Implement ECDSA sign and verify operations.

Very basic at the moment, doesn't hash the input first,
and uses OpenSSL's DER encoded signature as output.

diff --git a/src/openssl/ecdsa.c b/src/openssl/ecdsa.c
index 84fe8fd..000bfaa 100644 (file)
--- a/src/openssl/ecdsa.c
+++ b/src/openssl/ecdsa.c
@@ -70,12 +70,31 @@ size_t ecdsa_size(ecdsa_t *ecdsa) {
        return ECDSA_size(*ecdsa);
 }
 
+// TODO: hash first, standardise output format?
+
 bool ecdsa_sign(ecdsa_t *ecdsa, const void *in, size_t len, void *sig) {
-       logger(LOG_ERR, "Unable to perform ECDSA signature: %s", ERR_error_string(ERR_get_error(), NULL));
-       return false;   
+       unsigned int siglen = ECDSA_size(*ecdsa);
+       memset(sig, 0, siglen);
+
+       if(!ECDSA_sign(0, in, len, sig, &siglen, *ecdsa)) {
+               logger(LOG_DEBUG, "ECDSA_sign() failed: %s", ERR_error_string(ERR_get_error(), NULL));
+               return false;
+       }
+
+       if(siglen != ECDSA_size(*ecdsa)) {
+               logger(LOG_ERR, "Signature length %d != %d", siglen, ECDSA_size(*ecdsa));
+       }
+
+       return true;
 }
 
 bool ecdsa_verify(ecdsa_t *ecdsa, const void *in, size_t len, const void *sig) {
-       logger(LOG_ERR, "Unable to perform ECDSA verification: %s", ERR_error_string(ERR_get_error(), NULL));
-       return false;   
+       unsigned int siglen = ECDSA_size(*ecdsa);
+
+       if(!ECDSA_verify(0, in, len, sig, siglen, *ecdsa)) {
+               logger(LOG_DEBUG, "ECDSA_verify() failed: %s", ERR_error_string(ERR_get_error(), NULL));
+               return false;
+       }
+
+       return true;
 }