + 1];
+                let mut remainder     = [0; ($count * 2) + 1];
+                widebody_b2k[$count * 2] = 1;
+                for i in 0..k {
+                    widebody_self[i] = self.contents[i];
+                }
+                generic_div(&widebody_b2k, &widebody_self,
+                            &mut quotient, &mut remainder);
+                let mut result        = [0; $count + 1];
+                for (idx, val) in quotient.iter().enumerate() {
+                    if idx < ($count + 1) {
+                        result[idx] = *val;
+                    } else {
+                        if quotient[idx] != 0 {
+                            return None;
+                        }
+                    }
+                }
+                Some($barrett{k: k, progenitor: self.clone(), contents: result})
+            }
+
+            fn fastmod(&self, mu: &$barrett) -> $type {
+                // This algorithm is from our friends at the Handbook of
+                // Applied Cryptography, Chapter 14, Algorithm 14.42.
+                // Step #0:
+                //    Expand x so that it has the same size as the Barrett
+                //    value.
+                let mut x = [0; $count + 1];
+                for i in 0..$count {
+                    x[i] = self.contents[i];
+                }
+                // Step #1:
+                //    q1 <- floor(x / b^(k-1))
+                let mut q1 = x.clone();
+                generic_shr(&mut q1, &x, 64 * (mu.k - 1));
+                //    q2 <- q1 * mu
+                let q2 = expanding_mul(&q1, &mu.contents);
+                //    q3 <- floor(q2 / b^(k+1))
+                let mut q3big = q2.clone();
+                generic_shr(&mut q3big, &q2, 64 * (mu.k + 1));
+                let mut q3 = [0; $count + 1];
+                for (idx, val) in q3big.iter().enumerate() {
+                    if idx <= $count {
+                        q3[idx] = *val;
+                    } else {
+                        assert_eq!(*val, 0);
+                    }
+                }
+                // Step #2:
+                //    r1 <- x mod b^(k+1)
+                let mut r1 = x.clone();
+                for i in mu.k..($count+1) {
+                    r1[i] = 0;
+                }
+                //    r2 <- q3 * m mod b^(k+1)
+                let mut moddedm = [0; $count + 1];
+                for i in 0..mu.k {
+                    moddedm[i] = mu.progenitor.contents[i];
+                }
+                let mut r2 = q3.clone();
+                generic_mul(&mut r2, &q3, &moddedm);
+                //    r  <- r1 - r2
+                let mut r = r1.clone();
+                generic_sub(&mut r, &r2);
+                let is_negative = !ge(&r1, &r2);
+                // Step #3:
+                //    if r < 0 then r <- r + b^(k + 1)
+                if is_negative {
+                    let mut bk1 = [0; $count + 1];
+                    bk1[mu.k] = 1;
+                    generic_add(&mut r, &bk1);
+                }
+                // Step #4:
+                //    while r >= m do: r <- r - m.
+                while ge(&r, &moddedm) {
+                    generic_sub(&mut r, &moddedm);
+                }
+                // Step #5:
+                //    return r
+                let mut retval = [0; $count];
+                for i in 0..$count {
+                    retval[i] = r[i];
+                }
+                assert_eq!(r[$count], 0);
+                $type{ contents: retval }
+            }
+        }
+    }
+}
+

src/cryptonum/conversions.rs

@@ -0,0 +1,77 @@
+macro_rules! generate_unsigned_conversions
+{
+    ($type: ident, $count: expr) => {
+        generate_unsigned_primtype_conversions!($type, u8,  $count);
+        generate_unsigned_primtype_conversions!($type, u16, $count);
+        generate_unsigned_primtype_conversions!($type, u32, $count);
+        generate_unsigned_primtype_conversions!($type, u64, $count);
+    }
+}
+
+macro_rules! generate_signed_conversions
+{
+    ($type: ident, $base: ident) => {
+        generate_signed_primtype_conversions!($type, $base, i8,  u8);
+        generate_signed_primtype_conversions!($type, $base, i16, u16);
+        generate_signed_primtype_conversions!($type, $base, i32, u32);
+        generate_signed_primtype_conversions!($type, $base, i64, u64);
+    }
+}
+
+macro_rules! generate_unsigned_primtype_conversions
+{
+    ($type: ident, $base: ty, $count: expr) => {
+        generate_from!($type, $base, x, {
+            let mut res = $type{ contents: [0; $count] };
+            res.contents[0] = x as u64;
+            res
+        });
+        generate_into!($type, $base, self, {
+            self.contents[0] as $base
+        });
+    }
+}
+
+macro_rules! generate_signed_primtype_conversions
+{
+    ($type: ident, $untype: ident, $base: ident, $unbase: ident) => {
+        generate_from!($type, $unbase, x, {
+            $type{ negative: false, value: $untype::from(x) }
+        });
+        generate_into!($type, $unbase, self, {
+            self.value.contents[0] as $unbase
+        });
+        generate_from!($type, $base, x, {
+            let neg = x < 0;
+            $type{negative: neg, value: $untype::from(x.abs() as $unbase)}
+        });
+        generate_into!($type, $base, self, {
+            if self.negative {
+                let start = self.value.contents[0] as $unbase;
+                let mask = ($unbase::max_value() - 1) >> 1;
+                let res = (start & mask) as $base;
+                -res
+            } else {
+                self.value.contents[0] as $base
+            }
+        });
+    }
+}
+
+macro_rules! generate_from
+{
+    ($type: ident, $base: ty, $x: ident, $body: block) => {
+        impl From<$base> for $type {
+            fn from($x: $base) -> $type $body
+        }
+    }
+}
+
+macro_rules! generate_into
+{
+    ($type: ident, $base: ty, $self: ident, $body: block) => {
+        impl Into<$base> for $type {
+            fn into($self) -> $base $body
+        }
+    }
+}

src/cryptonum/extended_math.rs

@@ -1,71 +0,0 @@
-use cryptonum::signed::Signed;
-use cryptonum::traits::*;
-use std::ops::*;
-
-pub fn modinv<'a,T>(e: &T, phi: &T) -> T
-  where
-   T: Clone + CryptoNumBase + Ord,
-   T: AddAssign + SubAssign + MulAssign + DivAssign,
-   T: Add<Output=T> + Sub<Output=T> + Mul<Output=T> + Div<Output=T>,
-   &'a T: Sub<Output=T>,
-   T: 'a
-{
-    let (_, mut x, _) = extended_euclidean(e, phi);
-    let int_phi = Signed::<T>::new(phi.clone());
-    while x.is_negative() {
-        x += &int_phi;
-    }
-    x.abs()
-}
-
-pub fn modexp<T>(b: &T, e: &T, m: &T) -> T
-{
-    panic!("modexp")
-}
-
-pub fn extended_euclidean<T>(a: &T, b: &T) -> (Signed<T>, Signed<T>, Signed<T>)
-  where
-    T: Clone + CryptoNumBase + Div + Mul + Sub
-{
-    let posinta = Signed::<T>::new(a.clone());
-    let posintb = Signed::<T>::new(b.clone());
-    let (mut d, mut x, mut y) = egcd(&posinta, &posintb);
-
-    if d.is_negative() {
-        d.negate();
-        x.negate();
-        y.negate();
-    }
-
-    (d, x, y)
-}
-
-pub fn egcd<T>(a: &Signed<T>, b: &Signed<T>) -> (Signed<T>,Signed<T>,Signed<T>)
-  where
-    T: Clone + CryptoNumBase + Div + Mul + Sub
-{
-    let mut s         = Signed::<T>::zero();
-    let mut old_s     = Signed::<T>::from_u8(1);
-    let mut t         = Signed::<T>::from_u8(1);
-    let mut old_t     = Signed::<T>::zero();
-    let mut r         = b.clone();
-    let mut old_r     = a.clone();
-
-    while !r.is_zero() {
-        let quotient = old_r.clone() / r.clone();
-
-        let prov_r = r.clone();
-        let prov_s = s.clone();
-        let prov_t = t.clone();
-
-        r = old_r - (r * &quotient);
-        s = old_s - (s * &quotient);
-        t = old_t - (t * &quotient);
-
-        old_r = prov_r;
-        old_s = prov_s;
-        old_t = prov_t;
-    }
-
-    (old_r, old_s, old_t)
-}

src/cryptonum/mod.rs

@@ -3,16 +3,61 @@
 //! This module is designed to provide large, fixed-width number support for
 //! the rest of the Simple-Crypto libraries. Feel free to use it other places,
 //! of course, but that's its origin.
+//!
+//! Key generation is supported, using either the native `OsRng` or a random
+//! number generator of your choice. Obviously, you should be careful to use
+//! a cryptographically-sound random number generator sufficient for the
+//! security level you're going for.
+//!
+//! Signing and verification are via standard PKCS1 padding, but can be
+//! adjusted based on the exact hash you want. This library also supports
+//! somewhat arbitrary signing mechanisms used by your weirder network
+//! protocols. (I'm looking at you, Tor.)
+//!
+//! Encryption and decryption are via the OAEP mechanism, as described in
+//! NIST documents.
+//!
+#[macro_use]
+mod arithmetic_traits;
+#[macro_use]
+mod barrett;
+#[macro_use]
+mod conversions;
 mod core;
 #[macro_use]
-mod builder;
-//mod extended_math;
-// mod primes;
+mod modops;
+#[macro_use]
+mod primes;
+#[macro_use]
 mod signed;
-mod traits;
+#[macro_use]
 mod unsigned;
+mod traits;
+
+use cryptonum::core::*;
+use num::{BigUint,BigInt};
+use rand::Rng;
+use std::cmp::Ordering;
+use std::fmt::{Debug,Error,Formatter};
+use std::ops::*;
+pub use self::traits::*;
+use self::primes::SMALL_PRIMES;
+
+construct_unsigned!(U512,   BarretMu512,   u512,     8);
+construct_unsigned!(U1024,  BarretMu1024,  u1024,   16);
+construct_unsigned!(U2048,  BarretMu2048,  u2048,   32);
+construct_unsigned!(U3072,  BarretMu3072,  u3072,   48);
+construct_unsigned!(U4096,  BarretMu4096,  u4096,   64);
+construct_unsigned!(U7680,  BarretMu7680,  u7680,  120);
+construct_unsigned!(U8192,  BarretMu8192,  u8192,  128);
+construct_unsigned!(U15360, BarretMu15360, u15360, 240);
+
+construct_signed!(I512,   U512,   i512);
+construct_signed!(I1024,  U1024,  i1024);
+construct_signed!(I2048,  U2048,  i2048);
+construct_signed!(I3072,  U3072,  i3072);
+construct_signed!(I4096,  U4096,  i4096);
+construct_signed!(I7680,  U7680,  i7680);
+construct_signed!(I8192,  U8192,  i8192);
+construct_signed!(I15360, U15360, i15360);
 
-// pub use self::extended_math::{modexp,modinv,extended_euclidean,egcd};
-// pub use self::primes::{probably_prime};
-pub use self::signed::{Signed};
-pub use self::unsigned::{U512,U1024,U2048,U3072,U4096,U7680,U8192,U15360};

src/cryptonum/modops.rs

@@ -0,0 +1,16 @@
+macro_rules! derive_modulo_operations
+{
+    ($type: ident) => {
+        impl CryptoNumModOps for $type {
+            fn modinv(&self, _b: &Self) -> Self {
+                panic!("modinv");
+            }
+            fn modexp(&self, _a: &Self, _b: &Self) -> Self {
+                panic!("modexp");
+            }
+            fn modsq(&self, _v: &Self) -> Self {
+                panic!("modsq");
+            }
+        }
+    }
+}

src/cryptonum/primes.rs

@@ -1,9 +1,4 @@
-use cryptonum::extended_math::modexp;
-use cryptonum::traits::*;
-use rand::Rng;
-use std::ops::*;
-
-static SMALL_PRIMES: [u64; 310] = [
+pub static SMALL_PRIMES: [u32; 310] = [
       2,     3,     5,     7,    11,    13,    17,    19,    23,    29,
      31,    37,    41,    43,    47,    53,    59,    61,    67,    71,
      73,    79,    83,    89,    97,   101,   103,   107,   109,   113,
@@ -36,94 +31,89 @@ static SMALL_PRIMES: [u64; 310] = [
    1901,  1907,  1913,  1931,  1933,  1949,  1951,  1973,  1979,  1987,
    1993,  1997,  1999,  2003,  2011,  2017,  2027,  2029,  2039,  2053];
 
-
-pub fn probably_prime<G,T>(x: &T, g: &mut G, iters: usize) -> bool
-  where
-   G: Rng,
-   T: Clone + PartialOrd + Rem + Sub,
-   T: CryptoNumBase + CryptoNumSerialization,
+macro_rules! derive_prime_operations
 {
-    for tester in SMALL_PRIMES.iter() {
-        if (x % T::from_u64(*tester)) == T::zero() {
-            return false;
-        }
-    }
-    miller_rabin(g, x, iters)
-}
-
-fn miller_rabin<G,T>(g: &mut G, n: T, iters: usize) -> bool
-  where
-   G: Rng,
-   T: Clone + PartialEq + PartialOrd + Sub,
-   T: CryptoNumBase + CryptoNumSerialization,
-{
-    let one = T::from_u8(1);
-    let two = T::from_u8(2);
-    let nm1 = n - one;
-    // Quoth Wikipedia:
-    // write n - 1 as 2^r*d with d odd by factoring powers of 2 from n - 1
-    let mut d = nm1.clone();
-    let mut r = 0;
-    while d.is_even() {
-        d >>= 1;
-        r += 1;
-        assert!(r < n.bit_size());
-    }
-    // WitnessLoop: repeat k times
-    'WitnessLoop: for _k in 0..iters {
-        // pick a random integer a in the range [2, n - 2]
-        let a = random_in_range(g, &two, &nm1);
-        // x <- a^d mod n
-        let mut x = modexp(&a, &d, &n);
-        // if x = 1 or x = n - 1 then
-        if (&x == &one) || (&x == &nm1) {
-            // continue WitnessLoop
-            continue 'WitnessLoop;
-        }
-        // repeat r - 1 times:
-        for _i in 0..r {
-            // x <- x^2 mod n
-            x = modexp(&x, &two, &n);
-            // if x = 1 then
-            if &x == &one {
-                // return composite
-                return false;
+    ($type: ident, $count: expr) => {
+        impl $type {
+            fn miller_rabin<G: Rng>(&self, g: &mut G, iters: usize)
+                -> bool
+            {
+                let nm1 = self - $type::from(1 as u8);
+                // Quoth Wikipedia:
+                // write n - 1 as 2^r*d with d odd by factoring powers of 2 from n - 1
+                let mut d = nm1.clone();
+                let mut r = 0;
+                while d.is_even() {
+                    d >>= 1;
+                    r += 1;
+                    assert!(r < ($count * 64));
+                }
+                // WitnessLoop: repeat k times
+                'WitnessLoop: for _k in 0..iters {
+                    // pick a random integer a in the range [2, n - 2]
+                    let a = $type::random_in_range(g, &$type::from(2 as u8), &nm1);
+                    // x <- a^d mod n
+                    let mut x = a.modexp(&d, &self);
+                    // if x = 1 or x = n - 1 then
+                    if (&x == &$type::from(1 as u8)) || (&x == &nm1) {
+                        // continue WitnessLoop
+                        continue 'WitnessLoop;
+                    }
+                    // repeat r - 1 times:
+                    for _i in 0..r {
+                        // x <- x^2 mod n
+                        x = x.modexp(&$type::from(2 as u8), &self);
+                        // if x = 1 then
+                        if &x == &$type::from(1 as u8) {
+                            // return composite
+                            return false;
+                        }
+                        // if x = n - 1 then
+                        if &x == &nm1 {
+                            // continue WitnessLoop
+                            continue 'WitnessLoop;
+                        }
+                    }
+                    // return composite
+                    return false;
+                }
+                // return probably prime
+                true
             }
-            // if x = n - 1 then
-            if &x == &nm1 {
-                // continue WitnessLoop
-                continue 'WitnessLoop;
+
+            fn random_in_range<G: Rng>(rng: &mut G, min: &$type, max: &$type)
+                -> $type
+            {
+                loop {
+                    let candidate = $type::random_number(rng);
+                    if (&candidate >= min) && (&candidate < max) {
+                        return candidate;
+                    }
+                }
+            }
+
+            fn random_number<G: Rng>(rng: &mut G) -> $type {
+                let mut components = [0; $count];
+                for i in 0..$count {
+                    components[i] = rng.gen();
+                }
+                $type{ contents: components }
             }
         }
-        // return composite
-        return false;
-    }
-    // return probably prime
-    true
-}
 
-fn random_in_range<G,T>(rng: &mut G, min: &T, max: &T) -> T
-  where
-    G: Rng,
-    T: CryptoNumSerialization + PartialOrd
-{
-    assert_eq!(min.byte_size(), max.byte_size());
-    loop {
-        let candidate = random_number(rng, min.byte_size());
-
-        if (&candidate >= min) && (&candidate < max) {
-            return candidate;
+        impl CryptoNumPrimes for $type {
+            fn probably_prime<G: Rng>(&self, g: &mut G, iters: usize) -> bool {
+                for tester in SMALL_PRIMES.iter() {
+                    let testvalue = $type::from(*tester);
+                    if (self % testvalue).is_zero()  {
+                        return false;
+                    }
+                }
+                self.miller_rabin(g, iters)
+            }
+            fn generate_prime<G: Rng>(_g: &mut G, _iters: usize, _e: &Self, _min: &Self) -> Self {
+                panic!("generate_prime");
+            }
         }
     }
 }
-
-fn random_number<G,T>(rng: &mut G, bytelen: usize) -> T
-  where
-    G: Rng,
-    T: CryptoNumSerialization
-{
-    let components: Vec<u8> = rng.gen_iter().take(bytelen).collect();
-    T::from_bytes(&components)
-}
-
-

src/cryptonum/signed.rs

@@ -1,431 +1,237 @@
-use cryptonum::traits::*;
-use std::cmp::Ordering;
-use std::fmt::{Debug,Error,Formatter};
-use std::ops::*;
-
-pub struct Signed<T: Sized> {
-    positive: bool,
-    value: T
-}
-
-impl<T> Signed<T> {
-    pub fn new(v: T) -> Signed<T> {
-        Signed{ positive: true, value: v }
-    }
-
-    pub fn abs(&self) -> T
-      where T: Clone
-    {
-        self.value.clone()
-    }
-
-    pub fn is_positive(&self) -> bool
-      where T: CryptoNumBase
-    {
-        self.positive && !self.value.is_zero()
-    }
-
-    pub fn is_negative(&self) -> bool
-      where T: CryptoNumBase
-    {
-        !self.positive && !self.value.is_zero()
-    }
-
-    pub fn negate(&mut self)
-    {
-        self.positive = !self.positive;
-    }
-}
-
-impl<T: CryptoNumBase> CryptoNumBase for Signed<T> {
-    fn zero() -> Signed<T> {
-        Signed{ positive: true, value: T::zero() }
-    }
-    fn max_value() -> Signed<T> {
-        Signed{ positive: true, value: T::max_value() }
-    }
-    fn is_zero(&self) -> bool {
-        self.value.is_zero()
-    }
-    fn is_odd(&self) -> bool {
-        self.value.is_odd()
-    }
-    fn is_even(&self) -> bool {
-        self.value.is_even()
-    }
-    fn from_u8(x: u8) -> Signed<T> {
-        Signed{ positive: true, value: T::from_u8(x) }
-    }
-    fn to_u8(&self) -> u8 {
-        self.value.to_u8()
-    }
-    fn from_u16(x: u16) -> Signed<T> {
-        Signed{ positive: true, value: T::from_u16(x) }
-    }
-    fn to_u16(&self) -> u16 {
-        self.value.to_u16()
-    }
-    fn from_u32(x: u32) -> Signed<T> {
-        Signed{ positive: true, value: T::from_u32(x) }
-    }
-    fn to_u32(&self) -> u32 {
-        self.value.to_u32()
-    }
-    fn from_u64(x: u64) -> Signed<T> {
-        Signed{ positive: true, value: T::from_u64(x) }
-    }
-    fn to_u64(&self) -> u64 {
-        self.value.to_u64()
-    }
-}
-
-impl<T: CryptoNumFastMod> CryptoNumFastMod for Signed<T> {
-    type BarrettMu = T::BarrettMu;
-
-    fn barrett_mu(&self) -> Option<T::BarrettMu> {
-        if self.positive {
-            self.value.barrett_mu()
-        } else {
-            None
+macro_rules! construct_signed {
+    ($type: ident, $base: ident, $modname: ident) => {
+        #[derive(Clone,PartialEq,Eq)]
+        pub struct $type {
+            negative: bool,
+            value: $base
         }
-    }
 
-    fn fastmod(&self, mu: &T::BarrettMu) -> Signed<T> {
-        Signed{ positive: self.positive, value: self.value.fastmod(&mu) }
-    }
-}
-
-impl<T: Clone> Clone for Signed<T> {
-    fn clone(&self) -> Signed<T> {
-        Signed{ positive: self.positive, value: self.value.clone() }
-    }
-}
-
-impl<'a,T: PartialEq> PartialEq<&'a Signed<T>> for Signed<T> {
-    fn eq(&self, other: &&Signed<T>) -> bool {
-        (self.positive == other.positive) && (self.value == other.value)
-    }
-}
-
-impl<'a,T: PartialEq> PartialEq<Signed<T>> for &'a Signed<T> {
-    fn eq(&self, other: &Signed<T>) -> bool {
-        (self.positive == other.positive) && (self.value == other.value)
-    }
-}
-
-impl<T: PartialEq> PartialEq for Signed<T> {
-    fn eq(&self, other: &Signed<T>) -> bool {
-        (self.positive == other.positive) && (self.value == other.value)
-    }
-}
-
-impl<T: Eq> Eq for Signed<T> {}
-
-impl<T: Debug> Debug for Signed<T> {
-    fn fmt(&self, f: &mut Formatter) -> Result<(), Error> {
-        if self.positive {
-            f.write_str("+")?;
-        } else {
-            f.write_str("-")?;
-        }
-        self.value.fmt(f)
-    }
-}
-
-impl<T: Ord> Ord for Signed<T> {
-    fn cmp(&self, other: &Signed<T>) -> Ordering {
-        match (self.positive, other.positive) {
-            (true,  true)  => self.value.cmp(&other.value),
-            (true,  false) => Ordering::Greater,
-            (false, true)  => Ordering::Less,
-            (false, false) =>
-                self.value.cmp(&other.value).reverse()
-        }
-    }
-}
-
-impl<T: Ord> PartialOrd for Signed<T> {
-    fn partial_cmp(&self, other: &Signed<T>) -> Option<Ordering>{
-        Some(self.cmp(other))
-    }
-}
-
-//------------------------------------------------------------------------------
-
-impl<T: Clone> Neg for Signed<T> {
-    type Output = Signed<T>;
-
-    fn neg(self) -> Signed<T> {
-        Signed {
-            positive: !self.positive,
-            value: self.value.clone()
-        }
-    }
-}
-
-impl<'a,T: Clone> Neg for &'a Signed<T> {
-    type Output = Signed<T>;
-
-    fn neg(self) -> Signed<T> {
-        Signed {
-            positive: !self.positive,
-            value: self.value.clone()
-        }
-    }
-}
-
-//------------------------------------------------------------------------------
-
-impl<T> AddAssign for Signed<T>
-  where
-    T: Clone + Ord,
-    T: AddAssign + SubAssign,
-{
-    fn add_assign(&mut self, other: Signed<T>) {
-        match (self.positive, other.positive, self.value.cmp(&other.value)) {
-            // if the signs are the same, we maintain the sign and just increase
-            // the magnitude
-            (x, y, _) if x == y =>
-                self.value.add_assign(other.value),
-            // if the signs are different and the numbers are equal, we just set
-            // this to zero. However, we actually do the subtraction to make the
-            // timing roughly similar.
-            (_, _, Ordering::Equal) => {
-                self.positive = true;
-                self.value.sub_assign(other.value);
-            }
-            // if the signs are different and the first one is less than the
-            // second, then we flip the sign and subtract.
-            (_, _, Ordering::Less) => {
-                self.positive = !self.positive;
-                let temp = self.value.clone();
-                self.value = other.value.clone();
-                self.value.sub_assign(temp);
-            }
-            // if the signs are different and the first one is greater than the
-            // second, then we leave the sign and subtract.
-            (_, _, Ordering::Greater) => {
-                self.value.sub_assign(other.value);
-            }
-        }
-    }
-}
-
-impl<'a,T> AddAssign<&'a Signed<T>> for Signed<T>
-  where
-    T: Clone + Ord,
-    T: AddAssign + SubAssign,
-    T: AddAssign<&'a T> + SubAssign<&'a T>
-{
-    fn add_assign(&mut self, other: &'a Signed<T>) {
-        match (self.positive, other.positive, self.value.cmp(&other.value)) {
-            // if the signs are the same, we maintain the sign and just increase
-            // the magnitude
-            (x, y, _) if x == y =>
-                self.value.add_assign(&other.value),
-            // if the signs are different and the numbers are equal, we just set
-            // this to zero. However, we actually do the subtraction to make the
-            // timing roughly similar.
-            (_, _, Ordering::Equal) => {
-                self.positive = true;
-                self.value.sub_assign(&other.value);
-            }
-            // if the signs are different and the first one is less than the
-            // second, then we flip the sign and subtract.
-            (_, _, Ordering::Less) => {
-                self.positive = !self.positive;
-                let temp = self.value.clone();
-                self.value = other.value.clone();
-                self.value.sub_assign(temp);
-            }
-            // if the signs are different and the first one is greater than the
-            // second, then we leave the sign and subtract.
-            (_, _, Ordering::Greater) => {
-                self.value.sub_assign(&other.value);
-            }
-        }
-    }
-}
-
-math_operator!(Add,add,add_assign);
-
-//------------------------------------------------------------------------------
-
-impl<T> SubAssign for Signed<T>
-  where
-    T: Clone + Ord,
-    T: AddAssign + SubAssign,
-{
-    fn sub_assign(&mut self, other: Signed<T>) {
-        let mut other2 = other.clone();
-        other2.positive = !other.positive;
-        self.add_assign(other2);
-    }
-}
-
-impl<'a,T> SubAssign<&'a Signed<T>> for Signed<T>
-  where
-    T: Clone + Ord,
-    T: AddAssign + SubAssign,
-    T: AddAssign<&'a T> + SubAssign<&'a T>
-{
-    fn sub_assign(&mut self, other: &'a Signed<T>) {
-        let mut other2 = other.clone();
-        other2.positive = !other.positive;
-        self.add_assign(other2);
-    }
-}
-
-math_operator!(Sub,sub,sub_assign);
-
-//------------------------------------------------------------------------------
-
-impl<T> MulAssign for Signed<T>
-  where
-    T: MulAssign
-{
-    fn mul_assign(&mut self, other: Signed<T>) {
-        self.positive  = !(self.positive ^ other.positive);
-        self.value    *= other.value;
-    }
-}
-
-impl<'a,T> MulAssign<&'a Signed<T>> for Signed<T>
-  where
-    T: MulAssign + MulAssign<&'a T>
-{
-    fn mul_assign(&mut self, other: &'a Signed<T>) {
-        self.positive  = !(self.positive ^ other.positive);
-        self.value    *= &other.value;
-    }
-}
-
-math_operator!(Mul,mul,mul_assign);
-
-//------------------------------------------------------------------------------
-
-impl<T> DivAssign for Signed<T>
-  where
-    T: DivAssign
-{
-    fn div_assign(&mut self, other: Signed<T>) {
-        self.positive  = !(self.positive ^ other.positive);
-        self.value    /= other.value;
-    }
-}
-
-impl<'a,T> DivAssign<&'a Signed<T>> for Signed<T>
-  where
-    T: DivAssign + DivAssign<&'a T>
-{
-    fn div_assign(&mut self, other: &'a Signed<T>) {
-        self.positive  = !(self.positive ^ other.positive);
-        self.value    /= &other.value;
-    }
-}
-
-math_operator!(Div,div,div_assign);
-
-//------------------------------------------------------------------------------
-
-#[cfg(test)]
-mod tests {
-    use cryptonum::unsigned::U512;
-    use quickcheck::{Arbitrary,Gen};
-    use std::cmp::{max,min};
-    use super::*;
-
-    impl<T: Arbitrary + CryptoNumBase> Arbitrary for Signed<T> {
-        fn arbitrary<G: Gen>(g: &mut G) -> Signed<T> {
-            let value = T::arbitrary(g);
-            if value.is_zero() {
-                Signed {
-                    positive: true,
-                    value: value
+        impl Debug for $type {
+            fn fmt(&self, f: &mut Formatter) -> Result<(),Error> {
+                if self.negative {
+                    f.write_str("-")?;
+                } else {
+                    f.write_str("+")?;
                 }
-            } else {
-                Signed {
-                    positive: g.gen_weighted_bool(2),
-                    value: value
+                self.value.fmt(f)
+            }
+        }
+
+        impl<'a> PartialEq<&'a $type> for $type {
+            fn eq(&self, other: &&$type) -> bool {
+                (self.negative == other.negative) &&
+                (self.value    == other.value)
+            }
+        }
+
+        impl PartialOrd for $type {
+            fn partial_cmp(&self, other: &$type) -> Option<Ordering> {
+                Some(self.cmp(other))
+            }
+        }
+
+        impl Ord for $type {
+            fn cmp(&self, other: &$type) -> Ordering {
+                match (self.negative, other.negative) {
+                    (true,  true)  =>
+                        self.value.cmp(&other.value).reverse(),
+                    (true,  false) => Ordering::Greater,
+                    (false, true)  => Ordering::Less,
+                    (false, false) =>
+                        self.value.cmp(&other.value)
+                }
+            }
+        }
+
+        impl CryptoNumBase for $type {
+            fn zero() -> $type {
+                $type{ negative: false, value: $base::zero() }
+            }
+            fn max_value() -> $type {
+                $type{ negative: false, value: $base::max_value() }
+            }
+            fn is_zero(&self) -> bool {
+                self.value.is_zero()
+            }
+            fn is_odd(&self) -> bool {
+                self.value.is_odd()
+            }
+            fn is_even(&self) -> bool {
+                self.value.is_even()
+            }
+        }
+
+        impl CryptoNumFastMod for $type {
+            type BarrettMu = <$base as CryptoNumFastMod>::BarrettMu;
+
+            fn barrett_mu(&self) -> Option<Self::BarrettMu> {
+                if self.negative {
+                    None
+                } else {
+                    self.value.barrett_mu()
+                }
+            }
+
+            fn fastmod(&self, mu: &Self::BarrettMu) -> $type {
+                let res = self.value.fastmod(mu);
+                $type{ negative: self.negative, value: res }
+            }
+        }
+
+        impl CryptoNumSigned for $type {
+            type Unsigned = $base;
+
+            fn new(v: $base) -> $type {
+                $type{ negative: false, value: v.clone() }
+            }
+            fn abs(&self) -> $base {
+                self.value.clone()
+            }
+            fn is_positive(&self) -> bool {
+                !self.negative
+            }
+            fn is_negative(&self) -> bool {
+                self.negative
+            }
+        }
+
+        impl Neg for $type {
+            type Output = $type;
+
+            fn neg(self) -> $type {
+                (&self).neg()
+            }
+        }
+
+        impl<'a> Neg for &'a $type {
+            type Output = $type;
+
+            fn neg(self) -> $type {
+                if self.value.is_zero() {
+                    $type{ negative: false, value: self.value.clone() }
+                } else {
+                    $type{ negative: !self.negative, value: self.value.clone() }
+                }
+            }
+        }
+
+        define_arithmetic!($type,AddAssign,add_assign,Add,add,self,other,{
+            let signs_match = self.negative == other.negative;
+            let ordering    = self.value.cmp(&other.value);
+
+            match (signs_match, ordering) {
+                (true, _) =>
+                    // if the signs are the same, we maintain the sign and
+                    // just increase the magnitude
+                    self.value.add_assign(&other.value),
+                (false, Ordering::Equal) => {
+                    // if the signs are different and the numbers are equal,
+                    // we just set this to zero. However, we actually do the
+                    // subtraction to make the timing roughly similar.
+                    self.negative = false;
+                    self.value.sub_assign(&other.value)
+                }
+                (false, Ordering::Less) => {
+                    // if the signs are different and the first one is less
+                    // than the second, then we flip the sign and subtract.
+                    self.negative = !self.negative;
+                    let mut other_copy = other.value.clone();
+                    other_copy.sub_assign(&self.value);
+                    self.value = other_copy;
+                }
+                (false, Ordering::Greater) => {
+                    // if the signs are different and the first one is
+                    // greater than the second, then we leave the sign and
+                    // subtract.
+                    self.value.sub_assign(&other.value)
+                }
+            }
+        });
+
+        define_arithmetic!($type,SubAssign,sub_assign,Sub,sub,self,other,{
+            // this is a bit inefficient, but a heck of a lot easier.
+            let mut other2 = other.clone();
+            other2.negative = !other2.negative;
+            self.add_assign(&other2)
+        });
+
+        define_arithmetic!($type,MulAssign,mul_assign,Mul,mul,self,other,{
+            self.negative = self.negative ^ other.negative;
+            self.value.mul_assign(&other.value);
+        });
+
+        define_arithmetic!($type,DivAssign,div_assign,Div,div,self,other,{
+            self.negative = self.negative ^ other.negative;
+            self.value.div_assign(&other.value);
+        });
+
+        define_arithmetic!($type,RemAssign,rem_assign,Rem,rem,self,other,{
+            self.value.rem_assign(&other.value);
+        });
+
+        generate_signed_conversions!($type, $base);
+
+        #[cfg(test)]
+        mod $modname {
+            use quickcheck::{Arbitrary,Gen};
+            use super::*;
+
+            impl Arbitrary for $type {
+                fn arbitrary<G: Gen>(g: &mut G) -> $type {
+                    let value = $base::arbitrary(g);
+                    if value.is_zero() {
+                        $type{ negative: false, value: value }
+                    } else {
+                        $type{ negative: g.gen_weighted_bool(2), value: value }
+                    }
+                }
+            }
+
+            quickcheck! {
+                fn double_negation(x: $type) -> bool {
+                    (- (- &x)) == &x
+                }
+                fn add_identity(x: $type) -> bool {
+                    (&x + $type::zero()) == &x
+                }
+                fn add_commutivity(x: $type, y: $type) -> bool {
+                    (&x + &y) == (&y + &x)
+                }
+                fn add_associativity(a: $type, b: $type, c: $type) -> bool {
+                    // we shift these to get away from rollover
+                    let x = $type{ negative: a.negative, value: a.value >> 2 };
+                    let y = $type{ negative: b.negative, value: b.value >> 2 };
+                    let z = $type{ negative: c.negative, value: c.value >> 2 };
+                    (&x + (&y + &z)) == ((&x + &y) + &z)
+                }
+                fn sub_is_add_negation(x: $type, y: $type) -> bool {
+                    (&x - &y) == (&x + (- &y))
+                }
+                fn sub_destroys(x: $type) -> bool {
+                    (&x - &x) == $type::zero()
+                }
+                fn mul_identity(x: $type) -> bool {
+                    (&x * $type::from(1)) == &x
+                }
+                fn mul_commutivity(x: $type, y: $type) -> bool {
+                    (&x * &y) == (&y * &x)
+                }
+                fn mul_associativity(a: $type, b: $type, c: $type) -> bool {
+                    // we shift these to get away from rollover
+                    let s = (a.value.bit_size() / 2) - 2;
+                    let x = $type{ negative: a.negative, value: a.value >> s };
+                    let y = $type{ negative: b.negative, value: b.value >> s };
+                    let z = $type{ negative: c.negative, value: c.value >> s };
+                    (&x * (&y * &z)) == ((&x * &y) * &z)
+                }
+                #[ignore]
+                fn div_identity(a: $type) -> bool {
+                    &a / $type::from(1) == a
+                }
+                fn div_self_is_one(a: $type) -> bool {
+                    (&a / &a) == $type::from(1)
                 }
             }
         }
     }
-
-    quickcheck! {
-        fn double_negation(x: Signed<U512>) -> bool {
-            &x == (- (- &x))
-        }
-    }
-
-    quickcheck! {
-        fn add_associates(x: Signed<U512>, y: Signed<U512>, z: Signed<U512>)
-            -> bool
-        {
-            let mut a = x.clone();
-            let mut b = y.clone();
-            let mut c = z.clone();
-
-            // we shift these right because rollover makes for weird behavior
-            a.value >>= 2;
-            b.value >>= 2;
-            c.value >>= 2;
-
-            (&a + (&b + &c)) == ((&a + &b) + &c)
-        }
-        fn add_commutes(x: Signed<U512>, y: Signed<U512>) -> bool {
-            (&x + &y) == (&y + &x)
-        }
-        fn add_identity(x: Signed<U512>) -> bool {
-            let zero = Signed{ positive: true, value: U512::zero() };
-            (&x + &zero) == &x
-        }
-    }
-
-    quickcheck! {
-        fn sub_is_add_negation(x: Signed<U512>, y: Signed<U512>) -> bool {
-            (&x - &y) == (&x + (- &y))
-        }
-    }
-
-    quickcheck! {
-        fn mul_associates(x: Signed<U512>, y: Signed<U512>, z: Signed<U512>)
-            -> bool
-        {
-            let mut a = x.clone();
-            let mut b = y.clone();
-            let mut c = z.clone();
-
-            // we shift these right because rollover makes for weird behavior
-            a.value >>= 258;
-            b.value >>= 258;
-            c.value >>= 258;
-
-            (&a * (&b * &c)) == ((&a * &b) * &c)
-        }
-        fn mul_commutes(x: Signed<U512>, y: Signed<U512>) -> bool {
-            (&x * &y) == (&y * &x)
-        }
-        fn mul_identity(x: Signed<U512>) -> bool {
-            let one = Signed{ positive: true, value: U512::from_u8(1) };
-            (&x * &one) == &x
-        }
-    }
-
-    quickcheck! {
-        fn add_mul_distribution(x:Signed<U512>,y:Signed<U512>,z:Signed<U512>)
-            -> bool
-        {
-            let mut a = x.clone();
-            let mut b = y.clone();
-            let mut c = z.clone();
-
-            // we shift these right because rollover makes for weird behavior
-            a.value >>= 258;
-            b.value >>= 258;
-            c.value >>= 258;
-
-            (&a * (&b + &c)) == ((&a * &b) + (&a * &c))
-        }
-    }
 }

src/cryptonum/traits.rs

@@ -1,3 +1,5 @@
+use rand::Rng;
+
 pub trait CryptoNumBase {
     /// Generate the zero value for this type.
     fn zero() -> Self;
@@ -9,26 +11,6 @@ pub trait CryptoNumBase {
     fn is_odd(&self) -> bool;
     /// Test if the number is even (a.k.a., the low bit is clear)
     fn is_even(&self) -> bool;
-    /// Translate a `u8` to this type. This must be safe.
-    fn from_u8(x: u8) -> Self;
-    /// Convert this back into a `u8`. This is the equivalent of masking off
-    /// the lowest 8 bits and then casting to a `u8`.
-    fn to_u8(&self) -> u8;
-    /// Translate a `u16` to this type. This must be safe.
-    fn from_u16(x: u16) -> Self;
-    /// Convert this back into a `u16`. This is the equivalent of masking off
-    /// the lowest 16 bits and then casting to a `u16`.
-    fn to_u16(&self) -> u16;
-    /// Translate a `u32` to this type. This must be safe.
-    fn from_u32(x: u32) -> Self;
-    /// Convert this back into a `u32`. This is the equivalent of masking off
-    /// the lowest 32 bits and then casting to a `u32`.
-    fn to_u32(&self) -> u32;
-    /// Translate a `u64` to this type. This must be safe.
-    fn from_u64(x: u64) -> Self;
-    /// Convert this back into a `u64`. This is the equivalent of masking off
-    /// the lowest 64 bits and then casting to a `u64`.
-    fn to_u64(&self) -> u64;
 }
 
 pub trait CryptoNumSerialization {
@@ -56,3 +38,42 @@ pub trait CryptoNumFastMod {
     /// Faster modulo through the use of the Barrett constant, above.
     fn fastmod(&self, &Self::BarrettMu) -> Self;
 }
+
+pub trait CryptoNumSigned {
+    /// The unsigned type that this type is related to.
+    type Unsigned;
+
+    /// Generate a new signed number based on the given unsigned number.
+    fn new(x: Self::Unsigned) -> Self;
+    /// Get the absolute value of the signed number, turning it back into an
+    /// unsigned number.
+    fn abs(&self) -> Self::Unsigned;
+    /// Test if the number is negative.
+    fn is_negative(&self) -> bool;
+    /// Test if the number is positive.
+    fn is_positive(&self) -> bool;
+}
+
+pub trait CryptoNumModOps: Sized
+{
+    /// Compute the modular inverse of the number.
+    fn modinv(&self, b: &Self) -> Self;
+    /// Raise the number to the power of the first value, mod the second.
+    fn modexp(&self, a: &Self, b: &Self) -> Self;
+    /// Square the number, mod the given value.
+    fn modsq(&self, v: &Self) -> Self;
+}
+
+pub trait CryptoNumPrimes
+{
+    /// Determine if the given number is probably prime using a quick spot
+    /// check and Miller-Rabin, using the given random number generator
+    /// and number of iterations.
+    fn probably_prime<G: Rng>(&self, g: &mut G, iters: usize) -> bool;
+    /// Generate a prime using the given random number generator, using
+    /// the given number of rounds to determine if the number is probably
+    /// prime. The other two numbers are a number for which the generator
+    /// should have a GCD of 1, and the minimum value for the number.
+    fn generate_prime<G: Rng>(g: &mut G, iters: usize, e: &Self, min: &Self)
+        -> Self;
+}

src/cryptonum/unsigned.rs

@@ -1,14 +1,685 @@
-use cryptonum::core::*;
-use cryptonum::traits::*;
-use std::cmp::Ordering;
-use std::fmt::{Debug,Error,Formatter};
-use std::ops::*;
+macro_rules! construct_unsigned {
+    ($type: ident, $barrett: ident, $modname: ident, $count: expr) => {
+        #[derive(Clone)]
+        pub struct $type {
+            contents: [u64; $count]
+        }
 
-construct_unsigned!(U512,   BarretMu512,   u512,     8);
-construct_unsigned!(U1024,  BarretMu1024,  u1024,   16);
-construct_unsigned!(U2048,  BarretMu2048,  u2048,   32);
-construct_unsigned!(U3072,  BarretMu3072,  u3072,   48);
-construct_unsigned!(U4096,  BarretMu4096,  u4096,   64);
-construct_unsigned!(U7680,  BarretMu7680,  u7680,  120);
-construct_unsigned!(U8192,  BarretMu8192,  u8192,  128);
-construct_unsigned!(U15360, BarretMu15360, u15360, 240);
+        pub struct $barrett {
+            k: usize,
+            progenitor: $type,
+            contents: [u64; $count + 1]
+        }
+
+        impl PartialEq for $type {
+            fn eq(&self, other: &$type) -> bool {
+                for i in 0..$count {
+                    if self.contents[i] != other.contents[i] {
+                        return false;
+                    }
+                }
+                true
+            }
+        }
+
+        impl Eq for $type {}
+
+        impl Debug for $type {
+            fn fmt(&self, f: &mut Formatter) -> Result<(),Error> {
+                f.write_str("CryptoNum{{ ")?;
+                f.debug_list().entries(self.contents.iter()).finish()?;
+                f.write_str(" }}")
+            }
+        }
+
+        impl Debug for $barrett {
+            fn fmt(&self, f: &mut Formatter) -> Result<(),Error> {
+                f.write_str("BarrettMu{{ ")?;
+                f.write_fmt(format_args!("k = {}, ", self.k))?;
+                f.write_fmt(format_args!("progen = {:?}, ",self.progenitor))?;
+                f.write_str("contents: ")?;
+                f.debug_list().entries(self.contents.iter()).finish()?;
+                f.write_str(" }}")
+            }
+        }
+
+        generate_unsigned_conversions!($type, $count);
+
+        impl PartialOrd for $type {
+            fn partial_cmp(&self, other: &$type) -> Option<Ordering> {
+                Some(generic_cmp(&self.contents, &other.contents))
+            }
+        }
+
+        impl Ord for $type {
+            fn cmp(&self, other: &$type) -> Ordering {
+                generic_cmp(&self.contents, &other.contents)
+            }
+        }
+
+        impl Not for $type {
+            type Output = $type;
+
+            fn not(self) -> $type {
+                let mut output = self.clone();
+                generic_not(&mut output.contents);
+                output
+            }
+        }
+
+        impl<'a> Not for &'a $type {
+            type Output = $type;
+
+            fn not(self) -> $type {
+                let mut output = self.clone();
+                generic_not(&mut output.contents);
+                output
+            }
+        }
+
+        define_arithmetic!($type,BitOrAssign,bitor_assign,BitOr,bitor,self,other,{
+            generic_bitor(&mut self.contents, &other.contents);
+        });
+        define_arithmetic!($type,BitAndAssign,bitand_assign,BitAnd,bitand,self,other,{
+            generic_bitand(&mut self.contents, &other.contents);
+        });
+        define_arithmetic!($type,BitXorAssign,bitxor_assign,BitXor,bitxor,self,other,{
+            generic_bitxor(&mut self.contents, &other.contents);
+        });
+        define_arithmetic!($type,AddAssign,add_assign,Add,add,self,other,{
+            generic_add(&mut self.contents, &other.contents);
+        });
+        define_arithmetic!($type,SubAssign,sub_assign,Sub,sub,self,other,{
+            generic_sub(&mut self.contents, &other.contents);
+        });
+        define_arithmetic!($type,MulAssign,mul_assign,Mul,mul,self,other,{
+            let copy = self.contents.clone();
+            generic_mul(&mut self.contents, &copy, &other.contents);
+        });
+        define_arithmetic!($type,DivAssign,div_assign,Div,div,self,other,{
+            let mut dead = [0; $count];
+            let     copy = self.contents.clone();
+            generic_div(&copy, &other.contents,
+                        &mut self.contents, &mut dead);
+        });
+        define_arithmetic!($type,RemAssign,rem_assign,Rem,rem,self,other,{
+            let mut dead = [0; $count];
+            let     copy = self.contents.clone();
+            generic_div(&copy, &other.contents,
+                        &mut dead, &mut self.contents);
+        });
+
+        shifts!($type, usize);
+        shifts!($type, u64);
+        shifts!($type, i64);
+        shifts!($type, u32);
+        shifts!($type, i32);
+        shifts!($type, u16);
+        shifts!($type, i16);
+        shifts!($type, u8);
+        shifts!($type, i8);
+
+        impl CryptoNumBase for $type {
+            fn zero() -> $type {
+                $type { contents: [0; $count] }
+            }
+
+            fn max_value() -> $type {
+                $type { contents: [0xFFFFFFFFFFFFFFFF; $count] }
+            }
+
+            fn is_zero(&self) -> bool {
+                for x in self.contents.iter() {
+                    if *x != 0 {
+                        return false;
+                    }
+                }
+                true
+            }
+
+            fn is_odd(&self) -> bool {
+                (self.contents[0] & 1) == 1
+            }
+
+            fn is_even(&self) -> bool {
+                (self.contents[0] & 1) == 0
+            }
+        }
+
+        impl CryptoNumSerialization for $type {
+            fn bit_size(&self) -> usize {
+                $count * 64
+            }
+
+            fn byte_size(&self) -> usize {
+                $count * 8
+            }
+
+            fn to_bytes(&self) -> Vec<u8> {
+                let mut res = Vec::with_capacity($count * 8);
+                for x in self.contents.iter() {
+                    res.push( (x >> 56) as u8 );
+                    res.push( (x >> 48) as u8 );
+                    res.push( (x >> 40) as u8 );
+                    res.push( (x >> 32) as u8 );
+                    res.push( (x >> 24) as u8 );
+                    res.push( (x >> 16) as u8 );
+                    res.push( (x >>  8) as u8 );
+                    res.push( (x >>  0) as u8 );
+                }
+                res
+            }
+
+            fn from_bytes(x: &[u8]) -> $type {
+                let mut res = $type::zero();
+                let mut i = 0;
+
+                assert!(x.len() >= ($count * 8));
+                for chunk in x.chunks(8) {
+                    assert!(chunk.len() == 8);
+                    res.contents[i] = ((chunk[0] as u64) << 56) |
+                                      ((chunk[1] as u64) << 48) |
+                                      ((chunk[2] as u64) << 40) |
+                                      ((chunk[3] as u64) << 32) |
+                                      ((chunk[4] as u64) << 24) |
+                                      ((chunk[5] as u64) << 16) |
+                                      ((chunk[6] as u64) <<  8) |
+                                      ((chunk[7] as u64) <<  0);
+                    i += 1;
+                }
+                assert!(i == $count);
+                res
+            }
+        }
+
+        derive_barrett!($type, $barrett, $count);
+        derive_modulo_operations!($type);
+        derive_prime_operations!($type, $count);
+
+        impl Into<BigInt> for $type {
+            fn into(self) -> BigInt {
+                panic!("into bigint")
+            }
+        }
+
+        impl Into<BigUint> for $type {
+            fn into(self) -> BigUint {
+                panic!("into big uint")
+            }
+        }
+
+        impl From<BigInt> for $type {
+            fn from(_x: BigInt) -> Self {
+                panic!("from bigint")
+            }
+        }
+
+        impl From<BigUint> for $type {
+            fn from(_x: BigUint) -> Self {
+                panic!("from biguint")
+            }
+        }
+
+        #[cfg(test)]
+        mod $modname {
+            use quickcheck::{Arbitrary,Gen};
+            use super::*;
+
+            impl Arbitrary for $type {
+                fn arbitrary<G: Gen>(g: &mut G) -> $type {
+                    let mut res = [0; $count];
+
+                    for i in 0..$count {
+                        res[i] = g.next_u64();
+                    }
+                    $type{ contents: res }
+                }
+            }
+
+            #[test]
+            fn test_builders() {
+                let mut buffer = [0; $count];
+                assert_eq!($type{ contents: buffer }, $type::from(0 as u8));
+                buffer[0] = 0x7F;
+                assert_eq!($type{ contents: buffer }, $type::from(0x7F as u8));
+                buffer[0] = 0x7F7F;
+                assert_eq!($type{ contents: buffer }, $type::from(0x7F7F as u16));
+                buffer[0] = 0xCA5CADE5;
+                assert_eq!($type{ contents: buffer },
+                           $type::from(0xCA5CADE5 as u32));
+                assert_eq!($type{ contents: buffer },
+                           $type::from(0xCA5CADE5 as u32));
+                buffer[0] = 0xFFFFFFFFFFFFFFFF;
+                assert_eq!($type{ contents: buffer },
+                           $type::from(0xFFFFFFFFFFFFFFFF as u64));
+            }
+
+            #[test]
+            fn test_max() {
+                let max64: u64 = $type::from(u64::max_value()).into();
+                assert_eq!(max64, u64::max_value());
+                let max64v: u64 = $type::max_value().into();
+                assert_eq!(max64v, u64::max_value());
+                assert_eq!($type::max_value() + $type::from(1 as u8), $type::zero());
+            }
+
+            quickcheck! {
+                fn builder_u8_upgrade_u16(x: u8) -> bool {
+                    $type::from(x) == $type::from(x as u16)
+                }
+                fn builder_u16_upgrade_u32(x: u16) -> bool {
+                    $type::from(x) == $type::from(x as u32)
+                }
+                fn builder_u32_upgrade_u64(x: u32) -> bool {
+                    $type::from(x) == $type::from(x as u64)
+                }
+                fn builder_u8_roundtrips(x: u8) -> bool {
+                    let thereback: u8 = $type::from(x).into();
+                    x == thereback
+                }
+                fn builder_u16_roundtrips(x: u16) -> bool {
+                    let thereback: u16 = $type::from(x).into();
+                    x == thereback
+                }
+                fn builder_u32_roundtrips(x: u32) -> bool {
+                    let thereback: u32 = $type::from(x).into();
+                    x == thereback
+                }
+                fn builder_u64_roundtrips(x: u64) -> bool {
+                    let thereback: u64 = $type::from(x).into();
+                    x == thereback
+                }
+            }
+
+            quickcheck! {
+                fn partial_ord64_works(x: u64, y: u64) -> bool {
+                    let xbig = $type::from(x);
+                    let ybig = $type::from(y);
+                    xbig.partial_cmp(&ybig) == x.partial_cmp(&y)
+                }
+                fn ord64_works(x: u64, y: u64) -> bool {
+                    let xbig = $type::from(x);
+                    let ybig = $type::from(y);
+                    xbig.cmp(&ybig) == x.cmp(&y)
+                }
+            }
+
+            quickcheck! {
+                fn and_annulment(x: $type) -> bool {
+                    (x & $type::zero()) == $type::zero()
+                }
+                fn or_annulment(x: $type) -> bool {
+                    (x | $type::max_value()) == $type::max_value()
+                }
+                fn and_identity(x: $type) -> bool {
+                    (&x & $type::max_value()) == x
+                }
+                fn or_identity(x: $type) -> bool {
+                    (&x | $type::zero()) == x
+                }
+                fn and_idempotent(x: $type) -> bool {
+                    (&x & &x) == x
+                }
+                fn or_idempotent(x: $type) -> bool {
+                    (&x | &x) == x
+                }
+                fn and_complement(x: $type) -> bool {
+                    (&x & &x) == x
+                }
+                fn or_complement(x: $type) -> bool {
+                    (&x | !&x) == $type::max_value()
+                }
+                fn and_commutative(x: $type, y: $type) -> bool {
+                    (&x & &y) == (&y & &x)
+                }
+                fn or_commutative(x: $type, y: $type) -> bool {
+                    (&x | &y) == (&y | &x)
+                }
+                fn double_negation(x: $type) -> bool {
+                    !!&x == x
+                }
+                fn or_distributive(a: $type, b: $type, c: $type) -> bool {
+                    (&a & (&b | &c)) == ((&a & &b) | (&a & &c))
+                }
+                fn and_distributive(a: $type, b: $type, c: $type) -> bool {
+                    (&a | (&b & &c)) == ((&a | &b) & (&a | &c))
+                }
+                fn or_absorption(a: $type, b: $type) -> bool {
+                    (&a | (&a & &b)) == a
+                }
+                fn and_absorption(a: $type, b: $type) -> bool {
+                    (&a & (&a | &b)) == a
+                }
+                fn or_associative(a: $type, b: $type, c: $type) -> bool {
+                    (&a | (&b | &c)) == ((&a | &b) | &c)
+                }
+                fn and_associative(a: $type, b: $type, c: $type) -> bool {
+                    (&a & (&b & &c)) == ((&a & &b) & &c)
+                }
+                fn xor_as_defined(a: $type, b: $type) -> bool {
+                    (&a ^ &b) == ((&a | &b) & !(&a & &b))
+                }
+                fn small_or_check(x: u64, y: u64) -> bool {
+                    let x512 = $type::from(x);
+                    let y512 = $type::from(y);
+                    let z512 = x512 | y512;
+                    let res: u64 = z512.into();
+                    res == (x | y)
+                }
+                fn small_and_check(x: u64, y: u64) -> bool {
+                    let x512 = $type::from(x);
+                    let y512 = $type::from(y);
+                    let z512 = x512 & y512;
+                    let res: u64 = z512.into();
+                    res == (x & y)
+                }
+                fn small_xor_check(x: u64, y: u64) -> bool {
+                    let x512 = $type::from(x);
+                    let y512 = $type::from(y);
+                    let z512 = x512 ^ y512;
+                    let res: u64 = z512.into();
+                    res == (x ^ y)
+                }
+                fn small_neg_check(x: u64) -> bool {
+                    let x512 = $type::from(x);
+                    let z512 = !x512;
+                    let res: u64 = z512.into();
+                    res == !x
+                }
+            }
+
+            #[test]
+            fn shl_tests() {
+                let ones = [1; $count];
+                assert_eq!($type{ contents: ones.clone() } << 0,
+                           $type{ contents: ones.clone() });
+                let mut notones = [0; $count];
+                for i in 0..$count {
+                    notones[i] = (i + 1) as u64;
+                }
+                assert_eq!($type{ contents: notones.clone() } << 0,
+                           $type{ contents: notones.clone() });
+                assert_eq!($type{ contents: ones.clone() } << ($count * 64),
+                           $type::zero());
+                assert_eq!($type::from(2 as u8) << 1, $type::from(4 as u8));
+                let mut buffer = [0; $count];
+                buffer[1] = 1;
+                assert_eq!($type::from(1 as u8) << 64,
+                           $type{ contents: buffer.clone() });
+                buffer[0] = 0xFFFFFFFFFFFFFFFE;
+                assert_eq!($type::from(0xFFFFFFFFFFFFFFFF as u64) << 1,
+                           $type{ contents: buffer.clone() });
+                buffer[0] = 0;
+                buffer[1] = 4;
+                assert_eq!($type::from(1 as u8) << 66,
+                           $type{ contents: buffer.clone() });
+                assert_eq!($type::from(1 as u8) << 1, $type::from(2 as u8));
+            }
+
+            #[test]
+            fn shr_tests() {
+                let ones  = [1; $count];
+                assert_eq!($type{ contents: ones.clone() } >> 0,
+                           $type{ contents: ones.clone() });
+                let mut notones = [0; $count];
+                for i in 0..$count {
+                    notones[i] = (i + 1) as u64;
+                }
+                assert_eq!($type{ contents: ones.clone() } >> 0,
+                           $type{ contents: ones.clone() });
+                assert_eq!($type{ contents: ones.clone() } >> ($count * 64),
+                           $type::zero());
+                assert_eq!($type::from(2 as u8) >> 1,
+                           $type::from(1 as u8));
+                let mut oneleft = [0; $count];
+                oneleft[1] = 1;
+                assert_eq!($type{ contents: oneleft.clone() } >> 1,
+                           $type::from(0x8000000000000000 as u64));
+                assert_eq!($type{ contents: oneleft.clone() } >> 64,
+                           $type::from(1 as u64));
+                oneleft[1] = 4;
+                assert_eq!($type{ contents: oneleft.clone() } >> 66,
+                           $type::from(1 as u64));
+            }
+
+            quickcheck! {
+                fn shift_mask_equivr(x: $type, in_shift: usize) -> bool {
+                    let shift       = in_shift % ($count * 64);
+                    let mask        = $type::max_value() << shift;
+                    let masked_x    = &x & mask;
+                    let shift_maskr = (x >> shift) << shift;
+                    shift_maskr == masked_x
+                }
+                fn shift_mask_equivl(x: $type, in_shift: usize) -> bool {
+                    let shift       = in_shift % ($count * 64);
+                    let mask        = $type::max_value() >> shift;
+                    let masked_x    = &x & mask;
+                    let shift_maskl = (x << shift) >> shift;
+                    shift_maskl == masked_x
+                }
+            }
+
+            #[test]
+            fn add_tests() {
+                let ones = [1; $count];
+                let twos = [2; $count];
+                assert_eq!($type{ contents: ones.clone() } +
+                           $type{ contents: ones.clone() },
+                           $type{ contents: twos.clone() });
+                let mut buffer = [0; $count];
+                buffer[1] = 1;
+                assert_eq!($type::from(1 as u64) +
+                           $type::from(0xFFFFFFFFFFFFFFFF as u64),
+                           $type{ contents: buffer.clone() });
+                let mut high = [0; $count];
+                high[$count - 1] = 0xFFFFFFFFFFFFFFFF;
+                buffer[1] = 0;
+                buffer[$count - 1] = 1;
+                assert_eq!($type{ contents: buffer } + $type{ contents: high },
+                           $type{ contents: [0; $count] });
+            }
+
+            quickcheck! {
+                fn add_symmetry(a: $type, b: $type) -> bool {
+                    (&a + &b) == (&b + &a)
+                }
+                fn add_commutivity(a: $type, b: $type, c: $type) -> bool {
+                    (&a + (&b + &c)) == ((&a + &b) + &c)
+                }
+                fn add_identity(a: $type) -> bool {
+                    (&a + $type::zero()) == a
+                }
+            }
+
+            #[test]
+            fn sub_tests() {
+                let ones = [1; $count];
+                assert_eq!($type{ contents: ones.clone() } -
+                           $type{ contents: ones.clone() },
+                           $type::zero());
+                let mut buffer = [0; $count];
+                buffer[1] = 1;
+                assert_eq!($type{contents:buffer.clone()} - $type::from(1 as u8),
+                           $type::from(0xFFFFFFFFFFFFFFFF as u64));
+                assert_eq!($type::zero() - $type::from(1 as u8),
+                           $type::max_value());
+            }
+
+            quickcheck! {
+                fn sub_destroys(a: $type) -> bool {
+                    (&a - &a) == $type::zero()
+                }
+                fn sub_add_ident(a: $type, b: $type) -> bool {
+                    ((&a - &b) + &b) == a
+                }
+            }
+
+            #[test]
+            fn mul_tests() {
+                assert_eq!($type::from(1 as u8) * $type::from(1 as u8),
+                           $type::from(1 as u8));
+                assert_eq!($type::from(1 as u8) * $type::from(0 as u8),
+                           $type::from(0 as u8));
+                assert_eq!($type::from(1 as u8) * $type::from(2 as u8),
+                           $type::from(2 as u8));
+                let mut temp = $type::zero();
+                temp.contents[0] = 1;
+                temp.contents[1] = 0xFFFFFFFFFFFFFFFE;
+                assert_eq!($type::from(0xFFFFFFFFFFFFFFFF as u64) *
+                           $type::from(0xFFFFFFFFFFFFFFFF as u64),
+                           temp);
+                let effs = $type{ contents: [0xFFFFFFFFFFFFFFFF; $count] };
+                assert_eq!($type::from(1 as u8) * &effs, effs);
+                temp = effs.clone();
+                temp.contents[0] = temp.contents[0] - 1;
+                assert_eq!($type::from(2 as u8) * &effs, temp);
+            }
+
+            quickcheck! {
+                fn mul_symmetry(a: $type, b: $type) -> bool {
+                    (&a * &b) == (&b * &a)
+                }
+                fn mul_commutivity(a: $type, b: $type, c: $type) -> bool {
+                    (&a * (&b * &c)) == ((&a * &b) * &c)
+                }
+                fn mul_identity(a: $type) -> bool {
+                    (&a * $type::from(1 as u8)) == a
+                }
+                fn mul_zero(a: $type) -> bool {
+                    (&a * $type::zero()) == $type::zero()
+                }
+            }
+
+            quickcheck! {
+                fn addmul_distribution(a: $type, b: $type, c: $type) -> bool {
+                    (&a * (&b + &c)) == ((&a * &b) + (&a * &c))
+                }
+                fn submul_distribution(a: $type, b: $type, c: $type) -> bool {
+                    (&a * (&b - &c)) == ((&a * &b) - (&a * &c))
+                }
+                fn mul2shift1_equiv(a: $type) -> bool {
+                    (&a << 1) == (&a * $type::from(2 as u8))
+                }
+                fn mul16shift4_equiv(a: $type) -> bool {
+                    (&a << 4) == (&a * $type::from(16 as u8))
+                }
+            }
+
+            #[test]
+            fn div_tests() {
+                assert_eq!($type::from(2 as u8) / $type::from(2 as u8),
+                           $type::from(1 as u8));
+                assert_eq!($type::from(2 as u8) / $type::from(1 as u8),
+                           $type::from(2 as u8));
+                assert_eq!($type::from(4 as u8) / $type::from(3 as u8),
+                           $type::from(1 as u8));
+                assert_eq!($type::from(4 as u8) / $type::from(5 as u8),
+                           $type::from(0 as u8));
+                assert_eq!($type::from(4 as u8) / $type::from(4 as u8),
+                           $type::from(1 as u8));
+                let mut temp1 = $type::zero();
+                let mut temp2 = $type::zero();
+                temp1.contents[$count - 1] = 4;
+                temp2.contents[$count - 1] = 4;
+                assert_eq!(&temp1 / temp2, $type::from(1 as u8));
+                assert_eq!(&temp1 / $type::from(1 as u8), temp1);
+                temp1.contents[$count - 1] = u64::max_value();
+                assert_eq!(&temp1 / $type::from(1 as u8), temp1);
+            }
+
+            #[test]
+            #[should_panic]
+            fn div0_fails() {
+                $type::from(0xabcd as u16) / $type::zero();
+            }
+
+            #[test]
+            fn mod_tests() {
+                assert_eq!($type::from(4 as u16) % $type::from(5 as u16),
+                           $type::from(4 as u16));
+                assert_eq!($type::from(5 as u16) % $type::from(4 as u16),
+                           $type::from(1 as u16));
+                let fives = $type{ contents: [5; $count] };
+                let fours = $type{ contents: [4; $count] };
+                let ones  = $type{ contents: [1; $count] };
+                assert_eq!(fives % fours, ones);
+            }
+
+            quickcheck! {
+                #[ignore]
+                fn div_identity(a: $type) -> bool {
+                    &a / $type::from(1 as u16) == a
+                }
+                fn div_self_is_one(a: $type) -> bool {
+                    if a == $type::zero() {
+                        return true;
+                    }
+                    &a / &a == $type::from(1 as u16)
+                }
+                fn euclid_is_alive(a: $type, b: $type) -> bool {
+                    let q = &a / &b;
+                    let r = &a % &b;
+                    a == ((b * q) + r)
+                }
+            }
+
+            quickcheck! {
+                fn serialization_inverts(a: $type) -> bool {
+                    let bytes = a.to_bytes();
+                    let b = $type::from_bytes(&bytes);
+                    a == b
+                }
+            }
+
+            quickcheck! {
+                fn fastmod_works(a: $type, b: $type) -> bool {
+                    assert!(b != $type::zero());
+                    match b.barrett_mu() {
+                        None =>
+                            true,
+                        Some(barrett) => {
+                            a.fastmod(&barrett) == (&a % &b)
+                        }
+                    }
+                }
+            }
+        }
+    };
+}
+
+macro_rules! shifts {
+    ($type: ident, $shtype: ty) => {
+        shifts!($type, $shtype, ShlAssign, shl_assign, Shl, shl, generic_shl);
+        shifts!($type, $shtype, ShrAssign, shr_assign, Shr, shr, generic_shr);
+    };
+
+    ($type: ident, $shtype: ty, $asncl: ident, $asnfn: ident,
+     $cl: ident, $fn: ident, $impl: ident) => {
+        impl $asncl<$shtype> for $type {
+            fn $asnfn(&mut self, amount: $shtype) {
+                let copy = self.contents.clone();
+                $impl(&mut self.contents, &copy, amount as usize);
+            }
+        }
+
+        impl $cl<$shtype> for $type {
+            type Output = $type;
+
+            fn $fn(self, rhs: $shtype) -> $type {
+                let mut res = self.clone();
+                $impl(&mut res.contents, &self.contents, rhs as usize);
+                res
+            }
+        }
+
+        impl<'a> $cl<$shtype> for &'a $type {
+            type Output = $type;
+
+            fn $fn(self, rhs: $shtype) -> $type {
+                let mut res = self.clone();
+                $impl(&mut res.contents, &self.contents, rhs as usize);
+                res
+            }
+        }
+    }
+}

src/lib.rs

@@ -11,14 +11,24 @@
 //! when they should use it, and examples. For now, it mostly just fowards
 //! off to more detailed modules. Help requested!
 
+extern crate byteorder;
+extern crate digest;
+extern crate num;
 #[cfg(test)]
 #[macro_use]
 extern crate quickcheck;
 extern crate rand;
+extern crate sha1;
+extern crate sha2;
+extern crate simple_asn1;
 
 /// The cryptonum module provides support for large numbers at fixed,
 /// cryptographically-relevant sizes.
 pub mod cryptonum;
+/// The RSA module performs the basic operations for RSA, and should
+/// be used directly only if you're fairly confident about what you're
+/// doing.
+pub mod rsa;
 
 #[cfg(test)]
 mod test {

src/rsa/core.rs

@@ -0,0 +1,59 @@
+use cryptonum::{CryptoNumModOps};
+use num::BigUint;
+use rsa::errors::RSAError;
+use simple_asn1::{ASN1DecodeErr,ASN1Block};
+
+// encoding PKCS1 stuff
+pub fn pkcs1_pad(ident: &[u8], hash: &[u8], keylen: usize) -> Vec<u8> {
+    let mut idhash = Vec::new();
+    idhash.extend_from_slice(ident);
+    idhash.extend_from_slice(hash);
+    let tlen = idhash.len();
+    assert!(keylen > (tlen + 3));
+    let mut padding = Vec::new();
+    padding.resize(keylen - tlen - 3, 0xFF);
+    let mut result = vec![0x00, 0x01];
+    result.append(&mut padding);
+    result.push(0x00);
+    result.append(&mut idhash);
+    result
+}
+
+// the RSA encryption function
+pub fn ep<U: CryptoNumModOps>(n: &U, e: &U, m: &U) -> U {
+    m.modexp(e, n)
+}
+
+// the RSA decryption function
+pub fn dp<U: CryptoNumModOps>(n: &U, d: &U, c: &U) -> U {
+    c.modexp(d, n)
+}
+
+// the RSA signature generation function
+pub fn sp1<U: CryptoNumModOps>(n: &U, d: &U, m: &U) -> U {
+    m.modexp(d, n)
+}
+
+pub fn decode_biguint(b: &ASN1Block) -> Result<BigUint,RSAError> {
+    match b {
+        &ASN1Block::Integer(_, _, ref v) => {
+            match v.to_biguint() {
+                Some(sn) => Ok(sn),
+                _        => Err(RSAError::InvalidKey)
+            }
+        }
+        _ =>
+            Err(RSAError::ASN1DecodeErr(ASN1DecodeErr::EmptyBuffer))
+    }
+}
+
+
+// the RSA signature verification function
+pub fn vp1<U: CryptoNumModOps>(n: &U, e: &U, s: &U) -> U {
+    s.modexp(e, n)
+}
+
+pub fn xor_vecs(a: &Vec<u8>, b: &Vec<u8>) -> Vec<u8> {
+    a.iter().zip(b.iter()).map(|(a,b)| a^b).collect()
+}
+

src/rsa/errors.rs

@@ -0,0 +1,39 @@
+use simple_asn1::{ASN1DecodeErr};
+use std::io;
+
+#[derive(Debug)]
+pub enum RSAKeyGenError {
+    InvalidKeySize(usize), RngFailure(io::Error)
+}
+
+impl From<io::Error> for RSAKeyGenError {
+    fn from(e: io::Error) -> RSAKeyGenError {
+        RSAKeyGenError::RngFailure(e)
+    }
+}
+
+#[derive(Debug)]
+pub enum RSAError {
+    BadMessageSize,
+    KeyTooSmallForHash,
+    DecryptionError,
+    DecryptHashMismatch,
+    InvalidKey,
+    KeySizeMismatch,
+    RandomGenError(io::Error),
+    ASN1DecodeErr(ASN1DecodeErr)
+}
+
+impl From<io::Error> for RSAError {
+    fn from(e: io::Error) -> RSAError {
+        RSAError::RandomGenError(e)
+    }
+}
+
+impl From<ASN1DecodeErr> for RSAError {
+    fn from(e: ASN1DecodeErr) -> RSAError {
+        RSAError::ASN1DecodeErr(e)
+    }
+}
+
+

src/rsa/mod.rs

@@ -0,0 +1,228 @@
+//! # An implementation of RSA.
+//!
+//! This module is designed to provide implementations of the core routines
+//! used for asymmetric cryptography using RSA. It probably provides a bit
+//! more flexibility than beginners should play with, and definitely includes
+//! some capabilities largely targeted at legacy systems. New users should
+//! probably stick with the stuff in the root of this crate.
+mod core;
+mod errors;
+mod oaep;
+mod private;
+mod public;
+mod signing_hashes;
+
+use cryptonum::*;
+use rand::{OsRng,Rng};
+use std::cmp::PartialOrd;
+use std::ops::*;
+
+pub use self::errors::{RSAKeyGenError,RSAError};
+pub use self::oaep::{OAEPParams};
+pub use self::private::RSAPrivateKey;
+pub use self::public::RSAPublicKey;
+pub use self::signing_hashes::{SigningHash,
+                              SIGNING_HASH_NULL,   SIGNING_HASH_SHA1,
+                              SIGNING_HASH_SHA224, SIGNING_HASH_SHA256,
+                              SIGNING_HASH_SHA384, SIGNING_HASH_SHA512};
+
+/// An RSA public and private key.
+#[derive(Clone,Debug,PartialEq)]
+pub struct RSAKeyPair<Size>
+ where
+  Size: CryptoNumBase + CryptoNumSerialization
+{
+    pub private: RSAPrivateKey<Size>,
+    pub public:  RSAPublicKey<Size>
+}
+
+impl<T> RSAKeyPair<T>
+ where
+  T: Clone + Sized + PartialOrd + From<u64>,
+  T: CryptoNumBase + CryptoNumModOps + CryptoNumPrimes + CryptoNumSerialization,
+  T: Sub<Output=T> + Mul<Output=T> + Shl<usize,Output=T>
+{
+    /// Generates a fresh RSA key pair. If you actually want to protect data,
+    /// use a value greater than or equal to 2048. If you don't want to spend
+    /// all day waiting for RSA computations to finish, choose a value less
+    /// than or equal to 4096.
+    ///
+    /// This routine will use `OsRng` for entropy. If you want to use your
+    /// own random number generator, use `generate_w_rng`.
+    pub fn generate() -> Result<RSAKeyPair<T>,RSAKeyGenError> {
+        let mut rng = OsRng::new()?;
+        RSAKeyPair::<T>::generate_w_rng(&mut rng)
+    }
+
+    /// Generates a fresh RSA key pair of the given bit size. Valid bit sizes
+    /// are 512, 1024, 2048, 3072, 4096, 7680, 8192, and 15360. If you
+    /// actually want to protect data, use a value greater than or equal to
+    /// 2048. If you don't want to spend all day waiting for RSA computations
+    /// to finish, choose a value less than or equal to 4096.
+    ///
+    /// If you provide your own random number generator that is not `OsRng`,
+    /// you should know what you're doing, and be using a cryptographically-
+    /// strong RNG of your own choosing. We've warned you. Use a good one.
+    /// So now it's on you.
+    pub fn generate_w_rng<G: Rng>(rng: &mut G)
+        -> Result<RSAKeyPair<T>,RSAKeyGenError>
+    {
+        let e = T::from(65537);
+        let len_bits = e.bit_size();
+        match generate_pq(rng, &e) {
+            None =>
+                return Err(RSAKeyGenError::InvalidKeySize(len_bits)),
+            Some((p, q)) => {
+                let n = p.clone() * q.clone();
+                let phi = (p - T::from(1)) * (q - T::from(1));
+                let d = e.modinv(&phi);
+                let public_key  = RSAPublicKey::new(n.clone(), e);
+                let private_key = RSAPrivateKey::new(n, d);
+                return Ok(RSAKeyPair{ private: private_key, public: public_key })
+            }
+        }
+    }
+}
+
+pub fn generate_pq<'a,G,T>(rng: &mut G, e: &T) -> Option<(T,T)>
+ where
+  G: Rng,
+  T: Clone + PartialOrd + Shl<usize,Output=T> + Sub<Output=T> + From<u64>,
+  T: CryptoNumBase + CryptoNumPrimes + CryptoNumSerialization
+{
+    let bitlen = T::zero().bit_size();
+    let mindiff = T::from(1) << ((bitlen/2)-101);
+    let minval  = T::from(6074001000) << ((mindiff.bit_size()/2) - 33);
+    let p = T::generate_prime(rng, 7, e, &minval);
+
+    loop {
+        let q = T::generate_prime(rng, 7, e, &minval);
+
+        if diff(p.clone(), q.clone()) >= mindiff {
+            return Some((p, q));
+        }
+    }
+}
+
+fn diff<T: PartialOrd + Sub<Output=T>>(a: T, b: T) -> T
+{
+    if a > b {
+        a - b
+    } else {
+        b - a
+    }
+}
+
+#[cfg(test)]
+mod tests {
+    use quickcheck::{Arbitrary,Gen};
+    use rsa::core::{dp,ep,sp1,vp1};
+    use sha2::Sha224;
+    use simple_asn1::{der_decode,der_encode};
+    use super::*;
+
+    impl Arbitrary for RSAKeyPair<U512> {
+        fn arbitrary<G: Gen>(g: &mut G) -> RSAKeyPair<U512> {
+            RSAKeyPair::generate_w_rng(g).unwrap()
+        }
+    }
+
+    // Core primitive checks
+    quickcheck! {
+        fn ep_dp_inversion(kp: RSAKeyPair<U512>, m: U512) -> bool {
+            let realm = &m % &kp.public.n;
+            let ciphertext = ep(&kp.public.n, &kp.public.e, &realm);
+            let mprime = dp(&kp.private.n, &kp.private.d, &ciphertext);
+            mprime == m
+        }
+        fn sp_vp_inversion(kp: RSAKeyPair<U512>, m: U512) -> bool {
+            let realm = &m % &kp.public.n;
+            let sig = sp1(&kp.private.n, &kp.private.d, &realm);
+            let mprime = vp1(&kp.public.n, &kp.public.e, &sig);
+            mprime == m
+        }
+    }
+
+    // Public key serialization
+    quickcheck! {
+        fn asn1_encoding_inverts(kp: RSAKeyPair<U512>) -> bool {
+            let bytes = der_encode(&kp.public).unwrap();
+            let pubkey: RSAPublicKey<U512> = der_decode(&bytes).unwrap();
+            (pubkey.n == kp.public.n) && (pubkey.e == kp.public.e)
+        }
+    }
+
+    #[derive(Clone,Debug)]
+    struct Message {
+        m: Vec<u8>
+    }
+
+    impl Arbitrary for Message {
+        fn arbitrary<G: Gen>(g: &mut G) -> Message {
+            let len = 1 + (g.gen::<u8>() % 3);
+            let mut storage = Vec::new();
+            for _ in 0..len {
+                storage.push(g.gen::<u8>());
+            }
+            Message{ m: storage }
+        }
+    }
+
+    #[derive(Clone,Debug)]
+    struct KeyPairAndSigHash<T>
+      where
+        T: CryptoNumSerialization + CryptoNumBase
+    {
+        kp: RSAKeyPair<T>,
+        sh: &'static SigningHash
+    }
+
+    impl<T> Arbitrary for KeyPairAndSigHash<T>
+      where
+        T: Clone + Sized + PartialOrd + From<u64>,
+        T: CryptoNumBase + CryptoNumModOps,
+        T: CryptoNumPrimes + CryptoNumSerialization,
+        T: Sub<Output=T> + Mul<Output=T> + Shl<usize,Output=T>,
+        RSAKeyPair<T>: Arbitrary
+    {
+        fn arbitrary<G: Gen>(g: &mut G) -> KeyPairAndSigHash<T> {
+            let kp = RSAKeyPair::generate_w_rng(g).unwrap();
+            let size = kp.public.n.bit_size();
+            let mut hashes = vec![&SIGNING_HASH_SHA1];
+
+            if size >= 1024 {
+                hashes.push(&SIGNING_HASH_SHA224);
+            }
+
+            if size >= 2048 {
+                hashes.push(&SIGNING_HASH_SHA256);
+            }
+
+            if size >= 4096 {
+                hashes.push(&SIGNING_HASH_SHA384);
+                hashes.push(&SIGNING_HASH_SHA512);
+            }
+
+            let hash = g.choose(&hashes).unwrap().clone();
+            KeyPairAndSigHash{ kp: kp, sh: hash }
+        }
+    }
+
+    quickcheck! {
+        fn sign_verifies(kpsh: KeyPairAndSigHash<U512>, m: Message) -> bool {
+            let sig = kpsh.kp.private.sign(kpsh.sh, &m.m);
+            kpsh.kp.public.verify(kpsh.sh, &m.m, &sig)
+        }
+
+        fn enc_dec_roundtrips(kp: RSAKeyPair<U512>, m: Message) -> bool {
+            let oaep = OAEPParams {
+                hash: Sha224::default(),
+                label: "test".to_string()
+            };
+            let c = kp.public.encrypt(&oaep, &m.m).unwrap();
+            let mp = kp.private.decrypt(&oaep, &c).unwrap();
+
+            mp == m.m
+        }
+    }
+}

src/rsa/oaep.rs

@@ -0,0 +1,47 @@
+use byteorder::{BigEndian,ByteOrder};
+use digest::{FixedOutput,Input};
+
+/// Parameters for OAEP encryption and decryption: a hash function to use
+/// as part of the message generation function (MGF1, if you're curious),
+/// and any labels you want to include as part of the encryption.
+pub struct OAEPParams<H: Clone + Input + FixedOutput> {
+    pub hash: H,
+    pub label: String
+}
+
+impl<H: Clone + Input + FixedOutput> OAEPParams<H> {
+    pub fn new(hash: H, label: String)
+        -> OAEPParams<H>
+    {
+        OAEPParams { hash: hash, label: label }
+    }
+
+    pub fn hash_len(&self) -> usize {
+        self.hash.clone().fixed_result().as_slice().len()
+    }
+
+    pub fn hash(&self, input: &[u8]) -> Vec<u8> {
+        let mut digest = self.hash.clone();
+        digest.process(input);
+        digest.fixed_result().as_slice().to_vec()
+    }
+
+    pub fn mgf1(&self, input: &[u8], len: usize) -> Vec<u8> {
+        let mut res = Vec::with_capacity(len);
+        let mut counter: u32 = 0;
+
+        while res.len() < len {
+            let mut c: [u8; 4] = [0; 4];
+            BigEndian::write_u32(&mut c, counter);
+            let mut digest = self.hash.clone();
+            digest.process(input);
+            digest.process(&c);
+            let chunk = digest.fixed_result();
+            res.extend_from_slice(chunk.as_slice());
+            counter += 1;
+        }
+
+        res.truncate(len);
+        res
+    }
+}

src/rsa/private.rs

@@ -0,0 +1,117 @@
+use cryptonum::{CryptoNumBase,CryptoNumModOps,CryptoNumSerialization};
+use digest::{FixedOutput,Input};
+use rsa::core::{dp,sp1,pkcs1_pad,xor_vecs};
+use rsa::oaep::{OAEPParams};
+use rsa::errors::{RSAError};
+use rsa::signing_hashes::SigningHash;
+
+/// A RSA private key. As with public keys, I've left the size as a
+/// parameter: 2048-4096 is standard practice, 512-1024 is weak, and
+/// >4096 is going to be slow.
+#[derive(Clone,Debug,PartialEq)]
+pub struct RSAPrivateKey<Size>
+ where
+  Size: CryptoNumBase + CryptoNumSerialization
+{
+    pub(crate) n: Size,
+    pub(crate) d: Size
+}
+
+impl<U> RSAPrivateKey<U>
+ where
+  U: CryptoNumBase + CryptoNumModOps + CryptoNumSerialization
+{
+    /// Generate a private key, using the given `n` and `d` parameters
+    /// gathered from some other source. The length should be given in
+    /// bits.
+    pub fn new(n: U, d: U) -> RSAPrivateKey<U> {
+        RSAPrivateKey {
+            n: n,
+            d: d
+        }
+    }
+
+    /// Sign a message using the given hash.
+    pub fn sign(&self, sighash: &SigningHash, msg: &[u8]) -> Vec<u8> {
+        let hash = (sighash.run)(msg);
+        let em   = pkcs1_pad(&sighash.ident, &hash, self.d.byte_size());
+        let m    = U::from_bytes(&em);
+        let s    = sp1(&self.n, &self.d, &m);
+        let sig  = s.to_bytes();
+        sig
+    }
+
+    /// Decrypt a message with the given parameters.
+    pub fn decrypt<H: Clone + Input + FixedOutput>(&self, oaep: &OAEPParams<H>, msg: &[u8])
+        -> Result<Vec<u8>,RSAError>
+    {
+        let mut res = Vec::new();
+        let byte_len = self.d.byte_size();
+
+        for chunk in msg.chunks(byte_len) {
+            let mut dchunk = self.oaep_decrypt(oaep, chunk)?;
+            res.append(&mut dchunk);
+        }
+
+        Ok(res)
+    }
+
+    fn oaep_decrypt<H: Clone + Input + FixedOutput>(&self, oaep: &OAEPParams<H>, c: &[u8])
+        -> Result<Vec<u8>,RSAError>
+    {
+        let byte_len = self.d.byte_size();
+        // Step 1b
+        if c.len() != byte_len {
+            return Err(RSAError::DecryptionError);
+        }
+        // Step 1c
+        if byte_len < ((2 * oaep.hash_len()) + 2) {
+            return Err(RSAError::DecryptHashMismatch);
+        }
+        // Step 2a
+        let c_ip = U::from_bytes(&c);
+        // Step 2b
+        let m_ip = dp(&self.n, &self.d, &c_ip);
+        // Step 2c
+        let em = m_ip.to_bytes();
+        // Step 3a
+        let l_hash = oaep.hash(oaep.label.as_bytes());
+        // Step 3b
+        let (y, rest) = em.split_at(1);
+        let (masked_seed, masked_db) = rest.split_at(oaep.hash_len());
+        // Step 3c
+        let seed_mask = oaep.mgf1(masked_db, oaep.hash_len());
+        // Step 3d
+        let seed = xor_vecs(&masked_seed.to_vec(), &seed_mask);
+        // Step 3e
+        let db_mask = oaep.mgf1(&seed, byte_len - oaep.hash_len() - 1);
+        // Step 3f
+        let db = xor_vecs(&masked_db.to_vec(), &db_mask);
+        // Step 3g
+        let (l_hash2, ps_o_m) = db.split_at(oaep.hash_len());
+        let o_m = drop0s(ps_o_m);
+        let (o, m) = o_m.split_at(1);
+        // Checks!
+        if o != [1] {
+            return Err(RSAError::DecryptionError);
+        }
+        if l_hash != l_hash2 {
+            return Err(RSAError::DecryptionError);
+        }
+        if y != [0] {
+            return Err(RSAError::DecryptionError);
+        }
+
+        Ok(m.to_vec())
+    }
+}
+
+fn drop0s(a: &[u8]) -> &[u8] {
+    let mut idx = 0;
+
+    while (idx < a.len()) && (a[idx] == 0) {
+        idx = idx + 1;
+    }
+
+    &a[idx..]
+}

src/rsa/public.rs

@@ -0,0 +1,196 @@
+use cryptonum::{CryptoNumBase,CryptoNumModOps,CryptoNumSerialization};
+use digest::{FixedOutput,Input};
+use num::{BigInt,BigUint};
+use rand::{OsRng,Rng};
+use rsa::core::{ep,vp1,pkcs1_pad,xor_vecs,decode_biguint};
+use rsa::oaep::{OAEPParams};
+use rsa::errors::{RSAError};
+use rsa::signing_hashes::SigningHash;
+use simple_asn1::{FromASN1,ToASN1,ASN1DecodeErr,ASN1EncodeErr};
+use simple_asn1::{ASN1Block,ASN1Class};
+
+/// An RSA public key with the given modulus size. I've left the size as a
+/// parameter, instead of hardcoding particular values. That being said,
+/// you almost certainly want one of `U2048`, `U3072`, or `U4096` if you're
+/// being pretty standard; `U512` or `U1024` if you're interfacing with
+/// legacy code or want to build intentionally weak systems; or `U7680`,
+/// `U8192`, or `U15360` if you like things running very slowly.
+#[derive(Clone,Debug,PartialEq)]
+pub struct RSAPublicKey<Size>
+ where
+  Size: CryptoNumBase + CryptoNumSerialization
+{
+    pub(crate) n: Size,
+    pub(crate) e: Size
+}
+
+impl<U> RSAPublicKey<U>
+ where
+  U: CryptoNumBase + CryptoNumModOps + CryptoNumSerialization
+{
+    /// Create a new RSA public key from the given components, which you found
+    /// via some other mechanism.
+    pub fn new(n: U, e: U) -> RSAPublicKey<U> {
+        RSAPublicKey{ n: n, e: e }
+    }
+
+    /// Verify the signature for a given message, using the given signing hash,
+    /// return true iff the signature validates.
+    pub fn verify(&self, sighash: &SigningHash, msg: &[u8], sig: &[u8]) -> bool
+    {
+        let hash = (sighash.run)(msg);
+        let s    = U::from_bytes(sig);
+        let m    = vp1(&self.n, &self.e, &s);
+        let em   = s.to_bytes();
+        let em_  = pkcs1_pad(&sighash.ident, &hash, m.byte_size());
+        em == em_
+    }
+
+    /// Encrypt the given data with the public key and parameters, returning
+    /// the encrypted blob or an error encountered during encryption.
+    ///
+    /// OAEP encoding is used for this process, which requires a random number
+    /// generator. This version of the function uses `OsRng`. If you want to
+    /// use your own RNG, use `encrypt_w_rng`.
+    pub fn encrypt<H:Clone + Input + FixedOutput>(&self, oaep: &OAEPParams<H>,
+                                                  msg: &[u8])
+        -> Result<Vec<u8>,RSAError>
+    {
+        let mut g = OsRng::new()?;
+        self.encrypt_with_rng(&mut g, oaep, msg)
+    }
+
+    /// Encrypt the given data with the public key and parameters, returning
+    /// the encrypted blob or an error encountered during encryption. This
+    /// version also allows you to provide your own RNG, if you really feel
+    /// like shooting yourself in the foot.
+    pub fn encrypt_with_rng<G,H>(&self, g: &mut G, oaep: &OAEPParams<H>,
+                                 msg: &[u8])
+        -> Result<Vec<u8>,RSAError>
+      where G: Rng, H: Clone + Input + FixedOutput
+    {
+        let mylen = self.e.byte_size();
+
+        if mylen <= ((2 * oaep.hash_len()) + 2) {
+            return Err(RSAError::KeyTooSmallForHash);
+        }
+
+        let mut res = Vec::new();
+
+        for chunk in msg.chunks(mylen - (2 * oaep.hash_len()) - 2) {
+            let mut newchunk = self.oaep_encrypt(g, oaep, chunk)?;
+            res.append(&mut newchunk)
+        }
+
+        Ok(res)
+    }
+
+    fn oaep_encrypt<G,H>(&self, g: &mut G, oaep: &OAEPParams<H>, msg: &[u8])
+        -> Result<Vec<u8>,RSAError>
+     where
+       G: Rng, H:Clone + Input + FixedOutput
+    {
+        let mylen = self.e.byte_size();
+
+        // Step 1b
+        if msg.len() > (mylen - (2 * oaep.hash_len()) - 2) {
+            return Err(RSAError::BadMessageSize)
+        }
+        // Step 2a
+        let mut lhash = oaep.hash(oaep.label.as_bytes());
+        // Step 2b
+        let num0s = mylen - msg.len() - (2 * oaep.hash_len()) - 2;
+        let mut ps = Vec::new();
+        ps.resize(num0s, 0);
+        // Step 2c
+        let mut db = Vec::new();
+        db.append(&mut lhash);
+        db.append(&mut ps);
+        db.push(1);
+        db.extend_from_slice(msg);
+        // Step 2d
+        let seed : Vec<u8> = g.gen_iter().take(oaep.hash_len()).collect();
+        // Step 2e
+        let db_mask = oaep.mgf1(&seed, mylen - oaep.hash_len() - 1);
+        // Step 2f
+        let mut masked_db = xor_vecs(&db, &db_mask);
+        // Step 2g
+        let seed_mask = oaep.mgf1(&masked_db, oaep.hash_len());
+        // Step 2h
+        let mut masked_seed = xor_vecs(&seed, &seed_mask);
+        // Step 2i
+        let mut em = Vec::new();
+        em.push(0);
+        em.append(&mut masked_seed);
+        em.append(&mut masked_db);
+        // Step 3a
+        let m_i = U::from_bytes(&em);
+        // Step 3b
+        let c_i = ep(&self.n, &self.e, &m_i);
+        // Step 3c
+        let c = c_i.to_bytes();
+        Ok(c)
+    }
+}
+
+impl<T> FromASN1 for RSAPublicKey<T>
+  where
+    T: CryptoNumBase + CryptoNumSerialization,
+    T: From<BigUint>
+{
+    type Error = RSAError;
+
+    fn from_asn1(bs: &[ASN1Block])
+        -> Result<(RSAPublicKey<T>,&[ASN1Block]),RSAError>
+    {
+        match bs.split_first() {
+            None =>
+                Err(RSAError::ASN1DecodeErr(ASN1DecodeErr::EmptyBuffer)),
+            Some((&ASN1Block::Sequence(_, _, ref items), rest))
+                if items.len() == 2 =>
+            {
+                let numn = decode_biguint(&items[0])?;
+                let nume = decode_biguint(&items[1])?;
+                let nsize = numn.bits();
+                let mut rsa_size = 512;
+
+                while rsa_size < nsize {
+                    rsa_size = rsa_size + 256;
+                }
+                rsa_size /= 8;
+
+                if rsa_size != (T::zero()).bit_size() {
+                    return Err(RSAError::KeySizeMismatch);
+                }
+
+                let n = T::from(numn);
+                let e = T::from(nume);
+
+                let res = RSAPublicKey{ n: n, e: e };
+
+                Ok((res, rest))
+            }
+            Some(_) =>
+                Err(RSAError::InvalidKey)
+        }
+    }
+}
+
+impl<T> ToASN1 for RSAPublicKey<T>
+  where
+    T: Clone + Into<BigInt>,
+    T: CryptoNumBase + CryptoNumSerialization
+{
+    type Error = ASN1EncodeErr;
+
+    fn to_asn1_class(&self, c: ASN1Class)
+        -> Result<Vec<ASN1Block>,Self::Error>
+    {
+        let enc_n = ASN1Block::Integer(c, 0, self.n.clone().into());
+        let enc_e = ASN1Block::Integer(c, 0, self.e.clone().into());
+        let seq = ASN1Block::Sequence(c, 0, vec![enc_n, enc_e]);
+        Ok(vec![seq])
+    }
+}
+
+

src/rsa/signing_hashes.rs

@@ -0,0 +1,119 @@
+use digest::{FixedOutput,Input};
+use sha1::Sha1;
+use sha2::{Sha224,Sha256,Sha384,Sha512};
+use std::fmt;
+
+/// A hash that can be used to sign a message.
+#[derive(Clone)]
+pub struct SigningHash {
+    /// The name of this hash (only used for display purposes)
+    pub name: &'static str,
+    /// The approved identity string for the hash.
+    pub ident: &'static [u8],
+    /// The hash
+    pub run: fn(&[u8]) -> Vec<u8>
+}
+
+impl fmt::Debug for SigningHash {
+    fn fmt(&self, f: &mut fmt::Formatter) -> fmt::Result {
+        write!(f, "{}", self.name)
+    }
+}
+
+/// The "null" signing hash. This signing hash has no identity, and will
+/// simply pass the data through unhashed. You really should know what
+/// you're doing if you use this, and probably using a somewhat strange
+/// signing protocol. There's no good reason to use this in new code
+/// for a new protocol or system.
+pub static SIGNING_HASH_NULL: SigningHash = SigningHash {
+    name: "NULL",
+    ident: &[],
+    run: nohash
+};
+
+fn nohash(i: &[u8]) -> Vec<u8> {
+    i.to_vec()
+}
+
+/// Sign a hash based on SHA1. You shouldn't use this unless you're using
+/// very small keys, and this is the only one available to you. Even then,
+/// why are you using such small keys?!
+pub static SIGNING_HASH_SHA1: SigningHash = SigningHash {
+    name: "SHA1",
+    ident: &[0x30,0x21,0x30,0x09,0x06,0x05,0x2b,0x0e,0x03,
+             0x02,0x1a,0x05,0x00,0x04,0x14],
+    run: runsha1
+};
+
+fn runsha1(i: &[u8]) -> Vec<u8> {
+    let mut d = Sha1::default();
+    d.process(i);
+    d.fixed_result().as_slice().to_vec()
+}
+
+/// Sign a hash based on SHA2-224. This is the first reasonable choice
+/// we've come across, and is useful when you have smaller RSA key sizes.
+/// I wouldn't recommend it, though.
+pub static SIGNING_HASH_SHA224: SigningHash = SigningHash {
+    name: "SHA224",
+    ident: &[0x30,0x2d,0x30,0x0d,0x06,0x09,0x60,0x86,0x48,
+             0x01,0x65,0x03,0x04,0x02,0x04,0x05,0x00,0x04,
+             0x1c],
+    run: runsha224
+};
+
+fn runsha224(i: &[u8]) -> Vec<u8> {
+    let mut d = Sha224::default();
+    d.process(i);
+    d.fixed_result().as_slice().to_vec()
+}
+
+/// Sign a hash based on SHA2-256. The first one I'd recommend!
+pub static SIGNING_HASH_SHA256: SigningHash = SigningHash {
+    name: "SHA256",
+    ident: &[0x30,0x31,0x30,0x0d,0x06,0x09,0x60,0x86,0x48,
+             0x01,0x65,0x03,0x04,0x02,0x01,0x05,0x00,0x04,
+             0x20],
+    run: runsha256
+};
+
+fn runsha256(i: &[u8]) -> Vec<u8> {
+    let mut d = Sha256::default();
+    d.process(i);
+    d.fixed_result().as_slice().to_vec()
+}
+
+/// Sign a hash based on SHA2-384. Approximately 50% better than
+/// SHA-256.
+pub static SIGNING_HASH_SHA384: SigningHash = SigningHash {
+    name: "SHA384",
+    ident: &[0x30,0x41,0x30,0x0d,0x06,0x09,0x60,0x86,0x48,
+             0x01,0x65,0x03,0x04,0x02,0x02,0x05,0x00,0x04,
+             0x30],
+    run: runsha384
+};
+
+fn runsha384(i: &[u8]) -> Vec<u8> {
+    let mut d = Sha384::default();
+    d.process(i);
+    d.fixed_result().as_slice().to_vec()
+}
+
+/// Sign a hash based on SHA2-512. At this point, you're getting a bit
+/// silly. But if you want to through 8kbit RSA keys with a 512 bit SHA2
+/// signing hash, we're totally behind you.
+pub static SIGNING_HASH_SHA512: SigningHash = SigningHash {
+    name: "SHA512",
+    ident: &[0x30,0x51,0x30,0x0d,0x06,0x09,0x60,0x86,0x48,
+             0x01,0x65,0x03,0x04,0x02,0x03,0x05,0x00,0x04,
+             0x40],
+    run: runsha512
+};
+
+fn runsha512(i: &[u8]) -> Vec<u8> {
+    let mut d = Sha512::default();
+    d.process(i);
+    d.fixed_result().as_slice().to_vec()
+}
+
+