Use an OCTET STRING for the encoding of an OCSP nonce value.

The old raw format can't be handled by some implementations
and updates to RFC2560 will make this mandatory.

CHANGES

@@ -617,6 +617,13 @@
 
  Changes between 0.9.7c and 0.9.7d  [xx XXX XXXX]
 
+  *) When creating an OCSP nonce use an OCTET STRING inside the extnValue.
+     A clarification of RFC2560 will require the use of OCTET STRINGs and 
+     some implementations cannot handle the current raw format. Since OpenSSL
+     copies and compares OCSP nonces as opaque blobs without any attempt at
+     parsing them this should not create any compatibility issues.
+     [Steve Henson]
+
   *) New md flag EVP_MD_CTX_FLAG_REUSE this allows md_data to be reused when
      calling EVP_MD_CTX_copy_ex() to avoid calling OPENSSL_malloc(). Without
      this HMAC (and other) operations are several times slower than OpenSSL

crypto/ocsp/ocsp_ext.c

@@ -305,6 +305,8 @@ err:
 
 /* Add a nonce to an extension stack. A nonce can be specificed or if NULL
  * a random nonce will be generated.
+ * Note: OpenSSL 0.9.7d and later create an OCTET STRING containing the 
+ * nonce, previous versions used the raw nonce.
  */
 
 static int ocsp_add1_nonce(STACK_OF(X509_EXTENSION) **exts, unsigned char *val, int len)
@@ -313,20 +315,28 @@ static int ocsp_add1_nonce(STACK_OF(X509_EXTENSION) **exts, unsigned char *val,
 	ASN1_OCTET_STRING os;
 	int ret = 0;
 	if (len <= 0) len = OCSP_DEFAULT_NONCE_LENGTH;
-	if (val) tmpval = val;
+	/* Create the OCTET STRING manually by writing out the header and
+	 * appending the content octets. This avoids an extra memory allocation
+	 * operation in some cases. Applications should *NOT* do this because
+         * it relies on library internals.
+	 */
+	os.length = ASN1_object_size(0, len, V_ASN1_OCTET_STRING);
+	os.data = OPENSSL_malloc(os.length);
+	if (os.data == NULL)
+		goto err;
+	tmpval = os.data;
+	ASN1_put_object(&tmpval, 0, len, V_ASN1_OCTET_STRING, V_ASN1_UNIVERSAL);
+	if (val)
+		memcpy(tmpval, val, len);
 	else
-		{
-		if (!(tmpval = OPENSSL_malloc(len))) goto err;
 		RAND_pseudo_bytes(tmpval, len);
-		}
-	os.data = tmpval;
-	os.length = len;
 	if(!X509V3_add1_i2d(exts, NID_id_pkix_OCSP_Nonce,
 			&os, 0, X509V3_ADD_REPLACE))
 				goto err;
 	ret = 1;
 	err:
-	if(!val) OPENSSL_free(tmpval);
+	if (os.data)
+		OPENSSL_free(os.data);
 	return ret;
 	}