DSA support!

src/dsa/errors.rs

@@ -0,0 +1,20 @@
+use simple_asn1::ASN1DecodeErr;
+use rand;
+
+#[derive(Debug)]
+pub enum DSAError {
+    RandomGenError(rand::Error),
+    ASN1DecodeErr(ASN1DecodeErr)
+}
+
+impl From<rand::Error> for DSAError {
+    fn from(e: rand::Error) -> DSAError {
+        DSAError::RandomGenError(e)
+    }
+}
+
+impl From<ASN1DecodeErr> for DSAError {
+    fn from(e: ASN1DecodeErr) -> DSAError {
+        DSAError::ASN1DecodeErr(e)
+    }
+}