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#ifdef _WIN32
#include <winsock.h>
#else
#include <arpa/inet.h>
#endif
#include <string.h>
#include <openssl/evp.h>
#include <openssl/hmac.h>
#include "gost_lcl.h"
#include "e_gost_err.h"
int omac_imit_ctrl(EVP_MD_CTX *ctx, int type, int arg, void *ptr);
/*
* Function expects that out is a preallocated buffer of length
* defined as sum of shared_len and mac length defined by mac_nid
* */
int gost_kexp15(const unsigned char *shared_key, const int shared_len,
int cipher_nid, const unsigned char *cipher_key,
int mac_nid, unsigned char *mac_key,
const unsigned char *iv, const size_t ivlen,
unsigned char *out, int *out_len)
{
unsigned char iv_full[16], mac_buf[16];
unsigned int mac_len;
EVP_CIPHER_CTX *ciph = NULL;
EVP_MD_CTX *mac = NULL;
int ret = 0;
int len;
mac_len = (cipher_nid == NID_magma_ctr) ? 8 :
(cipher_nid == NID_grasshopper_ctr) ? 16 : 0;
if (mac_len == 0) {
GOSTerr(GOST_F_GOST_KEXP15, GOST_R_INVALID_CIPHER);
goto err;
}
/* we expect IV of half length */
memset(iv_full, 0, 16);
memcpy(iv_full, iv, ivlen);
mac = EVP_MD_CTX_new();
if (mac == NULL) {
GOSTerr(GOST_F_GOST_KEXP15, ERR_R_MALLOC_FAILURE);
goto err;
}
if (EVP_DigestInit_ex(mac, EVP_get_digestbynid(mac_nid), NULL) <= 0
|| omac_imit_ctrl(mac, EVP_MD_CTRL_SET_KEY, 32, mac_key) <= 0
|| omac_imit_ctrl(mac, EVP_MD_CTRL_XOF_LEN, mac_len, NULL) <= 0
|| EVP_DigestUpdate(mac, iv, ivlen) <= 0
|| EVP_DigestUpdate(mac, shared_key, shared_len) <= 0
/* As we set MAC length directly, we should not allow overwriting it */
|| EVP_DigestFinalXOF(mac, mac_buf, mac_len) <= 0) {
GOSTerr(GOST_F_GOST_KEXP15, ERR_R_INTERNAL_ERROR);
goto err;
}
ciph = EVP_CIPHER_CTX_new();
if (ciph == NULL) {
GOSTerr(GOST_F_GOST_KEXP15, ERR_R_MALLOC_FAILURE);
goto err;
}
if (EVP_CipherInit_ex
(ciph, EVP_get_cipherbynid(cipher_nid), NULL, NULL, NULL, 1) <= 0
|| EVP_CipherInit_ex(ciph, NULL, NULL, cipher_key, iv_full, 1) <= 0
|| EVP_CipherUpdate(ciph, out, &len, shared_key, shared_len) <= 0
|| EVP_CipherUpdate(ciph, out + shared_len, &len, mac_buf, mac_len) <= 0
|| EVP_CipherFinal_ex(ciph, out + shared_len + len, out_len) <= 0) {
GOSTerr(GOST_F_GOST_KEXP15, ERR_R_INTERNAL_ERROR);
goto err;
}
*out_len = shared_len + mac_len;
ret = 1;
err:
OPENSSL_cleanse(mac_buf, mac_len);
EVP_MD_CTX_free(mac);
EVP_CIPHER_CTX_free(ciph);
return ret;
}
/*
* Function expects that shared_key is a preallocated buffer
* with length defined as expkeylen + mac_len defined by mac_nid
* */
int gost_kimp15(const unsigned char *expkey, const size_t expkeylen,
int cipher_nid, const unsigned char *cipher_key,
int mac_nid, unsigned char *mac_key,
const unsigned char *iv, const size_t ivlen,
unsigned char *shared_key)
{
unsigned char iv_full[16], out[48], mac_buf[16];
unsigned int mac_len;
const size_t shared_len = 32;
EVP_CIPHER_CTX *ciph = NULL;
EVP_MD_CTX *mac = NULL;
int ret = 0;
int len;
mac_len = (cipher_nid == NID_magma_ctr) ? 8 :
(cipher_nid == NID_grasshopper_ctr) ? 16 : 0;
if (mac_len == 0) {
GOSTerr(GOST_F_GOST_KIMP15, GOST_R_INVALID_CIPHER);
goto err;
}
/* we expect IV of half length */
memset(iv_full, 0, 16);
memcpy(iv_full, iv, ivlen);
ciph = EVP_CIPHER_CTX_new();
if (ciph == NULL) {
GOSTerr(GOST_F_GOST_KIMP15, ERR_R_MALLOC_FAILURE);
goto err;
}
if (EVP_CipherInit_ex
(ciph, EVP_get_cipherbynid(cipher_nid), NULL, NULL, NULL, 0) <= 0
|| EVP_CipherInit_ex(ciph, NULL, NULL, cipher_key, iv_full, 0) <= 0
|| EVP_CipherUpdate(ciph, out, &len, expkey, expkeylen) <= 0
|| EVP_CipherFinal_ex(ciph, out + len, &len) <= 0) {
GOSTerr(GOST_F_GOST_KIMP15, ERR_R_INTERNAL_ERROR);
goto err;
}
/*Now we have shared key and mac in out[] */
mac = EVP_MD_CTX_new();
if (mac == NULL) {
GOSTerr(GOST_F_GOST_KIMP15, ERR_R_MALLOC_FAILURE);
goto err;
}
if (EVP_DigestInit_ex(mac, EVP_get_digestbynid(mac_nid), NULL) <= 0
|| omac_imit_ctrl(mac, EVP_MD_CTRL_SET_KEY, 32, mac_key) <= 0
|| omac_imit_ctrl(mac, EVP_MD_CTRL_XOF_LEN, mac_len, NULL) <= 0
|| EVP_DigestUpdate(mac, iv, ivlen) <= 0
|| EVP_DigestUpdate(mac, out, shared_len) <= 0
/* As we set MAC length directly, we should not allow overwriting it */
|| EVP_DigestFinalXOF(mac, mac_buf, mac_len) <= 0) {
GOSTerr(GOST_F_GOST_KIMP15, ERR_R_INTERNAL_ERROR);
goto err;
}
if (CRYPTO_memcmp(mac_buf, out + shared_len, mac_len) != 0) {
GOSTerr(GOST_F_GOST_KIMP15, GOST_R_BAD_MAC);
goto err;
}
memcpy(shared_key, out, shared_len);
ret = 1;
err:
OPENSSL_cleanse(out, sizeof(out));
EVP_MD_CTX_free(mac);
EVP_CIPHER_CTX_free(ciph);
return ret;
}
int gost_kdftree2012_256(unsigned char *keyout, size_t keyout_len,
const unsigned char *key, size_t keylen,
const unsigned char *label, size_t label_len,
const unsigned char *seed, size_t seed_len,
const size_t representation)
{
int iters, i = 0;
unsigned char zero = 0;
unsigned char *ptr = keyout;
HMAC_CTX *ctx;
unsigned char *len_ptr = NULL;
uint32_t len_repr = htonl(keyout_len * 8);
size_t len_repr_len = 4;
ctx = HMAC_CTX_new();
if (ctx == NULL) {
GOSTerr(GOST_F_GOST_KDFTREE2012_256, ERR_R_MALLOC_FAILURE);
return 0;
}
if ((keyout_len == 0) || (keyout_len % 32 != 0)) {
GOSTerr(GOST_F_GOST_KDFTREE2012_256, ERR_R_INTERNAL_ERROR);
return 0;
}
iters = keyout_len / 32;
len_ptr = (unsigned char *)&len_repr;
while (*len_ptr == 0) {
len_ptr++;
len_repr_len--;
}
for (i = 1; i <= iters; i++) {
uint32_t iter_net = htonl(i);
unsigned char *rep_ptr =
((unsigned char *)&iter_net) + (4 - representation);
if (HMAC_Init_ex(ctx, key, keylen,
EVP_get_digestbynid(NID_id_GostR3411_2012_256),
NULL) <= 0
|| HMAC_Update(ctx, rep_ptr, representation) <= 0
|| HMAC_Update(ctx, label, label_len) <= 0
|| HMAC_Update(ctx, &zero, 1) <= 0
|| HMAC_Update(ctx, seed, seed_len) <= 0
|| HMAC_Update(ctx, len_ptr, len_repr_len) <= 0
|| HMAC_Final(ctx, ptr, NULL) <= 0) {
GOSTerr(GOST_F_GOST_KDFTREE2012_256, ERR_R_INTERNAL_ERROR);
HMAC_CTX_free(ctx);
return 0;
}
HMAC_CTX_reset(ctx);
ptr += 32;
}
HMAC_CTX_free(ctx);
return 1;
}
int gost_tlstree(int cipher_nid, const unsigned char *in, unsigned char *out,
const unsigned char *tlsseq)
{
#ifndef L_ENDIAN
uint64_t gh_c1 = 0xFFFFFFFF00000000, gh_c2 = 0xFFFFFFFFFFF80000,
gh_c3 = 0xFFFFFFFFFFFFFFC0;
uint64_t mg_c1 = 0xFFFFFFC000000000, mg_c2 = 0xFFFFFFFFFE000000,
mg_c3 = 0xFFFFFFFFFFFFF000;
#else
uint64_t gh_c1 = 0x00000000FFFFFFFF, gh_c2 = 0x0000F8FFFFFFFFFF,
gh_c3 = 0xC0FFFFFFFFFFFFFF;
uint64_t mg_c1 = 0x00000000C0FFFFFF, mg_c2 = 0x000000FEFFFFFFFF,
mg_c3 = 0x00F0FFFFFFFFFFFF;
#endif
uint64_t c1, c2, c3;
uint64_t seed1, seed2, seed3;
uint64_t seq;
unsigned char ko1[32], ko2[32];
switch (cipher_nid) {
case NID_magma_cbc:
c1 = mg_c1;
c2 = mg_c2;
c3 = mg_c3;
break;
case NID_grasshopper_cbc:
c1 = gh_c1;
c2 = gh_c2;
c3 = gh_c3;
break;
default:
return 0;
}
memcpy(&seq, tlsseq, 8);
seed1 = seq & c1;
seed2 = seq & c2;
seed3 = seq & c3;
if (gost_kdftree2012_256(ko1, 32, in, 32, (const unsigned char *)"level1", 6,
(const unsigned char *)&seed1, 8, 1) <= 0
|| gost_kdftree2012_256(ko2, 32, ko1, 32, (const unsigned char *)"level2", 6,
(const unsigned char *)&seed2, 8, 1) <= 0
|| gost_kdftree2012_256(out, 32, ko2, 32, (const unsigned char *)"level3", 6,
(const unsigned char *)&seed3, 8, 1) <= 0)
return 0;
return 1;
}
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