apt/test/libapt/openmaybeclearsignedfile_test.cc, branch 1.6_alpha6 Debians commandline package manager https://git.kalnischkies.de/apt/atom?h=1.6_alpha6 2018-01-02T22:39:30Z Support cleartext signed InRelease files with CRLF line endings 2018-01-02T22:39:30Z David Kalnischkies david@kalnischkies.de 2018-01-02T14:14:58Z urn:sha1:dcc0759fea4bf65d5477678e287880927d2cc9be Commit 89c4c588b275 ("fix from David Kalnischkies for the InRelease gpg verification code (LP: #784473)") amended verification of cleartext signatures by a check whether the file to be verified actually starts with "-----BEGIN PGP SIGNATURE-----\n". However cleartext signed InRelease files have been found in the wild which use \r\n as line ending for this armor header line, presumably generated by a Windows PGP client. Such files are incorrectly deemed unsigned and result in the following (misleading) error: Clearsigned file isn't valid, got 'NOSPLIT' (does the network require authentication?) RFC 4880 specifies in 6.2 Forming ASCII Armor: That is to say, there is always a line ending preceding the starting five dashes, and following the ending five dashes. The header lines, therefore, MUST start at the beginning of a line, and MUST NOT have text other than whitespace following them on the same line. RFC 4880 does not seem to specify whether LF or CRLF is used as line ending for armor headers, but CR is generally considered whitespace (e.g. "man perlrecharclass"), hence using CRLF is legal even under the assumption that LF must be used. SplitClearSignedFile() is stripping whitespace (including CR) on lineend already before matching the string, so StartsWithGPGClearTextSignature() is adapted to use the same ignoring. As the earlier method is responsible for what apt will end up actually parsing nowadays as signed/unsigned this change has no implications for security. Thanks: Lukas Wunner for detailed report & initial patch! References: 89c4c588b275d098af33f36eeddea6fd75068342 Closes: 884922 warn if clearsigned file has ignored content parts 2016-12-31T01:29:19Z David Kalnischkies david@kalnischkies.de 2016-12-16T18:50:48Z urn:sha1:6376dfb8dfb99b9d182c2fb13aa34b2ac89805e3 Clearsigned files like InRelease, .dsc, .changes and co can potentially include unsigned or additional messages blocks ignored by gpg in verification, but a potential source of trouble in our own parsing attempts – and an unneeded risk as the usecases for the clearsigned files we deal with do not reasonably include unsigned parts (like emails or some such). This commit changes the silent ignoring to warnings for now to get an impression on how widespread unintended unsigned parts are, but eventually we want to turn these into hard errors.