fast-import: add mode to sign commits with invalid signatures

index 479c4081da..b3f42d4637 100644 --- a/Documentation/git-fast-import.adoc +++ b/Documentation/git-fast-import.adoc @@ -86,6 +86,10 @@ already trusted to run their own code. * `strip-if-invalid` will check signatures and, if they are invalid, will strip them and display a warning. The validation is performed in the same way as linkgit:git-verify-commit[1] does it. +* `sign-if-invalid[=<keyid>]`, similar to `strip-if-invalid`, verifies + commit signatures and replaces invalid signatures with newly created ones. + Valid signatures are left unchanged. If `<keyid>` is provided, that key is + used for signing; otherwise the configured default signing key is used. Options for Frontends ~~~~~~~~~~~~~~~~~~~~~

index 0c5d2386d8..13621b0d6a 100644 --- a/builtin/fast-export.c +++ b/builtin/fast-export.c @@ -64,7 +64,7 @@ static int parse_opt_sign_mode(const struct option *opt, if (unset) return 0; - if (parse_sign_mode(arg, val)) + if (parse_sign_mode(arg, val, NULL)) return error(_("unknown %s mode: %s"), opt->long_name, arg); return 0; @@ -825,6 +825,9 @@ static void handle_commit(struct commit *commit, struct rev_info *rev, case SIGN_STRIP_IF_INVALID: die(_("'strip-if-invalid' is not a valid mode for " "git fast-export with --signed-commits=<mode>")); + case SIGN_SIGN_IF_INVALID: + die(_("'sign-if-invalid' is not a valid mode for " + "git fast-export with --signed-commits=<mode>")); default: BUG("invalid signed_commit_mode value %d", signed_commit_mode); } @@ -970,6 +973,9 @@ static void handle_tag(const char *name, struct tag *tag) case SIGN_STRIP_IF_INVALID: die(_("'strip-if-invalid' is not a valid mode for " "git fast-export with --signed-tags=<mode>")); + case SIGN_SIGN_IF_INVALID: + die(_("'sign-if-invalid' is not a valid mode for " + "git fast-export with --signed-tags=<mode>")); default: BUG("invalid signed_commit_mode value %d", signed_commit_mode); }

index b8a7757cfd..935e688e33 100644 --- a/builtin/fast-import.c +++ b/builtin/fast-import.c @@ -190,6 +190,7 @@ static const char *global_prefix; static enum sign_mode signed_tag_mode = SIGN_VERBATIM; static enum sign_mode signed_commit_mode = SIGN_VERBATIM; +static const char *signed_commit_keyid; /* Memory pools */ static struct mem_pool fi_mem_pool = { @@ -2836,26 +2837,15 @@ static void finalize_commit_buffer(struct strbuf *new_data, strbuf_addbuf(new_data, msg); } -static void handle_strip_if_invalid(struct strbuf *new_data, - struct signature_data *sig_sha1, - struct signature_data *sig_sha256, - struct strbuf *msg) +static void warn_invalid_signature(struct signature_check *check, + const char *msg, enum sign_mode mode) { - struct strbuf tmp_buf = STRBUF_INIT; - struct signature_check signature_check = { 0 }; - int ret; - - /* Check signature in a temporary commit buffer */ - strbuf_addbuf(&tmp_buf, new_data); - finalize_commit_buffer(&tmp_buf, sig_sha1, sig_sha256, msg); - ret = verify_commit_buffer(tmp_buf.buf, tmp_buf.len, &signature_check); - - if (ret) { - const char *signer = signature_check.signer ? - signature_check.signer : _("unknown"); - const char *subject; - int subject_len = find_commit_subject(msg->buf, &subject); + const char *signer = check->signer ? check->signer : _("unknown"); + const char *subject; + int subject_len = find_commit_subject(msg, &subject); + switch (mode) { + case SIGN_STRIP_IF_INVALID: if (subject_len > 100) warning(_("stripping invalid signature for commit '%.100s...'\n" " allegedly by %s"), subject, signer); @@ -2865,6 +2855,67 @@ static void handle_strip_if_invalid(struct strbuf *new_data, else warning(_("stripping invalid signature for commit\n" " allegedly by %s"), signer); + break; + case SIGN_SIGN_IF_INVALID: + if (subject_len > 100) + warning(_("replacing invalid signature for commit '%.100s...'\n" + " allegedly by %s"), subject, signer); + else if (subject_len > 0) + warning(_("replacing invalid signature for commit '%.*s'\n" + " allegedly by %s"), subject_len, subject, signer); + else + warning(_("replacing invalid signature for commit\n" + " allegedly by %s"), signer); + break; + default: + BUG("unsupported signing mode"); + } +} + +static void handle_signature_if_invalid(struct strbuf *new_data, + struct signature_data *sig_sha1, + struct signature_data *sig_sha256, + struct strbuf *msg, + enum sign_mode mode) +{ + struct strbuf tmp_buf = STRBUF_INIT; + struct signature_check signature_check = { 0 }; + int ret; + + /* Check signature in a temporary commit buffer */ + strbuf_addbuf(&tmp_buf, new_data); + finalize_commit_buffer(&tmp_buf, sig_sha1, sig_sha256, msg); + ret = verify_commit_buffer(tmp_buf.buf, tmp_buf.len, &signature_check); + + if (ret) { + warn_invalid_signature(&signature_check, msg->buf, mode); + + if (mode == SIGN_SIGN_IF_INVALID) { + struct strbuf signature = STRBUF_INIT; + struct strbuf payload = STRBUF_INIT; + + /* + * NEEDSWORK: To properly support interoperability mode + * when signing commit signatures, the commit buffer + * must be provided in both the repository and + * compatibility object formats. As currently + * implemented, only the repository object format is + * considered meaning compatibility signatures cannot be + * generated. Thus, attempting to sign commit signatures + * in interoperability mode is currently unsupported. + */ + if (the_repository->compat_hash_algo) + die(_("signing commits in interoperability mode is unsupported")); + + strbuf_addstr(&payload, signature_check.payload); + if (sign_buffer(&payload, &signature, signed_commit_keyid, + SIGN_BUFFER_USE_DEFAULT_KEY)) + die(_("failed to sign commit object")); + add_header_signature(new_data, &signature, the_hash_algo); + + strbuf_release(&signature); + strbuf_release(&payload); + } finalize_commit_buffer(new_data, NULL, NULL, msg); } else { @@ -2927,6 +2978,7 @@ static void parse_new_commit(const char *arg) /* fallthru */ case SIGN_VERBATIM: case SIGN_STRIP_IF_INVALID: + case SIGN_SIGN_IF_INVALID: import_one_signature(&sig_sha1, &sig_sha256, v); break; @@ -3011,9 +3063,11 @@ static void parse_new_commit(const char *arg) "encoding %s\n", encoding); - if (signed_commit_mode == SIGN_STRIP_IF_INVALID && + if ((signed_commit_mode == SIGN_STRIP_IF_INVALID || + signed_commit_mode == SIGN_SIGN_IF_INVALID) && (sig_sha1.hash_algo || sig_sha256.hash_algo)) - handle_strip_if_invalid(&new_data, &sig_sha1, &sig_sha256, &msg); + handle_signature_if_invalid(&new_data, &sig_sha1, &sig_sha256, + &msg, signed_commit_mode); else finalize_commit_buffer(&new_data, &sig_sha1, &sig_sha256, &msg); @@ -3060,6 +3114,9 @@ static void handle_tag_signature(struct strbuf *msg, const char *name) case SIGN_STRIP_IF_INVALID: die(_("'strip-if-invalid' is not a valid mode for " "git fast-import with --signed-tags=<mode>")); + case SIGN_SIGN_IF_INVALID: + die(_("'sign-if-invalid' is not a valid mode for " + "git fast-import with --signed-tags=<mode>")); default: BUG("invalid signed_tag_mode value %d from tag '%s'", signed_tag_mode, name); @@ -3649,10 +3706,10 @@ static int parse_one_option(const char *option) } else if (skip_prefix(option, "export-pack-edges=", &option)) { option_export_pack_edges(option); } else if (skip_prefix(option, "signed-commits=", &option)) { - if (parse_sign_mode(option, &signed_commit_mode)) + if (parse_sign_mode(option, &signed_commit_mode, &signed_commit_keyid)) usagef(_("unknown --signed-commits mode '%s'"), option); } else if (skip_prefix(option, "signed-tags=", &option)) { - if (parse_sign_mode(option, &signed_tag_mode)) + if (parse_sign_mode(option, &signed_tag_mode, NULL)) usagef(_("unknown --signed-tags mode '%s'"), option); } else if (!strcmp(option, "quiet")) { show_stats = 0;

index 27eacbb632..d517425034 100644 --- a/gpg-interface.c +++ b/gpg-interface.c @@ -1152,21 +1152,28 @@ out: return ret; } -int parse_sign_mode(const char *arg, enum sign_mode *mode) +int parse_sign_mode(const char *arg, enum sign_mode *mode, const char **keyid) { - if (!strcmp(arg, "abort")) + if (!strcmp(arg, "abort")) { *mode = SIGN_ABORT; - else if (!strcmp(arg, "verbatim") || !strcmp(arg, "ignore")) + } else if (!strcmp(arg, "verbatim") || !strcmp(arg, "ignore")) { *mode = SIGN_VERBATIM; - else if (!strcmp(arg, "warn-verbatim") || !strcmp(arg, "warn")) + } else if (!strcmp(arg, "warn-verbatim") || !strcmp(arg, "warn")) { *mode = SIGN_WARN_VERBATIM; - else if (!strcmp(arg, "warn-strip")) + } else if (!strcmp(arg, "warn-strip")) { *mode = SIGN_WARN_STRIP; - else if (!strcmp(arg, "strip")) + } else if (!strcmp(arg, "strip")) { *mode = SIGN_STRIP; - else if (!strcmp(arg, "strip-if-invalid")) + } else if (!strcmp(arg, "strip-if-invalid")) { *mode = SIGN_STRIP_IF_INVALID; - else + } else if (!strcmp(arg, "sign-if-invalid")) { + *mode = SIGN_SIGN_IF_INVALID; + } else if (skip_prefix(arg, "sign-if-invalid=", &arg)) { + *mode = SIGN_SIGN_IF_INVALID; + if (keyid) + *keyid = arg; + } else { return -1; + } return 0; }

index 37f3ac42db..a365586ce1 100644 --- a/gpg-interface.h +++ b/gpg-interface.h @@ -120,12 +120,15 @@ enum sign_mode { SIGN_WARN_STRIP, SIGN_STRIP, SIGN_STRIP_IF_INVALID, + SIGN_SIGN_IF_INVALID, }; /* * Return 0 if `arg` can be parsed into an `enum sign_mode`. Return -1 - * otherwise. + * otherwise. If the parsed mode is SIGN_SIGN_IF_INVALID and GPG key provided in + * the arguments in the form `sign-if-invalid=<keyid>`, the key-ID is parsed + * into `char **keyid`. */ -int parse_sign_mode(const char *arg, enum sign_mode *mode); +int parse_sign_mode(const char *arg, enum sign_mode *mode, const char **keyid); #endif

index 022dae02e4..ac4228127a 100755 --- a/t/t9305-fast-import-signatures.sh +++ b/t/t9305-fast-import-signatures.sh @@ -103,71 +103,111 @@ test_expect_success GPG 'strip both OpenPGP signatures with --signed-commits=war test_line_count = 2 out ' -test_expect_success GPG 'import commit with no signature with --signed-commits=strip-if-invalid' ' - git fast-export main >output && - git -C new fast-import --quiet --signed-commits=strip-if-invalid <output >log 2>&1 && - test_must_be_empty log -' - -test_expect_success GPG 'keep valid OpenPGP signature with --signed-commits=strip-if-invalid' ' - rm -rf new && - git init new && - - git fast-export --signed-commits=verbatim openpgp-signing >output && - git -C new fast-import --quiet --signed-commits=strip-if-invalid <output >log 2>&1 && - IMPORTED=$(git -C new rev-parse --verify refs/heads/openpgp-signing) && - test $OPENPGP_SIGNING = $IMPORTED && - git -C new cat-file commit "$IMPORTED" >actual && - test_grep -E "^gpgsig(-sha256)? " actual && - test_must_be_empty log -' - -test_expect_success GPG 'strip signature invalidated by message change with --signed-commits=strip-if-invalid' ' +for mode in strip-if-invalid sign-if-invalid +do + test_expect_success GPG "import commit with no signature with --signed-commits=$mode" ' + git fast-export main >output && + git -C new fast-import --quiet --signed-commits=$mode <output >log 2>&1 && + test_must_be_empty log + ' + + test_expect_success GPG "keep valid OpenPGP signature with --signed-commits=$mode" ' + rm -rf new && + git init new && + + git fast-export --signed-commits=verbatim openpgp-signing >output && + git -C new fast-import --quiet --signed-commits=$mode <output >log 2>&1 && + IMPORTED=$(git -C new rev-parse --verify refs/heads/openpgp-signing) && + test $OPENPGP_SIGNING = $IMPORTED && + git -C new cat-file commit "$IMPORTED" >actual && + test_grep -E "^gpgsig(-sha256)? " actual && + test_must_be_empty log + ' + + test_expect_success GPG "handle signature invalidated by message change with --signed-commits=$mode" ' + rm -rf new && + git init new && + + git fast-export --signed-commits=verbatim openpgp-signing >output && + + # Change the commit message, which invalidates the signature. + # The commit message length should not change though, otherwise the + # corresponding `data <length>` command would have to be changed too. + sed "s/OpenPGP signed commit/OpenPGP forged commit/" output >modified && + + git -C new fast-import --quiet --signed-commits=$mode <modified >log 2>&1 && + + IMPORTED=$(git -C new rev-parse --verify refs/heads/openpgp-signing) && + test $OPENPGP_SIGNING != $IMPORTED && + git -C new cat-file commit "$IMPORTED" >actual && + + if test "$mode" = strip-if-invalid + then + test_grep "stripping invalid signature" log && + test_grep ! -E "^gpgsig" actual + else + test_grep "replacing invalid signature" log && + test_grep -E "^gpgsig(-sha256)? " actual && + git -C new verify-commit "$IMPORTED" + fi + ' + + test_expect_success GPGSM "keep valid X.509 signature with --signed-commits=$mode" ' + rm -rf new && + git init new && + + git fast-export --signed-commits=verbatim x509-signing >output && + git -C new fast-import --quiet --signed-commits=$mode <output >log 2>&1 && + IMPORTED=$(git -C new rev-parse --verify refs/heads/x509-signing) && + test $X509_SIGNING = $IMPORTED && + git -C new cat-file commit "$IMPORTED" >actual && + test_grep -E "^gpgsig(-sha256)? " actual && + test_must_be_empty log + ' + + test_expect_success GPGSSH "keep valid SSH signature with --signed-commits=$mode" ' + rm -rf new && + git init new && + + test_config -C new gpg.ssh.allowedSignersFile "${GPGSSH_ALLOWED_SIGNERS}" && + + git fast-export --signed-commits=verbatim ssh-signing >output && + git -C new fast-import --quiet --signed-commits=$mode <output >log 2>&1 && + IMPORTED=$(git -C new rev-parse --verify refs/heads/ssh-signing) && + test $SSH_SIGNING = $IMPORTED && + git -C new cat-file commit "$IMPORTED" >actual && + test_grep -E "^gpgsig(-sha256)? " actual && + test_must_be_empty log + ' +done + +test_expect_success GPGSSH "sign invalid commit with explicit keyid" ' rm -rf new && git init new && - git fast-export --signed-commits=verbatim openpgp-signing >output && + git fast-export --signed-commits=verbatim ssh-signing >output && # Change the commit message, which invalidates the signature. # The commit message length should not change though, otherwise the # corresponding `data <length>` command would have to be changed too. - sed "s/OpenPGP signed commit/OpenPGP forged commit/" output >modified && - - git -C new fast-import --quiet --signed-commits=strip-if-invalid <modified >log 2>&1 && - - IMPORTED=$(git -C new rev-parse --verify refs/heads/openpgp-signing) && - test $OPENPGP_SIGNING != $IMPORTED && - git -C new cat-file commit "$IMPORTED" >actual && - test_grep ! -E "^gpgsig" actual && - test_grep "stripping invalid signature" log -' - -test_expect_success GPGSM 'keep valid X.509 signature with --signed-commits=strip-if-invalid' ' - rm -rf new && - git init new && - - git fast-export --signed-commits=verbatim x509-signing >output && - git -C new fast-import --quiet --signed-commits=strip-if-invalid <output >log 2>&1 && - IMPORTED=$(git -C new rev-parse --verify refs/heads/x509-signing) && - test $X509_SIGNING = $IMPORTED && - git -C new cat-file commit "$IMPORTED" >actual && - test_grep -E "^gpgsig(-sha256)? " actual && - test_must_be_empty log -' - -test_expect_success GPGSSH 'keep valid SSH signature with --signed-commits=strip-if-invalid' ' - rm -rf new && - git init new && + sed "s/SSH signed commit/SSH forged commit/" output >modified && + # Configure the target repository with an invalid default signing key. + test_config -C new user.signingkey "not-a-real-key-id" && + test_config -C new gpg.format ssh && test_config -C new gpg.ssh.allowedSignersFile "${GPGSSH_ALLOWED_SIGNERS}" && + test_must_fail git -C new fast-import --quiet \ + --signed-commits=sign-if-invalid <modified >/dev/null 2>&1 && + + # Import using explicitly provided signing key. + git -C new fast-import --quiet \ + --signed-commits=sign-if-invalid="${GPGSSH_KEY_PRIMARY}" <modified && - git fast-export --signed-commits=verbatim ssh-signing >output && - git -C new fast-import --quiet --signed-commits=strip-if-invalid <output >log 2>&1 && IMPORTED=$(git -C new rev-parse --verify refs/heads/ssh-signing) && - test $SSH_SIGNING = $IMPORTED && + test $SSH_SIGNING != $IMPORTED && git -C new cat-file commit "$IMPORTED" >actual && test_grep -E "^gpgsig(-sha256)? " actual && - test_must_be_empty log + git -C new verify-commit "$IMPORTED" ' test_done