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Decouple gost_omac_acpkm from gost_grasshopper #519

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Merged
chipitsine merged 1 commit into from
Mar 11, 2026
Merged

Decouple gost_omac_acpkm from gost_grasshopper #519

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6 changes: 0 additions & 6 deletions gost_crypt.c
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Original file line number Diff line number Diff line change
Expand Up @@ -1678,10 +1678,4 @@ static int gost_imit_cleanup(EVP_MD_CTX *ctx)
memset(EVP_MD_CTX_md_data(ctx), 0, sizeof(struct ossl_gost_imit_ctx));
return 1;
}

/* Called directly by CMAC_ACPKM_Init() */
const EVP_CIPHER *cipher_gost_magma_ctracpkm()
{
return GOST_init_cipher(&magma_ctr_acpkm_cipher);
}
/* vim: set expandtab cinoptions=\:0,l1,t0,g0,(0 sw=4 : */
6 changes: 0 additions & 6 deletions gost_grasshopper_cipher.c
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Expand Up @@ -1254,10 +1254,4 @@ static int gost_grasshopper_cipher_ctl(EVP_CIPHER_CTX *ctx, int type, int arg, v
}
return 1;
}

/* Called directly by CMAC_ACPKM_Init() */
const EVP_CIPHER *cipher_gost_grasshopper_ctracpkm()
{
return GOST_init_cipher(&grasshopper_ctr_acpkm_cipher);
}
/* vim: set expandtab cinoptions=\:0,l1,t0,g0,(0 sw=4 : */
2 changes: 0 additions & 2 deletions gost_grasshopper_cipher.h
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Expand Up @@ -108,8 +108,6 @@ static int gost_grasshopper_cipher_ctl(EVP_CIPHER_CTX* ctx, int type, int arg, v

static int gost_grasshopper_mgm_ctrl(EVP_CIPHER_CTX *ctx, int type, int arg, void *ptr);

const EVP_CIPHER* cipher_gost_grasshopper_ctracpkm();

#if defined(__cplusplus)
}
#endif
Expand Down
2 changes: 0 additions & 2 deletions gost_lcl.h
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Expand Up @@ -335,8 +335,6 @@ typedef struct gost_cipher_st GOST_cipher;
EVP_CIPHER *GOST_init_cipher(GOST_cipher *c);
void GOST_deinit_cipher(GOST_cipher *c);

const EVP_CIPHER *cipher_gost_magma_ctracpkm();

/* ENGINE implementation data */
extern GOST_cipher Gost28147_89_cipher;
extern GOST_cipher Gost28147_89_cbc_cipher;
Expand Down
47 changes: 32 additions & 15 deletions gost_omac_acpkm.c
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Expand Up @@ -13,17 +13,17 @@

#include "e_gost_err.h"
#include "gost_lcl.h"
#include "gost_grasshopper_defines.h"
#include "gost_grasshopper_cipher.h"

#define ACPKM_T_MAX (GRASSHOPPER_KEY_SIZE + GRASSHOPPER_BLOCK_SIZE)
#define ACPKM_T_MAX (EVP_MAX_KEY_LENGTH + EVP_MAX_BLOCK_LENGTH)

/*
* CMAC code from crypto/cmac/cmac.c with ACPKM tweaks
*/
struct CMAC_ACPKM_CTX_st {
/* Cipher context to use */
EVP_CIPHER_CTX *cctx;
/* CTR-ACPKM cipher */
EVP_CIPHER* fetched_acpkm;
EVP_CIPHER_CTX *actx;
unsigned char km[ACPKM_T_MAX]; /* Key material */
/* Temporary block */
Expand Down Expand Up @@ -94,6 +94,7 @@ static void CMAC_ACPKM_CTX_free(CMAC_ACPKM_CTX *ctx)
return;
CMAC_ACPKM_CTX_cleanup(ctx);
EVP_CIPHER_CTX_free(ctx->cctx);
EVP_CIPHER_free(ctx->fetched_acpkm);
EVP_CIPHER_CTX_free(ctx->actx);
OPENSSL_free(ctx);
}
Expand All @@ -105,6 +106,11 @@ static int CMAC_ACPKM_CTX_copy(CMAC_ACPKM_CTX *out, const CMAC_ACPKM_CTX *in)
return 0;
if (!EVP_CIPHER_CTX_copy(out->cctx, in->cctx))
return 0;
if (in->fetched_acpkm) {
if (!EVP_CIPHER_up_ref(in->fetched_acpkm))
return 0;
}
out->fetched_acpkm = in->fetched_acpkm;
if (!EVP_CIPHER_CTX_copy(out->actx, in->actx))
return 0;
bl = EVP_CIPHER_CTX_block_size(in->cctx);
Expand All @@ -117,11 +123,22 @@ static int CMAC_ACPKM_CTX_copy(CMAC_ACPKM_CTX *out, const CMAC_ACPKM_CTX *in)
return 1;
}

static const EVP_CIPHER* get_cipher(const char *cipher_name, EVP_CIPHER **fetched_cipher) {
const EVP_CIPHER* cipher = NULL;
cipher = EVP_get_cipherbyname(cipher_name);
if (cipher)
return cipher;

*fetched_cipher = EVP_CIPHER_fetch(NULL, cipher_name, NULL);
cipher = *fetched_cipher;
return cipher;
}

static int CMAC_ACPKM_Init(CMAC_ACPKM_CTX *ctx, const void *key, size_t keylen,
const EVP_CIPHER *cipher, ENGINE *impl)
const EVP_CIPHER *cipher)
{
/* All zeros means restart */
if (!key && !cipher && !impl && keylen == 0) {
if (!key && !cipher && keylen == 0) {
/* Not initialised */
if (ctx->nlast_block == -1)
return 0;
Expand All @@ -136,28 +153,28 @@ static int CMAC_ACPKM_Init(CMAC_ACPKM_CTX *ctx, const void *key, size_t keylen,
if (cipher) {
const EVP_CIPHER *acpkm = NULL;

if (!EVP_EncryptInit_ex(ctx->cctx, cipher, impl, NULL, NULL))
if (!EVP_EncryptInit_ex(ctx->cctx, cipher, NULL, NULL, NULL))
return 0;
/* Unfortunately, EVP_CIPHER_is_a is bugged for an engine, EVP_CIPHER_nid is bugged for a provider. */
if (EVP_CIPHER_nid(cipher) == NID_undef) {
/* Looks like a provider */
if (EVP_CIPHER_is_a(cipher, SN_magma_cbc))
acpkm = cipher_gost_magma_ctracpkm();
acpkm = get_cipher(SN_magma_ctr_acpkm, &(ctx->fetched_acpkm));
else if (EVP_CIPHER_is_a(cipher, SN_grasshopper_cbc))
acpkm = cipher_gost_grasshopper_ctracpkm();
acpkm = get_cipher(SN_kuznyechik_ctr_acpkm, &(ctx->fetched_acpkm));
}
else {
/* Looks like an engine */
if (EVP_CIPHER_nid(cipher) == NID_magma_cbc)
acpkm = cipher_gost_magma_ctracpkm();
acpkm = get_cipher(SN_magma_ctr_acpkm, &(ctx->fetched_acpkm));
else if (EVP_CIPHER_nid(cipher) == NID_grasshopper_cbc)
acpkm = cipher_gost_grasshopper_ctracpkm();
acpkm = get_cipher(SN_kuznyechik_ctr_acpkm, &(ctx->fetched_acpkm));
}

if (acpkm == NULL)
return 0;

if (!EVP_EncryptInit_ex(ctx->actx, acpkm, impl, NULL, NULL))
if (!EVP_EncryptInit_ex(ctx->actx, acpkm, NULL, NULL, NULL))
return 0;
}
/* Non-NULL key means initialisation is complete */
Expand Down Expand Up @@ -365,7 +382,7 @@ static int omac_acpkm_imit_update(EVP_MD_CTX *ctx, const void *data,
return CMAC_ACPKM_Update(c->cmac_ctx, data, count);
}

int omac_acpkm_imit_final(EVP_MD_CTX *ctx, unsigned char *md)
static int omac_acpkm_imit_final(EVP_MD_CTX *ctx, unsigned char *md)
{
OMAC_ACPKM_CTX *c = EVP_MD_CTX_md_data(ctx);
unsigned char mac[MAX_GOST_OMAC_ACPKM_SIZE];
Expand Down Expand Up @@ -432,14 +449,14 @@ static int omac_acpkm_key(OMAC_ACPKM_CTX *c, const EVP_CIPHER *cipher,
return 0;
}

ret = CMAC_ACPKM_Init(c->cmac_ctx, key, key_size, cipher, NULL);
ret = CMAC_ACPKM_Init(c->cmac_ctx, key, key_size, cipher);
if (ret > 0) {
c->key_set = 1;
}
return 1;
}

int omac_acpkm_imit_ctrl(EVP_MD_CTX *ctx, int type, int arg, void *ptr)
static int omac_acpkm_imit_ctrl(EVP_MD_CTX *ctx, int type, int arg, void *ptr)
{
switch (type) {
case EVP_MD_CTRL_KEY_LEN:
Expand Down Expand Up @@ -548,7 +565,7 @@ int omac_acpkm_imit_ctrl(EVP_MD_CTX *ctx, int type, int arg, void *ptr)
GOST_digest kuznyechik_ctracpkm_omac_digest = {
.nid = NID_id_tc26_cipher_gostr3412_2015_kuznyechik_ctracpkm_omac,
.result_size = MAX_GOST_OMAC_ACPKM_SIZE,
.input_blocksize = GRASSHOPPER_BLOCK_SIZE,
.input_blocksize = 16,
.app_datasize = sizeof(OMAC_ACPKM_CTX),
.flags = EVP_MD_FLAG_XOF,
.init = grasshopper_omac_acpkm_init,
Expand Down
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