OpenSSL-SM2

1.

 

2.

 sm2_enc_dec.c

#include <stdio.h>
#include <stdlib.h>
#include <string.h>
#include <openssl/ec.h>
#include <openssl/evp.h>
 
int main(void)
{
    int ret = -1, i;
    EVP_PKEY_CTX *pctx = NULL, *ectx = NULL;
    EVP_PKEY *pkey = NULL;
    unsigned char message[16] = "2018121720181217";//{ 0x0, 0x1, 0x2, 0x3, 0x4, 0x5, 0x6, 0x7,0x8, 0x9, 0xA, 0xB, 0xC, 0xD, 0xE, 0xF };
    size_t message_len = sizeof(message);
    unsigned char *ciphertext = NULL, *plaintext = NULL;
    size_t ciphertext_len, plaintext_len;
    EC_KEY *key_pair = NULL;
    const BIGNUM *priv_key = NULL;
    char *priv_key_str = NULL;
 
    const EC_GROUP *group = NULL;
    const EC_POINT *pub_key = NULL;
    BN_CTX *ctx = NULL;
    BIGNUM *x_coordinate = NULL, *y_coordinate = NULL;
    char *x_coordinate_str = NULL, *y_coordinate_str = NULL;
 
/* create SM2 Ellipse Curve parameters and key pair */
    if ( !(pctx = EVP_PKEY_CTX_new_id(EVP_PKEY_EC, NULL)) )
    {
        goto clean_up;
    }
 
    if ( (EVP_PKEY_paramgen_init(pctx)) != 1 )
    {
        goto clean_up;
    }
 
    if ( (EVP_PKEY_CTX_set_ec_paramgen_curve_nid(pctx, NID_sm2)) <= 0 )
    {
        goto clean_up;
    }
 
    if ( (EVP_PKEY_keygen_init(pctx)) != 1 )
    {
        goto clean_up;
    }
 
    if ( (EVP_PKEY_keygen(pctx, &pkey)) != 1 )
    {
        goto clean_up;
    }
 
/* print SM2 key pair */
    if ( !(key_pair = EVP_PKEY_get0_EC_KEY(pkey)) )
    {
        goto clean_up;
    }
 
    if ( !(priv_key = EC_KEY_get0_private_key(key_pair)) )
    {
        goto clean_up;
    }
 
    if ( !(priv_key_str = BN_bn2hex(priv_key)) )
    {
        goto clean_up;
    }
    printf("SM2 private key (in hex form):
");
    printf("%s

", priv_key_str);
 
    if ( !(pub_key = EC_KEY_get0_public_key(key_pair)) )
    {
        goto clean_up;
    }
 
    if ( !(group = EC_KEY_get0_group(key_pair)) )
    {
        goto clean_up;
    }
 
    if ( !(ctx = BN_CTX_new()) )
    {
        goto clean_up;
    }
    BN_CTX_start(ctx);
    x_coordinate = BN_CTX_get(ctx);
    y_coordinate = BN_CTX_get(ctx);
    if ( !(y_coordinate) )
    {
        goto clean_up;
    }
    if ( !(EC_POINT_get_affine_coordinates(group, pub_key, x_coordinate, y_coordinate, ctx)) )
    {
        goto clean_up;
    }
    if ( !(x_coordinate_str = BN_bn2hex(x_coordinate)) )
    {
        goto clean_up;
    }
    printf("x coordinate in SM2 public key (in hex form):
");
    printf("%s

", x_coordinate_str);
 
    if ( !(y_coordinate_str = BN_bn2hex(y_coordinate)) )
    {
        goto clean_up;
    }
    printf("y coordinate in SM2 public key (in hex form):
");
    printf("%s

", y_coordinate_str);
 
/* compute SM2 encryption */
    if ( (EVP_PKEY_set_alias_type(pkey, EVP_PKEY_SM2)) != 1 )
    {
        goto clean_up;
    }
 
    if ( !(ectx = EVP_PKEY_CTX_new(pkey, NULL)) )
    {
        goto clean_up;
    }
 
    if ( (EVP_PKEY_encrypt_init(ectx)) != 1 )
    {
        goto clean_up;
    }
 
    if ( (EVP_PKEY_encrypt(ectx, NULL, &ciphertext_len, message, message_len)) != 1 )
    {
        goto clean_up;
    }
 
    if ( !(ciphertext = (unsigned char *)malloc(ciphertext_len)) )
    {
        goto clean_up;
    }
 
    if ( (EVP_PKEY_encrypt(ectx, ciphertext, &ciphertext_len, message, message_len)) != 1 )
    {
        goto clean_up;
    }
 
    printf("Message length: %d bytes.
", message_len);
    printf("Message:
");
    for (i = 0; i < (int)message_len; i++)
    {
        printf("0x%x  ", message[i]);
    }
    printf("

");
 
    printf("Ciphertext length: %d bytes.
", ciphertext_len);
    printf("Ciphertext (ASN.1 encode):
");
    for (i = 0; i < (int)ciphertext_len; i++)
    {
        printf("0x%x  ", ciphertext[i]);
    }
    printf("

");
 
/* compute SM2 decryption */
    if ( (EVP_PKEY_decrypt_init(ectx)) != 1 )
    {
        goto clean_up;
    }
 
    if ( (EVP_PKEY_decrypt(ectx, NULL, &plaintext_len, ciphertext, ciphertext_len)) != 1 )
    {
        goto clean_up;
    }
 
    if ( !(plaintext = (unsigned char *)malloc(plaintext_len)) )
    {
        goto clean_up;
    }
 
    if ( (EVP_PKEY_decrypt(ectx, plaintext, &plaintext_len, ciphertext, ciphertext_len)) != 1 )
    {
        goto clean_up;
    }
 
    printf("Decrypted plaintext length: %d bytes.
", plaintext_len);
    printf("Decrypted plaintext:
");
    for (i = 0; i < (int)plaintext_len; i++)
    {
        printf("0x%x  ", plaintext[i]);
    }
    printf("

");
 
    if ( plaintext_len != message_len )
    {
        printf("Decrypted data length error!
");
        goto clean_up;
    }
 
    if ( memcmp(plaintext, message, message_len) )
    {
        printf("Decrypt data failed!
");
        goto clean_up;
    }
    else
    {
        printf("Encrypt and decrypt data succeeded!
");
    }
 
    ret = 0;
clean_up:
    if (pctx)
    {
        EVP_PKEY_CTX_free(pctx);
    }
 
    if (pkey)
    {
        EVP_PKEY_free(pkey);
    }
 
    if (priv_key_str)
    {
        OPENSSL_free(priv_key_str);
    }
 
    if (ctx)
    {
        BN_CTX_end(ctx);
        BN_CTX_free(ctx);
    }
 
    if (x_coordinate_str)
    {
        OPENSSL_free(x_coordinate_str);
    }
 
    if (y_coordinate_str)
    {
        OPENSSL_free(y_coordinate_str);
    }
 
    if (ectx)
    {
        EVP_PKEY_CTX_free(ectx);
    }
 
    if (ciphertext)
    {
        free(ciphertext);
    }
 
    if (plaintext)
    {
        free(plaintext);
    }
 
        return 0;
}

sm2_sign.c

 
#include <stdio.h>
#include <stdlib.h>
#include <openssl/ec.h>
#include <openssl/evp.h>

int main(void)
{
    int ret = -1, i;
    EVP_PKEY_CTX* pctx = NULL, * sctx = NULL;
    EVP_PKEY* pkey = NULL;
    EVP_MD_CTX* md_ctx = NULL, * md_ctx_verify = NULL;
    unsigned char message[16] = "2018121720181217"; //{ 0x0, 0x1, 0x2, 0x3, 0x4, 0x5, 0x6, 0x7, 0x8, 0x9, 0xA, 0xB, 0xC, 0xD, 0xE, 0xF };
    size_t message_len = sizeof(message);
    unsigned char* sig = NULL;
    size_t sig_len;
    unsigned char sm2_id[] = { 0x31, 0x32, 0x33, 0x34, 0x35, 0x36, 0x37, 0x38,
                    0x31, 0x32, 0x33, 0x34, 0x35, 0x36, 0x37, 0x38 };
    unsigned int sm2_id_len = sizeof(sm2_id);
    EC_KEY* key_pair = NULL;
    const BIGNUM* priv_key = NULL;
    char* priv_key_str = NULL;
 
    const EC_GROUP* group = NULL;
    const EC_POINT* pub_key = NULL;
    BN_CTX* ctx = NULL;
    BIGNUM* x_coordinate = NULL, * y_coordinate = NULL;
    char* x_coordinate_str = NULL, * y_coordinate_str = NULL;
 
    /* create SM2 Ellipse Curve parameters and key pair */
    if ( !(pctx = EVP_PKEY_CTX_new_id(EVP_PKEY_EC, NULL)) )
    {
        goto clean_up;
    }
 
    if ( (EVP_PKEY_paramgen_init(pctx)) != 1 )
    {
        goto clean_up;
    }
 
    if ( (EVP_PKEY_CTX_set_ec_paramgen_curve_nid(pctx, NID_sm2)) <= 0 )
    {
        goto clean_up;
    }
 
    if ( (EVP_PKEY_keygen_init(pctx)) != 1 )
    {
        goto clean_up;
    }
 
    if ( (EVP_PKEY_keygen(pctx, &pkey)) != 1 )
    {
        goto clean_up;
    }
 
    /* print SM2 key pair */
    if ( !(key_pair = EVP_PKEY_get0_EC_KEY(pkey)) )
    {
        goto clean_up;
    }
 
    if ( !(priv_key = EC_KEY_get0_private_key(key_pair)) )
    {
        goto clean_up;
    }
 
    if ( !(priv_key_str = BN_bn2hex(priv_key)) )
    {
        goto clean_up;
    }
    printf("SM2 private key (in hex form):
");
    printf("%s

", priv_key_str);
 
    if ( !(pub_key = EC_KEY_get0_public_key(key_pair)) )
    {
        goto clean_up;
    }
 
    if ( !(group = EC_KEY_get0_group(key_pair)) )
    {
        goto clean_up;
    }
 
    if ( !(ctx = BN_CTX_new()) )
    {
        goto clean_up;
    }
    BN_CTX_start(ctx);
    x_coordinate = BN_CTX_get(ctx);
    y_coordinate = BN_CTX_get(ctx);
    if ( !(y_coordinate) )
    {
        goto clean_up;
    }
    if ( !(EC_POINT_get_affine_coordinates(group, pub_key, x_coordinate, y_coordinate, ctx)) )
    {
        goto clean_up;
    }
    if ( !(x_coordinate_str = BN_bn2hex(x_coordinate)) )
    {
        goto clean_up;
    }
    printf("x coordinate in SM2 public key (in hex form):
");
    printf("%s

", x_coordinate_str);
 
    if ( !(y_coordinate_str = BN_bn2hex(y_coordinate)) )
    {
        goto clean_up;
    }
    printf("y coordinate in SM2 public key (in hex form):
");
    printf("%s

", y_coordinate_str);
 
    /* compute SM2 signature */
    if ( (EVP_PKEY_set_alias_type(pkey, EVP_PKEY_SM2)) != 1 )
    {
        goto clean_up;
    }
 
    if ( !(md_ctx = EVP_MD_CTX_new()) )
    {
        goto clean_up;
    }
 
    if ( !(sctx = EVP_PKEY_CTX_new(pkey, NULL)) )
    {
        goto clean_up;
    }
 
    if ( EVP_PKEY_CTX_set1_id(sctx, sm2_id, sm2_id_len) <= 0 )
    {
        goto clean_up;
    }
 
    EVP_MD_CTX_set_pkey_ctx(md_ctx, sctx);
 
    if ( (EVP_DigestSignInit(md_ctx, NULL, EVP_sm3(), NULL, pkey)) != 1 )
    {
        goto clean_up;
    }
 
    if ( (EVP_DigestSignUpdate(md_ctx, message, message_len)) != 1 )
    {
        goto clean_up;
    }
 
    if ( (EVP_DigestSignFinal(md_ctx, NULL, &sig_len)) != 1 )
    {
        goto clean_up;
    }
 
    if ( !(sig = (unsigned char*)malloc(sig_len)) )
    {
        goto clean_up;
    }
 
    if ( (EVP_DigestSignFinal(md_ctx, sig, &sig_len)) != 1 )
    {
        goto clean_up;
    }
 
    printf("Message length: %d bytes.
", message_len);
    printf("Message:
");
    for (i = 0; i < (int)message_len; i++)
    {
        printf("0x%x  ", message[i]);
    }
    printf("

");
 
    printf("SM2 signature length: %d bytes.
", sig_len);
    printf("SM2 signature (ASN.1 encode):
");
    for (i = 0; i < (int)sig_len; i++)
    {
        printf("0x%x  ", sig[i]);
    }
    printf("

");
 
    /* verify SM2 signature */
    if ( !(md_ctx_verify = EVP_MD_CTX_new()) )
    {
        goto clean_up;
    }
 
    EVP_MD_CTX_set_pkey_ctx(md_ctx_verify, sctx);
 
    if ( (EVP_DigestVerifyInit(md_ctx_verify, NULL, EVP_sm3(), NULL, pkey)) != 1 )
    {
        goto clean_up;
    }
 
    if ( (EVP_DigestVerifyUpdate(md_ctx_verify, message, sizeof(message))) != 1 )
    {
        goto clean_up;
    }
 
    if ( (EVP_DigestVerifyFinal(md_ctx_verify, sig, sig_len)) != 1 )
    {
        printf("Verify SM2 signature failed!
");
        goto clean_up;
    }
    else
    {
        printf("Verify SM2 signature succeeded!
");
    }
 
    ret = 0;
clean_up:
    if (pctx)
    {
        EVP_PKEY_CTX_free(pctx);
    }
 
    if (pkey)
    {
        EVP_PKEY_free(pkey);
    }
 
    if (priv_key_str)
    {
        OPENSSL_free(priv_key_str);
    }
 
    if (ctx)
    {
        BN_CTX_end(ctx);
        BN_CTX_free(ctx);
    }
 
    if (x_coordinate_str)
    {
        OPENSSL_free(x_coordinate_str);
    }
 
    if (y_coordinate_str)
    {
        OPENSSL_free(y_coordinate_str);
    }
 
    if (md_ctx)
    {
        EVP_MD_CTX_free(md_ctx);
    }
 
    if (sctx)
    {
        EVP_PKEY_CTX_free(sctx);
    }
 
    if (sig)
    {
        free(sig);
    }
 
    if (md_ctx_verify)
    {
        EVP_MD_CTX_free(md_ctx_verify);
    }
        return 0;
}