OpenSSL 在 EVP_VerifyFinal 失败

Question

经过几天的互联网搜索和 openssl 文档的搜索，我遇到了困难。我正在尝试使用私钥对消息进行签名，然后使用公钥验证消息的真实性。

密钥生成代码：

    //Generate RSA Keys
    EVP_PKEY_CTX* KeyCtx = EVP_PKEY_CTX_new_id(EVP_PKEY_RSA, NULL);
    if (KeyCtx == nullptr)
        return false;

    if (EVP_PKEY_keygen_init(KeyCtx) <= 0)
        return false;

    if (EVP_PKEY_CTX_set_rsa_keygen_bits(KeyCtx, RSA_KeyLen) <= 0)
        return false;

    if (EVP_PKEY_keygen(KeyCtx, &m_ServerKeyPair) <= 0)
        return false;

    if (EVP_PKEY_keygen(KeyCtx, &m_ClientKeyPair) <= 0)
        return false;

    //Write Keys to EVP_PKEYS for actual internal encryption,BIO mem is wiped after read so we need a new copy
    PEM_read_bio_PrivateKey(KeyToPrivBio(m_ServerKeyPair), &m_ServerPrivateKey, NULL, NULL);
    PEM_read_bio_PUBKEY(KeyToPubBio(m_ServerKeyPair), &m_ServerPublicKey, NULL, NULL);
    PEM_read_bio_PrivateKey(KeyToPrivBio(m_ClientKeyPair), &m_ClientPrivateKey, NULL, NULL);
    PEM_read_bio_PUBKEY(KeyToPubBio(m_ClientKeyPair), &m_ClientPublicKey, NULL, NULL);

RSA 签名：

bool SecureCrypto::RSASign(const unsigned char* Msg, size_t MsgLen,unsigned char** EncMsg, size_t& MsgLenEnc)
{
    EVP_PKEY_size(m_ServerPrivateKey);
    *EncMsg = (unsigned char*)malloc(EVP_PKEY_size(m_ServerPrivateKey));

    if (EVP_SignInit_ex(m_RSASignCtx, EVP_sha1(), 0) <= 0)
    {
        printf("Failed Init\n");
        return false;
    }

    if (EVP_SignUpdate(m_RSASignCtx, Msg, MsgLen) <= 0)
    {
        printf("Failed Update\n");
        return false;
    }

    if (EVP_SignFinal(m_RSASignCtx, *EncMsg, &MsgLenEnc, m_ServerPrivateKey) <=0)
    {
        printf("Failed Final Sign\n");
        return false;
    }
    EVP_MD_CTX_cleanup(m_RSASignCtx);

    return true;
}

RSA 验证：

bool SecureCrypto::RSAVerifySignature(const unsigned char* MsgHash, size_t MsgHashLen,unsigned char* Msg, size_t MsgLen)
{
    if (EVP_VerifyInit(m_RSAVerifyCtx, EVP_sha1()) <= 0)
    {
        printf("Failed Verify Init\n");
        return false;
    }

    if (EVP_VerifyUpdate(m_RSAVerifyCtx, Msg, MsgLen) <= 0)
    {
        printf("Failed Verify \n");
        return false;
    }

    if (EVP_VerifyFinal(m_RSAVerifyCtx, MsgHash, MsgHashLen, m_ServerPublicKey)<=0);
    {
        printf("Failed Final Verify %s\n",ERR_error_string(ERR_get_error(),NULL));
        return false;
    }
    EVP_MD_CTX_cleanup(m_RSAVerifyCtx);
    return true;
}

密钥生成成功，我查看了它创建的密钥，它们似乎是有效的，格式为-----BEGIN PRIVATE KEY-----，一些大素数，-----END PRIVATE KEY-----。签名似乎成功并返回一个哈希值。 EVP_Verify 在最后一步 EVP_VerifyFinal 失败，ERR_error_string 报告：

error:00000000:lib(0):func(0):reason(0)

这显然没有帮助，有人可以指出我可能做错了什么。这是我第一次深入研究 openssl，所以这里可能存在一些大问题。

Answer 1

感谢 JWW 和 indiv，我能够解决我的问题，这是我使用旧 API 和不正确的返回检查的问题。解决方案：

bool SecureCrypto::RSASign(const unsigned char* Msg, size_t MsgLen,unsigned char** EncMsg, size_t* MsgLenEnc)
{
    if (EVP_DigestSignInit(m_RSASignCtx,NULL, EVP_sha256(), NULL,m_ServerPrivateKey) <= 0)
    {
        printf("Failed Init\n");
        return false;
    }

    if (EVP_DigestSignUpdate(m_RSASignCtx, Msg, MsgLen) <= 0)
    {
        printf("Failed Update\n");
        return false;
    }

    //Get Hash Size
    if (EVP_DigestSignFinal(m_RSASignCtx, NULL,MsgLenEnc) <=0)
    {
        printf("Failed Final Sign\n");
        return false;
    }

    //Allocate Space for hash
    *EncMsg = (unsigned char*)malloc(*MsgLenEnc);
    if (EVP_DigestSignFinal(m_RSASignCtx, *EncMsg, MsgLenEnc) <= 0)
    {
        printf("Failed Final Sign 1\n");
        return false;
    }

    EVP_MD_CTX_cleanup(m_RSASignCtx);

    return true;
}

bool SecureCrypto::RSAVerifySignature(const unsigned char* MsgHash, size_t MsgHashLen,unsigned char* Msg, size_t MsgLen,bool* Authentic)
{
    if (EVP_DigestVerifyInit(m_RSAVerifyCtx,NULL, EVP_sha256(),NULL,m_ServerPrivateKey) <= 0)
    {
        printf("Failed Verify Init\n");
        return false;
    }

    if (EVP_DigestVerifyUpdate(m_RSAVerifyCtx, Msg, MsgLen) <= 0)
    {
        printf("Failed Verify \n");
        return false;
    }

    int AuthStatus = EVP_DigestVerifyFinal(m_RSAVerifyCtx, (unsigned char*)MsgHash, MsgHashLen);

    if (AuthStatus==1)
    {
        //Message Authentic
        *Authentic = true;
        EVP_MD_CTX_cleanup(m_RSAVerifyCtx);
        return true;
    } else if(AuthStatus==0){
        //Message Not Authentic
        *Authentic = false;
        EVP_MD_CTX_cleanup(m_RSAVerifyCtx);
        return true; //Still did our job correctly
    } else{
        printf("Error\n");
        *Authentic = false;
        EVP_MD_CTX_cleanup(m_RSAVerifyCtx);
        return false;
    }
}

我不敢相信我错过了这么明显的例子，谢谢你们的帮助，抱歉我看起来很愚蠢哈哈。