base/libs/qdecoder/qHash.c

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/*
 * Copyright 2008 The qDecoder Project. All rights reserved.
 *
 * Redistribution and use in source and binary forms, with or without
 * modification, are permitted provided that the following conditions
 * are met:
 *
 * 1. Redistributions of source code must retain the above copyright
 *    notice, this list of conditions and the following disclaimer.
 * 2. Redistributions in binary form must reproduce the above copyright
 *    notice, this list of conditions and the following disclaimer in the
 *    documentation and/or other materials provided with the distribution.
 *
 * THIS SOFTWARE IS PROVIDED BY THE QDECODER PROJECT ``AS IS'' AND ANY
 * EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED
 * WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE
 * DISCLAIMED. IN NO EVENT SHALL THE QDECODER PROJECT BE LIABLE FOR ANY
 * DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES
 * (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES;
 * LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND
 * ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
 * (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF
 * THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
 */

#include <stdio.h>
#include <stdlib.h>
#include <stdbool.h>
#include <string.h>
#include <unistd.h>
#include <fcntl.h>
#include <sys/types.h>
#include <sys/stat.h>
#include "md5/md5_global.h"
#include "md5/md5.h"
#include "qDecoder.h"
#include "qInternal.h"

unsigned char *qHashMd5(const void *data, size_t nbytes) {
    if(data == NULL) return NULL;

    unsigned char *digest = (unsigned char*)malloc(sizeof(char) * (16 + 1));
    if (digest == NULL) return NULL;

    MD5_CTX context;
    MD5Init(&context);
    MD5Update(&context, (unsigned char*)data, (unsigned int)nbytes);
    MD5Final(digest, &context);
    digest[16] = '\0';

    return digest;
}

char *qHashMd5Str(const void *data, size_t nbytes) {
    if(data == NULL) return NULL;

    unsigned char *digest = qHashMd5(data, nbytes);
    if (digest == NULL) return NULL;

    char *md5hex = (char*)malloc(sizeof(char) * (16 * 2 + 1));
    if (md5hex == NULL) return NULL;

    int i;
    for (i = 0; i < 16; i++) {
        sprintf(md5hex + (i * 2), "%02x", digest[i]);
    }
    free(digest);

    return md5hex;
}

char *qHashMd5File(const char *filepath, size_t *nbytes) {
    int fd = open(filepath, O_RDONLY, 0);
    if (fd < 0) return NULL;

    struct stat st;
    if (fstat(fd, &st) < 0) return NULL;

    size_t size = st.st_size;
    if(nbytes != NULL) {
        if(*nbytes > size) *nbytes = size;
        else size = *nbytes;
    }

    MD5_CTX context;
    MD5Init(&context);
    ssize_t retr = 0;
    unsigned char buf[256*1024], szDigest[16];
    while (size > 0) {
        if (size > sizeof(buf)) retr = read(fd, buf, sizeof(buf));
        else retr = read(fd, buf, size);
        if (retr < 0) break;
        MD5Update(&context, buf, retr);
        size -= retr;
    }
    close(fd);
    MD5Final(szDigest, &context);

    if(nbytes != NULL) *nbytes -= size;

    char *md5hex = (char*)malloc(sizeof(char) * (16 * 2 + 1));
    if (md5hex == NULL) return NULL;

    int i;
    for (i = 0; i < 16; i++) {
        sprintf(md5hex + (i * 2), "%02x", szDigest[i]);
    }

    return md5hex;
}

unsigned int qHashFnv32(unsigned int max, const void *data, size_t nbytes) {
    if(data == NULL) return 0;

    unsigned char *dp;
    unsigned int hval = (unsigned int)0x811c9dc5;

    for (dp = (unsigned char *)data; *dp && nbytes > 0; dp++, nbytes--) {
        hval *= (unsigned int)0x01000193;
        hval ^= (unsigned int)*dp;
    }
    if (max > 0) hval %= max;

    return hval;
}

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