--- /dev/null	Thu Jan 01 00:00:00 1970 +0000
+++ b/libtomcrypt/src/pk/asn1/der/sequence/der_decode_sequence.c	Wed Mar 08 13:23:58 2006 +0000
@@ -0,0 +1,234 @@
+/* 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, [email protected], 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 $ */