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/* LibTomCrypt, modular cryptographic library -- Tom St Denis
*
* LibTomCrypt is a library that provides various cryptographic
* algorithms in a highly modular and flexible manner.
*
* The library is free for all purposes without any express
* guarantee it works.
*
* Tom St Denis, tomstdenis@gmail.com, http://libtomcrypt.org
*/
#include "tomcrypt.h"
#include <stdarg.h>
/**
@file der_decode_sequence.c
ASN.1 DER, decode a SEQUENCE, Tom St Denis
*/
#ifdef LTC_DER
/**
Decode a SEQUENCE
@param in The DER encoded input
@param inlen The size of the input
@param list The list of items to decode
@param outlen The number of items in the list
@return CRYPT_OK on success
*/
int der_decode_sequence(const unsigned char *in, unsigned long inlen,
ltc_asn1_list *list, unsigned long outlen)
{
int err, type;
unsigned long size, x, y, z, i, blksize;
void *data;
LTC_ARGCHK(in != NULL);
LTC_ARGCHK(list != NULL);
/* get blk size */
if (inlen < 2) {
return CRYPT_INVALID_PACKET;
}
/* sequence type? */
x = 0;
if (in[x++] != 0x30) {
return CRYPT_INVALID_PACKET;
}
if (in[x] < 128) {
blksize = in[x++];
} else if (in[x] & 0x80) {
if (in[x] < 0x81 || in[x] > 0x83) {
return CRYPT_INVALID_PACKET;
}
y = in[x++] & 0x7F;
/* would reading the len bytes overrun? */
if (x + y > inlen) {
return CRYPT_INVALID_PACKET;
}
/* read len */
blksize = 0;
while (y--) {
blksize = (blksize << 8) | (unsigned long)in[x++];
}
}
/* would this blksize overflow? */
if (x + blksize > inlen) {
return CRYPT_INVALID_PACKET;
}
/* ok read data */
inlen = blksize;
for (i = 0; i < outlen; i++) {
type = list[i].type;
size = list[i].size;
data = list[i].data;
if (type == LTC_ASN1_EOL) {
break;
}
switch (type) {
case LTC_ASN1_INTEGER:
z = inlen;
if ((err = der_decode_integer(in + x, z, data)) != CRYPT_OK) {
goto LBL_ERR;
}
if ((err = der_length_integer(data, &z)) != CRYPT_OK) {
goto LBL_ERR;
}
x += z;
inlen -= z;
break;
case LTC_ASN1_SHORT_INTEGER:
z = inlen;
if ((err = der_decode_short_integer(in + x, z, data)) != CRYPT_OK) {
goto LBL_ERR;
}
if ((err = der_length_short_integer(size, &z)) != CRYPT_OK) {
goto LBL_ERR;
}
x += z;
inlen -= z;
break;
case LTC_ASN1_BIT_STRING:
z = inlen;
if ((err = der_decode_bit_string(in + x, z, data, &size)) != CRYPT_OK) {
goto LBL_ERR;
}
list[i].size = size;
if ((err = der_length_bit_string(size, &z)) != CRYPT_OK) {
goto LBL_ERR;
}
x += z;
inlen -= z;
break;
case LTC_ASN1_OCTET_STRING:
z = inlen;
if ((err = der_decode_octet_string(in + x, z, data, &size)) != CRYPT_OK) {
goto LBL_ERR;
}
list[i].size = size;
if ((err = der_length_octet_string(size, &z)) != CRYPT_OK) {
goto LBL_ERR;
}
x += z;
inlen -= z;
break;
case LTC_ASN1_NULL:
if (inlen < 2 || in[x] != 0x05 || in[x+1] != 0x00) {
err = CRYPT_INVALID_PACKET;
goto LBL_ERR;
}
x += 2;
inlen -= 2;
break;
case LTC_ASN1_OBJECT_IDENTIFIER:
z = inlen;
if ((err = der_decode_object_identifier(in + x, z, data, &size)) != CRYPT_OK) {
goto LBL_ERR;
}
list[i].size = size;
if ((err = der_length_object_identifier(data, size, &z)) != CRYPT_OK) {
goto LBL_ERR;
}
x += z;
inlen -= z;
break;
case LTC_ASN1_IA5_STRING:
z = inlen;
if ((err = der_decode_ia5_string(in + x, z, data, &size)) != CRYPT_OK) {
goto LBL_ERR;
}
list[i].size = size;
if ((err = der_length_ia5_string(data, size, &z)) != CRYPT_OK) {
goto LBL_ERR;
}
x += z;
inlen -= z;
break;
case LTC_ASN1_PRINTABLE_STRING:
z = inlen;
if ((err = der_decode_printable_string(in + x, z, data, &size)) != CRYPT_OK) {
goto LBL_ERR;
}
list[i].size = size;
if ((err = der_length_printable_string(data, size, &z)) != CRYPT_OK) {
goto LBL_ERR;
}
x += z;
inlen -= z;
break;
case LTC_ASN1_UTCTIME:
z = inlen;
if ((err = der_decode_utctime(in + x, &z, data)) != CRYPT_OK) {
goto LBL_ERR;
}
x += z;
inlen -= z;
break;
case LTC_ASN1_SEQUENCE:
z = inlen;
if ((err = der_decode_sequence(in + x, z, data, size)) != CRYPT_OK) {
goto LBL_ERR;
}
if ((err = der_length_sequence(data, size, &z)) != CRYPT_OK) {
goto LBL_ERR;
}
x += z;
inlen -= z;
break;
case LTC_ASN1_CHOICE:
z = inlen;
if ((err = der_decode_choice(in + x, &z, data, size)) != CRYPT_OK) {
goto LBL_ERR;
}
x += z;
inlen -= z;
break;
default:
err = CRYPT_INVALID_ARG;
goto LBL_ERR;
}
}
err = CRYPT_OK;
LBL_ERR:
return err;
}
#endif
/* $Source: /cvs/libtom/libtomcrypt/src/pk/asn1/der/sequence/der_decode_sequence.c,v $ */
/* $Revision: 1.8 $ */
/* $Date: 2005/06/18 19:20:23 $ */
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