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Viewing changes to libtomcrypt/src/pk/dsa/dsa_import.c

  • Committer: Bazaar Package Importer
  • Author(s): Matt Johnston
  • Date: 2005-12-08 19:20:21 UTC
  • mfrom: (1.2.2 upstream)
  • Revision ID: james.westby@ubuntu.com-20051208192021-nyp9rwnt77nsg6ty
Tags: 0.47-1
* New upstream release.
* SECURITY: Fix incorrect buffer sizing.

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libtomcrypt/src/pk/dsa/dsa_import.c
 
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/* LibTomCrypt, modular cryptographic library -- Tom St Denis
 
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 *
 
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 * LibTomCrypt is a library that provides various cryptographic
 
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 * algorithms in a highly modular and flexible manner.
 
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 *
 
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 * The library is free for all purposes without any express
 
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 * guarantee it works.
 
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 *
 
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 * Tom St Denis, tomstdenis@gmail.com, http://libtomcrypt.org
 
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 */
 
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#include "tomcrypt.h"
 
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/**
 
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   @file dsa_import.c
 
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   DSA implementation, import a DSA key, Tom St Denis
 
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*/
 
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#ifdef MDSA
 
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/**
 
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   Import a DSA key 
 
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   @param in       The binary packet to import from
 
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   @param inlen    The length of the binary packet
 
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   @param key      [out] Where to store the imported key
 
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   @return CRYPT_OK if successful, upon error this function will free all allocated memory
 
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*/
 
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int dsa_import(const unsigned char *in, unsigned long inlen, dsa_key *key)
 
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{
 
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   unsigned char flags[1];
 
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   int           err;
 
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   LTC_ARGCHK(in  != NULL);
 
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   LTC_ARGCHK(key != NULL);
 
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   /* init key */
 
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   if (mp_init_multi(&key->p, &key->g, &key->q, &key->x, &key->y, NULL) != MP_OKAY) {
 
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      return CRYPT_MEM;
 
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   }
 
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   /* get key type */
 
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   if ((err = der_decode_sequence_multi(in, inlen,
 
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                                  LTC_ASN1_BIT_STRING, 1UL, flags,
 
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                                  LTC_ASN1_EOL, 0UL, NULL)) != CRYPT_OK) {
 
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      goto error;
 
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   }
 
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   if (flags[0] == 1) {
 
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      if ((err = der_decode_sequence_multi(in, inlen,
 
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                                 LTC_ASN1_BIT_STRING,   1UL, flags,
 
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                                 LTC_ASN1_INTEGER,      1UL, &key->g,
 
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                                 LTC_ASN1_INTEGER,      1UL, &key->p,
 
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                                 LTC_ASN1_INTEGER,      1UL, &key->q,
 
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                                 LTC_ASN1_INTEGER,      1UL, &key->y,
 
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                                 LTC_ASN1_INTEGER,      1UL, &key->x,
 
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                                 LTC_ASN1_EOL,          0UL, NULL)) != CRYPT_OK) {
 
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         goto error;
 
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      }
 
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      key->type = PK_PRIVATE;
 
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   } else {
 
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      if ((err = der_decode_sequence_multi(in, inlen,
 
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                                 LTC_ASN1_BIT_STRING,   1UL, flags,
 
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                                 LTC_ASN1_INTEGER,      1UL, &key->g,
 
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                                 LTC_ASN1_INTEGER,      1UL, &key->p,
 
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                                 LTC_ASN1_INTEGER,      1UL, &key->q,
 
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                                 LTC_ASN1_INTEGER,      1UL, &key->y,
 
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                                 LTC_ASN1_EOL,          0UL, NULL)) != CRYPT_OK) {
 
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         goto error;
 
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      }
 
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      key->type = PK_PUBLIC;
 
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  }
 
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  key->qord = mp_unsigned_bin_size(&key->q);
 
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  if (key->qord >= MDSA_MAX_GROUP || key->qord <= 15 ||
 
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      key->qord >= mp_unsigned_bin_size(&key->p) || (mp_unsigned_bin_size(&key->p) - key->qord) >= MDSA_DELTA) {
 
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      err = CRYPT_INVALID_PACKET;
 
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      goto error;
 
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   }
 
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  return CRYPT_OK;
 
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error: 
 
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   mp_clear_multi(&key->p, &key->g, &key->q, &key->x, &key->y, NULL);
 
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   return err;
 
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}
 
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#endif
 
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/* $Source: /cvs/libtom/libtomcrypt/src/pk/dsa/dsa_import.c,v $ */
 
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/* $Revision: 1.7 $ */
 
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/* $Date: 2005/06/08 23:31:17 $ */