使用ECDSA或DSA对预计算哈希进行签名

H(M)=M 可能有用。有可能满足这样一个习惯吗 HashTransformation ECDSA<ECP,H>::Signer ?

对程序如下。它提供了一个 IdentityHash 将输入复制到输出的类。它需要一个模板参数来指定哈希大小。

to_sign = MF(H(M)) .

$ cat test.cxx
#include "cryptlib.h"
#include "secblock.h"
#include "eccrypto.h"
#include "osrng.h"
#include "oids.h"
#include "hex.h"

#include <iostream>
#include <string>

using namespace CryptoPP;

template <unsigned int HASH_SIZE = 32>
class IdentityHash : public HashTransformation
{
public:
    CRYPTOPP_CONSTANT(DIGESTSIZE = HASH_SIZE)
    static const char * StaticAlgorithmName()
    {
        return "IdentityHash";
    }

    IdentityHash() : m_digest(HASH_SIZE), m_idx(0) {}

    virtual unsigned int DigestSize() const
    {
        return DIGESTSIZE;
    }

    virtual void Update(const byte *input, size_t length)
    {
        size_t s = STDMIN(STDMIN<size_t>(DIGESTSIZE, length),
                                         DIGESTSIZE - m_idx);    
        if (s)
            ::memcpy(&m_digest[m_idx], input, s);
        m_idx += s;
    }

    virtual void TruncatedFinal(byte *digest, size_t digestSize)
    {
        if (m_idx != DIGESTSIZE)
            throw Exception(Exception::OTHER_ERROR, "Input size must be " + IntToString(DIGESTSIZE));

        ThrowIfInvalidTruncatedSize(digestSize);

        if (digest)
            ::memcpy(digest, m_digest, digestSize);

        m_idx = 0;
    }

private:
    SecByteBlock m_digest;
    size_t m_idx;
};

int main(int argc, char* argv[])
{
    AutoSeededRandomPool prng;

    ECDSA<ECP, IdentityHash<32> >::PrivateKey privateKey;
    privateKey.Initialize(prng, ASN1::secp256r1());

    std::string message;
    message.resize(IdentityHash<32>::DIGESTSIZE);
    ::memset(&message[0], 0xAA, message.size());

    ECDSA<ECP, IdentityHash<32> >::Signer signer(privateKey);
    std::string signature;

    StringSource ss(message, true,
                        new SignerFilter(prng, signer,
                            new HexEncoder(new StringSink(signature))
                        ) // SignerFilter
                    ); // StringSource

    std::cout << "Signature: " << signature << std::endl;

    return 0;
}

我知道它编译并生成输出。我不知道输出是否正确:

skylake:cryptopp$ g++ test.cxx ./libcryptopp.a -o test.exe
skylake:cryptopp$ ./test.exe
Signature: cafb8fca487c7d5023fbc76ccf96f107f72a07fecca77254e8845a2c8f2ed0ee8b50b
8ee0702beb7572eaa30c8d250a7b082c79f2f02e58ccfb97d7091755e91

你可以测试 识别灰烬 具有以下内容。班级 识别灰烬 与上一个示例没有更改。这个 main

$ cat test.cxx
#include "cryptlib.h"
#include "secblock.h"

#include <iostream>
#include <string>

using namespace CryptoPP;

template <unsigned int HASH_SIZE = 32>
class IdentityHash : public HashTransformation
{
public:
    CRYPTOPP_CONSTANT(DIGESTSIZE = HASH_SIZE)
    static const char * StaticAlgorithmName()
    {
        return "IdentityHash";
    }

    IdentityHash() : m_digest(HASH_SIZE), m_idx(0) {}

    virtual unsigned int DigestSize() const
    {
        return DIGESTSIZE;
    }

    virtual void Update(const byte *input, size_t length)
    {
        size_t s = STDMIN(STDMIN<size_t>(DIGESTSIZE, length),
                                         DIGESTSIZE - m_idx);    
        if (s)
            ::memcpy(&m_digest[m_idx], input, s);
        m_idx += s;
    }

    virtual void TruncatedFinal(byte *digest, size_t digestSize)
    {
        if (m_idx != DIGESTSIZE)
            throw Exception(Exception::OTHER_ERROR, "Input size must be " + IntToString(DIGESTSIZE));

        ThrowIfInvalidTruncatedSize(digestSize);

        if (digest)
            ::memcpy(digest, m_digest, digestSize);

        m_idx = 0;
    }

private:
    SecByteBlock m_digest;
    size_t m_idx;
};

int main(int argc, char* argv[])
{
    std::string message;
    message.resize(IdentityHash<32>::DIGESTSIZE);
    ::memset(&message[0], 'A', message.size());

    IdentityHash<32> hash;
    hash.Update((const byte*)message.data(), message.size());

    std::string digest(32, 0);
    hash.TruncatedFinal((byte*)digest.data(), digest.size());

    std::cout << "Message: " << message << std::endl;
    std::cout << " Digest: " << digest << std::endl;

    return 0;
}

skylake:cryptopp$ g++ test.cxx ./libcryptopp.a -o test.exe
skylake:cryptopp$ ./test.exe
Message: AAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAA
 Digest: AAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAA