hash.h

Go to the documentation of this file.

#ifndef HASH_H__
#define HASH_H__
#include "block.h"
#include "config.h"
#include <openssl/sha.h>
#include <stdio.h>
#include "utils_ec.h"
class Hash {
    SHA_CTX hash;
    char buffer[HASH_BUFFER_SIZE];
    int size = 0;
    public:
    static const int DIGEST_SIZE = 20;
    Hash() {
        SHA1_Init(&hash);
    }
    ~Hash() {
    }
    void put(const void * data, int nbyte) {
        if (nbyte > HASH_BUFFER_SIZE)
            SHA1_Update(&hash, data, nbyte);
        else if(size + nbyte < HASH_BUFFER_SIZE) {
            memcpy(buffer+size, data, nbyte);
            size+=nbyte;
        } else {
            SHA1_Update(&hash, (char*)buffer, size);
            memcpy(buffer, data, nbyte);
            size = nbyte;
        }
    }
    void put_block(const block* block, int nblock=1){
        put(block, sizeof(block)*nblock);
    }
    void digest(char * a) {
        if(size > 0) {
            SHA1_Update(&hash, (char*)buffer, size);
            size=0;
        }
        SHA1_Final((unsigned char *)a, &hash);
    }
    void reset() {
        SHA1_Init(&hash);
        size=0;
    }
    static void hash_once(void * digest, const void * data, int nbyte) {
        (void )SHA1((const unsigned char *)data, nbyte, (unsigned char *)digest);
    }
    static block hash_for_block(const void * data, int nbyte) {
        char digest[20];
        hash_once(digest, data, nbyte);
        return _mm_load_si128((__m128i*)&digest[0]);
    }
    void put_eb(const eb_t * eb, int length) {
        uint8_t buffer[100];//large enough to hold one.
        for(int i = 0; i < length; ++i) {
            int eb_size = eb_size_bin(eb[i], false);
            eb_write_bin(buffer, eb_size, eb[i], false);
            put(buffer, eb_size);
        }
    }
};
#endif// HASH_H__