diff options
Diffstat (limited to 'crypto/sm2/sm2_crypt.c')
| -rw-r--r-- | crypto/sm2/sm2_crypt.c | 9 |
1 files changed, 8 insertions, 1 deletions
diff --git a/crypto/sm2/sm2_crypt.c b/crypto/sm2/sm2_crypt.c index 9e7887320c..9c69a45054 100644 --- a/crypto/sm2/sm2_crypt.c +++ b/crypto/sm2/sm2_crypt.c @@ -91,11 +91,18 @@ int sm2_ciphertext_size(const EC_KEY *key, const EVP_MD *digest, size_t 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; - *ct_size = 12 + 2 * field_size + (size_t)md_size + msg_len; + /* 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; } |