From 3ff55e9680cc99f330f25e48cd1422e3459c02de Mon Sep 17 00:00:00 2001
From: "Mark J. Cox" <mark@openssl.org>
Date: Thu, 28 Sep 2006 13:18:43 +0000
Subject: [PATCH] Fix buffer overflow in SSL_get_shared_ciphers() function.
 (CVE-2006-3738) [Tavis Ormandy and Will Drewry, Google Security Team]

Fix SSL client code which could crash if connecting to a
 malicious SSLv2 server.  (CVE-2006-4343)
[Tavis Ormandy and Will Drewry, Google Security Team]
---
 CHANGES       | 21 +++++++++++++++++++++
 ssl/s2_clnt.c |  3 ++-
 ssl/s3_srvr.c |  2 +-
 ssl/ssl_lib.c |  2 +-
 4 files changed, 25 insertions(+), 3 deletions(-)

diff --git a/CHANGES b/CHANGES
index 93db3118e1..11988efbf9 100644
--- a/CHANGES
+++ b/CHANGES
@@ -4,6 +4,13 @@
 
  Changes between 0.9.8d and 0.9.9  [xx XXX xxxx]
 
+  *) Fix buffer overflow in SSL_get_shared_ciphers() function.
+     (CVE-2006-3738) [Tavis Ormandy and Will Drewry, Google Security Team]
+
+  *) Fix SSL client code which could crash if connecting to a
+     malicious SSLv2 server.  (CVE-2006-4343)
+     [Tavis Ormandy and Will Drewry, Google Security Team]
+
   *) Add an X509_CRL_METHOD structure to allow CRL processing to be redirected
      to external functions. This can be used to increase CRL handling 
      efficiency especially when CRLs are very large by (for example) storing
@@ -408,6 +415,20 @@
 
  Changes between 0.9.8c and 0.9.8d  [xx XXX xxxx]
 
+  *) Introduce limits to prevent malicious keys being able to
+     cause a denial of service.  (CVE-2006-2940)
+     [Steve Henson, Bodo Moeller]
+
+  *) Fix ASN.1 parsing of certain invalid structures that can result
+     in a denial of service.  (CVE-2006-2937)  [Steve Henson]
+
+  *) Fix buffer overflow in SSL_get_shared_ciphers() function. 
+     (CVE-2006-3738) [Tavis Ormandy and Will Drewry, Google Security Team]
+
+  *) Fix SSL client code which could crash if connecting to a
+     malicious SSLv2 server.  (CVE-2006-4343)
+     [Tavis Ormandy and Will Drewry, Google Security Team]
+
   *) Since 0.9.8b, ciphersuite strings naming explicit ciphersuites
      match only those.  Before that, "AES256-SHA" would be interpreted
      as a pattern and match "AES128-SHA" too (since AES128-SHA got
diff --git a/ssl/s2_clnt.c b/ssl/s2_clnt.c
index 89f3f7d753..d9750d0935 100644
--- a/ssl/s2_clnt.c
+++ b/ssl/s2_clnt.c
@@ -520,7 +520,8 @@ static int get_server_hello(SSL *s)
 		CRYPTO_add(&s->session->peer->references, 1, CRYPTO_LOCK_X509);
 		}
 
-	if (s->session->peer != s->session->sess_cert->peer_key->x509)
+	if (s->session->sess_cert == NULL 
+      || s->session->peer != s->session->sess_cert->peer_key->x509)
 		/* can't happen */
 		{
 		ssl2_return_error(s, SSL2_PE_UNDEFINED_ERROR);
diff --git a/ssl/s3_srvr.c b/ssl/s3_srvr.c
index 85fa6849a2..a83f8ac763 100644
--- a/ssl/s3_srvr.c
+++ b/ssl/s3_srvr.c
@@ -2089,7 +2089,7 @@ int ssl3_get_client_key_exchange(SSL *s)
 
                 if (kssl_ctx->client_princ)
                         {
-                        int len = strlen(kssl_ctx->client_princ);
+                        size_t len = strlen(kssl_ctx->client_princ);
                         if ( len < SSL_MAX_KRB5_PRINCIPAL_LENGTH ) 
                                 {
                                 s->session->krb5_client_princ_len = len;
diff --git a/ssl/ssl_lib.c b/ssl/ssl_lib.c
index a8bc044cbe..44f82eb3ee 100644
--- a/ssl/ssl_lib.c
+++ b/ssl/ssl_lib.c
@@ -1272,7 +1272,7 @@ char *SSL_get_shared_ciphers(const SSL *s,char *buf,int len)
 		c=sk_SSL_CIPHER_value(sk,i);
 		for (cp=c->name; *cp; )
 			{
-			if (len-- == 0)
+			if (len-- <= 0)
 				{
 				*p='\0';
 				return(buf);
-- 
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