source: MondoRescue/branches/stable/mindi-busybox/coreutils/md5_sha1_sum.c@ 902

/* vi: set sw=4 ts=4: */
/*
 *  Copyright (C) 2003 Glenn L. McGrath
 *  Copyright (C) 2003-2004 Erik Andersen
 *
 * Licensed under the GPL v2 or later, see the file LICENSE in this tarball.
 */

#include <fcntl.h>
#include <limits.h>
#include <stdio.h>
#include <stdint.h>
#include <stdlib.h>
#include <string.h>
#include <unistd.h>

#include "busybox.h"

typedef enum { HASH_SHA1, HASH_MD5 } hash_algo_t;

#define FLAG_SILENT 1
#define FLAG_CHECK  2
#define FLAG_WARN   4

/* This might be useful elsewhere */
static unsigned char *hash_bin_to_hex(unsigned char *hash_value,
                                      unsigned char hash_length)
{
    int x, len, max;
    unsigned char *hex_value;

    max = (hash_length * 2) + 2;
    hex_value = xmalloc(max);
    for (x = len = 0; x < hash_length; x++) {
        len += snprintf((char*)(hex_value + len), max - len, "%02x", hash_value[x]);
    }
    return (hex_value);
}

static uint8_t *hash_file(const char *filename, hash_algo_t hash_algo)
{
    int src_fd, hash_len, count;
    union _ctx_ {
        sha1_ctx_t sha1;
        md5_ctx_t md5;
    } context;
    uint8_t *hash_value = NULL;
    RESERVE_CONFIG_UBUFFER(in_buf, 4096);
    void (*update)(const void*, size_t, void*);
    void (*final)(void*, void*);

    if (strcmp(filename, "-") == 0) {
        src_fd = STDIN_FILENO;
    } else if(0 > (src_fd = open(filename, O_RDONLY))) {
        bb_perror_msg("%s", filename);
        return NULL;
    }

    /* figure specific hash algorithims */
    if (ENABLE_MD5SUM && hash_algo==HASH_MD5) {
        md5_begin(&context.md5);
        update = (void (*)(const void*, size_t, void*))md5_hash;
        final = (void (*)(void*, void*))md5_end;
        hash_len = 16;
    } else if (ENABLE_SHA1SUM && hash_algo==HASH_SHA1) {
        sha1_begin(&context.sha1);
        update = (void (*)(const void*, size_t, void*))sha1_hash;
        final = (void (*)(void*, void*))sha1_end;
        hash_len = 20;
    } else {
        bb_error_msg_and_die("algorithm not supported");
    }

    while (0 < (count = read(src_fd, in_buf, 4096))) {
        update(in_buf, count, &context);
    }

    if (count == 0) {
        final(in_buf, &context);
        hash_value = hash_bin_to_hex(in_buf, hash_len);
    }

    RELEASE_CONFIG_BUFFER(in_buf);

    if (src_fd != STDIN_FILENO) {
        close(src_fd);
    }

    return hash_value;
}

/* This could become a common function for md5 as well, by using md5_stream */
static int hash_files(int argc, char **argv, hash_algo_t hash_algo)
{
    int return_value = EXIT_SUCCESS;
    uint8_t *hash_value;
    unsigned int flags;

    if (ENABLE_FEATURE_MD5_SHA1_SUM_CHECK)
        flags = bb_getopt_ulflags(argc, argv, "scw");
    else optind = 1;

    if (ENABLE_FEATURE_MD5_SHA1_SUM_CHECK && !(flags & FLAG_CHECK)) {
        if (flags & FLAG_SILENT) {
            bb_error_msg_and_die
                ("the -s option is meaningful only when verifying checksums");
        } else if (flags & FLAG_WARN) {
            bb_error_msg_and_die
                ("the -w option is meaningful only when verifying checksums");
        }
    }

    if (argc == optind) {
        argv[argc++] = "-";
    }

    if (ENABLE_FEATURE_MD5_SHA1_SUM_CHECK && flags & FLAG_CHECK) {
        FILE *pre_computed_stream;
        int count_total = 0;
        int count_failed = 0;
        char *file_ptr = argv[optind];
        char *line;

        if (optind + 1 != argc) {
            bb_error_msg_and_die
                ("only one argument may be specified when using -c");
        }

        if (strcmp(file_ptr, "-") == 0) {
            pre_computed_stream = stdin;
        } else {
            pre_computed_stream = bb_xfopen(file_ptr, "r");
        }

        while ((line = bb_get_chomped_line_from_file(pre_computed_stream)) != NULL) {
            char *filename_ptr;

            count_total++;
            filename_ptr = strstr(line, "  ");
            if (filename_ptr == NULL) {
                if (flags & FLAG_WARN) {
                    bb_error_msg("Invalid format");
                }
                count_failed++;
                return_value = EXIT_FAILURE;
                free(line);
                continue;
            }
            *filename_ptr = '\0';
            filename_ptr += 2;

            hash_value = hash_file(filename_ptr, hash_algo);

            if (hash_value && (strcmp((char*)hash_value, line) == 0)) {
                if (!(flags & FLAG_SILENT))
                    printf("%s: OK\n", filename_ptr);
            } else {
                if (!(flags & FLAG_SILENT))
                    printf("%s: FAILED\n", filename_ptr);
                count_failed++;
                return_value = EXIT_FAILURE;
            }
            /* possible free(NULL) */
            free(hash_value);
            free(line);
        }
        if (count_failed && !(flags & FLAG_SILENT)) {
            bb_error_msg("WARNING: %d of %d computed checksums did NOT match",
                         count_failed, count_total);
        }
        if (bb_fclose_nonstdin(pre_computed_stream) == EOF) {
            bb_perror_msg_and_die("Couldnt close file %s", file_ptr);
        }
    } else {
        while (optind < argc) {
            char *file_ptr = argv[optind++];

            hash_value = hash_file(file_ptr, hash_algo);
            if (hash_value == NULL) {
                return_value = EXIT_FAILURE;
            } else {
                printf("%s  %s\n", hash_value, file_ptr);
                free(hash_value);
            }
        }
    }
    return (return_value);
}

#ifdef CONFIG_MD5SUM
int md5sum_main(int argc, char **argv)
{
    return (hash_files(argc, argv, HASH_MD5));
}
#endif

#ifdef CONFIG_SHA1SUM
int sha1sum_main(int argc, char **argv)
{
    return (hash_files(argc, argv, HASH_SHA1));
}
#endif