Revision control
Copy as Markdown
Other Tools
/*-
* 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 "symmetric.h"
#include <cstring>
void
pgp_cipher_cfb_resync(pgp_crypt_t *crypt, const uint8_t *buf)
{
/* iv will be encrypted in the upcoming call to encrypt/decrypt */
memcpy(crypt->cfb.iv, buf, crypt->blocksize);
crypt->cfb.remaining = 0;
}
size_t
pgp_cipher_block_size(pgp_crypt_t *crypt)
{
return crypt->blocksize;
}
/* we rely on fact that in and out could be the same */
int
pgp_cipher_cfb_encrypt(pgp_crypt_t *crypt, uint8_t *out, const uint8_t *in, size_t bytes)
{
uint64_t *in64;
uint64_t buf64[512]; // 4KB - page size
uint64_t iv64[2];
size_t blocks, blockb;
size_t blsize = crypt->blocksize;
/* encrypting till the block boundary */
while (bytes && crypt->cfb.remaining) {
*out = *in++ ^ crypt->cfb.iv[blsize - crypt->cfb.remaining];
crypt->cfb.iv[blsize - crypt->cfb.remaining] = *out++;
crypt->cfb.remaining--;
bytes--;
}
if (!bytes) {
return 0;
}
/* encrypting full blocks */
if (bytes > blsize) {
memcpy(iv64, crypt->cfb.iv, blsize);
while ((blocks = bytes & ~(blsize - 1)) > 0) {
if (blocks > sizeof(buf64)) {
blocks = sizeof(buf64);
}
bytes -= blocks;
blockb = blocks;
memcpy(buf64, in, blockb);
in64 = buf64;
if (blsize == 16) {
blocks >>= 4;
while (blocks--) {
pgp_cipher_encrypt_block(crypt, (uint8_t *) iv64, 16);
*in64 ^= iv64[0];
iv64[0] = *in64++;
*in64 ^= iv64[1];
iv64[1] = *in64++;
}
} else {
blocks >>= 3;
while (blocks--) {
pgp_cipher_encrypt_block(crypt, (uint8_t *) iv64, 8);
*in64 ^= iv64[0];
iv64[0] = *in64++;
}
}
memcpy(out, buf64, blockb);
out += blockb;
in += blockb;
}
memcpy(crypt->cfb.iv, iv64, blsize);
}
if (!bytes) {
return 0;
}
pgp_cipher_encrypt_block(crypt, crypt->cfb.iv, blsize);
crypt->cfb.remaining = blsize;
/* encrypting tail */
while (bytes) {
*out = *in++ ^ crypt->cfb.iv[blsize - crypt->cfb.remaining];
crypt->cfb.iv[blsize - crypt->cfb.remaining] = *out++;
crypt->cfb.remaining--;
bytes--;
}
return 0;
}
/* we rely on fact that in and out could be the same */
int
pgp_cipher_cfb_decrypt(pgp_crypt_t *crypt, uint8_t *out, const uint8_t *in, size_t bytes)
{
/* for better code readability */
uint64_t *out64, *in64;
uint64_t inbuf64[512]; // 4KB - page size
uint64_t outbuf64[512];
uint64_t iv64[2];
size_t blocks, blockb;
size_t blsize = crypt->blocksize;
/* decrypting till the block boundary */
while (bytes && crypt->cfb.remaining) {
uint8_t c = *in++;
*out++ = c ^ crypt->cfb.iv[blsize - crypt->cfb.remaining];
crypt->cfb.iv[blsize - crypt->cfb.remaining] = c;
crypt->cfb.remaining--;
bytes--;
}
if (!bytes) {
return 0;
}
/* decrypting full blocks */
if (bytes > blsize) {
memcpy(iv64, crypt->cfb.iv, blsize);
while ((blocks = bytes & ~(blsize - 1)) > 0) {
if (blocks > sizeof(inbuf64)) {
blocks = sizeof(inbuf64);
}
bytes -= blocks;
blockb = blocks;
memcpy(inbuf64, in, blockb);
out64 = outbuf64;
in64 = inbuf64;
if (blsize == 16) {
blocks >>= 4;
while (blocks--) {
pgp_cipher_encrypt_block(crypt, (uint8_t *) iv64, 16);
*out64++ = *in64 ^ iv64[0];
iv64[0] = *in64++;
*out64++ = *in64 ^ iv64[1];
iv64[1] = *in64++;
}
} else {
blocks >>= 3;
while (blocks--) {
pgp_cipher_encrypt_block(crypt, (uint8_t *) iv64, 8);
*out64++ = *in64 ^ iv64[0];
iv64[0] = *in64++;
}
}
memcpy(out, outbuf64, blockb);
out += blockb;
in += blockb;
}
memcpy(crypt->cfb.iv, iv64, blsize);
}
if (!bytes) {
return 0;
}
pgp_cipher_encrypt_block(crypt, crypt->cfb.iv, blsize);
crypt->cfb.remaining = blsize;
/* decrypting tail */
while (bytes) {
uint8_t c = *in++;
*out++ = c ^ crypt->cfb.iv[blsize - crypt->cfb.remaining];
crypt->cfb.iv[blsize - crypt->cfb.remaining] = c;
crypt->cfb.remaining--;
bytes--;
}
return 0;
}
size_t
pgp_block_size(pgp_symm_alg_t alg)
{
switch (alg) {
case PGP_SA_IDEA:
case PGP_SA_TRIPLEDES:
case PGP_SA_CAST5:
case PGP_SA_BLOWFISH:
return 8;
case PGP_SA_AES_128:
case PGP_SA_AES_192:
case PGP_SA_AES_256:
case PGP_SA_TWOFISH:
case PGP_SA_CAMELLIA_128:
case PGP_SA_CAMELLIA_192:
case PGP_SA_CAMELLIA_256:
case PGP_SA_SM4:
return 16;
default:
return 0;
}
}
size_t
pgp_key_size(pgp_symm_alg_t alg)
{
/* Update MAX_SYMM_KEY_SIZE after adding algorithm
* with bigger key size.
*/
static_assert(32 == MAX_SYMM_KEY_SIZE, "MAX_SYMM_KEY_SIZE must be updated");
switch (alg) {
case PGP_SA_IDEA:
case PGP_SA_CAST5:
case PGP_SA_BLOWFISH:
case PGP_SA_AES_128:
case PGP_SA_CAMELLIA_128:
case PGP_SA_SM4:
return 16;
case PGP_SA_TRIPLEDES:
case PGP_SA_AES_192:
case PGP_SA_CAMELLIA_192:
return 24;
case PGP_SA_TWOFISH:
case PGP_SA_AES_256:
case PGP_SA_CAMELLIA_256:
return 32;
default:
return 0;
}
}
bool
pgp_is_sa_aes(pgp_symm_alg_t alg)
{
switch (alg) {
case PGP_SA_AES_128:
case PGP_SA_AES_192:
case PGP_SA_AES_256:
return true;
default:
return false;
}
}
#if defined(ENABLE_AEAD)
size_t
pgp_cipher_aead_granularity(pgp_crypt_t *crypt)
{
return crypt->aead.granularity;
}
size_t
pgp_cipher_aead_nonce(pgp_aead_alg_t aalg, const uint8_t *iv, uint8_t *nonce, size_t index)
{
switch (aalg) {
case PGP_AEAD_EAX:
/* The nonce for EAX mode is computed by treating the starting
initialization vector as a 16-octet, big-endian value and
exclusive-oring the low eight octets of it with the chunk index.
*/
memcpy(nonce, iv, PGP_AEAD_EAX_NONCE_LEN);
for (int i = 15; (i > 7) && index; i--) {
nonce[i] ^= index & 0xff;
index = index >> 8;
}
return PGP_AEAD_EAX_NONCE_LEN;
case PGP_AEAD_OCB:
/* The nonce for a chunk of chunk index "i" in OCB processing is defined as:
OCB-Nonce_{i} = IV[1..120] xor i
*/
memcpy(nonce, iv, PGP_AEAD_OCB_NONCE_LEN);
for (int i = 14; (i >= 0) && index; i--) {
nonce[i] ^= index & 0xff;
index = index >> 8;
}
return PGP_AEAD_OCB_NONCE_LEN;
default:
return 0;
}
}
#endif
size_t
pgp_cipher_aead_nonce_len(pgp_aead_alg_t aalg)
{
switch (aalg) {
case PGP_AEAD_EAX:
return PGP_AEAD_EAX_NONCE_LEN;
case PGP_AEAD_OCB:
return PGP_AEAD_OCB_NONCE_LEN;
default:
return 0;
}
}
size_t
pgp_cipher_aead_tag_len(pgp_aead_alg_t aalg)
{
switch (aalg) {
case PGP_AEAD_EAX:
case PGP_AEAD_OCB:
return PGP_AEAD_EAX_OCB_TAG_LEN;
default:
return 0;
}
}