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 69d047841e5ea90f1b132c1aaf8094f94ec721e5..6f6a922038f8ec34cf696ea051a24a24744041c2 100644 (file)
--- a/CHANGES
+++ b/CHANGES
@@ -4,6 +4,10 @@
 
  Changes between 1.0.0j and 1.0.0k [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 cecdb13c70901ab77367c563a1000dcaecaf0cff..097ec813ac24dbb42956a037ab5ecaab8fa3f995 100644 (file)
--- a/crypto/asn1/a_verify.c
+++ b/crypto/asn1/a_verify.c
@@ -136,6 +136,12 @@ int ASN1_item_verify(const ASN1_ITEM *it, X509_ALGOR *a, ASN1_BIT_STRING *signat
 
        int mdnid, pknid;
 
+       if (!pkey)
+               {
+               ASN1err(ASN1_F_ASN1_ITEM_VERIFY, ERR_R_PASSED_NULL_PARAMETER);
+               return -1;
+               }
+
        EVP_MD_CTX_init(&ctx);
 
        /* Convert signature OID into digest and public key OIDs */

diff --git a/crypto/ocsp/ocsp_vfy.c b/crypto/ocsp/ocsp_vfy.c
index 8a5e788d960fb4cadff36c352ad9c12cdf30dddb..276718304dd211d4be989fb750d8c95ff792feff 100644 (file)
--- 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;