diff --git a/contrib/pngexif/.editorconfig b/contrib/pngexif/.editorconfig new file mode 100644 index 000000000..ce8fbbfc1 --- /dev/null +++ b/contrib/pngexif/.editorconfig @@ -0,0 +1,11 @@ +# https://editorconfig.org + +root = true + +[*] +charset = utf-8 +indent_style = space +insert_final_newline = true +max_doc_length = 79 +max_line_length = 79 +trim_trailing_whitespace = true diff --git a/contrib/pngexif/.gitignore b/contrib/pngexif/.gitignore new file mode 100644 index 000000000..016f70a80 --- /dev/null +++ b/contrib/pngexif/.gitignore @@ -0,0 +1,3 @@ +__pycache__ +*.py[co] +*$py.class diff --git a/contrib/pngexif/.pylintrc b/contrib/pngexif/.pylintrc new file mode 100644 index 000000000..50cf1152d --- /dev/null +++ b/contrib/pngexif/.pylintrc @@ -0,0 +1,8 @@ +[COMPATIBILITY] +disable=consider-using-f-string + +[COMPLEXITY] +disable=too-many-branches,too-many-instance-attributes + +[STYLE] +disable=consider-using-in diff --git a/contrib/pngexif/LICENSE_MIT.txt b/contrib/pngexif/LICENSE_MIT.txt new file mode 100644 index 000000000..9cf106272 --- /dev/null +++ b/contrib/pngexif/LICENSE_MIT.txt @@ -0,0 +1,19 @@ +MIT License + +Permission is hereby granted, free of charge, to any person obtaining a copy +of this software and associated documentation files (the "Software"), to deal +in the Software without restriction, including without limitation the rights +to use, copy, modify, merge, publish, distribute, sublicense, and/or sell +copies of the Software, and to permit persons to whom the Software is +furnished to do so, subject to the following conditions: + +The above copyright notice and this permission notice shall be included in all +copies or substantial portions of the Software. + +THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR +IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY, +FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE +AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER +LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM, +OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE +SOFTWARE. diff --git a/contrib/pngexif/README.md b/contrib/pngexif/README.md new file mode 100644 index 000000000..c9ff88b64 --- /dev/null +++ b/contrib/pngexif/README.md @@ -0,0 +1,20 @@ +pngexifinfo +=========== + +Show the EXIF information embedded in a PNG file. + + +Sample usage +------------ + +Show the EXIF info inside a PNG file: + + pngexifinfo /path/to/file.png + +Show the EXIF info inside a raw `.exif` file, using base 16 for the EXIF tags: + + pngexifinfo --hex /path/to/file.exif + +Show the help text: + + pngexifinfo --help diff --git a/contrib/pngexif/bytepack.py b/contrib/pngexif/bytepack.py new file mode 100755 index 000000000..93af21994 --- /dev/null +++ b/contrib/pngexif/bytepack.py @@ -0,0 +1,48 @@ +#!/usr/bin/env python + +""" +Byte packing and unpacking utilities. + +Copyright (C) 2017-2020 Cosmin Truta. + +Use, modification and distribution are subject to the MIT License. +Please see the accompanying file LICENSE_MIT.txt +""" + +from __future__ import absolute_import, division, print_function + +import struct + + +def unpack_uint32be(buffer, offset=0): + """Unpack an unsigned int from its 32-bit big-endian representation.""" + return struct.unpack(">I", buffer[offset:offset + 4])[0] + + +def unpack_uint32le(buffer, offset=0): + """Unpack an unsigned int from its 32-bit little-endian representation.""" + return struct.unpack("H", buffer[offset:offset + 2])[0] + + +def unpack_uint16le(buffer, offset=0): + """Unpack an unsigned int from its 16-bit little-endian representation.""" + return struct.unpack(" "ascii" + value_or_offset >>= 24 + elif tag_type == 3: + # 3 --> "short" + value_or_offset >>= 16 + else: + # ... FIXME + pass + if count == 0: + raise RuntimeError("unsupported count=0 in tag 0x%x" % tag_id) + if tag_id == _TIFF_EXIF_IFD: + if tag_type != 4: + raise RuntimeError("incorrect tag type for EXIF IFD") + self._exif_ifd_offset = value_or_offset + elif tag_id == _GPS_IFD: + if tag_type != 4: + raise RuntimeError("incorrect tag type for GPS IFD") + self._gps_ifd_offset = value_or_offset + elif tag_id == _INTEROPERABILITY_IFD: + if tag_type != 4: + raise RuntimeError("incorrect tag type for Interop IFD") + self._interoperability_ifd_offset = value_or_offset + yield (tag_id, tag_type, count, value_or_offset) + + def tags(self): + """Yield all TIFF/EXIF tags.""" + if self._verbose: + print("TIFF IFD : 0x%08x" % self._global_ifd_offset) + for tag in self._tags_for_ifd(self._global_ifd_offset): + yield tag + if self._exif_ifd_offset > 0: + if self._verbose: + print("EXIF IFD : 0x%08x" % self._exif_ifd_offset) + for tag in self._tags_for_ifd(self._exif_ifd_offset): + yield tag + if self._gps_ifd_offset > 0: + if self._verbose: + print("GPS IFD : 0x%08x" % self._gps_ifd_offset) + for tag in self._tags_for_ifd(self._gps_ifd_offset): + yield tag + if self._interoperability_ifd_offset > 0: + if self._verbose: + print("Interoperability IFD : 0x%08x" % + self._interoperability_ifd_offset) + for tag in self._tags_for_ifd(self._interoperability_ifd_offset): + yield tag + + def tagid2str(self, tag_id): + """Return an informative string representation of a TIFF tag id.""" + idstr = _TIFF_TAGS.get(tag_id, "[Unknown]") + if self._hex: + idnum = "0x%04x" % tag_id + else: + idnum = "%d" % tag_id + return "%s (%s)" % (idstr, idnum) + + @staticmethod + def tagtype2str(tag_type): + """Return an informative string representation of a TIFF tag type.""" + typestr = _TIFF_TAG_TYPES.get(tag_type, "[unknown]") + return "%d:%s" % (tag_type, typestr) + + def tag2str(self, tag_id, tag_type, count, value_or_offset): + """Return an informative string representation of a TIFF tag tuple.""" + return "%s (type=%s) (count=%d) : 0x%08x" \ + % (self.tagid2str(tag_id), self.tagtype2str(tag_type), count, + value_or_offset) + + def _ui32(self): + """Decode a 32-bit unsigned int found at the current offset; + advance the offset by 4. + """ + if self._offset + 4 > len(self._buffer): + raise RuntimeError("out-of-bounds uint32 access in EXIF") + if self._endian == "MM": + result = unpack_uint32be(self._buffer, self._offset) + else: + result = unpack_uint32le(self._buffer, self._offset) + self._offset += 4 + return result + + def _ui16(self): + """Decode a 16-bit unsigned int found at the current offset; + advance the offset by 2. + """ + if self._offset + 2 > len(self._buffer): + raise RuntimeError("out-of-bounds uint16 access in EXIF") + if self._endian == "MM": + result = unpack_uint16be(self._buffer, self._offset) + else: + result = unpack_uint16le(self._buffer, self._offset) + self._offset += 2 + return result + + def _ui8(self): + """Decode an 8-bit unsigned int found at the current offset; + advance the offset by 1. + """ + if self._offset + 1 > len(self._buffer): + raise RuntimeError("out-of-bounds uint8 access in EXIF") + result = unpack_uint8(self._buffer, self._offset) + self._offset += 1 + return result + + +def print_raw_exif_info(buffer, **kwargs): + """Print the EXIF information found in a raw byte stream.""" + lister = ExifInfo(buffer, **kwargs) + print("EXIF (endian=%s)" % lister.endian()) + for (tag_id, tag_type, count, value_or_offset) in lister.tags(): + print(lister.tag2str(tag_id=tag_id, + tag_type=tag_type, + count=count, + value_or_offset=value_or_offset)) + + +if __name__ == "__main__": + # For testing only. + for arg in sys.argv[1:]: + with open(arg, "rb") as test_stream: + test_buffer = test_stream.read(_READ_DATA_SIZE_MAX) + print_raw_exif_info(test_buffer, hex=True, verbose=True) diff --git a/contrib/pngexif/pngexifinfo b/contrib/pngexif/pngexifinfo new file mode 100755 index 000000000..16f8eaab1 --- /dev/null +++ b/contrib/pngexif/pngexifinfo @@ -0,0 +1,10 @@ +#!/bin/sh +set -eu + +my_python="$(command -v python3 || command -v python)" || { + echo >&2 "error: program not found: Python interpreter" + exit 127 +} +my_python_flags="-BES" + +exec "$my_python" "$my_python_flags" "$(dirname "$0")/pngexifinfo.py" "$@" diff --git a/contrib/pngexif/pngexifinfo.bat b/contrib/pngexif/pngexifinfo.bat new file mode 100644 index 000000000..ab8bd358c --- /dev/null +++ b/contrib/pngexif/pngexifinfo.bat @@ -0,0 +1,4 @@ +@echo off +@setlocal enableextensions + +python.exe -BES %~dp0.\pngexifinfo.py %* diff --git a/contrib/pngexif/pngexifinfo.py b/contrib/pngexif/pngexifinfo.py new file mode 100755 index 000000000..37d4c4bcd --- /dev/null +++ b/contrib/pngexif/pngexifinfo.py @@ -0,0 +1,178 @@ +#!/usr/bin/env python + +""" +Show the PNG EXIF information. + +Copyright (C) 2017-2020 Cosmin Truta. + +Use, modification and distribution are subject to the MIT License. +Please see the accompanying file LICENSE_MIT.txt +""" + +from __future__ import absolute_import, division, print_function + +import argparse +import io +import re +import sys +import zlib + +from bytepack import unpack_uint32be, unpack_uint8 +from exifinfo import print_raw_exif_info + +_PNG_SIGNATURE = b"\x89PNG\x0d\x0a\x1a\x0a" +_PNG_CHUNK_SIZE_MAX = 0x7fffffff +_READ_DATA_SIZE_MAX = 0x3ffff + + +def print_error(msg): + """Print an error message to stderr.""" + sys.stderr.write("%s: error: %s\n" % (sys.argv[0], msg)) + + +def print_debug(msg): + """Print a debug message to stderr.""" + sys.stderr.write("%s: debug: %s\n" % (sys.argv[0], msg)) + + +def _check_png(condition, chunk_sig=None): + """Check a PNG-specific assertion.""" + if condition: + return + if chunk_sig is None: + raise RuntimeError("bad PNG data") + raise RuntimeError("bad PNG data in '%s'" % chunk_sig) + + +def _check_png_crc(data, checksum, chunk_sig): + """Check a CRC32 value inside a PNG stream.""" + if unpack_uint32be(data) == (checksum & 0xffffffff): + return + raise RuntimeError("bad PNG checksum in '%s'" % chunk_sig) + + +def _extract_png_exif(data, **kwargs): + """Extract the EXIF header and data from a PNG chunk.""" + debug = kwargs.get("debug", False) + if unpack_uint8(data, 0) == 0: + if debug: + print_debug("found compressed EXIF, compression method 0") + if (unpack_uint8(data, 1) & 0x0f) == 0x08: + data = zlib.decompress(data[1:]) + elif unpack_uint8(data, 1) == 0 \ + and (unpack_uint8(data, 5) & 0x0f) == 0x08: + if debug: + print_debug("found uncompressed-length EXIF field") + data_len = unpack_uint32be(data, 1) + data = zlib.decompress(data[5:]) + if data_len != len(data): + raise RuntimeError( + "incorrect uncompressed-length field in PNG EXIF") + else: + raise RuntimeError("invalid compression method in PNG EXIF") + if data.startswith(b"MM\x00\x2a") or data.startswith(b"II\x2a\x00"): + return data + raise RuntimeError("invalid TIFF/EXIF header in PNG EXIF") + + +def print_png_exif_info(instream, **kwargs): + """Print the EXIF information found in the given PNG datastream.""" + debug = kwargs.get("debug", False) + has_exif = False + while True: + chunk_hdr = instream.read(8) + _check_png(len(chunk_hdr) == 8) + chunk_len = unpack_uint32be(chunk_hdr, offset=0) + chunk_sig = chunk_hdr[4:8].decode("latin_1", errors="ignore") + _check_png(re.search(r"^[A-Za-z]{4}$", chunk_sig), chunk_sig=chunk_sig) + _check_png(chunk_len < _PNG_CHUNK_SIZE_MAX, chunk_sig=chunk_sig) + if debug: + print_debug("processing chunk: %s" % chunk_sig) + if chunk_len <= _READ_DATA_SIZE_MAX: + # The chunk size does not exceed an arbitrary, reasonable limit. + chunk_data = instream.read(chunk_len) + chunk_crc = instream.read(4) + _check_png(len(chunk_data) == chunk_len and len(chunk_crc) == 4, + chunk_sig=chunk_sig) + checksum = zlib.crc32(chunk_hdr[4:8]) + checksum = zlib.crc32(chunk_data, checksum) + _check_png_crc(chunk_crc, checksum, chunk_sig=chunk_sig) + else: + # The chunk is too big. Skip it. + instream.seek(chunk_len + 4, io.SEEK_CUR) + continue + if chunk_sig == "IEND": + _check_png(chunk_len == 0, chunk_sig=chunk_sig) + break + if chunk_sig.lower() in ["exif", "zxif"] and chunk_len > 8: + has_exif = True + exif_data = _extract_png_exif(chunk_data, **kwargs) + print_raw_exif_info(exif_data, **kwargs) + if not has_exif: + raise RuntimeError("no EXIF data in PNG stream") + + +def print_exif_info(file, **kwargs): + """Print the EXIF information found in the given file.""" + with open(file, "rb") as stream: + header = stream.read(4) + if header == _PNG_SIGNATURE[0:4]: + if stream.read(4) != _PNG_SIGNATURE[4:8]: + raise RuntimeError("corrupted PNG file") + print_png_exif_info(instream=stream, **kwargs) + elif header == b"II\x2a\x00" or header == b"MM\x00\x2a": + data = header + stream.read(_READ_DATA_SIZE_MAX) + print_raw_exif_info(data, **kwargs) + else: + raise RuntimeError("not a PNG file") + + +def main(): + """The main function.""" + parser = argparse.ArgumentParser( + prog="pngexifinfo", + usage="%(prog)s [options] [--] files...", + description="Show the PNG EXIF information.") + parser.add_argument("files", + metavar="file", + nargs="*", + help="a PNG file or a raw EXIF blob") + parser.add_argument("-x", + "--hex", + dest="hex", + action="store_true", + help="show EXIF tags in base 16") + parser.add_argument("-v", + "--verbose", + dest="verbose", + action="store_true", + help="run in verbose mode") + parser.add_argument("--debug", + dest="debug", + action="store_true", + help="run in debug mode") + args = parser.parse_args() + if not args.files: + parser.error("missing file operand") + result = 0 + for file in args.files: + try: + print_exif_info(file, + hex=args.hex, + debug=args.debug, + verbose=args.verbose) + except (IOError, OSError) as err: + print_error(str(err)) + result = 66 # os.EX_NOINPUT + except RuntimeError as err: + print_error("%s: %s" % (file, str(err))) + result = 69 # os.EX_UNAVAILABLE + parser.exit(result) + + +if __name__ == "__main__": + try: + main() + except KeyboardInterrupt: + sys.stderr.write("INTERRUPTED\n") + sys.exit(130) # SIGINT