commit f8d018a2747661d9b1d5533b9925e8fb745397c9
author Paul Bakker <p.j.bakker@polarssl.org> Sat Jun 29 12:16:17 2013 +0200
committer Paul Bakker <p.j.bakker@polarssl.org> Sat Jun 29 18:35:40 2013 +0200
tree 3585bbcd5f309ffb45674c3e2b7875c779f5f9c3
parent ce6ae233cb61e1bedf30da79b4aa71b097a509b8

Made asn1_get_alg() and asn1_get_alg_null() as generic functions

A generic function for retrieving the AlgorithmIdentifier structure with
its parameters and adapted X509, PKCS#5 and PKCS#12 to use them.

library/asn1parse.c

diff --git a/library/asn1parse.c b/library/asn1parse.c
index 2584774..b8823c1 100644
--- a/library/asn1parse.c
+++ b/library/asn1parse.c
@@ -1,7 +1,7 @@
 /*
  *  Generic ASN.1 parsing
  *
- *  Copyright (C) 2006-2011, Brainspark B.V.
+ *  Copyright (C) 2006-2013, Brainspark B.V.
  *
  *  This file is part of PolarSSL (http://www.polarssl.org)
  *  Lead Maintainer: Paul Bakker <polarssl_maintainer at polarssl.org>
@@ -257,4 +257,63 @@
     return( 0 );
 }
 
+int asn1_get_alg( unsigned char **p,
+                  const unsigned char *end,
+                  asn1_buf *alg, asn1_buf *params )
+{
+    int ret;
+    size_t len;
+
+    if( ( ret = asn1_get_tag( p, end, &len,
+            ASN1_CONSTRUCTED | ASN1_SEQUENCE ) ) != 0 )
+        return( ret );
+
+    end = *p + len;
+    alg->tag = **p;
+
+    if( ( ret = asn1_get_tag( p, end, &alg->len, ASN1_OID ) ) != 0 )
+        return( ret );
+
+    alg->p = *p;
+    *p += alg->len;
+
+    if( *p == end )
+    {
+        memset( params, 0, sizeof(asn1_buf) );
+        return( 0 );
+    }
+
+    params->tag = **p;
+    (*p)++;
+
+    if( ( ret = asn1_get_len( p, end, &params->len ) ) != 0 )
+        return( ret );
+
+    params->p = *p;
+    *p += params->len;
+
+    if( *p != end )
+        return( POLARSSL_ERR_ASN1_LENGTH_MISMATCH );
+
+    return( 0 );
+}
+
+int asn1_get_alg_null( unsigned char **p,
+                       const unsigned char *end,
+                       asn1_buf *alg )
+{
+    int ret;
+    asn1_buf params;
+
+    memset( &params, 0, sizeof(asn1_buf) );
+
+    if( ( ret = asn1_get_alg( p, end, alg, &params ) ) != 0 )
+        return( ret );
+
+    if( ( params.tag != ASN1_NULL && params.tag != 0 ) || params.len != 0 )
+        return( POLARSSL_ERR_ASN1_INVALID_DATA );
+
+    return( 0 );
+}
+
 #endif