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Fix CMS CTR-ACPKM decrypt after ASN.1 parameter reinit #528

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Fix CMS CTR-ACPKM decrypt after ASN.1 parameter reinit #528

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9bed31c
Fix CMS CTR-ACPKM decrypt after ASN.1 parameter reinit
rostislaved May 29, 2026
0d0a55a
add magma test
rostislaved May 29, 2026
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18 changes: 17 additions & 1 deletion gost_crypt.c
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Original file line number Diff line number Diff line change
Expand Up @@ -427,11 +427,18 @@ static int magma_cipher_init(GOST_cipher_ctx *ctx, const unsigned char *key,
const unsigned char *iv, int enc)
{
struct ossl_gost_cipher_ctx *c = GOST_cipher_ctx_get_cipher_data(ctx);
int key_meshing = c->key_meshing;
int key_meshing_set = c->key_meshing_set;

/* FIXME this is just initializtion check */
if (GOST_cipher_ctx_get_app_data(ctx) == NULL) {
if (!gost_cipher_set_param(c, NID_id_tc26_gost_28147_param_Z))
return 0;
GOST_cipher_ctx_set_app_data(ctx, GOST_cipher_ctx_get_cipher_data(ctx));
if (key_meshing_set) {
c->key_meshing = key_meshing;
c->key_meshing_set = key_meshing_set;
}

if (enc) {
if (init_zero_kdf_seed(c->kdf_seed) == 0)
Expand All @@ -452,9 +459,11 @@ static int magma_cipher_init(GOST_cipher_ctx *ctx, const unsigned char *key,

if (GOST_cipher_ctx_nid(ctx) == NID_magma_ctr_acpkm
|| GOST_cipher_ctx_nid(ctx) == NID_magma_ctr_acpkm_omac) {
c->key_meshing = 1024;
if (!c->key_meshing_set)
c->key_meshing = 1024;
} else {
c->key_meshing = 0;
c->key_meshing_set = 0;
}

c->count = 0;
Expand Down Expand Up @@ -1155,6 +1164,7 @@ static int gost_cipher_ctl(GOST_cipher_ctx *ctx, int type, int arg, void *ptr)
GOST_cipher_ctx_get_cipher_data(ctx);
int nid;
int cur_meshing;
int cur_meshing_set;
int ret;

if (c == NULL) {
Expand All @@ -1171,8 +1181,10 @@ static int gost_cipher_ctl(GOST_cipher_ctx *ctx, int type, int arg, void *ptr)
}

cur_meshing = c->key_meshing;
cur_meshing_set = c->key_meshing_set;
ret = gost_cipher_set_param(c, nid);
c->key_meshing = cur_meshing;
c->key_meshing_set = cur_meshing_set;
return ret;
} else {
return 0;
Expand All @@ -1191,6 +1203,7 @@ static int gost_cipher_ctl(GOST_cipher_ctx *ctx, int type, int arg, void *ptr)
}

c->key_meshing = arg;
c->key_meshing_set = 1;
return 1;
}
default:
Expand Down Expand Up @@ -1260,6 +1273,7 @@ static int magma_cipher_ctl(GOST_cipher_ctx *ctx, int type, int arg, void *ptr)
}

c->key_meshing = arg;
c->key_meshing_set = 1;
return 1;
}
case EVP_CTRL_TLSTREE:
Expand Down Expand Up @@ -1472,6 +1486,7 @@ static int magma_set_asn1_parameters (GOST_cipher_ctx *ctx, ASN1_TYPE *params)
{
struct ossl_gost_cipher_ctx *c = GOST_cipher_ctx_get_cipher_data(ctx);
c->key_meshing = 8192;
c->key_meshing_set = 1;

/*
* Same lazy kdf_seed init as in gost_grasshopper_set_asn1_parameters:
Expand All @@ -1493,6 +1508,7 @@ static int magma_get_asn1_parameters(GOST_cipher_ctx *ctx, ASN1_TYPE *params)
unsigned char iv[16];

c->key_meshing = 8192;
c->key_meshing_set = 1;

if (gost2015_get_asn1_params(params, MAGMA_UKM_LEN, iv, 4, c->kdf_seed) == 0)
return -1;
Expand Down
9 changes: 7 additions & 2 deletions gost_grasshopper_cipher.c
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Original file line number Diff line number Diff line change
Expand Up @@ -334,7 +334,8 @@ gost_grasshopper_cipher_init_ctracpkm(GOST_cipher_ctx
/* NB: setting type makes EVP do_cipher callback useless */
c->c.type = GRASSHOPPER_CIPHER_CTRACPKM;
GOST_cipher_ctx_set_num(ctx, 0);
c->section_size = 4096;
if (!c->section_size_set)
c->section_size = 4096;

return gost_grasshopper_cipher_init(ctx, key, iv, enc);
}
Expand All @@ -350,7 +351,8 @@ gost_grasshopper_cipher_init_ctracpkm_omac(GOST_cipher_ctx
/* NB: setting type makes EVP do_cipher callback useless */
c->c.type = GRASSHOPPER_CIPHER_CTRACPKMOMAC;
GOST_cipher_ctx_set_num(ctx, 0);
c->section_size = 4096;
if (!c->section_size_set)
c->section_size = 4096;

if (key) {
unsigned char cipher_key[32];
Expand Down Expand Up @@ -1005,6 +1007,7 @@ static int gost_grasshopper_set_asn1_parameters(GOST_cipher_ctx *ctx, ASN1_TYPE

/* CMS implies 256kb section_size */
ctr->section_size = 256*1024;
ctr->section_size_set = 1;

return gost2015_set_asn1_params(params,
GOST_cipher_ctx_original_iv(ctx), 8, ctr->kdf_seed);
Expand All @@ -1030,6 +1033,7 @@ gost_grasshopper_get_asn1_parameters(GOST_cipher_ctx *ctx, ASN1_TYPE *params)

/* CMS implies 256kb section_size */
ctr->section_size = 256*1024;
ctr->section_size_set = 1;
return 1;
}
return 0;
Expand Down Expand Up @@ -1171,6 +1175,7 @@ static int gost_grasshopper_cipher_ctl(GOST_cipher_ctx *ctx, int type, int arg,
|| (arg % GRASSHOPPER_BLOCK_SIZE))
return -1;
c->section_size = arg;
c->section_size_set = 1;
break;
}
case EVP_CTRL_TLSTREE:
Expand Down
1 change: 1 addition & 0 deletions gost_grasshopper_cipher.h
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Original file line number Diff line number Diff line change
Expand Up @@ -34,6 +34,7 @@ typedef struct {
grasshopper_w128_t partial_buffer;
unsigned int section_size; /* After how much bytes mesh the key,
if 0 never mesh and work like plain ctr. */
unsigned int section_size_set;
unsigned char kdf_seed[8];
unsigned char tag[16];
EVP_MD_CTX *omac_ctx;
Expand Down
2 changes: 1 addition & 1 deletion gost_lcl.h
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Original file line number Diff line number Diff line change
Expand Up @@ -217,6 +217,7 @@ struct ossl_gost_cipher_ctx {
int paramNID;
unsigned int count;
int key_meshing;
int key_meshing_set;
unsigned char kdf_seed[8];
unsigned char tag[8];
gost_ctx cctx;
Expand Down Expand Up @@ -387,4 +388,3 @@ extern GOST_NID_JOB kuznyechik_mgm_NID;

#endif
/* vim: set expandtab cinoptions=\:0,l1,t0,g0,(0 sw=4 : */

66 changes: 66 additions & 0 deletions test_ciphers.c
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Original file line number Diff line number Diff line change
Expand Up @@ -580,6 +580,59 @@ static int test_provider_alg_id_param(const EVP_CIPHER *type, const char *name,
return ret | test;
}

static int test_engine_asn1_acpkm_reinit(const EVP_CIPHER *type, const char *name,
const unsigned char *key,
const unsigned char *iv)
{
EVP_CIPHER_CTX *enc;
EVP_CIPHER_CTX *dec;
ASN1_TYPE *params;
unsigned char pt[8192];
unsigned char ct[8192];
unsigned char out[8192];
int outlen = 0, tmplen = 0, total = 0;
int ret = 0, test;
size_t i;

if (EVP_CIPHER_get0_provider(type) != NULL
|| (strcmp(name, SN_id_tc26_cipher_gostr3412_2015_kuznyechik_ctracpkm) != 0
&& strcmp(name, SN_magma_ctr_acpkm) != 0))
return 0;

enc = EVP_CIPHER_CTX_new();
dec = EVP_CIPHER_CTX_new();
params = ASN1_TYPE_new();
T(enc != NULL && dec != NULL && params != NULL);

for (i = 0; i < sizeof(pt); i++)
pt[i] = (unsigned char)(i & 0xff);

printf("Engine ASN1 ACPKM reinit test [%s]: ", name);
T(EVP_CipherInit_ex(enc, type, NULL, key, iv, 1));
T(EVP_CIPHER_param_to_asn1(enc, params) > 0);
T(EVP_CipherUpdate(enc, ct, &outlen, pt, (int)sizeof(pt)));
total = outlen;
T(EVP_CipherFinal_ex(enc, ct + total, &tmplen));
total += tmplen;
T(total == (int)sizeof(pt));

T(EVP_CipherInit_ex(dec, type, NULL, NULL, NULL, 0));
T(EVP_CIPHER_asn1_to_param(dec, params) > 0);
T(EVP_CipherInit_ex(dec, NULL, NULL, key, NULL, 0));
T(EVP_CipherUpdate(dec, out, &outlen, ct, total));
total = outlen;
T(EVP_CipherFinal_ex(dec, out + total, &tmplen));
total += tmplen;

TEST_ASSERT(total != (int)sizeof(pt) || memcmp(out, pt, sizeof(pt)));
ret |= test;

EVP_CIPHER_CTX_free(enc);
EVP_CIPHER_CTX_free(dec);
ASN1_TYPE_free(params);
return ret;
}

static int test_provider_padded_decrypt_case(const EVP_CIPHER *type,
const char *name,
const unsigned char *key,
Expand Down Expand Up @@ -784,9 +837,22 @@ int main(int argc, char **argv)
ret |= test_provider_padded_decrypt(ciph, t->algname, t->block,
t->key, t->iv);
}
ret |= test_engine_asn1_acpkm_reinit(ciph, t->algname, t->key, t->iv);

EVP_CIPHER_free(ciph);
}
{
EVP_CIPHER *ciph;

ERR_set_mark();
T((ciph = (EVP_CIPHER *)EVP_get_cipherbyname(SN_magma_ctr_acpkm))
|| (ciph = EVP_CIPHER_fetch(NULL, SN_magma_ctr_acpkm, NULL)));
ERR_pop_to_mark();

ret |= test_engine_asn1_acpkm_reinit(ciph, SN_magma_ctr_acpkm,
Km, iv_ctr);
EVP_CIPHER_free(ciph);
}

warn_all_untested();

Expand Down