/
soter_rsa_key.c
639 lines (551 loc) · 15.4 KB
/
soter_rsa_key.c
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/*
* Copyright (c) 2015 Cossack Labs Limited
*
* Licensed under the Apache License, Version 2.0 (the "License");
* you may not use this file except in compliance with the License.
* You may obtain a copy of the License at
*
* http://www.apache.org/licenses/LICENSE-2.0
*
* Unless required by applicable law or agreed to in writing, software
* distributed under the License is distributed on an "AS IS" BASIS,
* WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
* See the License for the specific language governing permissions and
* limitations under the License.
*/
#include "soter/soter_rsa_key.h"
#include <string.h>
#include <openssl/evp.h>
#include <openssl/rsa.h>
#include "soter/portable_endian.h"
static size_t rsa_pub_key_size(int mod_size)
{
switch (mod_size) {
case 128: /* 1024 */
return sizeof(soter_rsa_pub_key_1024_t);
case 256: /* 2048 */
return sizeof(soter_rsa_pub_key_2048_t);
case 512: /* 4096 */
return sizeof(soter_rsa_pub_key_4096_t);
case 1024: /* 8192 */
return sizeof(soter_rsa_pub_key_8192_t);
default:
return 0;
}
}
static size_t rsa_priv_key_size(int mod_size)
{
switch (mod_size) {
case 128: /* 1024 */
return sizeof(soter_rsa_priv_key_1024_t);
case 256: /* 2048 */
return sizeof(soter_rsa_priv_key_2048_t);
case 512: /* 4096 */
return sizeof(soter_rsa_priv_key_4096_t);
case 1024: /* 8192 */
return sizeof(soter_rsa_priv_key_8192_t);
default:
return 0;
}
}
static char* rsa_pub_key_tag(int mod_size)
{
switch (mod_size) {
case 128: /* 1024 */
return RSA_PUB_KEY_TAG(1024);
case 256: /* 2048 */
return RSA_PUB_KEY_TAG(2048);
case 512: /* 4096 */
return RSA_PUB_KEY_TAG(4096);
case 1024: /* 8192 */
return RSA_PUB_KEY_TAG(8192);
default:
return NULL;
}
}
static char* rsa_priv_key_tag(int mod_size)
{
switch (mod_size) {
case 128: /* 1024 */
return RSA_PRIV_KEY_TAG(1024);
case 256: /* 2048 */
return RSA_PRIV_KEY_TAG(2048);
case 512: /* 4096 */
return RSA_PRIV_KEY_TAG(4096);
case 1024: /* 8192 */
return RSA_PRIV_KEY_TAG(8192);
default:
return NULL;
}
}
static bool is_mod_size_supported(int mod_size)
{
switch (mod_size) {
case 128:
case 256:
case 512:
case 1024:
return true;
default:
return false;
}
}
static soter_status_t bignum_to_bytes(const BIGNUM* bn, uint8_t* to, size_t to_length)
{
size_t bn_size = (size_t)BN_num_bytes(bn);
size_t bytes_copied;
if (bn_size > to_length) {
return SOTER_FAIL;
}
bytes_copied = BN_bn2bin(bn, to + (to_length - bn_size));
if (bytes_copied != bn_size) {
return SOTER_FAIL;
}
memset(to, 0, to_length - bn_size);
return SOTER_SUCCESS;
}
soter_status_t soter_engine_specific_to_rsa_pub_key(const soter_engine_specific_rsa_key_t* engine_key,
soter_container_hdr_t* key,
size_t* key_length)
{
EVP_PKEY* pkey = (EVP_PKEY*)engine_key;
RSA* rsa;
soter_status_t res;
int rsa_mod_size;
size_t output_length;
uint32_t* pub_exp;
if (!key_length) {
return SOTER_INVALID_PARAMETER;
}
if (EVP_PKEY_RSA != EVP_PKEY_id(pkey)) {
return SOTER_INVALID_PARAMETER;
}
rsa = EVP_PKEY_get1_RSA((EVP_PKEY*)pkey);
if (NULL == rsa) {
return SOTER_FAIL;
}
rsa_mod_size = RSA_size(rsa);
if (!is_mod_size_supported(rsa_mod_size)) {
res = SOTER_INVALID_PARAMETER;
goto err;
}
output_length = rsa_pub_key_size(rsa_mod_size);
if ((!key) || (output_length > *key_length)) {
*key_length = output_length;
res = SOTER_BUFFER_TOO_SMALL;
goto err;
}
pub_exp = (uint32_t*)((unsigned char*)(key + 1) + rsa_mod_size);
const BIGNUM* rsa_e;
BIGNUM* rsa_n;
#if OPENSSL_VERSION_NUMBER < 0x10100000L
rsa_e = rsa->e;
rsa_n = rsa->n;
#else
RSA_get0_key(rsa, (const BIGNUM**)&rsa_n, &rsa_e, NULL);
#endif
if (BN_is_word(rsa_e, RSA_F4)) {
*pub_exp = htobe32(RSA_F4);
} else if (BN_is_word(rsa_e, RSA_3)) {
*pub_exp = htobe32(RSA_3);
} else {
res = SOTER_INVALID_PARAMETER;
goto err;
}
res = bignum_to_bytes(rsa_n, (unsigned char*)(key + 1), rsa_mod_size);
if (SOTER_SUCCESS != res) {
goto err;
}
memcpy(key->tag, rsa_pub_key_tag(rsa_mod_size), SOTER_CONTAINER_TAG_LENGTH);
key->size = htobe32(output_length);
soter_update_container_checksum(key);
*key_length = output_length;
res = SOTER_SUCCESS;
err:
/* Free extra reference on RSA object provided by EVP_PKEY_get1_RSA */
RSA_free(rsa);
return res;
}
soter_status_t soter_engine_specific_to_rsa_priv_key(const soter_engine_specific_rsa_key_t* engine_key,
soter_container_hdr_t* key,
size_t* key_length)
{
EVP_PKEY* pkey = (EVP_PKEY*)engine_key;
RSA* rsa;
soter_status_t res;
int rsa_mod_size;
size_t output_length;
uint32_t* pub_exp;
unsigned char* curr_bn = (unsigned char*)(key + 1);
if (!key_length) {
return SOTER_INVALID_PARAMETER;
}
if (EVP_PKEY_RSA != EVP_PKEY_id(pkey)) {
return SOTER_INVALID_PARAMETER;
}
rsa = EVP_PKEY_get1_RSA((EVP_PKEY*)pkey);
if (NULL == rsa) {
return SOTER_FAIL;
}
rsa_mod_size = RSA_size(rsa);
if (!is_mod_size_supported(rsa_mod_size)) {
res = SOTER_INVALID_PARAMETER;
goto err;
}
output_length = rsa_priv_key_size(rsa_mod_size);
if ((!key) || (output_length > *key_length)) {
*key_length = output_length;
res = SOTER_BUFFER_TOO_SMALL;
goto err;
}
pub_exp = (uint32_t*)(curr_bn + ((rsa_mod_size * 4) + (rsa_mod_size / 2)));
const BIGNUM* rsa_e;
const BIGNUM* rsa_d;
const BIGNUM* rsa_n;
#if OPENSSL_VERSION_NUMBER < 0x10100000L
rsa_e = rsa->e;
rsa_d = rsa->d;
rsa_n = rsa->n;
#else
RSA_get0_key(rsa, &rsa_n, &rsa_e, &rsa_d);
#endif
if (BN_is_word(rsa_e, RSA_F4)) {
*pub_exp = htobe32(RSA_F4);
} else if (BN_is_word(rsa_e, RSA_3)) {
*pub_exp = htobe32(RSA_3);
} else {
res = SOTER_INVALID_PARAMETER;
goto err;
}
/* Private exponent */
res = bignum_to_bytes(rsa_d, curr_bn, rsa_mod_size);
if (SOTER_SUCCESS != res) {
goto err;
}
curr_bn += rsa_mod_size;
const BIGNUM* rsa_p;
const BIGNUM* rsa_q;
#if OPENSSL_VERSION_NUMBER < 0x10100000L
rsa_p = rsa->p;
rsa_q = rsa->q;
#else
RSA_get0_factors(rsa, &rsa_p, &rsa_q);
#endif
/* p */
res = bignum_to_bytes(rsa_p, curr_bn, rsa_mod_size / 2);
if (SOTER_SUCCESS != res) {
goto err;
}
curr_bn += rsa_mod_size / 2;
/* q */
res = bignum_to_bytes(rsa_q, curr_bn, rsa_mod_size / 2);
if (SOTER_SUCCESS != res) {
goto err;
}
curr_bn += rsa_mod_size / 2;
const BIGNUM* rsa_dmp1;
const BIGNUM* rsa_dmq1;
const BIGNUM* rsa_iqmp;
#if OPENSSL_VERSION_NUMBER < 0x10100000L
rsa_dmp1 = rsa->dmp1;
rsa_dmq1 = rsa->dmq1;
rsa_iqmp = rsa->iqmp;
#else
RSA_get0_crt_params(rsa, &rsa_dmp1, &rsa_dmq1, &rsa_iqmp);
#endif
/* dp */
res = bignum_to_bytes(rsa_dmp1, curr_bn, rsa_mod_size / 2);
if (SOTER_SUCCESS != res) {
goto err;
}
curr_bn += rsa_mod_size / 2;
/* dq */
res = bignum_to_bytes(rsa_dmq1, curr_bn, rsa_mod_size / 2);
if (SOTER_SUCCESS != res) {
goto err;
}
curr_bn += rsa_mod_size / 2;
/* qp */
res = bignum_to_bytes(rsa_iqmp, curr_bn, rsa_mod_size / 2);
if (SOTER_SUCCESS != res) {
goto err;
}
curr_bn += rsa_mod_size / 2;
/* modulus */
res = bignum_to_bytes(rsa_n, curr_bn, rsa_mod_size);
if (SOTER_SUCCESS != res) {
goto err;
}
memcpy(key->tag, rsa_priv_key_tag(rsa_mod_size), SOTER_CONTAINER_TAG_LENGTH);
key->size = htobe32(output_length);
soter_update_container_checksum(key);
*key_length = output_length;
res = SOTER_SUCCESS;
err:
/* Free extra reference on RSA object provided by EVP_PKEY_get1_RSA */
RSA_free(rsa);
// if (SOTER_SUCCESS != res)
// {
// /* Zero output memory to avoid leaking private key information */
// memset(key, 0, *key_length);
// }
return res;
}
/* TODO: Maybe, basic container validation should be put in separate functions outside of
* engine-specific code */
soter_status_t soter_rsa_pub_key_to_engine_specific(const soter_container_hdr_t* key,
size_t key_length,
soter_engine_specific_rsa_key_t** engine_key)
{
int rsa_mod_size;
RSA* rsa;
EVP_PKEY* pkey = (EVP_PKEY*)(*engine_key);
const uint32_t* pub_exp;
if (key_length != be32toh(key->size)) {
return SOTER_INVALID_PARAMETER;
}
/* Validate tag */
if (memcmp(key->tag, RSA_PUB_KEY_PREF, strlen(RSA_PUB_KEY_PREF))) {
return SOTER_INVALID_PARAMETER;
}
if (SOTER_SUCCESS != soter_verify_container_checksum(key)) {
return SOTER_DATA_CORRUPT;
}
switch (key->tag[3]) {
case '1':
rsa_mod_size = 128;
break;
case '2':
rsa_mod_size = 256;
break;
case '4':
rsa_mod_size = 512;
break;
case '8':
rsa_mod_size = 1024;
break;
default:
return SOTER_INVALID_PARAMETER;
}
if (key_length < rsa_pub_key_size(rsa_mod_size)) {
return SOTER_INVALID_PARAMETER;
}
pub_exp = (const uint32_t*)((unsigned char*)(key + 1) + rsa_mod_size);
switch (be32toh(*pub_exp)) {
case RSA_3:
case RSA_F4:
break;
default:
return SOTER_INVALID_PARAMETER;
}
rsa = RSA_new();
if (!rsa) {
return SOTER_NO_MEMORY;
}
BIGNUM* rsa_n = BN_new();
if (!rsa_n) {
return SOTER_NO_MEMORY;
}
BIGNUM* rsa_e = BN_new();
if (!rsa_e) {
RSA_free(rsa);
BN_free(rsa_n);
return SOTER_NO_MEMORY;
}
if (!BN_set_word(rsa_e, be32toh(*pub_exp))) {
BN_free(rsa_n);
BN_free(rsa_e);
RSA_free(rsa);
return SOTER_FAIL;
}
if (!BN_bin2bn((const unsigned char*)(key + 1), rsa_mod_size, rsa_n)) {
BN_free(rsa_n);
BN_free(rsa_e);
RSA_free(rsa);
return SOTER_FAIL;
}
#if OPENSSL_VERSION_NUMBER < 0x10100000L
rsa->e = rsa_e;
rsa->n = rsa_n;
#else
RSA_set0_key(rsa, rsa_n, rsa_e, NULL);
#endif
if (!EVP_PKEY_assign_RSA(pkey, rsa)) {
BN_free(rsa_n);
BN_free(rsa_e);
RSA_free(rsa);
return SOTER_FAIL;
}
/* EVP_PKEY_assign_RSA does not increment the reference count, so no need to free RSA object */
return SOTER_SUCCESS;
}
soter_status_t soter_rsa_priv_key_to_engine_specific(const soter_container_hdr_t* key,
size_t key_length,
soter_engine_specific_rsa_key_t** engine_key)
{
int rsa_mod_size;
RSA* rsa;
EVP_PKEY* pkey = (EVP_PKEY*)(*engine_key);
const uint32_t* pub_exp;
const unsigned char* curr_bn = (const unsigned char*)(key + 1);
if (key_length != be32toh(key->size)) {
return SOTER_INVALID_PARAMETER;
}
/* Validate tag */
if (memcmp(key->tag, RSA_PRIV_KEY_PREF, strlen(RSA_PRIV_KEY_PREF))) {
return SOTER_INVALID_PARAMETER;
}
if (SOTER_SUCCESS != soter_verify_container_checksum(key)) {
return SOTER_DATA_CORRUPT;
}
switch (key->tag[3]) {
case '1':
rsa_mod_size = 128;
break;
case '2':
rsa_mod_size = 256;
break;
case '4':
rsa_mod_size = 512;
break;
case '8':
rsa_mod_size = 1024;
break;
default:
return SOTER_INVALID_PARAMETER;
}
if (key_length < rsa_priv_key_size(rsa_mod_size)) {
return SOTER_INVALID_PARAMETER;
}
pub_exp = (const uint32_t*)(curr_bn + ((rsa_mod_size * 4) + (rsa_mod_size / 2)));
;
switch (be32toh(*pub_exp)) {
case RSA_3:
case RSA_F4:
break;
default:
return SOTER_INVALID_PARAMETER;
}
rsa = RSA_new();
if (!rsa) {
return SOTER_NO_MEMORY;
}
BIGNUM* rsa_e = BN_new();
if (!rsa_e) {
RSA_free(rsa);
return SOTER_NO_MEMORY;
}
if (!BN_set_word(rsa_e, be32toh(*pub_exp))) {
RSA_free(rsa);
return SOTER_FAIL;
}
/* Private exponent */
BIGNUM* rsa_d = BN_new();
if (!rsa_d) {
RSA_free(rsa);
return SOTER_NO_MEMORY;
}
if (!BN_bin2bn(curr_bn, rsa_mod_size, rsa_d)) {
RSA_free(rsa);
return SOTER_FAIL;
}
curr_bn += rsa_mod_size;
BIGNUM* rsa_p = BN_new();
if (!rsa_p) {
RSA_free(rsa);
return SOTER_NO_MEMORY;
}
if (!BN_bin2bn(curr_bn, rsa_mod_size / 2, rsa_p)) {
RSA_free(rsa);
return SOTER_FAIL;
}
curr_bn += rsa_mod_size / 2;
/* q */
BIGNUM* rsa_q = BN_new();
if (!rsa_q) {
RSA_free(rsa);
return SOTER_NO_MEMORY;
}
if (!BN_bin2bn(curr_bn, rsa_mod_size / 2, rsa_q)) {
RSA_free(rsa);
return SOTER_FAIL;
}
curr_bn += rsa_mod_size / 2;
/* dp */
BIGNUM* rsa_dmp1 = BN_new();
if (!rsa_dmp1) {
RSA_free(rsa);
return SOTER_NO_MEMORY;
}
if (!BN_bin2bn(curr_bn, rsa_mod_size / 2, rsa_dmp1)) {
RSA_free(rsa);
return SOTER_FAIL;
}
curr_bn += rsa_mod_size / 2;
/* dq */
BIGNUM* rsa_dmq1 = BN_new();
if (!rsa_dmq1) {
RSA_free(rsa);
return SOTER_NO_MEMORY;
}
if (!BN_bin2bn(curr_bn, rsa_mod_size / 2, rsa_dmq1)) {
RSA_free(rsa);
return SOTER_FAIL;
}
curr_bn += rsa_mod_size / 2;
/* qp */
BIGNUM* rsa_iqmp = BN_new();
if (!rsa_iqmp) {
RSA_free(rsa);
return SOTER_NO_MEMORY;
}
if (!BN_bin2bn(curr_bn, rsa_mod_size / 2, rsa_iqmp)) {
RSA_free(rsa);
return SOTER_FAIL;
}
curr_bn += rsa_mod_size / 2;
/* modulus */
BIGNUM* rsa_n = BN_new();
if (!rsa_n) {
RSA_free(rsa);
return SOTER_NO_MEMORY;
}
if (!BN_bin2bn(curr_bn, rsa_mod_size, rsa_n)) {
RSA_free(rsa);
return SOTER_FAIL;
}
/* If at least one CRT parameter is zero, free them */
if (BN_is_zero(rsa_p) || BN_is_zero(rsa_q) || BN_is_zero(rsa_dmp1) || BN_is_zero(rsa_dmq1)
|| BN_is_zero(rsa_iqmp)) {
BN_free(rsa_p);
rsa_p = NULL;
BN_free(rsa_q);
rsa_q = NULL;
BN_free(rsa_dmp1);
rsa_dmp1 = NULL;
BN_free(rsa_dmq1);
rsa_dmq1 = NULL;
BN_free(rsa_iqmp);
rsa_iqmp = NULL;
}
#if OPENSSL_VERSION_NUMBER < 0x10100000L
rsa->n = rsa_n;
rsa->e = rsa_e;
rsa->d = rsa_d;
rsa->dmq1 = rsa_dmq1;
rsa->dmp1 = rsa_dmp1;
rsa->iqmp = rsa_iqmp;
rsa->q = rsa_q;
rsa->p = rsa_p;
#else
RSA_set0_key(rsa, rsa_n, rsa_e, rsa_d);
RSA_set0_factors(rsa, rsa_p, rsa_q);
RSA_set0_crt_params(rsa, rsa_dmp1, rsa_dmq1, rsa_iqmp);
#endif
if (!EVP_PKEY_assign_RSA(pkey, rsa)) {
RSA_free(rsa);
return SOTER_FAIL;
}
/* EVP_PKEY_assign_RSA does not increment the reference count, so no need to free RSA object */
return SOTER_SUCCESS;
}