From: Luke Shumaker <lukeshu@xxxxxxxxxxx>
fast-export has an existing --signed-tags= flag that controls how to
handle tag signatures. However, there is no equivalent for commit
signatures; it just silently strips the signature out of the commit
(analogously to --signed-tags=strip).
While signatures are generally problematic for fast-export/fast-import
(because hashes are likely to change), if they're going to support tag
signatures, there's no reason to not also support commit signatures.
So, implement signed-commits.
On the fast-export side, try to be as much like signed-tags as possible,
in both implementation and in user-interface; with the exception that
the default should be `--signed-commits=strip` (compared to the default
`--signed-tags=abort`), in order to continue defaulting to the
historical behavior. Only bother implementing "gpgsig", not
"gpgsig-sha256"; the existing signed-tag support doesn't implement
"gpgsig-sha256" either.
On the fast-import side, I'm not entirely sure that I got the ordering
correct between "gpgsig" and "encoding" when generating the commit
object.
Signed-off-by: Luke Shumaker <lukeshu@xxxxxxxxxxx>
---
Documentation/git-fast-export.txt | 12 +++++
Documentation/git-fast-import.txt | 7 +++
builtin/fast-export.c | 86 +++++++++++++++++++++++++------
builtin/fast-import.c | 15 ++++++
t/t9350-fast-export.sh | 70 +++++++++++++++++++++++++
5 files changed, 174 insertions(+), 16 deletions(-)
diff --git a/Documentation/git-fast-export.txt b/Documentation/git-fast-export.txt
index d4a2bfe037..6fdb678b54 100644
--- a/Documentation/git-fast-export.txt
+++ b/Documentation/git-fast-export.txt
@@ -39,6 +39,18 @@ warning will be displayed, with 'verbatim', they will be silently
exported and with 'warn-verbatim', they will be exported, but you will
see a warning.
+--signed-commits=(verbatim|warn-verbatim|warn-strip|strip|abort)::
+ Specify how to handle signed commits. Since any transformation
+ after the export can change the commit (which can also happen
+ when excluding revisions) the signatures will not match.
++
+When asking to 'abort', this program will die when encountering a
+signed commit. With 'strip' (which is the default), the commits will
+silently be made unsigned, with 'warn-strip' they will be made
+unsigned but a warning will be displayed, with 'verbatim', they will
+be silently exported and with 'warn-verbatim', they will be exported,
+but you will see a warning.
+
--tag-of-filtered-object=(abort|drop|rewrite)::
Specify how to handle tags whose tagged object is filtered out.
Since revisions and files to export can be limited by path,
diff --git a/Documentation/git-fast-import.txt b/Documentation/git-fast-import.txt
index 458af0a2d6..3d0c5dbf7d 100644
--- a/Documentation/git-fast-import.txt
+++ b/Documentation/git-fast-import.txt
@@ -437,6 +437,7 @@ change to the project.
original-oid?
('author' (SP <name>)? SP LT <email> GT SP <when> LF)?
'committer' (SP <name>)? SP LT <email> GT SP <when> LF
+ ('gpgsig' LF data)?
('encoding' SP <encoding> LF)?
data
('from' SP <commit-ish> LF)?
@@ -505,6 +506,12 @@ that was selected by the --date-format=<fmt> command-line option.
See ``Date Formats'' above for the set of supported formats, and
their syntax.
+`gpgsig`
+^^^^^^^^
+
+The optional `gpgsig` command is used to include a PGP/GPG signature
+that signs the commit data.
+
`encoding`
^^^^^^^^^^
The optional `encoding` command indicates the encoding of the commit
diff --git a/builtin/fast-export.c b/builtin/fast-export.c
index d121dd2ee6..d48adbc9b9 100644
--- a/builtin/fast-export.c
+++ b/builtin/fast-export.c
@@ -30,8 +30,11 @@ static const char *fast_export_usage[] = {
NULL
};
+enum sign_mode { SIGN_ABORT, SIGN_VERBATIM, SIGN_STRIP, SIGN_VERBATIM_WARN, SIGN_STRIP_WARN };
+
static int progress;
-static enum { SIGNED_TAG_ABORT, VERBATIM, WARN, WARN_STRIP, STRIP } signed_tag_mode = SIGNED_TAG_ABORT;
+static enum sign_mode signed_tag_mode = SIGN_ABORT;
+static enum sign_mode signed_commit_mode = SIGN_STRIP;
static enum { TAG_FILTERING_ABORT, DROP, REWRITE } tag_of_filtered_mode = TAG_FILTERING_ABORT;
static enum { REENCODE_ABORT, REENCODE_YES, REENCODE_NO } reencode_mode = REENCODE_ABORT;
static int fake_missing_tagger;
@@ -48,21 +51,24 @@ static int anonymize;
static struct hashmap anonymized_seeds;
static struct revision_sources revision_sources;
-static int parse_opt_signed_tag_mode(const struct option *opt,
+static int parse_opt_sign_mode(const struct option *opt,
const char *arg, int unset)
{
- if (unset || !strcmp(arg, "abort"))
- signed_tag_mode = SIGNED_TAG_ABORT;
+ enum sign_mode *valptr = opt->value;
+ if (unset)
+ return 0;
+ else if (!strcmp(arg, "abort"))
+ *valptr = SIGN_ABORT;
else if (!strcmp(arg, "verbatim") || !strcmp(arg, "ignore"))
- signed_tag_mode = VERBATIM;
+ *valptr = SIGN_VERBATIM;
else if (!strcmp(arg, "warn-verbatim") || !strcmp(arg, "warn"))
- signed_tag_mode = WARN;
+ *valptr = SIGN_VERBATIM_WARN;
else if (!strcmp(arg, "warn-strip"))
- signed_tag_mode = WARN_STRIP;
+ *valptr = SIGN_STRIP_WARN;
else if (!strcmp(arg, "strip"))
- signed_tag_mode = STRIP;
+ *valptr = SIGN_STRIP;
else
- return error("Unknown signed-tags mode: %s", arg);
+ return error("Unknown %s mode: %s", opt->long_name, arg);
return 0;
}
@@ -499,6 +505,28 @@ static void show_filemodify(struct diff_queue_struct *q,
}
}
+static const char *find_signature(const char *begin, const char *end)
+{
+ const char *needle = "\ngpgsig ";
+ char *bod, *eod, *eol;
+
+ bod = memmem(begin, end ? end - begin : strlen(begin),
+ needle, strlen(needle));
+ if (!bod)
+ return NULL;
+ bod += strlen(needle);
+ eod = strchrnul(bod, '\n');
+ while (eod[0] == '\n' && eod[1] == ' ') {
+ eod = strchrnul(eod+1, '\n');
+ }
+ *eod = '\0';
+
+ while ((eol = strstr(bod, "\n ")))
+ memmove(eol+1, eol+2, strlen(eol+1));
+
+ return bod;
+}
+
static const char *find_encoding(const char *begin, const char *end)
{
const char *needle = "\nencoding ";
@@ -621,7 +649,7 @@ static void handle_commit(struct commit *commit, struct rev_info *rev,
int saved_output_format = rev->diffopt.output_format;
const char *commit_buffer;
const char *author, *author_end, *committer, *committer_end;
- const char *encoding, *message;
+ const char *encoding, *signature, *message;
char *reencoded = NULL;
struct commit_list *p;
const char *refname;
@@ -644,6 +672,7 @@ static void handle_commit(struct commit *commit, struct rev_info *rev,
committer++;
committer_end = strchrnul(committer, '\n');
message = strstr(committer_end, "\n\n");
+ signature = find_signature(committer_end, message);
encoding = find_encoding(committer_end, message);
if (message)
message += 2;
@@ -703,6 +732,28 @@ static void handle_commit(struct commit *commit, struct rev_info *rev,
printf("%.*s\n%.*s\n",
(int)(author_end - author), author,
(int)(committer_end - committer), committer);
+ if (signature)
+ switch(signed_commit_mode) {
+ case SIGN_ABORT:
+ die("encountered signed commit %s; use "
+ "--signed-commits=<mode> to handle it",
+ oid_to_hex(&commit->object.oid));
+ case SIGN_VERBATIM_WARN:
+ warning("exporting signed commit %s",
+ oid_to_hex(&commit->object.oid));
+ /* fallthru */
+ case SIGN_VERBATIM:
+ printf("gpgsig\ndata %u\n%s",
+ (unsigned)strlen(signature),
+ signature);
+ break;
+ case SIGN_STRIP_WARN:
+ warning("stripping signature from commit %s",
+ oid_to_hex(&commit->object.oid));
+ /* fallthru */
+ case SIGN_STRIP:
+ break;
+ }
if (!reencoded && encoding)
printf("encoding %s\n", encoding);
printf("data %u\n%s",
@@ -830,21 +881,21 @@ static void handle_tag(const char *name, struct tag *tag)
"\n-----BEGIN PGP SIGNATURE-----\n");
if (signature)
switch(signed_tag_mode) {
- case SIGNED_TAG_ABORT:
+ case SIGN_ABORT:
die("encountered signed tag %s; use "
"--signed-tags=<mode> to handle it",
oid_to_hex(&tag->object.oid));
- case WARN:
+ case SIGN_VERBATIM_WARN:
warning("exporting signed tag %s",
oid_to_hex(&tag->object.oid));
/* fallthru */
- case VERBATIM:
+ case SIGN_VERBATIM:
break;
- case WARN_STRIP:
+ case SIGN_STRIP_WARN:
warning("stripping signature from tag %s",
oid_to_hex(&tag->object.oid));
/* fallthru */
- case STRIP:
+ case SIGN_STRIP:
message_size = signature + 1 - message;
break;
}
@@ -1197,7 +1248,10 @@ int cmd_fast_export(int argc, const char **argv, const char *prefix)
N_("show progress after <n> objects")),
OPT_CALLBACK(0, "signed-tags", &signed_tag_mode, N_("mode"),
N_("select handling of signed tags"),
- parse_opt_signed_tag_mode),
+ parse_opt_sign_mode),
+ OPT_CALLBACK(0, "signed-commits", &signed_commit_mode, N_("mode"),
+ N_("select handling of signed commits"),
+ parse_opt_sign_mode),
OPT_CALLBACK(0, "tag-of-filtered-object", &tag_of_filtered_mode, N_("mode"),
N_("select handling of tags that tag filtered objects"),
parse_opt_tag_of_filtered_mode),
diff --git a/builtin/fast-import.c b/builtin/fast-import.c
index 3afa81cf9a..74d08e09fd 100644
--- a/builtin/fast-import.c
+++ b/builtin/fast-import.c
@@ -2669,7 +2669,9 @@ static struct hash_list *parse_merge(unsigned int *count)
static void parse_new_commit(const char *arg)
{
+ static struct strbuf sig = STRBUF_INIT;
static struct strbuf msg = STRBUF_INIT;
+ struct string_list siglines = STRING_LIST_INIT_NODUP;
struct branch *b;
char *author = NULL;
char *committer = NULL;
@@ -2696,6 +2698,12 @@ static void parse_new_commit(const char *arg)
}
if (!committer)
die("Expected committer but didn't get one");
+ if (!strcmp(command_buf.buf, "gpgsig")) {
+ read_next_command();
+ parse_data(&sig, 0, NULL);
+ read_next_command();
+ } else
+ strbuf_setlen(&sig, 0);
if (skip_prefix(command_buf.buf, "encoding ", &v)) {
encoding = xstrdup(v);
read_next_command();
@@ -2769,8 +2777,15 @@ static void parse_new_commit(const char *arg)
strbuf_addf(&new_data,
"encoding %s\n",
encoding);
+ if (sig.len) {
+ strbuf_addstr(&new_data, "gpgsig ");
+ string_list_split_in_place(&siglines, sig.buf, '\n', -1);
+ strbuf_add_separated_string_list(&new_data, "\n ", &siglines);
+ strbuf_addch(&new_data, '\n');
+ }
strbuf_addch(&new_data, '\n');
strbuf_addbuf(&new_data, &msg);
+ string_list_clear(&siglines, 1);
free(author);
free(committer);
free(encoding);
diff --git a/t/t9350-fast-export.sh b/t/t9350-fast-export.sh
index db0e58b1e8..49a2827be2 100755
--- a/t/t9350-fast-export.sh
+++ b/t/t9350-fast-export.sh
@@ -8,6 +8,7 @@ GIT_TEST_DEFAULT_INITIAL_BRANCH_NAME=main
export GIT_TEST_DEFAULT_INITIAL_BRANCH_NAME
. ./test-lib.sh
+. "$TEST_DIRECTORY/lib-gpg.sh"
test_expect_success 'setup' '
@@ -278,9 +279,78 @@ test_expect_success 'signed-tags=warn-strip' '
test -s err
'
+test_expect_success GPG 'set up signed commit' '
+
+ # Generate a commit with both "gpgsig" and "encoding" set, so
+ # that we can test that fast-import gets the ordering correct
+ # between the two.
+ test_config i18n.commitEncoding ISO-8859-1 &&
+ git checkout -f -b commit-signing main &&
+ echo Sign your name > file-sign &&
+ git add file-sign &&
+ git commit -S -m "signed commit" &&
+ COMMIT_SIGNING=$(git rev-parse --verify commit-signing)
+
+'
+
+test_expect_success GPG 'signed-commits=abort' '
+
+ test_must_fail git fast-export --signed-commits=abort commit-signing
+
+'
+
+test_expect_success GPG 'signed-commits=verbatim' '
+
+ git fast-export --signed-commits=verbatim --reencode=no commit-signing >output &&
+ grep ^gpgsig output &&
+ grep "encoding ISO-8859-1" output &&
+ (cd new &&
+ git fast-import &&
+ test $COMMIT_SIGNING = $(git rev-parse --verify refs/heads/commit-signing)) <output
+
+'
+
+test_expect_success GPG 'signed-commits=warn-verbatim' '
+
+ git fast-export --signed-commits=warn-verbatim --reencode=no commit-signing >output 2>err &&
+ grep ^gpgsig output &&
+ grep "encoding ISO-8859-1" output &&
+ test -s err &&
+ (cd new &&
+ git fast-import &&
+ test $COMMIT_SIGNING = $(git rev-parse --verify refs/heads/commit-signing)) <output
+
+'
+
+test_expect_success GPG 'signed-commits=strip' '
+
+ git fast-export --signed-commits=strip --reencode=no commit-signing >output &&
+ ! grep ^gpgsig output &&
+ grep "^encoding ISO-8859-1" output &&
+ sed "s/commit-signing/commit-strip-signing/" output |
+ (cd new &&
+ git fast-import &&
+ test $COMMIT_SIGNING != $(git rev-parse --verify refs/heads/commit-strip-signing))
+
+'
+
+test_expect_success GPG 'signed-commits=warn-strip' '
+
+ git fast-export --signed-commits=warn-strip --reencode=no commit-signing >output 2>err &&
+ ! grep ^gpgsig output &&
+ grep "^encoding ISO-8859-1" output &&
+ test -s err &&
+ sed "s/commit-signing/commit-strip-signing/" output |
+ (cd new &&
+ git fast-import &&
+ test $COMMIT_SIGNING != $(git rev-parse --verify refs/heads/commit-strip-signing))
+
+'
+
test_expect_success 'setup submodule' '
git checkout -f main &&
+ { git update-ref -d refs/heads/commit-signing || true; } &&
mkdir sub &&
(
cd sub &&
--
2.31.1
