sha512sum.c

#include <stdio.h>
#include <string.h>
#include <sys/types.h>
#include <sys/stat.h>
#include <sys/xattr.h>
#include <fcntl.h>
#include <time.h>
#include <unistd.h>
#include <openssl/sha.h>
#include <errno.h>
#include <limits.h>
#include <stdint.h>
#include "libhash.h"

#define BLOCKSIZE 4096
#define XATTR_SHA512HASH "trusted.sha512.control.lth.se"


struct __attribute__((__packed__)) hash_attr {
  time_t hash_time;
  time_t mtime;
  uint32_t mtime_nsec;
  uint8_t hash[SHA512_DIGEST_LENGTH];
};

int hash_sha512_buf(char *buf,
                 size_t length,
                 unsigned char *hash)
{
  SHA512_CTX ctx;
  
  SHA512_Init(&ctx);
  SHA512_Update(&ctx, buf, length);
  SHA512_Final(hash, &ctx);

  return 0;
}

int hash_sha512_file(char *filename,
                  time_t mtime,
                  int64_t mtime_nsec,
                  int flags,
                  time_t maxage,
                  unsigned char *hash)
{
  int fd;
  int result = 0, recalc = 1;
  struct hash_attr hash_attr;

  if (flags & FLAGS_CLEAR_XATTR) {
    if (removexattr(filename, XATTR_SHA512HASH) != 0) {
      if (errno != ENODATA) {
        result = -1;
        fprintf(stderr, "Failed to remove xattr '%s'\n", filename);
        goto out;
      } else if ((flags & FLAGS_VERBOSE_MASK) > FLAGS_VERBOSE2) {
        fprintf(stderr, "No xattr for '%s'\n", filename);
      }
    } else {
      if ((flags & FLAGS_VERBOSE_MASK) > FLAGS_VERBOSE2) {
        fprintf(stderr, "Removed xattr for '%s'\n", filename);
      }
    }
  }
  if (flags & FLAGS_NO_CALC_HASH) {
    // We should not calculate hash
    goto out;
  }

  if (flags & FLAGS_READ_XATTR) {