使用Crypto++获取ECDSA签名

Question

我必须使用Crypto++在变量中获取ECDSA签名。

我试着在启动SignMessage之后拿到它，但是签名是空的。

我怎么才能得到它呢？

Answer 1

你有没有看过Crypto++维基？Elliptic Curve Digital Signature Algorithm上有很多东西。

不太清楚你在做什么，或者哪里出了问题，所以这里有一个来自wiki的拷贝和粘贴：

签名：

ECDSA<ECP, SHA1>::PrivateKey privateKey;
privateKey.Load(...);

AutoSeededRandomPool prng;
string message = "Yoda said, Do or do not. There is no try.";
string signature;

StringSource ss1( message, true /*pump all*/,
    new SignerFilter( prng,
        ECDSA<ECP,SHA1>::Signer( privateKey ),
        new StringSink( signature )
    ) // SignerFilter
); // StringSource

验证：

ECDSA<ECP, SHA1>::PublicKey publicKey;
publicKey.Load(...);

// Result of the verification process
bool result = false;

// Exactly what was signed in the previous step
string message = ...;
// Output from the signing operation in the previous step
string signature = ...;

StringSource ss2( signature+message, true /*pump all*/,
    new SignatureVerificationFilter(
        ECDSA<ECP,SHA1>::Verifier(publicKey),
        new ArraySink( (byte*)&result, sizeof(result) )
    ) // SignatureVerificationFilter
);

// Verification failure?
if( !result ) {...}

如果您希望验证抛出失败，请尝试：

static const int VERIFICATION_FLAGS = SIGNATURE_AT_BEGIN | THROW_EXCEPTION;
StringSource ss3( signature+message, true /*pump all*/,
    new SignatureVerificationFilter(
        ECDSA<ECP,SHA1>::Verifier(publicKey),
        NULL, /* No need for attached filter */
        VERIFICATION_FLAGS
    ) // SignatureVerificationFilter
);