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/*-
* Copyright (c) 2021-2024 Ribose Inc.
* All rights reserved.
*
* Redistribution and use in source and binary forms, with or without
* modification, are permitted provided that the following conditions
* are met:
* 1. Redistributions of source code must retain the above copyright
* notice, this list of conditions and the following disclaimer.
* 2. Redistributions in binary form must reproduce the above copyright
* notice, this list of conditions and the following disclaimer in the
* documentation and/or other materials provided with the distribution.
*
* THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
* ``AS IS'' AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED
* TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR
* PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT HOLDERS OR CONTRIBUTORS
* BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR
* CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF
* SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS
* INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN
* CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE)
* ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE
* POSSIBILITY OF SUCH DAMAGE.
*/
#include "config.h"
#include "defaults.h"
#include <string.h>
#include <stdlib.h>
#include <assert.h>
#include <openssl/evp.h>
#include <openssl/err.h>
#include "mem.h"
#include "utils.h"
#include "repgp/repgp_def.h"
#include "symmetric.h"
static const char *
pgp_sa_to_openssl_string(int alg, bool silent = false)
{
switch (alg) {
#if defined(ENABLE_IDEA)
case PGP_SA_IDEA:
return "idea-ecb";
#endif
case PGP_SA_TRIPLEDES:
return "des-ede3";
#if defined(ENABLE_CAST5)
case PGP_SA_CAST5:
return "cast5-ecb";
#endif
#if defined(ENABLE_BLOWFISH)
case PGP_SA_BLOWFISH:
return "bf-ecb";
#endif
case PGP_SA_AES_128:
return "aes-128-ecb";
case PGP_SA_AES_192:
return "aes-192-ecb";
case PGP_SA_AES_256:
return "aes-256-ecb";
#if defined(ENABLE_SM2)
case PGP_SA_SM4:
return "sm4-ecb";
#endif
case PGP_SA_CAMELLIA_128:
return "camellia-128-ecb";
case PGP_SA_CAMELLIA_192:
return "camellia-192-ecb";
case PGP_SA_CAMELLIA_256:
return "camellia-256-ecb";
default:
if (!silent) {
RNP_LOG("Unsupported symmetric algorithm %d", alg);
}
return NULL;
}
}
bool
pgp_cipher_cfb_start(pgp_crypt_t * crypt,
pgp_symm_alg_t alg,
const uint8_t *key,
const uint8_t *iv)
{
memset(crypt, 0x0, sizeof(*crypt));
const char *cipher_name = pgp_sa_to_openssl_string(alg);
if (!cipher_name) {
RNP_LOG("Unsupported algorithm: %d", alg);
return false;
}
const EVP_CIPHER *cipher = EVP_get_cipherbyname(cipher_name);
if (!cipher) {
/* LCOV_EXCL_START */
RNP_LOG("Cipher %s is not supported by OpenSSL.", cipher_name);
return false;
/* LCOV_EXCL_END */
}
crypt->alg = alg;
crypt->blocksize = pgp_block_size(alg);
EVP_CIPHER_CTX *ctx = EVP_CIPHER_CTX_new();
int res = EVP_EncryptInit_ex(ctx, cipher, NULL, key, iv);
if (res != 1) {
/* LCOV_EXCL_START */
RNP_LOG("Failed to initialize cipher.");
EVP_CIPHER_CTX_free(ctx);
return false;
/* LCOV_EXCL_END */
}
crypt->cfb.obj = ctx;
if (iv) {
// Otherwise left as all zeros via memset at start of function
memcpy(crypt->cfb.iv, iv, crypt->blocksize);
}
crypt->cfb.remaining = 0;
return true;
}
int
pgp_cipher_cfb_finish(pgp_crypt_t *crypt)
{
if (!crypt) {
return 0; // LCOV_EXCL_LINE
}
if (crypt->cfb.obj) {
EVP_CIPHER_CTX_free(crypt->cfb.obj);
crypt->cfb.obj = NULL;
}
OPENSSL_cleanse((uint8_t *) crypt, sizeof(*crypt));
return 0;
}
int
pgp_cipher_encrypt_block(pgp_crypt_t *crypt, uint8_t *iv, size_t blsize)
{
int outlen = blsize;
int res = EVP_EncryptUpdate(crypt->cfb.obj, iv, &outlen, iv, (int) blsize);
if (outlen != (int) blsize) {
RNP_LOG("Bad outlen: must be %zu", blsize); // LCOV_EXCL_LINE
}
return res;
}
bool
pgp_is_sa_supported(int alg, bool silent)
{
return pgp_sa_to_openssl_string(alg, silent);
}
#if defined(ENABLE_AEAD)
static const char *
openssl_aead_name(pgp_symm_alg_t ealg, pgp_aead_alg_t aalg)
{
switch (aalg) {
case PGP_AEAD_OCB:
break;
default:
RNP_LOG("Only OCB mode is supported by the OpenSSL backend.");
return NULL;
}
switch (ealg) {
case PGP_SA_AES_128:
return "AES-128-OCB";
case PGP_SA_AES_192:
return "AES-192-OCB";
case PGP_SA_AES_256:
return "AES-256-OCB";
default:
RNP_LOG("Only AES-OCB is supported by the OpenSSL backend.");
return NULL;
}
}
bool
pgp_cipher_aead_init(pgp_crypt_t * crypt,
pgp_symm_alg_t ealg,
pgp_aead_alg_t aalg,
const uint8_t *key,
bool decrypt)
{
memset(crypt, 0x0, sizeof(*crypt));
/* OpenSSL backend currently supports only AES-OCB */
const char *algname = openssl_aead_name(ealg, aalg);
if (!algname) {
return false;
}
auto cipher = EVP_get_cipherbyname(algname);
if (!cipher) {
/* LCOV_EXCL_START */
RNP_LOG("Cipher %s is not supported.", algname);
return false;
/* LCOV_EXCL_END */
}
/* Create and setup context */
EVP_CIPHER_CTX *ctx = EVP_CIPHER_CTX_new();
if (!ctx) {
/* LCOV_EXCL_START */
RNP_LOG("Failed to create cipher context: %lu", ERR_peek_last_error());
return false;
/* LCOV_EXCL_END */
}
crypt->aead.key = new rnp::secure_bytes(key, key + pgp_key_size(ealg));
crypt->alg = ealg;
crypt->blocksize = pgp_block_size(ealg);
crypt->aead.cipher = cipher;
crypt->aead.obj = ctx;
crypt->aead.alg = aalg;
crypt->aead.decrypt = decrypt;
crypt->aead.granularity = crypt->blocksize;
crypt->aead.taglen = PGP_AEAD_EAX_OCB_TAG_LEN;
crypt->aead.ad_len = 0;
crypt->aead.n_len = pgp_cipher_aead_nonce_len(aalg);
return true;
}
bool
pgp_cipher_aead_set_ad(pgp_crypt_t *crypt, const uint8_t *ad, size_t len)
{
delete crypt->aead.ad;
crypt->aead.ad = NULL;
if (ad && len) {
crypt->aead.ad = new rnp::secure_bytes(ad, ad + len);
}
crypt->aead.ad_len = len;
return true;
}
bool
pgp_cipher_aead_start(pgp_crypt_t *crypt, const uint8_t *nonce, size_t len)
{
auto &aead = crypt->aead;
auto ctx = aead.obj;
int enc = aead.decrypt ? 0 : 1;
assert(len == aead.n_len);
EVP_CIPHER_CTX_reset(ctx);
if (EVP_CipherInit_ex(ctx, aead.cipher, NULL, NULL, NULL, enc) != 1) {
/* LCOV_EXCL_START */
RNP_LOG("Failed to initialize cipher: %lu", ERR_peek_last_error());
return false;
/* LCOV_EXCL_END */
}
if (EVP_CIPHER_CTX_ctrl(ctx, EVP_CTRL_AEAD_SET_IVLEN, aead.n_len, NULL) != 1) {
/* LCOV_EXCL_START */
RNP_LOG("Failed to set nonce length: %lu", ERR_peek_last_error());
return false;
/* LCOV_EXCL_END */
}
if (EVP_CipherInit_ex(ctx, NULL, NULL, aead.key->data(), nonce, enc) != 1) {
/* LCOV_EXCL_START */
RNP_LOG("Failed to start cipher: %lu", ERR_peek_last_error());
return false;
/* LCOV_EXCL_END */
}
int adlen = 0;
if (aead.ad_len &&
EVP_CipherUpdate(ctx, NULL, &adlen, aead.ad->data(), aead.ad_len) != 1) {
/* LCOV_EXCL_START */
RNP_LOG("Failed to set AD: %lu", ERR_peek_last_error());
return false;
/* LCOV_EXCL_END */
}
return true;
}
bool
pgp_cipher_aead_update(
pgp_crypt_t &crypt, uint8_t *out, const uint8_t *in, size_t len, size_t &read)
{
if (!len) {
return true;
}
int out_len = 0;
bool res = EVP_CipherUpdate(crypt.aead.obj, out, &out_len, in, len) == 1;
if (!res) {
RNP_LOG("Failed to update cipher: %lu", ERR_peek_last_error()); // LCOV_EXCL_LINE
}
assert(out_len == (int) len);
read = len;
return res;
}
void
pgp_cipher_aead_reset(pgp_crypt_t *crypt)
{
/* Do nothing as subsequent pgp_cipher_aead_start() call will reset context */
}
bool
pgp_cipher_aead_finish(pgp_crypt_t *crypt, uint8_t *out, const uint8_t *in, size_t len)
{
auto &aead = crypt->aead;
auto ctx = aead.obj;
if (aead.decrypt) {
assert(len >= aead.taglen);
if (len < aead.taglen) {
/* LCOV_EXCL_START */
RNP_LOG("Invalid state: too few input bytes.");
return false;
/* LCOV_EXCL_END */
}
size_t data_len = len - aead.taglen;
int out_len = 0;
if (EVP_CipherUpdate(ctx, out, &out_len, in, data_len) != 1) {
/* LCOV_EXCL_START */
RNP_LOG("Failed to update cipher: %lu", ERR_peek_last_error());
return false;
/* LCOV_EXCL_END */
}
uint8_t tag[PGP_AEAD_MAX_TAG_LEN] = {0};
memcpy(tag, in + data_len, aead.taglen);
if (EVP_CIPHER_CTX_ctrl(ctx, EVP_CTRL_AEAD_SET_TAG, aead.taglen, tag) != 1) {
/* LCOV_EXCL_START */
RNP_LOG("Failed to set tag: %lu", ERR_peek_last_error());
return false;
/* LCOV_EXCL_END */
}
int out_len2 = 0;
if (EVP_CipherFinal_ex(ctx, out + out_len, &out_len2) != 1) {
/* Zero value if auth tag is incorrect */
if (ERR_peek_last_error()) {
/* LCOV_EXCL_START */
RNP_LOG("Failed to finish AEAD decryption: %lu", ERR_peek_last_error());
/* LCOV_EXCL_END */
}
return false;
}
assert(out_len + out_len2 == (int) (len - aead.taglen));
} else {
int out_len = 0;
if (EVP_CipherUpdate(ctx, out, &out_len, in, len) != 1) {
/* LCOV_EXCL_START */
RNP_LOG("Failed to update cipher: %lu", ERR_peek_last_error());
return false;
/* LCOV_EXCL_END */
}
int out_len2 = 0;
if (EVP_CipherFinal_ex(ctx, out + out_len, &out_len2) != 1) {
/* LCOV_EXCL_START */
RNP_LOG("Failed to finish AEAD encryption: %lu", ERR_peek_last_error());
return false;
/* LCOV_EXCL_END */
}
assert(out_len + out_len2 == (int) len);
if (EVP_CIPHER_CTX_ctrl(ctx, EVP_CTRL_AEAD_GET_TAG, aead.taglen, out + len) != 1) {
/* LCOV_EXCL_START */
RNP_LOG("Failed to get tag: %lu", ERR_peek_last_error());
return false;
/* LCOV_EXCL_END */
}
}
return true;
}
void
pgp_cipher_aead_destroy(pgp_crypt_t *crypt)
{
if (crypt->aead.obj) {
EVP_CIPHER_CTX_free(crypt->aead.obj);
}
delete crypt->aead.key;
delete crypt->aead.ad;
memset(crypt, 0x0, sizeof(*crypt));
}
#endif