Replaced system SQLite with SQLCipher to support encrypted database
This commit is contained in:
Oleksii Zghurskyi
172
Sources/DataLiteC/libtomcrypt/pk/rsa/rsa_exptmod.c
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172
Sources/DataLiteC/libtomcrypt/pk/rsa/rsa_exptmod.c
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/* 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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/**
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@file rsa_exptmod.c
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RSA PKCS exptmod, Tom St Denis
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Added RSA blinding --nmav
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*/
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#ifdef LTC_MRSA
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/**
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Compute an RSA modular exponentiation
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@param in The input data to send into RSA
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@param inlen The length of the input (octets)
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@param out [out] The destination
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@param outlen [in/out] The max size and resulting size of the output
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@param which Which exponent to use, e.g. PK_PRIVATE or PK_PUBLIC
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@param key The RSA key to use
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@return CRYPT_OK if successful
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*/
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int rsa_exptmod(const unsigned char *in, unsigned long inlen,
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unsigned char *out, unsigned long *outlen, int which,
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const rsa_key *key)
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{
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void *tmp, *tmpa, *tmpb;
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#ifdef LTC_RSA_BLINDING
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void *rnd, *rndi /* inverse of rnd */;
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#endif
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unsigned long x;
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int err, has_crt_parameters;
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LTC_ARGCHK(in != NULL);
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LTC_ARGCHK(out != NULL);
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LTC_ARGCHK(outlen != NULL);
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LTC_ARGCHK(key != NULL);
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/* is the key of the right type for the operation? */
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if (which == PK_PRIVATE && (key->type != PK_PRIVATE)) {
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return CRYPT_PK_NOT_PRIVATE;
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}
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/* must be a private or public operation */
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if (which != PK_PRIVATE && which != PK_PUBLIC) {
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return CRYPT_PK_INVALID_TYPE;
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}
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/* init and copy into tmp */
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if ((err = ltc_mp_init_multi(&tmp, &tmpa, &tmpb,
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#ifdef LTC_RSA_BLINDING
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&rnd, &rndi,
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#endif /* LTC_RSA_BLINDING */
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NULL)) != CRYPT_OK)
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{ return err; }
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if ((err = ltc_mp_read_unsigned_bin(tmp, in, (int)inlen)) != CRYPT_OK)
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{ goto error; }
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/* sanity check on the input */
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if (ltc_mp_cmp(key->N, tmp) == LTC_MP_LT) {
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err = CRYPT_PK_INVALID_SIZE;
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goto error;
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}
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/* are we using the private exponent and is the key optimized? */
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if (which == PK_PRIVATE) {
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#ifdef LTC_RSA_BLINDING
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/* do blinding */
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err = ltc_mp_rand(rnd, ltc_mp_get_digit_count(key->N));
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if (err != CRYPT_OK) {
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goto error;
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}
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/* rndi = 1/rnd mod N */
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err = ltc_mp_invmod(rnd, key->N, rndi);
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if (err != CRYPT_OK) {
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goto error;
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}
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/* rnd = rnd^e */
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err = ltc_mp_exptmod( rnd, key->e, key->N, rnd);
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if (err != CRYPT_OK) {
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goto error;
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}
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/* tmp = tmp*rnd mod N */
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err = ltc_mp_mulmod( tmp, rnd, key->N, tmp);
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if (err != CRYPT_OK) {
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goto error;
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}
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#endif /* LTC_RSA_BLINDING */
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has_crt_parameters = (key->p != NULL) && (ltc_mp_get_digit_count(key->p) != 0) &&
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(key->q != NULL) && (ltc_mp_get_digit_count(key->q) != 0) &&
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(key->dP != NULL) && (ltc_mp_get_digit_count(key->dP) != 0) &&
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(key->dQ != NULL) && (ltc_mp_get_digit_count(key->dQ) != 0) &&
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(key->qP != NULL) && (ltc_mp_get_digit_count(key->qP) != 0);
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if (!has_crt_parameters) {
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/*
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* In case CRT optimization parameters are not provided,
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* the private key is directly used to exptmod it
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*/
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if ((err = ltc_mp_exptmod(tmp, key->d, key->N, tmp)) != CRYPT_OK) { goto error; }
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} else {
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/* tmpa = tmp^dP mod p */
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if ((err = ltc_mp_exptmod(tmp, key->dP, key->p, tmpa)) != CRYPT_OK) { goto error; }
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/* tmpb = tmp^dQ mod q */
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if ((err = ltc_mp_exptmod(tmp, key->dQ, key->q, tmpb)) != CRYPT_OK) { goto error; }
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/* tmp = (tmpa - tmpb) * qInv (mod p) */
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if ((err = ltc_mp_sub(tmpa, tmpb, tmp)) != CRYPT_OK) { goto error; }
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if ((err = ltc_mp_mulmod(tmp, key->qP, key->p, tmp)) != CRYPT_OK) { goto error; }
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/* tmp = tmpb + q * tmp */
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if ((err = ltc_mp_mul(tmp, key->q, tmp)) != CRYPT_OK) { goto error; }
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if ((err = ltc_mp_add(tmp, tmpb, tmp)) != CRYPT_OK) { goto error; }
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}
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#ifdef LTC_RSA_BLINDING
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/* unblind */
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err = ltc_mp_mulmod( tmp, rndi, key->N, tmp);
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if (err != CRYPT_OK) {
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goto error;
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}
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#endif
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#ifdef LTC_RSA_CRT_HARDENING
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if (has_crt_parameters) {
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if ((err = ltc_mp_exptmod(tmp, key->e, key->N, tmpa)) != CRYPT_OK) { goto error; }
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if ((err = ltc_mp_read_unsigned_bin(tmpb, in, (int)inlen)) != CRYPT_OK) { goto error; }
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if (ltc_mp_cmp(tmpa, tmpb) != LTC_MP_EQ) { err = CRYPT_ERROR; goto error; }
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}
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#endif
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} else {
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/* exptmod it */
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if ((err = ltc_mp_exptmod(tmp, key->e, key->N, tmp)) != CRYPT_OK) { goto error; }
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}
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/* read it back */
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x = (unsigned long)ltc_mp_unsigned_bin_size(key->N);
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if (x > *outlen) {
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*outlen = x;
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err = CRYPT_BUFFER_OVERFLOW;
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goto error;
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}
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/* this should never happen ... */
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if (ltc_mp_unsigned_bin_size(tmp) > ltc_mp_unsigned_bin_size(key->N)) {
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err = CRYPT_ERROR;
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goto error;
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}
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*outlen = x;
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/* convert it */
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zeromem(out, x);
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if ((err = ltc_mp_to_unsigned_bin(tmp, out+(x-ltc_mp_unsigned_bin_size(tmp)))) != CRYPT_OK) { goto error; }
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/* clean up and return */
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err = CRYPT_OK;
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error:
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ltc_mp_deinit_multi(
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#ifdef LTC_RSA_BLINDING
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rndi, rnd,
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#endif /* LTC_RSA_BLINDING */
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tmpb, tmpa, tmp, NULL);
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return err;
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}
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#endif
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