// Read a file into memory; optionally (retouch_flag == RETOUCH_DO_MASK) mask
// the retouched entries back to their original value (such that SHA-1 checks
// don't fail due to randomization); store the file contents and associated
// metadata in *file.
//
// Return 0 on success.
int LoadFileContents(const char* filename, FileContents* file,
int retouch_flag) {
file->data = NULL;
// A special 'filename' beginning with "MTD:" or "EMMC:" means to
// load the contents of a partition.
if (strncmp(filename, "MTD:", 4) == 0 ||
strncmp(filename, "EMMC:", 5) == 0) {
return LoadPartitionContents(filename, file);
}
if (stat(filename, &file->st) != 0) {
printf("failed to stat \"%s\": %s\n", filename, strerror(errno));
return -1;
}
file->size = file->st.st_size;
file->data = malloc(file->size);
FILE* f = fopen(filename, "rb");
if (f == NULL) {
printf("failed to open \"%s\": %s\n", filename, strerror(errno));
free(file->data);
file->data = NULL;
return -1;
}
ssize_t bytes_read = fread(file->data, 1, file->size, f);
if (bytes_read != file->size) {
printf("short read of \"%s\" (%ld bytes of %ld)\n",
filename, (long)bytes_read, (long)file->size);
free(file->data);
file->data = NULL;
return -1;
}
fclose(f);
// apply_patch[_check] functions are blind to randomization. Randomization
// is taken care of in [Undo]RetouchBinariesFn. If there is a mismatch
// within a file, this means the file is assumed "corrupt" for simplicity.
if (retouch_flag) {
int32_t desired_offset = 0;
if (retouch_mask_data(file->data, file->size,
&desired_offset, NULL) != RETOUCH_DATA_MATCHED) {
printf("error trying to mask retouch entries\n");
free(file->data);
file->data = NULL;
return -1;
}
}
SHA_hash(file->data, file->size, file->sha1);
return 0;
}
/*
* This function flashes a given image to the target partition. It verifies
* the target cheksum first, and will return if target has the desired hash.
* It checks the checksum of the given source image before flashing, and
* verifies the target partition afterwards. The function is idempotent.
* Returns zero on success.
*/
int applypatch_flash(const char* source_filename, const char* target_filename,
const char* target_sha1_str, size_t target_size) {
printf("flash %s: ", target_filename);
uint8_t target_sha1[SHA_DIGEST_SIZE];
if (ParseSha1(target_sha1_str, target_sha1) != 0) {
printf("failed to parse tgt-sha1 \"%s\"\n", target_sha1_str);
return 1;
}
FileContents source_file;
source_file.data = NULL;
std::string target_str(target_filename);
std::vector<std::string> pieces = android::base::Split(target_str, ":");
if (pieces.size() != 2 || (pieces[0] != "MTD" && pieces[0] != "EMMC")) {
printf("invalid target name \"%s\"", target_filename);
return 1;
}
// Load the target into the source_file object to see if already applied.
pieces.push_back(std::to_string(target_size));
pieces.push_back(target_sha1_str);
std::string fullname = android::base::Join(pieces, ':');
if (LoadPartitionContents(fullname.c_str(), &source_file) == 0 &&
memcmp(source_file.sha1, target_sha1, SHA_DIGEST_SIZE) == 0) {
// The early-exit case: the image was already applied, this partition
// has the desired hash, nothing for us to do.
printf("already %s\n", short_sha1(target_sha1).c_str());
free(source_file.data);
return 0;
}
if (LoadFileContents(source_filename, &source_file) == 0) {
if (memcmp(source_file.sha1, target_sha1, SHA_DIGEST_SIZE) != 0) {
// The source doesn't have desired checksum.
printf("source \"%s\" doesn't have expected sha1 sum\n", source_filename);
printf("expected: %s, found: %s\n", short_sha1(target_sha1).c_str(),
short_sha1(source_file.sha1).c_str());
free(source_file.data);
return 1;
}
}
if (WriteToPartition(source_file.data, target_size, target_filename) != 0) {
printf("write of copied data to %s failed\n", target_filename);
free(source_file.data);
return 1;
}
free(source_file.data);
return 0;
}
// Read a file into memory; store the file contents and associated
// metadata in *file.
//
// Return 0 on success.
int LoadFileContents(const char* filename, FileContents* file) {
file->data = NULL;
// A special 'filename' beginning with "MTD:" or "EMMC:" means to
// load the contents of a partition.
if (strncmp(filename, "MTD:", 4) == 0 ||
strncmp(filename, "EMMC:", 5) == 0) {
return LoadPartitionContents(filename, file);
}
if (stat(filename, &file->st) != 0) {
printf("failed to stat \"%s\": %s\n", filename, strerror(errno));
return -1;
}
file->size = file->st.st_size;
file->data = malloc(file->size);
FILE* f = fopen(filename, "rb");
if (f == NULL) {
printf("failed to open \"%s\": %s\n", filename, strerror(errno));
free(file->data);
file->data = NULL;
return -1;
}
ssize_t bytes_read = fread(file->data, 1, file->size, f);
if (bytes_read != file->size) {
printf("short read of \"%s\" (%ld bytes of %ld)\n",
filename, (long)bytes_read, (long)file->size);
free(file->data);
file->data = NULL;
return -1;
}
fclose(f);
SHA_hash(file->data, file->size, file->sha1);
return 0;
}
