- Extracted ASN.1 parsing code from the X.509 parsing code. Added new module.
diff --git a/library/asn1parse.c b/library/asn1parse.c
new file mode 100644
index 0000000..09f67fa
--- /dev/null
+++ b/library/asn1parse.c
@@ -0,0 +1,260 @@
+/*
+ * Generic ASN.1 parsing
+ *
+ * Copyright (C) 2006-2011, Brainspark B.V.
+ *
+ * This file is part of PolarSSL (http://www.polarssl.org)
+ * Lead Maintainer: Paul Bakker <polarssl_maintainer at polarssl.org>
+ *
+ * All rights reserved.
+ *
+ * This program is free software; you can redistribute it and/or modify
+ * it under the terms of the GNU General Public License as published by
+ * the Free Software Foundation; either version 2 of the License, or
+ * (at your option) any later version.
+ *
+ * This program is distributed in the hope that it will be useful,
+ * but WITHOUT ANY WARRANTY; without even the implied warranty of
+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
+ * GNU General Public License for more details.
+ *
+ * You should have received a copy of the GNU General Public License along
+ * with this program; if not, write to the Free Software Foundation, Inc.,
+ * 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA.
+ */
+
+#include "polarssl/config.h"
+
+#if defined(POLARSSL_ASN1_PARSE_C)
+
+#include "polarssl/asn1.h"
+
+#if defined(POLARSSL_BIGNUM_C)
+#include "polarssl/bignum.h"
+#endif
+
+#include <string.h>
+#include <stdlib.h>
+#include <time.h>
+
+/*
+ * ASN.1 DER decoding routines
+ */
+int asn1_get_len( unsigned char **p,
+ const unsigned char *end,
+ size_t *len )
+{
+ if( ( end - *p ) < 1 )
+ return( POLARSSL_ERR_ASN1_OUT_OF_DATA );
+
+ if( ( **p & 0x80 ) == 0 )
+ *len = *(*p)++;
+ else
+ {
+ switch( **p & 0x7F )
+ {
+ case 1:
+ if( ( end - *p ) < 2 )
+ return( POLARSSL_ERR_ASN1_OUT_OF_DATA );
+
+ *len = (*p)[1];
+ (*p) += 2;
+ break;
+
+ case 2:
+ if( ( end - *p ) < 3 )
+ return( POLARSSL_ERR_ASN1_OUT_OF_DATA );
+
+ *len = ( (*p)[1] << 8 ) | (*p)[2];
+ (*p) += 3;
+ break;
+
+ case 3:
+ if( ( end - *p ) < 4 )
+ return( POLARSSL_ERR_ASN1_OUT_OF_DATA );
+
+ *len = ( (*p)[1] << 16 ) | ( (*p)[2] << 8 ) | (*p)[3];
+ (*p) += 4;
+ break;
+
+ case 4:
+ if( ( end - *p ) < 5 )
+ return( POLARSSL_ERR_ASN1_OUT_OF_DATA );
+
+ *len = ( (*p)[1] << 24 ) | ( (*p)[2] << 16 ) | ( (*p)[3] << 8 ) | (*p)[4];
+ (*p) += 5;
+ break;
+
+ default:
+ return( POLARSSL_ERR_ASN1_INVALID_LENGTH );
+ }
+ }
+
+ if( *len > (size_t) ( end - *p ) )
+ return( POLARSSL_ERR_ASN1_OUT_OF_DATA );
+
+ return( 0 );
+}
+
+int asn1_get_tag( unsigned char **p,
+ const unsigned char *end,
+ size_t *len, int tag )
+{
+ if( ( end - *p ) < 1 )
+ return( POLARSSL_ERR_ASN1_OUT_OF_DATA );
+
+ if( **p != tag )
+ return( POLARSSL_ERR_ASN1_UNEXPECTED_TAG );
+
+ (*p)++;
+
+ return( asn1_get_len( p, end, len ) );
+}
+
+int asn1_get_bool( unsigned char **p,
+ const unsigned char *end,
+ int *val )
+{
+ int ret;
+ size_t len;
+
+ if( ( ret = asn1_get_tag( p, end, &len, ASN1_BOOLEAN ) ) != 0 )
+ return( ret );
+
+ if( len != 1 )
+ return( POLARSSL_ERR_ASN1_INVALID_LENGTH );
+
+ *val = ( **p != 0 ) ? 1 : 0;
+ (*p)++;
+
+ return( 0 );
+}
+
+int asn1_get_int( unsigned char **p,
+ const unsigned char *end,
+ int *val )
+{
+ int ret;
+ size_t len;
+
+ if( ( ret = asn1_get_tag( p, end, &len, ASN1_INTEGER ) ) != 0 )
+ return( ret );
+
+ if( len > sizeof( int ) || ( **p & 0x80 ) != 0 )
+ return( POLARSSL_ERR_ASN1_INVALID_LENGTH );
+
+ *val = 0;
+
+ while( len-- > 0 )
+ {
+ *val = ( *val << 8 ) | **p;
+ (*p)++;
+ }
+
+ return( 0 );
+}
+
+#if defined(POLARSSL_BIGNUM_C)
+int asn1_get_mpi( unsigned char **p,
+ const unsigned char *end,
+ mpi *X )
+{
+ int ret;
+ size_t len;
+
+ if( ( ret = asn1_get_tag( p, end, &len, ASN1_INTEGER ) ) != 0 )
+ return( ret );
+
+ ret = mpi_read_binary( X, *p, len );
+
+ *p += len;
+
+ return( ret );
+}
+#endif /* POLARSSL_BIGNUM_C */
+
+int asn1_get_bitstring( unsigned char **p, const unsigned char *end,
+ asn1_bitstring *bs)
+{
+ int ret;
+
+ /* Certificate type is a single byte bitstring */
+ if( ( ret = asn1_get_tag( p, end, &bs->len, ASN1_BIT_STRING ) ) != 0 )
+ return( ret );
+
+ /* Check length, subtract one for actual bit string length */
+ if ( bs->len < 1 )
+ return( POLARSSL_ERR_ASN1_OUT_OF_DATA );
+ bs->len -= 1;
+
+ /* Get number of unused bits, ensure unused bits <= 7 */
+ bs->unused_bits = **p;
+ if( bs->unused_bits > 7 )
+ return( POLARSSL_ERR_ASN1_INVALID_LENGTH );
+ (*p)++;
+
+ /* Get actual bitstring */
+ bs->p = *p;
+ *p += bs->len;
+
+ if( *p != end )
+ return( POLARSSL_ERR_ASN1_LENGTH_MISMATCH );
+
+ return 0;
+}
+
+
+/*
+ * Parses and splits an ASN.1 "SEQUENCE OF <tag>"
+ */
+int asn1_get_sequence_of( unsigned char **p,
+ const unsigned char *end,
+ asn1_sequence *cur,
+ int tag)
+{
+ int ret;
+ size_t len;
+ asn1_buf *buf;
+
+ /* Get main sequence tag */
+ if( ( ret = asn1_get_tag( p, end, &len,
+ ASN1_CONSTRUCTED | ASN1_SEQUENCE ) ) != 0 )
+ return( ret );
+
+ if( *p + len != end )
+ return( POLARSSL_ERR_ASN1_LENGTH_MISMATCH );
+
+ while( *p < end )
+ {
+ buf = &(cur->buf);
+ buf->tag = **p;
+
+ if( ( ret = asn1_get_tag( p, end, &buf->len, tag ) ) != 0 )
+ return( ret );
+
+ buf->p = *p;
+ *p += buf->len;
+
+ /* Allocate and assign next pointer */
+ if (*p < end)
+ {
+ cur->next = (asn1_sequence *) malloc(
+ sizeof( asn1_sequence ) );
+
+ if( cur->next == NULL )
+ return( 1 );
+
+ cur = cur->next;
+ }
+ }
+
+ /* Set final sequence entry's next pointer to NULL */
+ cur->next = NULL;
+
+ if( *p != end )
+ return( POLARSSL_ERR_ASN1_LENGTH_MISMATCH );
+
+ return( 0 );
+}
+
+#endif