From mboxrd@z Thu Jan 1 00:00:00 1970 From: Junio C Hamano Subject: [PATCH v4 1/5] Split GPG interface into its own helper library Date: Wed, 19 Oct 2011 17:36:59 -0700 Message-ID: <1319071023-31919-2-git-send-email-gitster@pobox.com> References: <1318983645-18897-1-git-send-email-gitster@pobox.com> <1319071023-31919-1-git-send-email-gitster@pobox.com> To: git@vger.kernel.org X-From: git-owner@vger.kernel.org Thu Oct 20 02:37:20 2011 Return-path: Envelope-to: gcvg-git-2@lo.gmane.org Received: from vger.kernel.org ([209.132.180.67]) by lo.gmane.org with esmtp (Exim 4.69) (envelope-from ) id 1RGgdL-0007SN-Nm for gcvg-git-2@lo.gmane.org; Thu, 20 Oct 2011 02:37:20 +0200 Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1755667Ab1JTAhK (ORCPT ); Wed, 19 Oct 2011 20:37:10 -0400 Received: from b-pb-sasl-quonix.pobox.com ([208.72.237.35]:32947 "EHLO smtp.pobox.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1755501Ab1JTAhI (ORCPT ); Wed, 19 Oct 2011 20:37:08 -0400 Received: from smtp.pobox.com (unknown [127.0.0.1]) by b-sasl-quonix.pobox.com (Postfix) with ESMTP id 7D5776940 for ; Wed, 19 Oct 2011 20:37:07 -0400 (EDT) DKIM-Signature: v=1; a=rsa-sha1; c=relaxed; d=pobox.com; h=from:to :subject:date:message-id:in-reply-to:references; s=sasl; bh=aIYs nfqC+fUicVbtX97mufsvhSw=; b=toDkqDQTLUw3bZofbHMsdgAuUcvUmrx0jHk/ uabybuaWewgG++i4mqJtXN5o5LcwG2uB5doqB+/wsBNxcmg0IjB5Lp30idL0LegQ JVu05Nfx/pPvPlQfYXB58SR7P9I5CdKXypwxrRjmDGRdch/Ub+n5sVoAJFLQx2/z 2Mefpko= DomainKey-Signature: a=rsa-sha1; c=nofws; d=pobox.com; h=from:to:subject :date:message-id:in-reply-to:references; q=dns; s=sasl; b=V4P3wI TIt4a4mu8Ft3DI3Q/qsTeYYXb1badis2XgmNB6izgKMpiOWxM+7APHR4rt2xMDqr o/kB1bN9hdPrSZoVwEeyQg+biuFy+3QpTdtJ6LewfBgUIDk1Mv2lKTB/4LCIdS1P LnIIPzT1qIW0CL9wX98alS8rI1bg2pEK5YO24= Received: from b-pb-sasl-quonix.pobox.com (unknown [127.0.0.1]) by b-sasl-quonix.pobox.com (Postfix) with ESMTP id 75669693F for ; Wed, 19 Oct 2011 20:37:07 -0400 (EDT) Received: from pobox.com (unknown [76.102.170.102]) (using TLSv1 with cipher DHE-RSA-AES128-SHA (128/128 bits)) (No client certificate requested) by b-sasl-quonix.pobox.com (Postfix) with ESMTPSA id 9C965693E for ; Wed, 19 Oct 2011 20:37:06 -0400 (EDT) X-Mailer: git-send-email 1.7.7.498.g3f2e50 In-Reply-To: <1319071023-31919-1-git-send-email-gitster@pobox.com> X-Pobox-Relay-ID: A34667E6-FAB3-11E0-9B98-9DB42E706CDE-77302942!b-pb-sasl-quonix.pobox.com Sender: git-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: git@vger.kernel.org Archived-At: This mostly moves existing code from builtin/tag.c (for signing) and builtin/verify-tag.c (for verifying) to a new gpg-interface.c file to provide a more generic library interface. - sign_buffer() takes a payload strbuf, a signature strbuf, and a signing key, runs "gpg" to produce a detached signature for the payload, and appends it to the signature strbuf. The contents of a signed tag that concatenates the payload and the detached signature can be produced by giving the same strbuf as payload and signature strbuf. - verify_signed_buffer() takes a payload and a detached signature as pairs, and runs "gpg --verify" to see if the payload matches the signature. It can optionally capture the output from GPG to allow the callers to pretty-print it in a way more suitable for their contexts. "verify-tag" (aka "tag -v") used to save the whole tag contents as if it is a detached signature, and fed gpg the payload part of the tag. It relied on gpg to fail when the given tag is not signed but just is annotated. The updated run_gpg_verify() function detects the lack of detached signature in the input, and errors out without bothering "gpg". Signed-off-by: Junio C Hamano --- Makefile | 2 + builtin/tag.c | 76 ++------------------------- builtin/verify-tag.c | 35 ++----------- gpg-interface.c | 138 ++++++++++++++++++++++++++++++++++++++++++++++++++ gpg-interface.h | 10 ++++ tag.c | 5 ++ 6 files changed, 166 insertions(+), 100 deletions(-) create mode 100644 gpg-interface.c create mode 100644 gpg-interface.h diff --git a/Makefile b/Makefile index 8d6d451..2183223 100644 --- a/Makefile +++ b/Makefile @@ -530,6 +530,7 @@ LIB_H += exec_cmd.h LIB_H += fsck.h LIB_H += gettext.h LIB_H += git-compat-util.h +LIB_H += gpg-interface.h LIB_H += graph.h LIB_H += grep.h LIB_H += hash.h @@ -620,6 +621,7 @@ LIB_OBJS += entry.o LIB_OBJS += environment.o LIB_OBJS += exec_cmd.o LIB_OBJS += fsck.o +LIB_OBJS += gpg-interface.o LIB_OBJS += graph.o LIB_OBJS += grep.o LIB_OBJS += hash.o diff --git a/builtin/tag.c b/builtin/tag.c index 667515e..fb0d4a1 100644 --- a/builtin/tag.c +++ b/builtin/tag.c @@ -14,6 +14,7 @@ #include "parse-options.h" #include "diff.h" #include "revision.h" +#include "gpg-interface.h" static const char * const git_tag_usage[] = { "git tag [-a|-s|-u ] [-f] [-m |-F ] []", @@ -23,8 +24,6 @@ static const char * const git_tag_usage[] = { NULL }; -static char signingkey[1000]; - struct tag_filter { const char **patterns; int lines; @@ -208,60 +207,7 @@ static int verify_tag(const char *name, const char *ref, static int do_sign(struct strbuf *buffer) { - struct child_process gpg; - const char *args[4]; - char *bracket; - int len; - int i, j; - - if (!*signingkey) { - if (strlcpy(signingkey, git_committer_info(IDENT_ERROR_ON_NO_NAME), - sizeof(signingkey)) > sizeof(signingkey) - 1) - return error(_("committer info too long.")); - bracket = strchr(signingkey, '>'); - if (bracket) - bracket[1] = '\0'; - } - - /* When the username signingkey is bad, program could be terminated - * because gpg exits without reading and then write gets SIGPIPE. */ - signal(SIGPIPE, SIG_IGN); - - memset(&gpg, 0, sizeof(gpg)); - gpg.argv = args; - gpg.in = -1; - gpg.out = -1; - args[0] = "gpg"; - args[1] = "-bsau"; - args[2] = signingkey; - args[3] = NULL; - - if (start_command(&gpg)) - return error(_("could not run gpg.")); - - if (write_in_full(gpg.in, buffer->buf, buffer->len) != buffer->len) { - close(gpg.in); - close(gpg.out); - finish_command(&gpg); - return error(_("gpg did not accept the tag data")); - } - close(gpg.in); - len = strbuf_read(buffer, gpg.out, 1024); - close(gpg.out); - - if (finish_command(&gpg) || !len || len < 0) - return error(_("gpg failed to sign the tag")); - - /* Strip CR from the line endings, in case we are on Windows. */ - for (i = j = 0; i < buffer->len; i++) - if (buffer->buf[i] != '\r') { - if (i != j) - buffer->buf[j] = buffer->buf[i]; - j++; - } - strbuf_setlen(buffer, j); - - return 0; + return sign_buffer(buffer, buffer, get_signing_key()); } static const char tag_template[] = @@ -270,21 +216,11 @@ static const char tag_template[] = "# Write a tag message\n" "#\n"); -static void set_signingkey(const char *value) -{ - if (strlcpy(signingkey, value, sizeof(signingkey)) >= sizeof(signingkey)) - die(_("signing key value too long (%.10s...)"), value); -} - static int git_tag_config(const char *var, const char *value, void *cb) { - if (!strcmp(var, "user.signingkey")) { - if (!value) - return config_error_nonbool(var); - set_signingkey(value); - return 0; - } - + int status = git_gpg_config(var, value, cb); + if (status) + return status; return git_default_config(var, value, cb); } @@ -463,7 +399,7 @@ int cmd_tag(int argc, const char **argv, const char *prefix) if (keyid) { sign = 1; - set_signingkey(keyid); + set_signing_key(keyid); } if (sign) annotate = 1; diff --git a/builtin/verify-tag.c b/builtin/verify-tag.c index 3134766..28c2174 100644 --- a/builtin/verify-tag.c +++ b/builtin/verify-tag.c @@ -11,6 +11,7 @@ #include "run-command.h" #include #include "parse-options.h" +#include "gpg-interface.h" static const char * const verify_tag_usage[] = { "git verify-tag [-v|--verbose] ...", @@ -19,42 +20,16 @@ static const char * const verify_tag_usage[] = { static int run_gpg_verify(const char *buf, unsigned long size, int verbose) { - struct child_process gpg; - const char *args_gpg[] = {"gpg", "--verify", "FILE", "-", NULL}; - char path[PATH_MAX]; - size_t len; - int fd, ret; + int len; - fd = git_mkstemp(path, PATH_MAX, ".git_vtag_tmpXXXXXX"); - if (fd < 0) - return error("could not create temporary file '%s': %s", - path, strerror(errno)); - if (write_in_full(fd, buf, size) < 0) - return error("failed writing temporary file '%s': %s", - path, strerror(errno)); - close(fd); - - /* find the length without signature */ len = parse_signature(buf, size); if (verbose) write_in_full(1, buf, len); - memset(&gpg, 0, sizeof(gpg)); - gpg.argv = args_gpg; - gpg.in = -1; - args_gpg[2] = path; - if (start_command(&gpg)) { - unlink(path); - return error("could not run gpg."); - } - - write_in_full(gpg.in, buf, len); - close(gpg.in); - ret = finish_command(&gpg); + if (size == len) + return error("no signature found"); - unlink_or_warn(path); - - return ret; + return verify_signed_buffer(buf, len, buf + len, size - len, NULL); } static int verify_tag(const char *name, int verbose) diff --git a/gpg-interface.c b/gpg-interface.c new file mode 100644 index 0000000..ff232c8 --- /dev/null +++ b/gpg-interface.c @@ -0,0 +1,138 @@ +#include "cache.h" +#include "run-command.h" +#include "strbuf.h" +#include "gpg-interface.h" +#include "sigchain.h" + +static char *configured_signing_key; + +void set_signing_key(const char *key) +{ + free(configured_signing_key); + configured_signing_key = xstrdup(key); +} + +int git_gpg_config(const char *var, const char *value, void *cb) +{ + if (!strcmp(var, "user.signingkey")) { + if (!value) + return config_error_nonbool(var); + set_signing_key(value); + } + return 0; +} + +const char *get_signing_key(void) +{ + if (configured_signing_key) + return configured_signing_key; + return git_committer_info(IDENT_ERROR_ON_NO_NAME|IDENT_NO_DATE); +} + +/* + * Create a detached signature for the contents of "buffer" and append + * it after "signature"; "buffer" and "signature" can be the same + * strbuf instance, which would cause the detached signature appended + * at the end. + */ +int sign_buffer(struct strbuf *buffer, struct strbuf *signature, const char *signing_key) +{ + struct child_process gpg; + const char *args[4]; + ssize_t len; + size_t i, j, bottom; + + memset(&gpg, 0, sizeof(gpg)); + gpg.argv = args; + gpg.in = -1; + gpg.out = -1; + args[0] = "gpg"; + args[1] = "-bsau"; + args[2] = signing_key; + args[3] = NULL; + + if (start_command(&gpg)) + return error(_("could not run gpg.")); + + /* + * When the username signingkey is bad, program could be terminated + * because gpg exits without reading and then write gets SIGPIPE. + */ + sigchain_push(SIGPIPE, SIG_IGN); + + if (write_in_full(gpg.in, buffer->buf, buffer->len) != buffer->len) { + close(gpg.in); + close(gpg.out); + finish_command(&gpg); + return error(_("gpg did not accept the data")); + } + close(gpg.in); + + bottom = signature->len; + len = strbuf_read(signature, gpg.out, 1024); + close(gpg.out); + + sigchain_pop(SIGPIPE); + + if (finish_command(&gpg) || !len || len < 0) + return error(_("gpg failed to sign the data")); + + /* Strip CR from the line endings, in case we are on Windows. */ + for (i = j = bottom; i < signature->len; i++) + if (signature->buf[i] != '\r') { + if (i != j) + signature->buf[j] = signature->buf[i]; + j++; + } + strbuf_setlen(signature, j); + + return 0; +} + +/* + * Run "gpg" to see if the payload matches the detached signature. + * gpg_output_to tells where the output from "gpg" should go: + * < 0: /dev/null + * = 0: standard error of the calling process + * > 0: the specified file descriptor + */ +int verify_signed_buffer(const char *payload, size_t payload_size, + const char *signature, size_t signature_size, + struct strbuf *gpg_output) +{ + struct child_process gpg; + const char *args_gpg[] = {"gpg", "--verify", "FILE", "-", NULL}; + char path[PATH_MAX]; + int fd, ret; + + fd = git_mkstemp(path, PATH_MAX, ".git_vtag_tmpXXXXXX"); + if (fd < 0) + return error("could not create temporary file '%s': %s", + path, strerror(errno)); + if (write_in_full(fd, signature, signature_size) < 0) + return error("failed writing detached signature to '%s': %s", + path, strerror(errno)); + close(fd); + + memset(&gpg, 0, sizeof(gpg)); + gpg.argv = args_gpg; + gpg.in = -1; + if (gpg_output) + gpg.err = -1; + args_gpg[2] = path; + if (start_command(&gpg)) { + unlink(path); + return error("could not run gpg."); + } + + write_in_full(gpg.in, payload, payload_size); + close(gpg.in); + + if (gpg_output) + strbuf_read(gpg_output, gpg.err, 0); + ret = finish_command(&gpg); + + unlink_or_warn(path); + + return ret; +} diff --git a/gpg-interface.h b/gpg-interface.h new file mode 100644 index 0000000..b9c3608 --- /dev/null +++ b/gpg-interface.h @@ -0,0 +1,10 @@ +#ifndef GPG_INTERFACE_H +#define GPG_INTERFACE_H + +extern int sign_buffer(struct strbuf *buffer, struct strbuf *signature, const char *signing_key); +extern int verify_signed_buffer(const char *payload, size_t payload_size, const char *signature, size_t signature_size, struct strbuf *gpg_output); +extern int git_gpg_config(const char *, const char *, void *); +extern void set_signing_key(const char *); +extern const char *get_signing_key(void); + +#endif diff --git a/tag.c b/tag.c index 7d38cc0..3aa186d 100644 --- a/tag.c +++ b/tag.c @@ -139,6 +139,11 @@ int parse_tag(struct tag *item) return ret; } +/* + * Look at a signed tag object, and return the offset where + * the embedded detached signature begins, or the end of the + * data when there is no such signature. + */ size_t parse_signature(const char *buf, unsigned long size) { char *eol; -- 1.7.7.498.g3f2e50