git-commit-vandalism/t/t7030-verify-tag.sh

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#!/bin/sh
test_description='signed tag tests'
. ./test-lib.sh
. "$TEST_DIRECTORY/lib-gpg.sh"
test_expect_success GPG 'create signed tags' '
echo 1 >file && git add file &&
test_tick && git commit -m initial &&
git tag -s -m initial initial &&
git branch side &&
echo 2 >file && test_tick && git commit -a -m second &&
git tag -s -m second second &&
git checkout side &&
echo 3 >elif && git add elif &&
test_tick && git commit -m "third on side" &&
git checkout master &&
test_tick && git merge -S side &&
git tag -s -m merge merge &&
echo 4 >file && test_tick && git commit -a -S -m "fourth unsigned" &&
git tag -a -m fourth-unsigned fourth-unsigned &&
test_tick && git commit --amend -S -m "fourth signed" &&
git tag -s -m fourth fourth-signed &&
echo 5 >file && test_tick && git commit -a -m "fifth" &&
git tag fifth-unsigned &&
git config commit.gpgsign true &&
echo 6 >file && test_tick && git commit -a -m "sixth" &&
git tag -a -m sixth sixth-unsigned &&
test_tick && git rebase -f HEAD^^ && git tag -s -m 6th sixth-signed HEAD^ &&
git tag -m seventh -s seventh-signed &&
echo 8 >file && test_tick && git commit -a -m eighth &&
git tag -uB7227189 -m eighth eighth-signed-alt
'
test_expect_success GPGSM 'create signed tags x509 ' '
test_config gpg.format x509 &&
test_config user.signingkey $GIT_COMMITTER_EMAIL &&
echo 9 >file && test_tick && git commit -a -m "ninth gpgsm-signed" &&
git tag -s -m ninth ninth-signed-x509
'
test_expect_success GPG 'verify and show signatures' '
(
for tag in initial second merge fourth-signed sixth-signed seventh-signed
do
git verify-tag $tag 2>actual &&
grep "Good signature from" actual &&
! grep "BAD signature from" actual &&
echo $tag OK || exit 1
done
) &&
(
for tag in fourth-unsigned fifth-unsigned sixth-unsigned
do
test_must_fail git verify-tag $tag 2>actual &&
! grep "Good signature from" actual &&
! grep "BAD signature from" actual &&
echo $tag OK || exit 1
done
) &&
(
for tag in eighth-signed-alt
do
git verify-tag $tag 2>actual &&
grep "Good signature from" actual &&
! grep "BAD signature from" actual &&
grep "not certified" actual &&
echo $tag OK || exit 1
done
)
'
test_expect_success GPGSM 'verify and show signatures x509' '
git verify-tag ninth-signed-x509 2>actual &&
grep "Good signature from" actual &&
! grep "BAD signature from" actual &&
echo ninth-signed-x509 OK
'
gpg-interface: add minTrustLevel as a configuration option Previously, signature verification for merge and pull operations checked if the key had a trust-level of either TRUST_NEVER or TRUST_UNDEFINED in verify_merge_signature(). If that was the case, the process die()d. The other code paths that did signature verification relied entirely on the return code from check_commit_signature(). And signatures made with a good key, irregardless of its trust level, was considered valid by check_commit_signature(). This difference in behavior might induce users to erroneously assume that the trust level of a key in their keyring is always considered by Git, even for operations where it is not (e.g. during a verify-commit or verify-tag). The way it worked was by gpg-interface.c storing the result from the key/signature status *and* the lowest-two trust levels in the `result` member of the signature_check structure (the last of these status lines that were encountered got written to `result`). These are documented in GPG under the subsection `General status codes` and `Key related`, respectively [1]. The GPG documentation says the following on the TRUST_ status codes [1]: """ These are several similar status codes: - TRUST_UNDEFINED <error_token> - TRUST_NEVER <error_token> - TRUST_MARGINAL [0 [<validation_model>]] - TRUST_FULLY [0 [<validation_model>]] - TRUST_ULTIMATE [0 [<validation_model>]] For good signatures one of these status lines are emitted to indicate the validity of the key used to create the signature. The error token values are currently only emitted by gpgsm. """ My interpretation is that the trust level is conceptionally different from the validity of the key and/or signature. That seems to also have been the assumption of the old code in check_signature() where a result of 'G' (as in GOODSIG) and 'U' (as in TRUST_NEVER or TRUST_UNDEFINED) were both considered a success. The two cases where a result of 'U' had special meaning were in verify_merge_signature() (where this caused git to die()) and in format_commit_one() (where it affected the output of the %G? format specifier). I think it makes sense to refactor the processing of TRUST_ status lines such that users can configure a minimum trust level that is enforced globally, rather than have individual parts of git (e.g. merge) do it themselves (except for a grace period with backward compatibility). I also think it makes sense to not store the trust level in the same struct member as the key/signature status. While the presence of a TRUST_ status code does imply that the signature is good (see the first paragraph in the included snippet above), as far as I can tell, the order of the status lines from GPG isn't well-defined; thus it would seem plausible that the trust level could be overwritten with the key/signature status if they were stored in the same member of the signature_check structure. This patch introduces a new configuration option: gpg.minTrustLevel. It consolidates trust-level verification to gpg-interface.c and adds a new `trust_level` member to the signature_check structure. Backward-compatibility is maintained by introducing a special case in verify_merge_signature() such that if no user-configurable gpg.minTrustLevel is set, then the old behavior of rejecting TRUST_UNDEFINED and TRUST_NEVER is enforced. If, on the other hand, gpg.minTrustLevel is set, then that value overrides the old behavior. Similarly, the %G? format specifier will continue show 'U' for signatures made with a key that has a trust level of TRUST_UNDEFINED or TRUST_NEVER, even though the 'U' character no longer exist in the `result` member of the signature_check structure. A new format specifier, %GT, is also introduced for users that want to show all possible trust levels for a signature. Another approach would have been to simply drop the trust-level requirement in verify_merge_signature(). This would also have made the behavior consistent with other parts of git that perform signature verification. However, requiring a minimum trust level for signing keys does seem to have a real-world use-case. For example, the build system used by the Qubes OS project currently parses the raw output from verify-tag in order to assert a minimum trust level for keys used to sign git tags [2]. [1] https://git.gnupg.org/cgi-bin/gitweb.cgi?p=gnupg.git;a=blob;f=doc/doc/DETAILS;h=bd00006e933ac56719b1edd2478ecd79273eae72;hb=refs/heads/master [2] https://github.com/QubesOS/qubes-builder/blob/9674c1991deef45b1a1b1c71fddfab14ba50dccf/scripts/verify-git-tag#L43 Signed-off-by: Hans Jerry Illikainen <hji@dyntopia.com> Signed-off-by: Junio C Hamano <gitster@pobox.com>
2019-12-27 14:55:57 +01:00
test_expect_success GPGSM 'verify and show signatures x509 with low minTrustLevel' '
test_config gpg.minTrustLevel undefined &&
git verify-tag ninth-signed-x509 2>actual &&
grep "Good signature from" actual &&
! grep "BAD signature from" actual &&
echo ninth-signed-x509 OK
'
test_expect_success GPGSM 'verify and show signatures x509 with matching minTrustLevel' '
test_config gpg.minTrustLevel fully &&
git verify-tag ninth-signed-x509 2>actual &&
grep "Good signature from" actual &&
! grep "BAD signature from" actual &&
echo ninth-signed-x509 OK
'
test_expect_success GPGSM 'verify and show signatures x509 with high minTrustLevel' '
test_config gpg.minTrustLevel ultimate &&
test_must_fail git verify-tag ninth-signed-x509 2>actual &&
grep "Good signature from" actual &&
! grep "BAD signature from" actual &&
echo ninth-signed-x509 OK
'
test_expect_success GPG 'detect fudged signature' '
git cat-file tag seventh-signed >raw &&
tests: make forging GPG signed commits and tags more robust A couple of test scripts create forged GPG signed commits or tags to check that such forgery can't fool various git commands' signature verification. All but one of those test scripts are prone to occasional failures because the forgery creates a bogus GPG signature, and git commands error out with an unexpected error message, e.g. "Commit deadbeef does not have a GPG signature" instead of "... has a bad GPG signature". 't5573-pull-verify-signatures.sh', 't7510-signed-commit.sh' and 't7612-merge-verify-signatures.sh' create forged signed commits like this: git commit -S -m "bad on side" && git cat-file commit side-bad >raw && sed -e "s/bad/forged bad/" raw >forged && git hash-object -w -t commit forged >forged.commit On rare occasions the given pattern occurs not only in the commit message but in the GPG signature as well, and after it's replaced in the signature the resulting signature becomes invalid, GPG will report CRC error and that it couldn't find any signature, which will then ultimately cause the test failure. Since in all three cases the pattern to be replaced during the forgery is the first word of the commit message's subject line, and since the GPG signature in the commit object is indented by a space, let's just anchor those patterns to the beginning of the line to prevent this issue. The test script 't7030-verify-tag.sh' creates a forged signed tag object in a similar way by replacing the pattern "seventh", but the GPG signature in tag objects is not indented by a space, so the above solution is not applicable in this case. However, in the tag object in question the pattern "seventh" occurs not only in the tag message but in the 'tag' header as well. To create a forged tag object it's sufficient to replace only one of the two occurences, so modify the sed script to limit the pattern to the 'tag' header (i.e. a line beginning with "tag ", which, because of the space character, can never occur in the base64-encoded GPG signature). Note that the forgery in 't7004-tag.sh' is not affected by this issue: while 't7004' does create a forged signed tag kind of the same way, it replaces "signed-tag" in the tag object, which, because of the '-' character, can never occur in the base64-encoded GPG signarute. Signed-off-by: SZEDER Gábor <szeder.dev@gmail.com> Signed-off-by: Junio C Hamano <gitster@pobox.com>
2018-06-04 15:39:26 +02:00
sed -e "/^tag / s/seventh/7th forged/" raw >forged1 &&
git hash-object -w -t tag forged1 >forged1.tag &&
test_must_fail git verify-tag $(cat forged1.tag) 2>actual1 &&
grep "BAD signature from" actual1 &&
! grep "Good signature from" actual1
'
test_expect_success GPG 'verify signatures with --raw' '
(
for tag in initial second merge fourth-signed sixth-signed seventh-signed
do
git verify-tag --raw $tag 2>actual &&
grep "GOODSIG" actual &&
! grep "BADSIG" actual &&
echo $tag OK || exit 1
done
) &&
(
for tag in fourth-unsigned fifth-unsigned sixth-unsigned
do
test_must_fail git verify-tag --raw $tag 2>actual &&
! grep "GOODSIG" actual &&
! grep "BADSIG" actual &&
echo $tag OK || exit 1
done
) &&
(
for tag in eighth-signed-alt
do
git verify-tag --raw $tag 2>actual &&
grep "GOODSIG" actual &&
! grep "BADSIG" actual &&
grep "TRUST_UNDEFINED" actual &&
echo $tag OK || exit 1
done
)
'
test_expect_success GPGSM 'verify signatures with --raw x509' '
git verify-tag --raw ninth-signed-x509 2>actual &&
grep "GOODSIG" actual &&
! grep "BADSIG" actual &&
echo ninth-signed-x509 OK
'
test_expect_success GPG 'verify multiple tags' '
tags="fourth-signed sixth-signed seventh-signed" &&
for i in $tags
do
git verify-tag -v --raw $i || return 1
done >expect.stdout 2>expect.stderr.1 &&
grep "^.GNUPG:." <expect.stderr.1 >expect.stderr &&
git verify-tag -v --raw $tags >actual.stdout 2>actual.stderr.1 &&
grep "^.GNUPG:." <actual.stderr.1 >actual.stderr &&
test_cmp expect.stdout actual.stdout &&
test_cmp expect.stderr actual.stderr
'
test_expect_success GPGSM 'verify multiple tags x509' '
tags="seventh-signed ninth-signed-x509" &&
for i in $tags
do
git verify-tag -v --raw $i || return 1
done >expect.stdout 2>expect.stderr.1 &&
grep "^.GNUPG:." <expect.stderr.1 >expect.stderr &&
git verify-tag -v --raw $tags >actual.stdout 2>actual.stderr.1 &&
grep "^.GNUPG:." <actual.stderr.1 >actual.stderr &&
test_cmp expect.stdout actual.stdout &&
test_cmp expect.stderr actual.stderr
'
t7004, t7030: fix here-doc syntax errors Jan Palus noticed that some here-doc are spelled incorrectly, resulting the entire remainder of the test snippet being slurped into the "expect" file as if it were data, e.g. in this sequence cat >expect <<EOF && ... expectation ... EOF git $cmd_being_tested >actual && test_cmp expect actual the last command of the test is "cat" that sends everything to 'expect' and succeeds. Fixing these issues in t7004 and t7030 reveals that "git tag -v" and "git verify-tag" with their --format option do not work as the test was expecting originally. Instead of showing both valid tags and tags with incorrect signatures on their output, tags that do not pass verification are omitted from the output. Another breakage that is uncovered is that these tests must be restricted to environment where gpg is available. Arguably, that is a safer behaviour, and because the format specifiers like %(tag) do not have a way to show if the signature verifies correctly, the command with the --format option cannot be used to get a list of tags annotated with their signature validity anyway. For now, let's fix the here-doc syntax, update the expectation to match the reality, and update the test prerequisite. Maybe later when we extend the --format language available to "git tag -v" and "git verify-tag" to include things like "%(gpg:status)", we may want to change the behaviour so that piping a list of tag names into xargs git verify-tag --format='%(gpg:status) %(tag)' becomes a good way to produce such a list, but that is a separate topic. Noticed-by: Jan Palus <jan.palus@gmail.com> Helped-by: Jeff King <peff@peff.net> Signed-off-by: Santiago Torres <santiago@nyu.edu> Signed-off-by: Junio C Hamano <gitster@pobox.com>
2017-03-23 23:28:47 +01:00
test_expect_success GPG 'verifying tag with --format' '
cat >expect <<-\EOF &&
tagname : fourth-signed
t7004, t7030: fix here-doc syntax errors Jan Palus noticed that some here-doc are spelled incorrectly, resulting the entire remainder of the test snippet being slurped into the "expect" file as if it were data, e.g. in this sequence cat >expect <<EOF && ... expectation ... EOF git $cmd_being_tested >actual && test_cmp expect actual the last command of the test is "cat" that sends everything to 'expect' and succeeds. Fixing these issues in t7004 and t7030 reveals that "git tag -v" and "git verify-tag" with their --format option do not work as the test was expecting originally. Instead of showing both valid tags and tags with incorrect signatures on their output, tags that do not pass verification are omitted from the output. Another breakage that is uncovered is that these tests must be restricted to environment where gpg is available. Arguably, that is a safer behaviour, and because the format specifiers like %(tag) do not have a way to show if the signature verifies correctly, the command with the --format option cannot be used to get a list of tags annotated with their signature validity anyway. For now, let's fix the here-doc syntax, update the expectation to match the reality, and update the test prerequisite. Maybe later when we extend the --format language available to "git tag -v" and "git verify-tag" to include things like "%(gpg:status)", we may want to change the behaviour so that piping a list of tag names into xargs git verify-tag --format='%(gpg:status) %(tag)' becomes a good way to produce such a list, but that is a separate topic. Noticed-by: Jan Palus <jan.palus@gmail.com> Helped-by: Jeff King <peff@peff.net> Signed-off-by: Santiago Torres <santiago@nyu.edu> Signed-off-by: Junio C Hamano <gitster@pobox.com>
2017-03-23 23:28:47 +01:00
EOF
git verify-tag --format="tagname : %(tag)" "fourth-signed" >actual &&
test_cmp expect actual
'
t7004, t7030: fix here-doc syntax errors Jan Palus noticed that some here-doc are spelled incorrectly, resulting the entire remainder of the test snippet being slurped into the "expect" file as if it were data, e.g. in this sequence cat >expect <<EOF && ... expectation ... EOF git $cmd_being_tested >actual && test_cmp expect actual the last command of the test is "cat" that sends everything to 'expect' and succeeds. Fixing these issues in t7004 and t7030 reveals that "git tag -v" and "git verify-tag" with their --format option do not work as the test was expecting originally. Instead of showing both valid tags and tags with incorrect signatures on their output, tags that do not pass verification are omitted from the output. Another breakage that is uncovered is that these tests must be restricted to environment where gpg is available. Arguably, that is a safer behaviour, and because the format specifiers like %(tag) do not have a way to show if the signature verifies correctly, the command with the --format option cannot be used to get a list of tags annotated with their signature validity anyway. For now, let's fix the here-doc syntax, update the expectation to match the reality, and update the test prerequisite. Maybe later when we extend the --format language available to "git tag -v" and "git verify-tag" to include things like "%(gpg:status)", we may want to change the behaviour so that piping a list of tag names into xargs git verify-tag --format='%(gpg:status) %(tag)' becomes a good way to produce such a list, but that is a separate topic. Noticed-by: Jan Palus <jan.palus@gmail.com> Helped-by: Jeff King <peff@peff.net> Signed-off-by: Santiago Torres <santiago@nyu.edu> Signed-off-by: Junio C Hamano <gitster@pobox.com>
2017-03-23 23:28:47 +01:00
test_expect_success GPG 'verifying a forged tag with --format should fail silently' '
test_must_fail git verify-tag --format="tagname : %(tag)" $(cat forged1.tag) >actual-forged &&
test_must_be_empty actual-forged
'
test_done