hash函数

macOS hash 函数封装

头文件 Hash.h

#ifndef Hash_h#define Hash_h#include <stdint.h>#include <vector>class Hash final {public:    enum struct Algorithm {        Md5,        Sha1,    };public:    typedef std::vector<uint8_t> Data;public:    static Data md5(const Data &data);    static Data sha1(const Data &data);public:    ~Hash();    explicit Hash(Algorithm alg);    Hash(Hash &&hash) noexcept;    Hash &operator=(Hash &&hash) noexcept;    void update(const Data &data);    Data final();private:    struct HashImpl *_impl = nullptr;};#endif /* Hash_h */

实现文件 Hash.cpp

#include "Hash.h"#include <CommonCrypto/CommonDigest.h>#include <assert.h>struct HashImpl {public:    virtual ~HashImpl() = default;    virtual void update(const Hash::Data &data) = 0;    virtual Hash::Data final() = 0;};class Md5Impl : public HashImpl {public:    Md5Impl()    {        CC_MD5_Init(&_ctx);    }    void update(const Hash::Data &data) override    {        CC_MD5_Update(&_ctx, data.data(), static_cast<CC_LONG>(data.size()));    }    Hash::Data final() override    {        unsigned char md[CC_MD5_DIGEST_LENGTH];        CC_MD5_Final(md, &_ctx);        return Hash::Data(std::cbegin(md), std::cend(md));    }private:    CC_MD5_CTX _ctx;};class Sha1Impl : public HashImpl {public:    Sha1Impl()    {        CC_SHA1_Init(&_ctx);    }    void update(const Hash::Data &data) override    {        CC_SHA1_Update(&_ctx, data.data(), static_cast<CC_LONG>(data.size()));    }    Hash::Data final() override    {        unsigned char md[CC_SHA1_DIGEST_LENGTH];        CC_SHA1_Final(md, &_ctx);        return Hash::Data(std::cbegin(md), std::cend(md));    }private:    CC_SHA1_CTX _ctx;};#pragma mark -Hash::~Hash(){    delete _impl;}Hash::Hash(Algorithm alg){    switch (alg) {    case Algorithm::Md5:        _impl = new Md5Impl();        break;    case Algorithm::Sha1:        _impl = new Sha1Impl();        break;    }}Hash::Hash(Hash &&hash) noexcept : _impl(hash._impl){    hash._impl = nullptr;}Hash &Hash::operator=(Hash &&hash) noexcept{    assert(&hash != this);    delete _impl;    _impl = hash._impl;    hash._impl = nullptr;    return *this;}void Hash::update(const Data &data){    _impl->update(data);}Hash::Data Hash::final(){    return _impl->final();}#pragma mark -Hash::Data Hash::md5(const Data &data){    Hash md5(Algorithm::Md5);    md5.update(data);    return md5.final();}Hash::Data Hash::sha1(const Data &data){    Hash sha1(Algorithm::Sha1);    sha1.update(data);    return sha1.final();}

示例

#include <string>#include "Hash.h"int main(){    std::string str = "hello, world";    Hash::Data data(str.cbegin(), str.cend());    auto md5 = Hash::md5(data);    // ...    auto sha1 = Hash::sha1(data);    // ...}