c - OpenSSL ECDSA 签名有效性

Question

来自OpenSSL documentation

使用命名曲线 prime256v1(又名 P-256)创建给定 SHA-256 哈希值的 ECDSA 签名。

第二步:使用 ECDSA_do_sign() 计算 SHA-256 哈希值的 ECDSA 签名:

sig = ECDSA_do_sign(digest, 32, eckey);
if (sig == NULL) {
   /* error */
}

或使用 ECDSA_sign():

unsigned char *buffer, *pp;
int            buf_len;
buf_len = ECDSA_size(eckey);
buffer  = OPENSSL_malloc(buf_len);
pp = buffer;
if (ECDSA_sign(0, dgst, dgstlen, pp, &buf_len, eckey) == 0) {
   /* error */
}

第三步:使用ECDSA_do_verify()验证创建的ECDSA签名:

ret = ECDSA_do_verify(digest, 32, sig, eckey);

或使用 ECDSA_verify():

ret = ECDSA_verify(0, digest, 32, buffer, buf_len, eckey);

最后评估返回值:

if (ret == 1) {
   /* signature ok */
} else if (ret == 0) {
   /* incorrect signature */
} else {
   /* error */
}

文件结束

这让我明白，我需要验证使用 ECDSA_do_sign 或 ECDSA_sign 创建的每个签名，是吗？创建的签名会无效吗？

Answer 1

来自NIST PUB 186-4 - Digital Signature Standard第 4.7 节:

Signature verification may be performed by any party (i.e., the signatory, the intended recipient or any other party) using the signatory’s public key. A signatory may wish to verify that the computed signature is correct, perhaps before sending the signed message to the intended recipient. The intended recipient (or any other party) verifies the signature to determine its authenticity.

(其中签名者是签名创建者)