Add ECDSA_SIG accessor.

Reviewed-by: Richard Levitte <levitte@openssl.org>

crypto/ec/ec_asn1.c

@@ -1303,8 +1303,6 @@ int i2o_ECPublicKey(EC_KEY *a, unsigned char **out)
     return buf_len;
 }
 
-#include <openssl/ecdsa.h>
-
 ASN1_SEQUENCE(ECDSA_SIG) = {
         ASN1_SIMPLE(ECDSA_SIG, r, CBIGNUM),
         ASN1_SIMPLE(ECDSA_SIG, s, CBIGNUM)
@@ -1313,3 +1311,11 @@ ASN1_SEQUENCE(ECDSA_SIG) = {
 DECLARE_ASN1_FUNCTIONS_const(ECDSA_SIG)
 DECLARE_ASN1_ENCODE_FUNCTIONS_const(ECDSA_SIG, ECDSA_SIG)
 IMPLEMENT_ASN1_FUNCTIONS_const(ECDSA_SIG)
+
+void ECDSA_SIG_get0(BIGNUM **pr, BIGNUM **ps, ECDSA_SIG *sig)
+{
+    if (pr)
+        *pr = sig->r;
+    if (ps)
+        *ps = sig->s;
+}

include/openssl/ec.h

@@ -1028,6 +1028,14 @@ int i2d_ECDSA_SIG(const ECDSA_SIG *sig, unsigned char **pp);
  */
 ECDSA_SIG *d2i_ECDSA_SIG(ECDSA_SIG **sig, const unsigned char **pp, long len);
 
+/** Accessor for r and s fields of ECDSA_SIG
+ *  \param  sig  pointer to ECDSA_SIG pointer
+ *  \param  pr   pointer to BIGNUM pointer for r (may be NULL)
+ *  \param  ps   pointer to BIGNUM pointer for s (may be NULL)
+ */
+void ECDSA_SIG_get0(BIGNUM **pr, BIGNUM **ps, ECDSA_SIG *sig);
+
+
 # define ECParameters_dup(x) ASN1_dup_of(EC_KEY,i2d_ECParameters,d2i_ECParameters,x)
 
 # ifndef __cplusplus