From 1f59a84308f638f6bce1d0d3432134457b49d9d8 Mon Sep 17 00:00:00 2001
From: "Dr. Stephen Henson" <steve@openssl.org>
Date: Sun, 14 Aug 2011 13:45:19 +0000
Subject: [PATCH] Remove hard coded ecdsaWithSHA1 hack in ssl routines and
 check for RSA using OBJ xref utilities instead of string comparison with OID
 name.

This removes the arbitrary restriction on using SHA1 only with some ECC
ciphersuites.
---
 CHANGES       |  5 +++++
 ssl/ssl_lib.c | 32 +++++++++++++-------------------
 2 files changed, 18 insertions(+), 19 deletions(-)

diff --git a/CHANGES b/CHANGES
index 011df12db3..65bbce6c39 100644
--- a/CHANGES
+++ b/CHANGES
@@ -404,6 +404,11 @@
 
  Changes between 1.0.0d and 1.0.0e [xx XXX xxxx]
 
+  *) Remove hard coded ecdsaWithSHA1 signature tests in ssl code and check
+     signature public key algorithm by using OID xref utilities instead.
+     Before this you could only use some ECC ciphersuites with SHA1 only.
+     [Steve Henson]
+
   *) Add protection against ECDSA timing attacks as mentioned in the paper
      by Billy Bob Brumley and Nicola Tuveri, see:
 
diff --git a/ssl/ssl_lib.c b/ssl/ssl_lib.c
index 6ed9ca51c0..22039fb168 100644
--- a/ssl/ssl_lib.c
+++ b/ssl/ssl_lib.c
@@ -1996,7 +1996,7 @@ void ssl_set_cert_masks(CERT *c, const SSL_CIPHER *cipher)
 #endif
 	X509 *x = NULL;
 	EVP_PKEY *ecc_pkey = NULL;
-	int signature_nid = 0;
+	int signature_nid = 0, pk_nid = 0, md_nid = 0;
 
 	if (c == NULL) return;
 
@@ -2126,18 +2126,15 @@ void ssl_set_cert_masks(CERT *c, const SSL_CIPHER *cipher)
 		    EVP_PKEY_bits(ecc_pkey) : 0;
 		EVP_PKEY_free(ecc_pkey);
 		if ((x->sig_alg) && (x->sig_alg->algorithm))
+			{
 			signature_nid = OBJ_obj2nid(x->sig_alg->algorithm);
+			OBJ_find_sigid_algs(signature_nid, &md_nid, &pk_nid);
+			}
 #ifndef OPENSSL_NO_ECDH
 		if (ecdh_ok)
 			{
-			const char *sig = OBJ_nid2ln(signature_nid);
-			if (sig == NULL)
-				{
-				ERR_clear_error();
-				sig = "unknown";
-				}
-				
-			if (strstr(sig, "WithRSA"))
+
+			if (pk_nid == NID_rsaEncryption || pk_nid == NID_rsa)
 				{
 				mask_k|=SSL_kECDHr;
 				mask_a|=SSL_aECDH;
@@ -2148,7 +2145,7 @@ void ssl_set_cert_masks(CERT *c, const SSL_CIPHER *cipher)
 					}
 				}
 
-			if (signature_nid == NID_ecdsa_with_SHA1)
+			if (pk_nid == NID_X9_62_id_ecPublicKey)
 				{
 				mask_k|=SSL_kECDHe;
 				mask_a|=SSL_aECDH;
@@ -2202,7 +2199,7 @@ int ssl_check_srvr_ecc_cert_and_alg(X509 *x, SSL *s)
 	unsigned long alg_k, alg_a;
 	EVP_PKEY *pkey = NULL;
 	int keysize = 0;
-	int signature_nid = 0;
+	int signature_nid = 0, md_nid = 0, pk_nid = 0;
 	const SSL_CIPHER *cs = s->s3->tmp.new_cipher;
 
 	alg_k = cs->algorithm_mkey;
@@ -2221,7 +2218,10 @@ int ssl_check_srvr_ecc_cert_and_alg(X509 *x, SSL *s)
 	/* This call populates the ex_flags field correctly */
 	X509_check_purpose(x, -1, 0);
 	if ((x->sig_alg) && (x->sig_alg->algorithm))
+		{
 		signature_nid = OBJ_obj2nid(x->sig_alg->algorithm);
+		OBJ_find_sigid_algs(signature_nid, &md_nid, &pk_nid);
+		}
 	if (alg_k & SSL_kECDHe || alg_k & SSL_kECDHr)
 		{
 		/* key usage, if present, must allow key agreement */
@@ -2233,7 +2233,7 @@ int ssl_check_srvr_ecc_cert_and_alg(X509 *x, SSL *s)
 		if ((alg_k & SSL_kECDHe) && TLS1_get_version(s) < TLS1_2_VERSION)
 			{
 			/* signature alg must be ECDSA */
-			if (signature_nid != NID_ecdsa_with_SHA1)
+			if (pk_nid != NID_X9_62_id_ecPublicKey)
 				{
 				SSLerr(SSL_F_SSL_CHECK_SRVR_ECC_CERT_AND_ALG, SSL_R_ECC_CERT_SHOULD_HAVE_SHA1_SIGNATURE);
 				return 0;
@@ -2243,13 +2243,7 @@ int ssl_check_srvr_ecc_cert_and_alg(X509 *x, SSL *s)
 			{
 			/* signature alg must be RSA */
 
-			const char *sig = OBJ_nid2ln(signature_nid);
-			if (sig == NULL)
-				{
-				ERR_clear_error();
-				sig = "unknown";
-				}
-			if (strstr(sig, "WithRSA") == NULL)
+			if (pk_nid != NID_rsaEncryption && pk_nid != NID_rsa)
 				{
 				SSLerr(SSL_F_SSL_CHECK_SRVR_ECC_CERT_AND_ALG, SSL_R_ECC_CERT_SHOULD_HAVE_RSA_SIGNATURE);
 				return 0;
-- 
2.25.1