* https://www.openssl.org/source/license.html
*/
-#include <openssl/sm2.h>
+#include "internal/sm2.h"
+#include "internal/sm2err.h"
+#include "internal/ec_int.h" /* ecdh_KDF_X9_63() */
+#include <openssl/err.h>
#include <openssl/evp.h>
#include <openssl/bn.h>
#include <openssl/asn1.h>
IMPLEMENT_ASN1_FUNCTIONS(SM2_Ciphertext)
-static size_t EC_field_size(const EC_GROUP *group)
+static size_t ec_field_size(const EC_GROUP *group)
{
/* Is there some simpler way to do this? */
BIGNUM *p = BN_new();
if (p == NULL || a == NULL || b == NULL)
goto done;
- EC_GROUP_get_curve_GFp(group, p, a, b, NULL);
+ if (!EC_GROUP_get_curve(group, p, a, b, NULL))
+ goto done;
field_size = (BN_num_bits(p) + 7) / 8;
done:
return field_size;
}
-size_t SM2_plaintext_size(const EC_KEY *key, const EVP_MD *digest, size_t msg_len)
+int sm2_plaintext_size(const EC_KEY *key, const EVP_MD *digest, size_t msg_len,
+ size_t *pt_size)
{
- const size_t field_size = EC_field_size(EC_KEY_get0_group(key));
- const size_t md_size = EVP_MD_size(digest);
-
- const size_t overhead = 10 + 2 * field_size + md_size;
- if(msg_len <= overhead)
- return 0;
-
- return msg_len - overhead;
+ const size_t field_size = ec_field_size(EC_KEY_get0_group(key));
+ const int md_size = EVP_MD_size(digest);
+ size_t overhead;
+
+ if (md_size < 0) {
+ SM2err(SM2_F_SM2_PLAINTEXT_SIZE, SM2_R_INVALID_DIGEST);
+ return 0;
+ }
+ if (field_size == 0) {
+ SM2err(SM2_F_SM2_PLAINTEXT_SIZE, SM2_R_INVALID_FIELD);
+ return 0;
+ }
+
+ overhead = 10 + 2 * field_size + (size_t)md_size;
+ if (msg_len <= overhead) {
+ SM2err(SM2_F_SM2_PLAINTEXT_SIZE, SM2_R_INVALID_ENCODING);
+ return 0;
+ }
+
+ *pt_size = msg_len - overhead;
+ return 1;
}
-size_t SM2_ciphertext_size(const EC_KEY *key, const EVP_MD *digest, size_t msg_len)
+int sm2_ciphertext_size(const EC_KEY *key, const EVP_MD *digest, size_t msg_len,
+ size_t *ct_size)
{
- const size_t field_size = EC_field_size(EC_KEY_get0_group(key));
- const size_t md_size = EVP_MD_size(digest);
- return 10 + 2 * field_size + md_size + msg_len;
+ const size_t field_size = ec_field_size(EC_KEY_get0_group(key));
+ const int md_size = EVP_MD_size(digest);
+ size_t sz;
+
+ if (field_size == 0 || md_size < 0)
+ return 0;
+
+ /* Integer and string are simple type; set constructed = 0, means primitive and definite length encoding. */
+ sz = 2 * ASN1_object_size(0, field_size + 1, V_ASN1_INTEGER)
+ + ASN1_object_size(0, md_size, V_ASN1_OCTET_STRING)
+ + ASN1_object_size(0, msg_len, V_ASN1_OCTET_STRING);
+ /* Sequence is structured type; set constructed = 1, means constructed and definite length encoding. */
+ *ct_size = ASN1_object_size(1, sz, V_ASN1_SEQUENCE);
+
+ return 1;
}
-int SM2_encrypt(const EC_KEY *key,
+int sm2_encrypt(const EC_KEY *key,
const EVP_MD *digest,
const uint8_t *msg,
size_t msg_len, uint8_t *ciphertext_buf, size_t *ciphertext_len)
{
- int rc = 0;
+ int rc = 0, ciphertext_leni;
size_t i;
BN_CTX *ctx = NULL;
BIGNUM *k = NULL;
BIGNUM *y1 = NULL;
BIGNUM *x2 = NULL;
BIGNUM *y2 = NULL;
-
EVP_MD_CTX *hash = EVP_MD_CTX_new();
-
struct SM2_Ciphertext_st ctext_struct;
const EC_GROUP *group = EC_KEY_get0_group(key);
const BIGNUM *order = EC_GROUP_get0_order(group);
EC_POINT *kG = NULL;
EC_POINT *kP = NULL;
uint8_t *msg_mask = NULL;
-
uint8_t *x2y2 = NULL;
uint8_t *C3 = NULL;
+ size_t field_size;
+ const int C3_size = EVP_MD_size(digest);
- const size_t field_size = EC_field_size(group);
- const size_t C3_size = EVP_MD_size(digest);
+ /* NULL these before any "goto done" */
+ ctext_struct.C2 = NULL;
+ ctext_struct.C3 = NULL;
- if (field_size == 0 || C3_size == 0)
- goto done;
+ if (hash == NULL || C3_size <= 0) {
+ SM2err(SM2_F_SM2_ENCRYPT, ERR_R_INTERNAL_ERROR);
+ goto done;
+ }
+
+ field_size = ec_field_size(group);
+ if (field_size == 0) {
+ SM2err(SM2_F_SM2_ENCRYPT, ERR_R_INTERNAL_ERROR);
+ goto done;
+ }
kG = EC_POINT_new(group);
kP = EC_POINT_new(group);
- if (kG == NULL || kP == NULL)
- goto done;
-
ctx = BN_CTX_new();
- if (ctx == NULL)
- goto done;
+ if (kG == NULL || kP == NULL || ctx == NULL) {
+ SM2err(SM2_F_SM2_ENCRYPT, ERR_R_MALLOC_FAILURE);
+ goto done;
+ }
BN_CTX_start(ctx);
k = BN_CTX_get(ctx);
y1 = BN_CTX_get(ctx);
y2 = BN_CTX_get(ctx);
- if (y2 == NULL)
- goto done;
+ if (y2 == NULL) {
+ SM2err(SM2_F_SM2_ENCRYPT, ERR_R_BN_LIB);
+ goto done;
+ }
x2y2 = OPENSSL_zalloc(2 * field_size);
C3 = OPENSSL_zalloc(C3_size);
- if (x2y2 == NULL || C3 == NULL)
- goto done;
+ if (x2y2 == NULL || C3 == NULL) {
+ SM2err(SM2_F_SM2_ENCRYPT, ERR_R_MALLOC_FAILURE);
+ goto done;
+ }
memset(ciphertext_buf, 0, *ciphertext_len);
- BN_priv_rand_range(k, order);
-
- if (EC_POINT_mul(group, kG, k, NULL, NULL, ctx) == 0)
- goto done;
-
- if (EC_POINT_get_affine_coordinates_GFp(group, kG, x1, y1, ctx) == 0)
+ if (!BN_priv_rand_range(k, order)) {
+ SM2err(SM2_F_SM2_ENCRYPT, ERR_R_INTERNAL_ERROR);
goto done;
+ }
- if (EC_POINT_mul(group, kP, NULL, P, k, ctx) == 0)
+ if (!EC_POINT_mul(group, kG, k, NULL, NULL, ctx)
+ || !EC_POINT_get_affine_coordinates(group, kG, x1, y1, ctx)
+ || !EC_POINT_mul(group, kP, NULL, P, k, ctx)
+ || !EC_POINT_get_affine_coordinates(group, kP, x2, y2, ctx)) {
+ SM2err(SM2_F_SM2_ENCRYPT, ERR_R_EC_LIB);
goto done;
+ }
- if (EC_POINT_get_affine_coordinates_GFp(group, kP, x2, y2, ctx) == 0)
+ if (BN_bn2binpad(x2, x2y2, field_size) < 0
+ || BN_bn2binpad(y2, x2y2 + field_size, field_size) < 0) {
+ SM2err(SM2_F_SM2_ENCRYPT, ERR_R_INTERNAL_ERROR);
goto done;
-
- BN_bn2binpad(x2, x2y2, field_size);
- BN_bn2binpad(y2, x2y2 + field_size, field_size);
+ }
msg_mask = OPENSSL_zalloc(msg_len);
- if (msg_mask == NULL)
+ if (msg_mask == NULL) {
+ SM2err(SM2_F_SM2_ENCRYPT, ERR_R_MALLOC_FAILURE);
goto done;
+ }
/* X9.63 with no salt happens to match the KDF used in SM2 */
- if (ECDH_KDF_X9_62(msg_mask, msg_len, x2y2, 2 * field_size, NULL, 0, digest)
- == 0)
+ if (!ecdh_KDF_X9_63(msg_mask, msg_len, x2y2, 2 * field_size, NULL, 0,
+ digest)) {
+ SM2err(SM2_F_SM2_ENCRYPT, ERR_R_EVP_LIB);
goto done;
+ }
for (i = 0; i != msg_len; ++i)
msg_mask[i] ^= msg[i];
- if (EVP_DigestInit(hash, digest) == 0)
- goto done;
-
- if (EVP_DigestUpdate(hash, x2y2, field_size) == 0)
- goto done;
-
- if (EVP_DigestUpdate(hash, msg, msg_len) == 0)
- goto done;
-
- if (EVP_DigestUpdate(hash, x2y2 + field_size, field_size) == 0)
- goto done;
-
- if (EVP_DigestFinal(hash, C3, NULL) == 0)
+ if (EVP_DigestInit(hash, digest) == 0
+ || EVP_DigestUpdate(hash, x2y2, field_size) == 0
+ || EVP_DigestUpdate(hash, msg, msg_len) == 0
+ || EVP_DigestUpdate(hash, x2y2 + field_size, field_size) == 0
+ || EVP_DigestFinal(hash, C3, NULL) == 0) {
+ SM2err(SM2_F_SM2_ENCRYPT, ERR_R_EVP_LIB);
goto done;
+ }
ctext_struct.C1x = x1;
ctext_struct.C1y = y1;
ctext_struct.C3 = ASN1_OCTET_STRING_new();
- ASN1_OCTET_STRING_set(ctext_struct.C3, C3, C3_size);
ctext_struct.C2 = ASN1_OCTET_STRING_new();
- ASN1_OCTET_STRING_set(ctext_struct.C2, msg_mask, msg_len);
- *ciphertext_len = i2d_SM2_Ciphertext(&ctext_struct, &ciphertext_buf);
+ if (ctext_struct.C3 == NULL || ctext_struct.C2 == NULL) {
+ SM2err(SM2_F_SM2_ENCRYPT, ERR_R_MALLOC_FAILURE);
+ goto done;
+ }
+ if (!ASN1_OCTET_STRING_set(ctext_struct.C3, C3, C3_size)
+ || !ASN1_OCTET_STRING_set(ctext_struct.C2, msg_mask, msg_len)) {
+ SM2err(SM2_F_SM2_ENCRYPT, ERR_R_INTERNAL_ERROR);
+ goto done;
+ }
- ASN1_OCTET_STRING_free(ctext_struct.C2);
- ASN1_OCTET_STRING_free(ctext_struct.C3);
+ ciphertext_leni = i2d_SM2_Ciphertext(&ctext_struct, &ciphertext_buf);
+ /* Ensure cast to size_t is safe */
+ if (ciphertext_leni < 0) {
+ SM2err(SM2_F_SM2_ENCRYPT, ERR_R_INTERNAL_ERROR);
+ goto done;
+ }
+ *ciphertext_len = (size_t)ciphertext_leni;
rc = 1;
done:
+ ASN1_OCTET_STRING_free(ctext_struct.C2);
+ ASN1_OCTET_STRING_free(ctext_struct.C3);
OPENSSL_free(msg_mask);
OPENSSL_free(x2y2);
OPENSSL_free(C3);
return rc;
}
-int SM2_decrypt(const EC_KEY *key,
+int sm2_decrypt(const EC_KEY *key,
const EVP_MD *digest,
const uint8_t *ciphertext,
size_t ciphertext_len, uint8_t *ptext_buf, size_t *ptext_len)
{
int rc = 0;
int i;
-
BN_CTX *ctx = NULL;
const EC_GROUP *group = EC_KEY_get0_group(key);
EC_POINT *C1 = NULL;
struct SM2_Ciphertext_st *sm2_ctext = NULL;
BIGNUM *x2 = NULL;
BIGNUM *y2 = NULL;
-
uint8_t *x2y2 = NULL;
uint8_t *computed_C3 = NULL;
-
- const size_t field_size = EC_field_size(group);
+ const size_t field_size = ec_field_size(group);
const int hash_size = EVP_MD_size(digest);
-
uint8_t *msg_mask = NULL;
const uint8_t *C2 = NULL;
const uint8_t *C3 = NULL;
int msg_len = 0;
EVP_MD_CTX *hash = NULL;
- if (field_size == 0 || hash_size == 0)
+ if (field_size == 0 || hash_size <= 0)
goto done;
memset(ptext_buf, 0xFF, *ptext_len);
sm2_ctext = d2i_SM2_Ciphertext(NULL, &ciphertext, ciphertext_len);
- if (sm2_ctext == NULL)
+ if (sm2_ctext == NULL) {
+ SM2err(SM2_F_SM2_DECRYPT, SM2_R_ASN1_ERROR);
goto done;
+ }
- if (sm2_ctext->C3->length != hash_size)
+ if (sm2_ctext->C3->length != hash_size) {
+ SM2err(SM2_F_SM2_DECRYPT, SM2_R_INVALID_ENCODING);
goto done;
+ }
C2 = sm2_ctext->C2->data;
C3 = sm2_ctext->C3->data;
msg_len = sm2_ctext->C2->length;
ctx = BN_CTX_new();
- if (ctx == NULL)
- goto done;
+ if (ctx == NULL) {
+ SM2err(SM2_F_SM2_DECRYPT, ERR_R_MALLOC_FAILURE);
+ goto done;
+ }
BN_CTX_start(ctx);
x2 = BN_CTX_get(ctx);
y2 = BN_CTX_get(ctx);
- if(y2 == NULL)
- goto done;
+ if (y2 == NULL) {
+ SM2err(SM2_F_SM2_DECRYPT, ERR_R_BN_LIB);
+ goto done;
+ }
msg_mask = OPENSSL_zalloc(msg_len);
x2y2 = OPENSSL_zalloc(2 * field_size);
computed_C3 = OPENSSL_zalloc(hash_size);
- if(msg_mask == NULL || x2y2 == NULL || computed_C3 == NULL)
- goto done;
-
- C1 = EC_POINT_new(group);
- if (C1 == NULL)
+ if (msg_mask == NULL || x2y2 == NULL || computed_C3 == NULL) {
+ SM2err(SM2_F_SM2_DECRYPT, ERR_R_MALLOC_FAILURE);
goto done;
+ }
- if (EC_POINT_set_affine_coordinates_GFp
- (group, C1, sm2_ctext->C1x, sm2_ctext->C1y, ctx) == 0)
+ C1 = EC_POINT_new(group);
+ if (C1 == NULL) {
+ SM2err(SM2_F_SM2_DECRYPT, ERR_R_MALLOC_FAILURE);
goto done;
-
- if (EC_POINT_mul(group, C1, NULL, C1, EC_KEY_get0_private_key(key), ctx) ==
- 0)
+ }
+
+ if (!EC_POINT_set_affine_coordinates(group, C1, sm2_ctext->C1x,
+ sm2_ctext->C1y, ctx)
+ || !EC_POINT_mul(group, C1, NULL, C1, EC_KEY_get0_private_key(key),
+ ctx)
+ || !EC_POINT_get_affine_coordinates(group, C1, x2, y2, ctx)) {
+ SM2err(SM2_F_SM2_DECRYPT, ERR_R_EC_LIB);
goto done;
+ }
- if (EC_POINT_get_affine_coordinates_GFp(group, C1, x2, y2, ctx) == 0)
- goto done;
-
- BN_bn2binpad(x2, x2y2, field_size);
- BN_bn2binpad(y2, x2y2 + field_size, field_size);
-
- if (ECDH_KDF_X9_62(msg_mask, msg_len, x2y2, 2 * field_size, NULL, 0, digest)
- == 0)
+ if (BN_bn2binpad(x2, x2y2, field_size) < 0
+ || BN_bn2binpad(y2, x2y2 + field_size, field_size) < 0
+ || !ecdh_KDF_X9_63(msg_mask, msg_len, x2y2, 2 * field_size, NULL, 0,
+ digest)) {
+ SM2err(SM2_F_SM2_DECRYPT, ERR_R_INTERNAL_ERROR);
goto done;
+ }
for (i = 0; i != msg_len; ++i)
ptext_buf[i] = C2[i] ^ msg_mask[i];
hash = EVP_MD_CTX_new();
-
- if (hash == NULL)
- goto done;
-
- if (EVP_DigestInit(hash, digest) == 0)
+ if (hash == NULL) {
+ SM2err(SM2_F_SM2_DECRYPT, ERR_R_MALLOC_FAILURE);
goto done;
-
- if (EVP_DigestUpdate(hash, x2y2, field_size) == 0)
- goto done;
-
- if (EVP_DigestUpdate(hash, ptext_buf, msg_len) == 0)
- goto done;
-
- if (EVP_DigestUpdate(hash, x2y2 + field_size, field_size) == 0)
- goto done;
-
- if (EVP_DigestFinal(hash, computed_C3, NULL) == 0)
+ }
+
+ if (!EVP_DigestInit(hash, digest)
+ || !EVP_DigestUpdate(hash, x2y2, field_size)
+ || !EVP_DigestUpdate(hash, ptext_buf, msg_len)
+ || !EVP_DigestUpdate(hash, x2y2 + field_size, field_size)
+ || !EVP_DigestFinal(hash, computed_C3, NULL)) {
+ SM2err(SM2_F_SM2_DECRYPT, ERR_R_EVP_LIB);
goto done;
+ }
- if (memcmp(computed_C3, C3, hash_size) != 0)
+ if (CRYPTO_memcmp(computed_C3, C3, hash_size) != 0) {
+ SM2err(SM2_F_SM2_DECRYPT, SM2_R_INVALID_DIGEST);
goto done;
+ }
rc = 1;
*ptext_len = msg_len;
done:
-
if (rc == 0)
memset(ptext_buf, 0, *ptext_len);