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