| // SPDX-License-Identifier: BSD-2-Clause |
| /* 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. |
| */ |
| #include "tomcrypt_private.h" |
| |
| /** |
| @file dsa_import.c |
| DSA implementation, import a DSA key, Tom St Denis |
| */ |
| |
| #ifdef LTC_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) |
| { |
| int err, stat; |
| unsigned long zero = 0, len; |
| unsigned char* tmpbuf = NULL; |
| unsigned char flags[1]; |
| |
| 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; |
| } |
| |
| /* try to match the old libtomcrypt format */ |
| err = der_decode_sequence_multi(in, inlen, LTC_ASN1_BIT_STRING, 1UL, flags, |
| LTC_ASN1_EOL, 0UL, NULL); |
| |
| if (err == CRYPT_OK || err == CRYPT_INPUT_TOO_LONG) { |
| /* private key */ |
| 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 LBL_ERR; |
| } |
| key->type = PK_PRIVATE; |
| goto LBL_OK; |
| } |
| /* public key */ |
| else if (flags[0] == 0) { |
| 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 LBL_ERR; |
| } |
| key->type = PK_PUBLIC; |
| goto LBL_OK; |
| } |
| else { |
| err = CRYPT_INVALID_PACKET; |
| goto LBL_ERR; |
| } |
| } |
| /* get key type */ |
| if ((err = der_decode_sequence_multi(in, inlen, |
| LTC_ASN1_SHORT_INTEGER, 1UL, &zero, |
| LTC_ASN1_INTEGER, 1UL, key->p, |
| LTC_ASN1_INTEGER, 1UL, key->q, |
| LTC_ASN1_INTEGER, 1UL, key->g, |
| LTC_ASN1_INTEGER, 1UL, key->y, |
| LTC_ASN1_INTEGER, 1UL, key->x, |
| LTC_ASN1_EOL, 0UL, NULL)) == CRYPT_OK) { |
| |
| key->type = PK_PRIVATE; |
| } else { /* public */ |
| ltc_asn1_list params[3]; |
| unsigned long tmpbuf_len = inlen; |
| |
| LTC_SET_ASN1(params, 0, LTC_ASN1_INTEGER, key->p, 1UL); |
| LTC_SET_ASN1(params, 1, LTC_ASN1_INTEGER, key->q, 1UL); |
| LTC_SET_ASN1(params, 2, LTC_ASN1_INTEGER, key->g, 1UL); |
| |
| tmpbuf = XCALLOC(1, tmpbuf_len); |
| if (tmpbuf == NULL) { |
| err = CRYPT_MEM; |
| goto LBL_ERR; |
| } |
| |
| len = 3; |
| err = x509_decode_subject_public_key_info(in, inlen, PKA_DSA, |
| tmpbuf, &tmpbuf_len, |
| LTC_ASN1_SEQUENCE, params, &len); |
| if (err != CRYPT_OK) { |
| XFREE(tmpbuf); |
| goto LBL_ERR; |
| } |
| |
| if ((err=der_decode_integer(tmpbuf, tmpbuf_len, key->y)) != CRYPT_OK) { |
| XFREE(tmpbuf); |
| goto LBL_ERR; |
| } |
| |
| XFREE(tmpbuf); |
| key->type = PK_PUBLIC; |
| } |
| |
| LBL_OK: |
| key->qord = mp_unsigned_bin_size(key->q); |
| |
| /* quick p, q, g validation, without primality testing */ |
| if ((err = dsa_int_validate_pqg(key, &stat)) != CRYPT_OK) { |
| goto LBL_ERR; |
| } |
| if (stat == 0) { |
| err = CRYPT_INVALID_PACKET; |
| goto LBL_ERR; |
| } |
| /* validate x, y */ |
| if ((err = dsa_int_validate_xy(key, &stat)) != CRYPT_OK) { |
| goto LBL_ERR; |
| } |
| if (stat == 0) { |
| err = CRYPT_INVALID_PACKET; |
| goto LBL_ERR; |
| } |
| |
| return CRYPT_OK; |
| LBL_ERR: |
| dsa_free(key); |
| return err; |
| } |
| |
| #endif |
| |
| /* ref: $Format:%D$ */ |
| /* git commit: $Format:%H$ */ |
| /* commit time: $Format:%ai$ */ |