Mercurial > dropbear
view libtomcrypt/src/pk/dsa/dsa_import.c @ 817:a625f9e135a4
Constant time memcmp for the hmac and password crypt
author | Matt Johnston <matt@ucc.asn.au> |
---|---|
date | Thu, 03 Oct 2013 22:25:30 +0800 (2013-10-03) |
parents | 0cbe8f6dbf9e |
children | f849a5ca2efc |
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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.com */ #include "tomcrypt.h" /** @file dsa_import.c DSA implementation, import a DSA key, Tom St Denis */ #ifdef MDSA /** Import a DSA key @param in The binary packet to import from @param inlen The length of the binary packet @param key [out] Where to store the imported key @return CRYPT_OK if successful, upon error this function will free all allocated memory */ int dsa_import(const unsigned char *in, unsigned long inlen, dsa_key *key) { unsigned char flags[1]; int err; LTC_ARGCHK(in != NULL); LTC_ARGCHK(key != NULL); LTC_ARGCHK(ltc_mp.name != NULL); /* init key */ if (mp_init_multi(&key->p, &key->g, &key->q, &key->x, &key->y, NULL) != CRYPT_OK) { return CRYPT_MEM; } /* get key type */ if ((err = der_decode_sequence_multi(in, inlen, LTC_ASN1_BIT_STRING, 1UL, flags, LTC_ASN1_EOL, 0UL, NULL)) != CRYPT_OK) { goto error; } if (flags[0] == 1) { if ((err = der_decode_sequence_multi(in, inlen, LTC_ASN1_BIT_STRING, 1UL, flags, LTC_ASN1_INTEGER, 1UL, key->g, LTC_ASN1_INTEGER, 1UL, key->p, LTC_ASN1_INTEGER, 1UL, key->q, LTC_ASN1_INTEGER, 1UL, key->y, LTC_ASN1_INTEGER, 1UL, key->x, LTC_ASN1_EOL, 0UL, NULL)) != CRYPT_OK) { goto error; } key->type = PK_PRIVATE; } else { if ((err = der_decode_sequence_multi(in, inlen, LTC_ASN1_BIT_STRING, 1UL, flags, LTC_ASN1_INTEGER, 1UL, key->g, LTC_ASN1_INTEGER, 1UL, key->p, LTC_ASN1_INTEGER, 1UL, key->q, LTC_ASN1_INTEGER, 1UL, key->y, LTC_ASN1_EOL, 0UL, NULL)) != CRYPT_OK) { goto error; } key->type = PK_PUBLIC; } key->qord = mp_unsigned_bin_size(key->q); if (key->qord >= MDSA_MAX_GROUP || key->qord <= 15 || (unsigned long)key->qord >= mp_unsigned_bin_size(key->p) || (mp_unsigned_bin_size(key->p) - key->qord) >= MDSA_DELTA) { err = CRYPT_INVALID_PACKET; goto error; } return CRYPT_OK; error: mp_clear_multi(key->p, key->g, key->q, key->x, key->y, NULL); return err; } #endif /* $Source: /cvs/libtom/libtomcrypt/src/pk/dsa/dsa_import.c,v $ */ /* $Revision: 1.12 $ */ /* $Date: 2006/03/31 14:15:35 $ */