CryptDecrypt winapi函数出错?

时间:2011-11-25 18:05:37

标签: c++ cryptoapi

我编写了一个简单的程序来加载openssl生成的公钥,以解密由公钥的私钥加密的字符串。但我不知道为什么我会失败

b = CryptDecrypt(hKey,NULL,FALSE,0,pbEncrypt,&cbEncrypt);

我收到错误“8009000D NTE_NO_KEY 钥匙不存在。“。有人可以向我解释这个吗?

void DecodeString() 
{

    CHAR* publicKey = 
        "-----BEGIN PUBLIC KEY-----"
        "MIIBIjANBgkqhkiG9w0BAQEFAAOCAQ8AMIIBCgKCAQEAv+yyzdZaqcE7qOOZ8pyN"
        "o1n3PS2U/ewT2gGSQeixP+VixQGrxnssT3zlbeUND8CVX+tZGwkcIZZD09Rkx9vh"
        "z7vLUFD7dngupo/aL6pfehb95citD31DUswc9BTJjQySpSSG6zWDSBJMELDYaCa4"
        "MIU7odoCg2EbQBwRWX7upWiR+shyxnPYklY8ZUpVCtIdHXmPO5eMaI1elftqNw1N"
        "n/Id4pFFif11Lmny3s3ADfItuyMfTwU6jwgsPaoqrX5FCnurlAVl/mcfpMVpsPju"
        "XWw2IlvZP5SkTW4G6V+Bt+xDI6SW3dvMi6gJngHLUKekbhZxcFWuv3hus8ojpo+I"
        "mwIDAQAB"
        "-----END PUBLIC KEY-----";

    BYTE* derPubKey;
    DWORD derPubKeyLen;
    BOOL b = CryptStringToBinaryA(publicKey, 0, CRYPT_STRING_BASE64HEADER, NULL, &derPubKeyLen, NULL, NULL);
    DWORD error = GetLastError();
    _ASSERT(error == 0);
    _ASSERT(b == TRUE);
    derPubKey = new BYTE[derPubKeyLen];
    b = CryptStringToBinaryA(publicKey, 0, CRYPT_STRING_BASE64HEADER, derPubKey, &derPubKeyLen, NULL, NULL);
    error = GetLastError();
    _ASSERT(error == 0);
    _ASSERT(b == TRUE);
    CERT_PUBLIC_KEY_INFO *publicKeyInfo;
    DWORD publicKeyInfoLen;
    HCRYPTPROV hProv = 0;
    HCRYPTKEY hKey = 0;
    b = CryptDecodeObjectEx(X509_ASN_ENCODING, X509_PUBLIC_KEY_INFO, derPubKey, derPubKeyLen, CRYPT_ENCODE_ALLOC_FLAG, NULL, &publicKeyInfo, &publicKeyInfoLen);
    error = GetLastError();
    _ASSERT(error == 0);
    _ASSERT(b == TRUE);
    b = CryptAcquireContext(&hProv, NULL, NULL, PROV_RSA_FULL, CRYPT_VERIFYCONTEXT);
    error = GetLastError();
    _ASSERT(error == 0);
    _ASSERT(b == TRUE);
    b = CryptImportPublicKeyInfo(hProv, X509_ASN_ENCODING, publicKeyInfo, &hKey);
    error = GetLastError();
    _ASSERT(error == 0);
    _ASSERT(b == TRUE);
    //same test decrypt
    CHAR* sameTest = "nJZ6MN6MIrpbLQiRvfLFIHHzneQBe2rucaKSykXeHgf8Zth5FNPZPdiPhWcHq0/K"
        "KgRHv2ON+gPyFbjsdDl2cixPgNGXs1FfI/RvkH+Icn+6rYq5uPBM5oQVriyiWI9/"
        "QiC56LP0ooouqLg9e2U5zJmC/ftCODkFyL748Fx3godXzDl1mNB7bx/Ua6Z93KeB"
        "OgNvYZH3tcZZYlgoX4GVf4ocO0aZ8pQjEB8p9hMWfIDRCIckDAncy21tHDmWDqZ4"
        "H7CZjbdNyaiWe5Cr6+CYs25+r3AdIlXOKWuphgbckKDHh4r7nMX0AX+iHXGjCgkM"
        "iwi4yz7wF+Ow/CcGHkAMTQ==";

    BYTE* pbEncrypt = 0;
    DWORD cbEncrypt = 0;
    b = CryptStringToBinaryA(sameTest, 0, CRYPT_STRING_BASE64, NULL, &cbEncrypt, NULL, NULL);
    error = GetLastError();
    _ASSERT(error == 0);
    _ASSERT(b == TRUE);
    pbEncrypt = new BYTE[cbEncrypt];
    printf("%s\n",(CHAR*)pbEncrypt);
    b = CryptStringToBinaryA(sameTest, 0, CRYPT_STRING_BASE64, pbEncrypt, &cbEncrypt, NULL, NULL);
    error = GetLastError();
    _ASSERT(error == 0);
    _ASSERT(b == TRUE);
    printf("%s\n",(CHAR*)pbEncrypt);
    b = CryptDecrypt(hKey,NULL,FALSE,0,pbEncrypt,&cbEncrypt);
    error = GetLastError();
    _ASSERT(error == 0);
    _ASSERT(b == TRUE);
    printf("%s\n",(CHAR*)pbEncrypt);
}

1 个答案:

答案 0 :(得分:3)

您无法使用公钥解密使用私钥加密的内容。公钥仅用于加密,而私钥只能用于解密。

来自Wikipedia

  

[...]公钥加密中使用的区别技术是   使用非对称密钥算法,其中密钥用于加密   消息与用于解密它的密钥不同。每个用户都有一个   加密密钥对 - 公共加密密钥和私有密钥   解密密钥。公开的加密密钥是广泛的   分布式,而私有解密密钥只有   接受者。邮件使用收件人的公钥加密,并且   只能使用相应的私钥解密。[...]