From fbc09f3cb62daaf2059f5e7a216bc8d977c742b9 Mon Sep 17 00:00:00 2001
From: Paul Bakker <p.j.bakker@polarssl.org>
Date: Wed, 12 Oct 2011 09:56:41 +0000
Subject: [PATCH]  - Added an EXPLICIT tag number parameter to x509_get_ext()

---
 ChangeLog           |  1 +
 library/x509parse.c | 11 ++++++-----
 2 files changed, 7 insertions(+), 5 deletions(-)

diff --git a/ChangeLog b/ChangeLog
index 000f7cd25..df7283ef7 100644
--- a/ChangeLog
+++ b/ChangeLog
@@ -14,6 +14,7 @@ Changes
    * Fixed rsa_encrypt and rsa_decrypt examples to use public key for
      encryption and private key for decryption. (Closes ticket #34)
    * Inceased maximum size of ASN1 length reads to 32-bits.
+   * Added an EXPLICIT tag number parameter to x509_get_ext()
 
 Bugfix
    * Fixed faulty HMAC-MD2 implementation. Found by dibac. (Closes
diff --git a/library/x509parse.c b/library/x509parse.c
index bdafb22ea..5f1bdbddc 100644
--- a/library/x509parse.c
+++ b/library/x509parse.c
@@ -756,7 +756,7 @@ static int x509_get_uid( unsigned char **p,
  */
 static int x509_get_ext( unsigned char **p,
                          const unsigned char *end,
-                         x509_buf *ext )
+                         x509_buf *ext, int tag )
 {
     int ret;
     size_t len;
@@ -767,7 +767,7 @@ static int x509_get_ext( unsigned char **p,
     ext->tag = **p;
 
     if( ( ret = asn1_get_tag( p, end, &ext->len,
-            ASN1_CONTEXT_SPECIFIC | ASN1_CONSTRUCTED | 3 ) ) != 0 )
+            ASN1_CONTEXT_SPECIFIC | ASN1_CONSTRUCTED | tag ) ) != 0 )
         return( ret );
 
     ext->p = *p;
@@ -800,9 +800,10 @@ static int x509_get_crl_ext( unsigned char **p,
                              x509_buf *ext )
 {
     int ret;
-    size_t len;
+    size_t len = 0;
 
-    if( ( ret = x509_get_ext( p, end, ext ) ) != 0 )
+    /* Get explicit tag */
+    if( ( ret = x509_get_ext( p, end, ext, 0) ) != 0 )
     {
         if( ret == POLARSSL_ERR_ASN1_UNEXPECTED_TAG )
             return( 0 );
@@ -951,7 +952,7 @@ static int x509_get_crt_ext( unsigned char **p,
     size_t len;
     unsigned char *end_ext_data, *end_ext_octet;
 
-    if( ( ret = x509_get_ext( p, end, &crt->v3_ext ) ) != 0 )
+    if( ( ret = x509_get_ext( p, end, &crt->v3_ext, 3 ) ) != 0 )
     {
         if( ret == POLARSSL_ERR_ASN1_UNEXPECTED_TAG )
             return( 0 );