sha256_c_client/src/main.c

#include <stdint.h>
#include <stdlib.h>
#include <stdio.h>
#include <string.h>

#include "sha.h"

static void print_digest_words(const sha256_digest_t digest) {
    for (int i = 0; i < 8; ++i) {
        printf("%08x", digest[i]);
    }
    putchar('\n');
}

int main(void) {
    char path[4096] = {0};
    sha256_digest_t digest = {0};

    if (fgets(path, (int)sizeof(path), stdin) == NULL) {
        fprintf(stderr, "Failed to read file path from stdin\n");
        return 1;
    }

    path[strcspn(path, "\r\n")] = '\0';
    if (path[0] == '\0') {
        fprintf(stderr, "Empty file path\n");
        return 1;
    }

    FILE *fp = fopen(path, "rb");
    if (fp == NULL) {
        fprintf(stderr, "Failed to open file: %s\n", path);
        return 1;
    }

    if (_fseeki64(fp, 0, SEEK_END) != 0) {
        fprintf(stderr, "Failed to seek file end: %s\n", path);
        fclose(fp);
        return 1;
    }

    const long long file_size_ll = _ftelli64(fp);
    if (file_size_ll < 0) {
        fprintf(stderr, "Failed to get file size: %s\n", path);
        fclose(fp);
        return 1;
    }

    if (_fseeki64(fp, 0, SEEK_SET) != 0) {
        fprintf(stderr, "Failed to seek file start: %s\n", path);
        fclose(fp);
        return 1;
    }

    const uint64_t full_size = (uint64_t)file_size_ll;
    size_t alloc_size = (size_t)full_size;
    if ((uint64_t)alloc_size != full_size) {
        fprintf(stderr, "File is too large for this client: %s\n", path);
        fclose(fp);
        return 1;
    }
    if (alloc_size == 0) { 
        alloc_size = 1;
    }

    unsigned char *data = (unsigned char *)malloc(alloc_size);
    if (data == NULL) {
        fprintf(stderr, "Out of memory while reading: %s\n", path);
        fclose(fp);
        return 1;
    }

    if (full_size > 0) {
        const size_t read_size = fread(data, 1, (size_t)full_size, fp);
        if (read_size != (size_t)full_size) {
            fprintf(stderr, "Failed to read file: %s\n", path);
            free(data);
            fclose(fp);
            return 1;
        }
    }
    fclose(fp);

    void *rc = Sha256(data, full_size, full_size, digest, 1);
    free(data);
    if (rc != 0) {
        fprintf(stderr, "Sha256 failed, rc=%p\n", rc);
        return 1;
    }

    printf("Digest (library word order): ");
    print_digest_words(digest);

    return 0;
}