+def hash_key(hashname):
+ return '%ssum' % hashname
+
+################################################################################
+
+def create_hash(where, files, hashname, hashfunc):
+ """
+ create_hash extends the passed files dict with the given hash by
+ iterating over all files on disk and passing them to the hashing
+ function given.
+ """
+
+ rejmsg = []
+ for f in files.keys():
+ try:
+ file_handle = open_file(f)
+ except CantOpenError:
+ rejmsg.append("Could not open file %s for checksumming" % (f))
+
+ files[f][hash_key(hashname)] = hashfunc(file_handle)
+
+ file_handle.close()
+ return rejmsg
+
+################################################################################
+
+def check_hash(where, files, hashname, hashfunc):
+ """
+ check_hash checks the given hash in the files dict against the actual
+ files on disk. The hash values need to be present consistently in
+ all file entries. It does not modify its input in any way.
+ """
+
+ rejmsg = []
+ for f in files.keys():
+ file_handle = None
+ try:
+ try:
+ file_handle = open_file(f)
+
+ # Check for the hash entry, to not trigger a KeyError.
+ if not files[f].has_key(hash_key(hashname)):
+ rejmsg.append("%s: misses %s checksum in %s" % (f, hashname,
+ where))
+ continue
+
+ # Actually check the hash for correctness.
+ if hashfunc(file_handle) != files[f][hash_key(hashname)]:
+ rejmsg.append("%s: %s check failed in %s" % (f, hashname,
+ where))
+ except CantOpenError:
+ # TODO: This happens when the file is in the pool.
+ # warn("Cannot open file %s" % f)
+ continue
+ finally:
+ if file_handle:
+ file_handle.close()
+ return rejmsg
+
+################################################################################
+
+def check_size(where, files):
+ """
+ check_size checks the file sizes in the passed files dict against the
+ files on disk.
+ """
+
+ rejmsg = []
+ for f in files.keys():
+ try:
+ entry = os.stat(f)
+ except OSError, exc:
+ if exc.errno == 2:
+ # TODO: This happens when the file is in the pool.
+ continue
+ raise
+
+ actual_size = entry[stat.ST_SIZE]
+ size = int(files[f]["size"])
+ if size != actual_size:
+ rejmsg.append("%s: actual file size (%s) does not match size (%s) in %s"
+ % (f, actual_size, size, where))
+ return rejmsg
+
+################################################################################
+
+def check_hash_fields(what, manifest):
+ """
+ check_hash_fields ensures that there are no checksum fields in the
+ given dict that we do not know about.
+ """
+
+ rejmsg = []
+ hashes = map(lambda x: x[0], known_hashes)
+ for field in manifest:
+ if field.startswith("checksums-"):
+ hashname = field.split("-",1)[1]
+ if hashname not in hashes:
+ rejmsg.append("Unsupported checksum field for %s "\
+ "in %s" % (hashname, what))
+ return rejmsg
+
+################################################################################
+
+def _ensure_changes_hash(changes, format, version, files, hashname, hashfunc):
+ if format >= version:
+ # The version should contain the specified hash.
+ func = check_hash
+
+ # Import hashes from the changes
+ rejmsg = parse_checksums(".changes", files, changes, hashname)
+ if len(rejmsg) > 0:
+ return rejmsg