When --verify-signatures is specified on the command-line of git-merge
or git-pull, check whether the commits being merged have good gpg
signatures and abort the merge in case they do not. This allows e.g.
auto-deployment from untrusted repo hosts.
Signed-off-by: Sebastian Götte <jaseg@xxxxxxxxxxxxxxxxxxxxxxxx>
---
Documentation/merge-options.txt | 4 +++
builtin/merge.c | 31 ++++++++++++++++++++++-
git-pull.sh | 10 ++++++--
t/t7612-merge-verify-signatures.sh | 52 ++++++++++++++++++++++++++++++++++++++
4 files changed, 94 insertions(+), 3 deletions(-)
diff --git a/Documentation/merge-options.txt b/Documentation/merge-options.txt
index 0bcbe0a..2f76ab5 100644
--- a/Documentation/merge-options.txt
+++ b/Documentation/merge-options.txt
@@ -83,6 +83,10 @@ option can be used to override --squash.
Pass merge strategy specific option through to the merge
strategy.
+--verify-signatures::
+--no-verify-signatures::
+ Verify that the commits being merged have good trusted GPG signatures
+
--summary::
--no-summary::
Synonyms to --stat and --no-stat; these are deprecated and will be
diff --git a/builtin/merge.c b/builtin/merge.c
index 7c8922c..b3788aa 100644
--- a/builtin/merge.c
+++ b/builtin/merge.c
@@ -49,7 +49,7 @@ static const char * const builtin_merge_usage[] = {
static int show_diffstat = 1, shortlog_len = -1, squash;
static int option_commit = 1, allow_fast_forward = 1;
static int fast_forward_only, option_edit = -1;
-static int allow_trivial = 1, have_message;
+static int allow_trivial = 1, have_message, verify_signatures;
static int overwrite_ignore = 1;
static struct strbuf merge_msg = STRBUF_INIT;
static struct strategy **use_strategies;
@@ -199,6 +199,8 @@ static struct option builtin_merge_options[] = {
OPT_BOOLEAN(0, "ff-only", &fast_forward_only,
N_("abort if fast-forward is not possible")),
OPT_RERERE_AUTOUPDATE(&allow_rerere_auto),
+ OPT_BOOLEAN(0, "verify-signatures", &verify_signatures,
+ N_("Verify that the named commit has a valid GPG signature")),
OPT_CALLBACK('s', "strategy", &use_strategies, N_("strategy"),
N_("merge strategy to use"), option_parse_strategy),
OPT_CALLBACK('X', "strategy-option", &xopts, N_("option=value"),
@@ -1233,6 +1235,33 @@ int cmd_merge(int argc, const char **argv, const char *prefix)
usage_with_options(builtin_merge_usage,
builtin_merge_options);
+ if (verify_signatures) {
+ /* Verify the commit signatures */
+ for (p = remoteheads; p; p = p->next) {
+ struct commit *commit = p->item;
+ struct signature signature;
+ signature.check_result = 0;
+
+ check_commit_signature(commit, &signature);
+
+ char hex[41];
+ strcpy(hex, find_unique_abbrev(commit->object.sha1, DEFAULT_ABBREV));
+ switch(signature.check_result){
+ case 'G':
+ if (verbosity >= 0)
+ printf(_("Commit %s has a good GPG signature by %s\n"), hex, signature.signer);
+ break;
+ case 'B':
+ die(_("Commmit %s has a bad GPG signature allegedly by %s."), hex, signature.signer);
+ default: /* 'N' */
+ die(_("Commmit %s does not have a good GPG signature. In fact, commit %s does not have a GPG signature at all."), hex, hex);
+ }
+
+ free(signature.gpg_output);
+ free(signature.signer);
+ }
+ }
+
strbuf_addstr(&buf, "merge");
for (p = remoteheads; p; p = p->next)
strbuf_addf(&buf, " %s", merge_remote_util(p->item)->name);
diff --git a/git-pull.sh b/git-pull.sh
index 266e682..705940d 100755
--- a/git-pull.sh
+++ b/git-pull.sh
@@ -39,7 +39,7 @@ test -z "$(git ls-files -u)" || die_conflict
test -f "$GIT_DIR/MERGE_HEAD" && die_merge
strategy_args= diffstat= no_commit= squash= no_ff= ff_only=
-log_arg= verbosity= progress= recurse_submodules=
+log_arg= verbosity= progress= recurse_submodules= verify_signatures=
merge_args= edit=
curr_branch=$(git symbolic-ref -q HEAD)
curr_branch_short="${curr_branch#refs/heads/}"
@@ -125,6 +125,12 @@ do
--no-recurse-submodules)
recurse_submodules=--no-recurse-submodules
;;
+ --verify-signatures)
+ verify_signatures=--verify-signatures
+ ;;
+ --no-verify-signatures)
+ verify_signatures=--no-verify-signatures
+ ;;
--d|--dr|--dry|--dry-|--dry-r|--dry-ru|--dry-run)
dry_run=--dry-run
;;
@@ -283,7 +289,7 @@ true)
eval="$eval --onto $merge_head ${oldremoteref:-$merge_head}"
;;
*)
- eval="git-merge $diffstat $no_commit $edit $squash $no_ff $ff_only"
+ eval="git-merge $diffstat $no_commit $verify_signatures $edit $squash $no_ff $ff_only"
eval="$eval $log_arg $strategy_args $merge_args $verbosity $progress"
eval="$eval \"\$merge_name\" HEAD $merge_head"
;;
diff --git a/t/t7612-merge-verify-signatures.sh b/t/t7612-merge-verify-signatures.sh
new file mode 100755
index 0000000..31b67dd
--- /dev/null
+++ b/t/t7612-merge-verify-signatures.sh
@@ -0,0 +1,52 @@
+#!/bin/sh
+
+test_description='merge signature verification tests'
+. ./test-lib.sh
+. "$TEST_DIRECTORY/lib-gpg.sh"
+
+test_expect_success GPG 'create signed commits' '
+ echo 1 >file && git add file &&
+ test_tick && git commit -m initial &&
+ git tag initial &&
+
+ git checkout -b side-signed &&
+ echo 3 >elif && git add elif &&
+ test_tick && git commit -S -m "signed on side" &&
+ git checkout initial &&
+
+ git checkout -b side-unsigned &&
+ echo 3 >foo && git add foo &&
+ test_tick && git commit -m "unsigned on side" &&
+ git checkout initial &&
+
+ git checkout -b side-bad &&
+ echo 3 >bar && git add bar &&
+ test_tick && 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 &&
+ git checkout initial &&
+
+ git checkout master
+'
+
+test_expect_success GPG 'merge unsigned commit with verification' '
+ test_must_fail git merge --ff-only --verify-signatures side-unsigned 2> mergeerror &&
+ grep "does not have a GPG signature" mergeerror
+'
+
+test_expect_success GPG 'merge commit with bad signature with verification' '
+ test_must_fail git merge --ff-only --verify-signatures $(cat forged.commit) 2> mergeerror &&
+ grep "has a bad GPG signature" mergeerror
+'
+
+test_expect_success GPG 'merge signed commit with verification' '
+ git merge -v --ff-only --verify-signatures side-signed > mergeoutput &&
+ grep "has a good GPG signature" mergeoutput
+'
+
+test_expect_success GPG 'merge commit with bad signature without verification' '
+ git merge $(cat forged.commit)
+'
+
+test_done
--
1.8.1.5
--
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