File openssl-CVE-2014-3572.patch of Package openssl.6981

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File openssl-CVE-2014-3572.patch of Package openssl.6981

commit ef28c6d6767a6a30df5add36171894c96628fe98
Author: Dr. Stephen Henson <steve@openssl.org>
Date:   Fri Oct 24 12:30:33 2014 +0100

ECDH downgrade bug fix.
    
    Fix bug where an OpenSSL client would accept a handshake using an
    ephemeral ECDH ciphersuites with the server key exchange message omitted.
    
    Thanks to Karthikeyan Bhargavan for reporting this issue.
    
    CVE-2014-3572
    Reviewed-by: Matt Caswell <matt@openssl.org>
    
    (cherry picked from commit b15f8769644b00ef7283521593360b7b2135cb63)

Index: openssl-1.0.1i/ssl/s3_clnt.c
===================================================================
--- openssl-1.0.1i.orig/ssl/s3_clnt.c	2015-01-08 13:13:24.167899760 +0100
+++ openssl-1.0.1i/ssl/s3_clnt.c	2015-01-08 13:37:47.300042642 +0100
@@ -1295,6 +1295,8 @@ int ssl3_get_key_exchange(SSL *s)
 	int encoded_pt_len = 0;
 #endif
 
+	EVP_MD_CTX_init(&md_ctx);
+
 	/* use same message size as in ssl3_get_certificate_request()
 	 * as ServerKeyExchange message may be skipped */
 	n=s->method->ssl_get_message(s,
@@ -1305,14 +1307,26 @@ int ssl3_get_key_exchange(SSL *s)
 		&ok);
 	if (!ok) return((int)n);
 
+	alg_k=s->s3->tmp.new_cipher->algorithm_mkey;
+
 	if (s->s3->tmp.message_type != SSL3_MT_SERVER_KEY_EXCHANGE)
 		{
+		/*
+		 * Can't skip server key exchange if this is an ephemeral
+		 * ciphersuite.
+		 */
+		if (alg_k & (SSL_kEDH|SSL_kEECDH))
+			{
+			SSLerr(SSL_F_SSL3_GET_KEY_EXCHANGE, SSL_R_UNEXPECTED_MESSAGE);
+			al = SSL_AD_UNEXPECTED_MESSAGE;
+			goto f_err;
+			}
 #ifndef OPENSSL_NO_PSK
 		/* In plain PSK ciphersuite, ServerKeyExchange can be
 		   omitted if no identity hint is sent. Set
 		   session->sess_cert anyway to avoid problems
 		   later.*/
-		if (s->s3->tmp.new_cipher->algorithm_mkey & SSL_kPSK)
+		if (alg_k & SSL_kPSK)
 			{
 			s->session->sess_cert=ssl_sess_cert_new();
 			if (s->ctx->psk_identity_hint)
@@ -1355,9 +1369,7 @@ int ssl3_get_key_exchange(SSL *s)
 		}
 
 	param_len=0;
-	alg_k=s->s3->tmp.new_cipher->algorithm_mkey;
 	alg_a=s->s3->tmp.new_cipher->algorithm_auth;
-	EVP_MD_CTX_init(&md_ctx);
 
 #ifndef OPENSSL_NO_PSK
 	if (alg_k & SSL_kPSK)

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