// sha1_check(data)
// to return the sha1 of the data (given in the format returned by
// read_file).
//
// sha1_check(data, sha1_hex, [sha1_hex, ...])
// returns the sha1 of the file if it matches any of the hex
// strings passed, or "" if it does not equal any of them.
//
Value* Sha1CheckFn(const char* name, State* state, int argc, Expr* argv[]) {
if (argc < 1) {
return ErrorAbort(state, "%s() expects at least 1 arg", name);
}
Value** args = ReadValueVarArgs(state, argc, argv);
if (args == NULL) {
return NULL;
}
if (args[0]->size < 0) {
fprintf(stderr, "%s(): no file contents received", name);
return StringValue(strdup(""));
}
uint8_t digest[SHA_DIGEST_SIZE];
SHA(args[0]->data, args[0]->size, digest);
FreeValue(args[0]);
if (argc == 1) {
return StringValue(PrintSha1(digest));
}
int i;
uint8_t* arg_digest = malloc(SHA_DIGEST_SIZE);
for (i = 1; i < argc; ++i) {
if (args[i]->type != VAL_STRING) {
fprintf(stderr, "%s(): arg %d is not a string; skipping",
name, i);
} else if (ParseSha1(args[i]->data, arg_digest) != 0) {
// Warn about bad args and skip them.
fprintf(stderr, "%s(): error parsing \"%s\" as sha-1; skipping",
name, args[i]->data);
} else if (memcmp(digest, arg_digest, SHA_DIGEST_SIZE) == 0) {
break;
}
FreeValue(args[i]);
}
if (i >= argc) {
// Didn't match any of the hex strings; return false.
return StringValue(strdup(""));
}
// Found a match; free all the remaining arguments and return the
// matched one.
int j;
for (j = i+1; j < argc; ++j) {
FreeValue(args[j]);
}
return args[i];
}
Value* RangeSha1Fn(const char* name, State* state, int argc, Expr* argv[]) {
Value* blockdev_filename;
Value* ranges;
const uint8_t* digest = NULL;
if (ReadValueArgs(state, argv, 2, &blockdev_filename, &ranges) < 0) {
return NULL;
}
if (blockdev_filename->type != VAL_STRING) {
ErrorAbort(state, "blockdev_filename argument to %s must be string", name);
goto done;
}
if (ranges->type != VAL_STRING) {
ErrorAbort(state, "ranges argument to %s must be string", name);
goto done;
}
int fd = open(blockdev_filename->data, O_RDWR);
if (fd < 0) {
ErrorAbort(state, "failed to open %s: %s", blockdev_filename->data, strerror(errno));
goto done;
}
RangeSet* rs = parse_range(ranges->data);
uint8_t buffer[BLOCKSIZE];
SHA_CTX ctx;
SHA_init(&ctx);
int i, j;
for (i = 0; i < rs->count; ++i) {
check_lseek(fd, (off64_t)rs->pos[i*2] * BLOCKSIZE, SEEK_SET);
for (j = rs->pos[i*2]; j < rs->pos[i*2+1]; ++j) {
readblock(fd, buffer, BLOCKSIZE);
SHA_update(&ctx, buffer, BLOCKSIZE);
}
}
digest = SHA_final(&ctx);
close(fd);
done:
FreeValue(blockdev_filename);
FreeValue(ranges);
if (digest == NULL) {
return StringValue(strdup(""));
} else {
return StringValue(PrintSha1(digest));
}
}