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refactor: use EVP_MAC in gost_tls12_additional_kdftree #522

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Merged
chipitsine merged 2 commits into from
Apr 2, 2026
+32 −15
Merged

refactor: use EVP_MAC in gost_tls12_additional_kdftree #522

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refactor: use EVP_MAC in gost_tls12_additional_kdftree
Mar 31, 2026
7fda7e7
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VladGud Apr 2, 2026
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47 changes: 32 additions & 15 deletions gost_tls12_additional_kdftree.c
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Original file line number Diff line number Diff line change
@@ -1,9 +1,10 @@
#include <string.h>

#include <openssl/buffer.h>
#include <openssl/core_names.h>
#include <openssl/err.h>
#include <openssl/evp.h>
#include <openssl/hmac.h>
#include <openssl/params.h>

#include "gost_tls12_additional.h"
#include "e_gost_err.h"
Expand All @@ -29,19 +30,34 @@ int gost_kdftree2012_256(unsigned char *keyout, size_t keyout_len,
int iters, i = 0;
unsigned char zero = 0;
unsigned char *ptr = keyout;
HMAC_CTX *ctx;
EVP_MAC *mac = NULL;
EVP_MAC_CTX *ctx = NULL;
unsigned char *len_ptr = NULL;
uint32_t len_repr = be32(keyout_len * 8);
size_t len_repr_len = 4;
OSSL_PARAM params[] = {
OSSL_PARAM_utf8_string(OSSL_MAC_PARAM_DIGEST,
(char *)SN_id_GostR3411_2012_256, 0),
OSSL_PARAM_END
};

ctx = HMAC_CTX_new();
mac = EVP_MAC_fetch(NULL, OSSL_MAC_NAME_HMAC, NULL);
if (mac == NULL) {
GOSTerr(GOST_F_GOST_KDFTREE2012_256, ERR_R_INTERNAL_ERROR);
return 0;
}

ctx = EVP_MAC_CTX_new(mac);
if (ctx == NULL) {
GOSTerr(GOST_F_GOST_KDFTREE2012_256, ERR_R_MALLOC_FAILURE);
EVP_MAC_free(mac);
return 0;
}

if ((keyout_len == 0) || (keyout_len % 32 != 0)) {
GOSTerr(GOST_F_GOST_KDFTREE2012_256, ERR_R_INTERNAL_ERROR);
EVP_MAC_CTX_free(ctx);
EVP_MAC_free(mac);
return 0;
}
iters = keyout_len / 32;
Expand All @@ -56,26 +72,27 @@ int gost_kdftree2012_256(unsigned char *keyout, size_t keyout_len,
uint32_t iter_net = be32(i);
unsigned char *rep_ptr =
((unsigned char *)&iter_net) + (4 - representation);
size_t out_len = 0;

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) {
if (EVP_MAC_init(ctx, key, keylen, params) <= 0
|| EVP_MAC_update(ctx, rep_ptr, representation) <= 0
|| EVP_MAC_update(ctx, label, label_len) <= 0
|| EVP_MAC_update(ctx, &zero, 1) <= 0
|| EVP_MAC_update(ctx, seed, seed_len) <= 0
|| EVP_MAC_update(ctx, len_ptr, len_repr_len) <= 0
|| EVP_MAC_final(ctx, ptr, &out_len, 32) <= 0
|| out_len != 32) {
GOSTerr(GOST_F_GOST_KDFTREE2012_256, ERR_R_INTERNAL_ERROR);
HMAC_CTX_free(ctx);
EVP_MAC_CTX_free(ctx);
EVP_MAC_free(mac);
return 0;
}

HMAC_CTX_reset(ctx);
ptr += 32;
}

HMAC_CTX_free(ctx);
EVP_MAC_CTX_free(ctx);
EVP_MAC_free(mac);

return 1;
}
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