Shawn O. PearceIf the user has misconfigured `user.signingkey` in their .git/config or just doesn't have any secret keys on their keyring and they ask for a signed tag with `git tag -s` we better make sure the resulting tag was actually signed by gpg.
Prior versions of builtin git-tag allowed this failure to slip by without error as they were not checking the return value of the finish_command() so they did not notice when gpg exited with an error exit status. They also did not fail if gpg produced an empty output or if read_in_full received an error from the read system call while trying to read the pipe back from gpg.
Finally we did not actually honor any return value from the do_sign function as it returns ssize_t but was being stored into an unsigned long. This caused the compiler to optimize out the die condition, allowing git-tag to continue along and create the tag object.
With these issues fixed `git-tag -s` will now fail to create the tag and will report a non-zero exit status to its caller, thereby allowing automated helper scripts to detect (and recover from) failure if gpg is not working properly.
Signed-off-by: Shawn O. Pearce <spearce@spearce.org> ---
I think this and my prior contrib/workdir patch should both go into maint. This one in particular; it hurt us today when an automated tool that runs `git tag -s` didn't notice the GnuPG problems.
builtin-tag.c | 8 +++++--- t/t7004-tag.sh | 7 +++++++ 2 files changed, 12 insertions(+), 3 deletions(-)
Show changes to 2 files +12 −3
builtin-tag.c, t/t7004-tag.sh
diff --git a/builtin-tag.c b/builtin-tag.c index 348919c..aadf850 100644 --- a/builtin-tag.c +++ b/builtin-tag.c @@ -217,7 +217,8 @@ static ssize_t do_sign(char *buffer, size_t size, size_t max) gpg.close_in = 0; len = read_in_full(gpg.out, buffer + size, max - size); - finish_command(&gpg); + if (finish_command(&gpg) || !len || len < 0) + return error("gpg failed to sign the tag"); if (len == max - size) return error("could not read the entire signature from gpg."); @@ -310,9 +311,10 @@ static void create_tag(const unsigned char *object, const char *tag, size += header_len; if (sign) { - size = do_sign(buffer, size, max_size); - if (size < 0) + ssize_t r = do_sign(buffer, size, max_size); + if (r < 0) die("unable to sign the tag"); + size = r; } if (write_sha1_file(buffer, size, tag_type, result) < 0) diff --git a/t/t7004-tag.sh b/t/t7004-tag.sh index 606d4f2..0d07bc3 100755 --- a/t/t7004-tag.sh +++ b/t/t7004-tag.sh @@ -990,6 +990,13 @@ test_expect_success \ git diff expect actual ' +# try to sign with bad user.signingkey +git config user.signingkey BobTheMouse +test_expect_failure \ + 'git-tag -s fails if gpg is misconfigured' \ + 'git tag -s -m tail tag-gpg-failure' +git config --unset user.signingkey + # try to verify without gpg: rm -rf gpghome
-- 1.5.3.1.840.g0fedbc
