Mac: Generate valid <keygen> data if challenge string is empty

net/base/keygen_handler_mac.cc

 // Copyright (c) 2010 The Chromium Authors. All rights reserved.
 // Use of this source code is governed by a BSD-style license that can be
 // found in the LICENSE file.
 
 #include "net/base/keygen_handler.h"
 
 #include <Security/SecAsn1Coder.h>
 #include <Security/SecAsn1Templates.h>
 #include <Security/Security.h>
 
 #include "base/base64.h"
 #include "base/logging.h"
 #include "base/scoped_cftyperef.h"
 
 // These are in Security.framework but not declared in a public header.
 extern const SecAsn1Template kSecAsn1AlgorithmIDTemplate[];
 extern const SecAsn1Template kSecAsn1SubjectPublicKeyInfoTemplate[];
 
 namespace net {
 
 // Declarations of Netscape keygen cert structures for ASN.1 encoding:
 
 struct PublicKeyAndChallenge {
   CSSM_X509_SUBJECT_PUBLIC_KEY_INFO spki;
   CSSM_DATA challenge_string;
 };
 
+const SecAsn1Template kIA5StringTemplate[] = {

[wtc, 2010/04/19 22:43:45]

Nit: add a comment to explain why we can't use
kSecAsn1IA5StringTemplate from the Security Framework.

+    { SEC_ASN1_IA5_STRING, 0, NULL, sizeof(CSSM_DATA) }
+};
+
 static const SecAsn1Template kPublicKeyAndChallengeTemplate[] = {
   {
     SEC_ASN1_SEQUENCE,
     0,
     NULL,
     sizeof(PublicKeyAndChallenge)
   },
   {
     SEC_ASN1_INLINE,
     offsetof(PublicKeyAndChallenge, spki),
     kSecAsn1SubjectPublicKeyInfoTemplate
   },
   {
     SEC_ASN1_INLINE,
     offsetof(PublicKeyAndChallenge, challenge_string),
-    kSecAsn1IA5StringTemplate
+    kIA5StringTemplate
   },
   {
     0
   }
 };
 
 struct SignedPublicKeyAndChallenge {
   PublicKeyAndChallenge pkac;
   CSSM_X509_ALGORITHM_IDENTIFIER signature_algorithm;
   CSSM_DATA signature;
@@ skipping 194 matching lines @@
                                         CSSM_ALGID_MD5WithRSA,
                                         &cc_handle);
   if (err)
     return err;
   err = CSSM_SignData(cc_handle, &data, 1, CSSM_ALGID_NONE, signature);
   CSSM_DeleteContext(cc_handle);
   return err;
 }
 
 }  // namespace net