107 lines
3.6 KiB
C
107 lines
3.6 KiB
C
/* LibTomCrypt, modular cryptographic library -- Tom St Denis */
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/* SPDX-License-Identifier: Unlicense */
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#include "tomcrypt_private.h"
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#pragma clang diagnostic push
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#pragma clang diagnostic ignored "-Wconversion"
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#pragma clang diagnostic ignored "-Wshorten-64-to-32"
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/**
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@file ecc_import.c
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ECC Crypto, Tom St Denis
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*/
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#if defined(LTC_MECC) && defined(LTC_DER)
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/**
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Import an ECC key from a binary packet
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@param in The packet to import
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@param inlen The length of the packet
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@param key [out] The destination of the import
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@return CRYPT_OK if successful, upon error all allocated memory will be freed
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*/
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int ecc_import(const unsigned char *in, unsigned long inlen, ecc_key *key)
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{
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return ecc_import_ex(in, inlen, key, NULL);
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}
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/**
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Import an ECC key from a binary packet, using user supplied domain params rather than one of the NIST ones
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@param in The packet to import
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@param inlen The length of the packet
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@param key [out] The destination of the import
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@param cu pointer to user supplied params; must be the same as the params used when exporting
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@return CRYPT_OK if successful, upon error all allocated memory will be freed
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*/
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int ecc_import_ex(const unsigned char *in, unsigned long inlen, ecc_key *key, const ltc_ecc_curve *cu)
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{
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unsigned long key_size;
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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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LTC_ARGCHK(ltc_mp.name != NULL);
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/* find out what type of key it is */
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err = der_decode_sequence_multi(in, inlen, LTC_ASN1_BIT_STRING, 1UL, flags,
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LTC_ASN1_SHORT_INTEGER, 1UL, &key_size,
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LTC_ASN1_EOL, 0UL, NULL);
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if (err != CRYPT_OK && err != CRYPT_INPUT_TOO_LONG) {
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return err;
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}
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/* allocate & initialize the key */
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if (cu == NULL) {
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if ((err = ecc_set_curve_by_size(key_size, key)) != CRYPT_OK) { goto done; }
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} else {
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if ((err = ecc_set_curve(cu, key)) != CRYPT_OK) { goto done; }
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}
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if (flags[0] == 1) {
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/* private key */
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key->type = PK_PRIVATE;
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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_SHORT_INTEGER, 1UL, &key_size,
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LTC_ASN1_INTEGER, 1UL, key->pubkey.x,
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LTC_ASN1_INTEGER, 1UL, key->pubkey.y,
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LTC_ASN1_INTEGER, 1UL, key->k,
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LTC_ASN1_EOL, 0UL, NULL)) != CRYPT_OK) {
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goto done;
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}
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} else if (flags[0] == 0) {
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/* public key */
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key->type = PK_PUBLIC;
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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_SHORT_INTEGER, 1UL, &key_size,
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LTC_ASN1_INTEGER, 1UL, key->pubkey.x,
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LTC_ASN1_INTEGER, 1UL, key->pubkey.y,
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LTC_ASN1_EOL, 0UL, NULL)) != CRYPT_OK) {
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goto done;
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}
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}
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else {
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err = CRYPT_INVALID_PACKET;
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goto done;
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}
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/* set z */
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if ((err = ltc_mp_set(key->pubkey.z, 1)) != CRYPT_OK) { goto done; }
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/* point on the curve + other checks */
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if ((err = ltc_ecc_verify_key(key)) != CRYPT_OK) { goto done; }
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/* we're good */
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return CRYPT_OK;
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done:
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ecc_free(key);
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return err;
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}
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#endif
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#pragma clang diagnostic pop
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