Question

抱歉愚蠢的问题，我看过很多例子，但无法找到答案。尝试使用rsa加密和解密文件：

加密

 ptext = (unsigned char *)malloc(key_size);
    ctext = (unsigned char *)malloc(key_size);
    while (1) {
            inlen = _read(in, ptext, key_size);
            if (inlen <= 0) break;
            outlen = RSA_public_encrypt(inlen, ptext, ctext, pubKey, 
    RSA_PKCS1_PADDING);
            if (outlen != RSA_size(pubKey)) exit(-1);
            _write(out, ctext, outlen);
        }

解密：

while (1) {     
        inlen = _read(in, ctext, key_size);
        printf("Read %i bytes\n", inlen);
        if (inlen <= 0) break;
        outlen = RSA_private_decrypt(key_size-11, ctext, ptext, privKey, RSA_PKCS1_PADDING);
        printf("RSA returns %i\n", outlen);
        if (outlen < 0)
        {
            fprintf(stderr, "OpenSSL error: %s\n", ERR_error_string(ERR_get_error(), NULL));
            exit(0);
        }
        _write(out, ptext, outlen);
}

节目输出：

Read 431 bytes
RSA returns -1
OpenSSL error: error:0407109F:rsa routines:RSA_padding_check_PKCS1_type_2:pkcs decoding error

key_size或key_size-11 - ＆gt;没有变化。帮助plz绕过这个错误。

Answer 1

对于RSA解密，flen必须是RSA_size(pubkey)，而不是RSA_size(pubkey) - 11。因此像

outlen = RSA_private_decrypt(RSA_size(pubKey), ctext, ptext, privKey, RSA_PKCS1_PADDING);

应该有效。解密的明文应包含在ctext[0] ... ctext[outlen-1]。

中

Answer 2

这就是我在我的项目中使用RSA crypt函数的方法。尝试与您的实施进行比较

int rsa_oaep_encrypt(EVP_PKEY *publicKey, const unsigned char *plaintext, const size_t plaintextLen, unsigned char *ciphertext, size_t *ciphertextLen)
{
 int sts = -1;
 if ( (*ciphertextLen = RSA_public_encrypt(plaintextLen, plaintext, ciphertext, publicKey->pkey.rsa, RSA_PKCS1_OAEP_PADDING)) > 0)
    sts = 0;
 return sts;
}

int rsa_oaep_decrypt(EVP_PKEY *privateKey, const unsigned char *ciphertext, const size_t ciphertextLen, unsigned char *plaintext, size_t *plaintextLen)
{
 int sts = -1;
 if ( (*plaintextLen = RSA_private_decrypt(ciphertextLen, ciphertext, plaintext, privateKey->pkey.rsa, RSA_PKCS1_OAEP_PADDING)) > 0)
    sts = 0;
 return sts;
}

RSA_private_decrypt错误

2 个答案: