From: Dr. Stephen Henson <steve@openssl.org>
Date: Thu, 24 Jan 2013 13:30:42 +0000 (+0000)
Subject: Don't try and verify signatures if key is NULL (CVE-2013-0166)
X-Git-Tag: OpenSSL_0_9_8y~22
X-Git-Url: https://git.librecmc.org/?a=commitdiff_plain;h=66e8211c0b1347970096e04b18aa52567c325200;p=oweals%2Fopenssl.git

Don't try and verify signatures if key is NULL (CVE-2013-0166)
Add additional check to catch this in ASN1_item_verify too.
---

diff --git a/CHANGES b/CHANGES
index 199e70fc72..8adac3b6d4 100644
--- a/CHANGES
+++ b/CHANGES
@@ -4,6 +4,10 @@
 
  Changes between 0.9.8x and 0.9.8y [xx XXX xxxx]
 
+  *) Return an error when checking OCSP signatures when key is NULL.
+     This fixes a DoS attack. (CVE-2013-0166)
+     [Steve Henson]
+
   *) Call OCSP Stapling callback after ciphersuite has been chosen, so
      the right response is stapled. Also change SSL_get_certificate()
      so it returns the certificate actually sent.
diff --git a/crypto/asn1/a_verify.c b/crypto/asn1/a_verify.c
index da3efaaf8d..7ded69b170 100644
--- a/crypto/asn1/a_verify.c
+++ b/crypto/asn1/a_verify.c
@@ -138,6 +138,12 @@ int ASN1_item_verify(const ASN1_ITEM *it, X509_ALGOR *a, ASN1_BIT_STRING *signat
 	unsigned char *buf_in=NULL;
 	int ret= -1,i,inl;
 
+	if (!pkey)
+		{
+		ASN1err(ASN1_F_ASN1_ITEM_VERIFY, ERR_R_PASSED_NULL_PARAMETER);
+		return -1;
+		}
+
 	EVP_MD_CTX_init(&ctx);
 	i=OBJ_obj2nid(a->algorithm);
 	type=EVP_get_digestbyname(OBJ_nid2sn(i));
diff --git a/crypto/ocsp/ocsp_vfy.c b/crypto/ocsp/ocsp_vfy.c
index d3b446c5f9..f24080fa0e 100644
--- a/crypto/ocsp/ocsp_vfy.c
+++ b/crypto/ocsp/ocsp_vfy.c
@@ -91,9 +91,12 @@ int OCSP_basic_verify(OCSP_BASICRESP *bs, STACK_OF(X509) *certs,
 		{
 		EVP_PKEY *skey;
 		skey = X509_get_pubkey(signer);
-		ret = OCSP_BASICRESP_verify(bs, skey, 0);
-		EVP_PKEY_free(skey);
-		if(ret <= 0)
+		if (skey)
+			{
+			ret = OCSP_BASICRESP_verify(bs, skey, 0);
+			EVP_PKEY_free(skey);
+			}
+		if(!skey || ret <= 0)
 			{
 			OCSPerr(OCSP_F_OCSP_BASIC_VERIFY, OCSP_R_SIGNATURE_FAILURE);
 			goto end;