[PATCH v2 5/9] gpg-interface: introduce an abstraction for multiple gpg formats

From

Henning Schild <henning.schild@siemens.com>

Date

Jul 10, 2018, 08:52 UTC

Message-ID

<93d74df91b9f5c68dfd8a03f576d7428491976c0.1531208187.git.henning.schild@siemens.com>

In-Reply-To

<cover.1531208187.git.henning.schild@siemens.com>

Signed-off-by: Henning Schild <henning.schild@siemens.com>
---
 gpg-interface.c | 74 ++++++++++++++++++++++++++++++++++++++++++++-------------
 1 file changed, 58 insertions(+), 16 deletions(-)

diff --git a/gpg-interface.c b/gpg-interface.c
index ed0e55917..0a8d1bff3 100644
--- a/gpg-interface.c
+++ b/gpg-interface.c
@@ -7,12 +7,46 @@
 #include "tempfile.h"
 
 static char *configured_signing_key;
-static const char *gpg_format = "openpgp";
-static const char *gpg_program = "gpg";
+struct gpg_format_data {
+	const char *format;
+	const char *program;
+	const char *extra_args_verify[1];
+	const char *sigs[2];
+};
 
 #define PGP_SIGNATURE "-----BEGIN PGP SIGNATURE-----"
 #define PGP_MESSAGE "-----BEGIN PGP MESSAGE-----"
 
+enum gpgformats { PGP_FMT };
+struct gpg_format_data gpg_formats[] = {
+	{ .format = "openpgp", .program = "gpg",
+	  .extra_args_verify = { "--keyid-format=long" },
+	  .sigs = { PGP_SIGNATURE, PGP_MESSAGE }
+	},
+};
+static const char *gpg_format = "openpgp";
+
+static struct gpg_format_data *get_format_data(const char *str)
+{
+	int i;
+	for (i = 0; i < ARRAY_SIZE(gpg_formats); i++)
+		if (!strcasecmp(gpg_formats[i].format, str))
+			return gpg_formats + i;
+	return NULL;
+}
+
+static struct gpg_format_data *get_format_data_by_sig(const char *sig)
+{
+	int i, j;
+	for (i = 0; i < ARRAY_SIZE(gpg_formats); i++)
+		for (j = 0; j < ARRAY_SIZE(gpg_formats[i].sigs); j++)
+			if (gpg_formats[i].sigs[j] && 
+			    !strncmp(gpg_formats[i].sigs[j], sig,
+				     strlen(gpg_formats[i].sigs[j])))
+				return gpg_formats + i;
+	return NULL;
+}
+
 void signature_check_clear(struct signature_check *sigc)
 {
 	FREE_AND_NULL(sigc->payload);
@@ -104,8 +138,7 @@ void print_signature_buffer(const struct signature_check *sigc, unsigned flags)
 
 static int is_gpg_start(const char *line)
 {
-	return starts_with(line, PGP_SIGNATURE) ||
-		starts_with(line, PGP_MESSAGE);
+	return (get_format_data_by_sig(line) != NULL);
 }
 
 size_t parse_signature(const char *buf, size_t size)
@@ -140,18 +173,14 @@ int git_gpg_config(const char *var, const char *value, void *cb)
 	}
 
 	if (!strcmp(var, "gpg.format")) {
-		if (strcasecmp(value, "openpgp"))
+		if (!get_format_data(value))
 			return error("malformed value for %s: %s", var, value);
 		return git_config_string(&gpg_format, var, value);
 	}
 
-	if (!strcmp(var, "gpg.program")) {
-		if (!value)
-			return config_error_nonbool(var);
-		gpg_program = xstrdup(value);
-		return 0;
-	}
-
+	if (!strcmp(var, "gpg.program"))
+		return git_config_string(&gpg_formats[PGP_FMT].program, var,
+					 value);
 	return 0;
 }
 
@@ -165,12 +194,16 @@ const char *get_signing_key(void)
 int sign_buffer(struct strbuf *buffer, struct strbuf *signature, const char *signing_key)
 {
 	struct child_process gpg = CHILD_PROCESS_INIT;
+	struct gpg_format_data *fmt;
 	int ret;
 	size_t i, j, bottom;
 	struct strbuf gpg_status = STRBUF_INIT;
 
+	fmt = get_format_data(gpg_format);
+	if (!fmt)
+		BUG("bad gpg_format '%s'", gpg_format);
 	argv_array_pushl(&gpg.args,
-			 gpg_program,
+			 fmt->program,
 			 "--status-fd=2",
 			 "-bsau", signing_key,
 			 NULL);
@@ -208,8 +241,9 @@ int verify_signed_buffer(const char *payload, size_t payload_size,
 			 struct strbuf *gpg_output, struct strbuf *gpg_status)
 {
 	struct child_process gpg = CHILD_PROCESS_INIT;
+	struct gpg_format_data *fmt;
 	struct tempfile *temp;
-	int ret;
+	int ret, i;
 	struct strbuf buf = STRBUF_INIT;
 
 	temp = mks_tempfile_t(".git_vtag_tmpXXXXXX");
@@ -223,10 +257,18 @@ int verify_signed_buffer(const char *payload, size_t payload_size,
 		return -1;
 	}
 
+	fmt = get_format_data_by_sig(signature);
+	assert(fmt);
+
+	argv_array_pushl(&gpg.args,
+			 fmt->program, NULL);
+	for (i = 0; i < ARRAY_SIZE(fmt->extra_args_verify); i++)
+		if (fmt->extra_args_verify[i])
+			argv_array_pushl(&gpg.args,
+					 fmt->extra_args_verify[i], NULL);
+
 	argv_array_pushl(&gpg.args,
-			 gpg_program,
 			 "--status-fd=1",
-			 "--keyid-format=long",
 			 "--verify", temp->filename.buf, "-",
 			 NULL);
 

-- 
2.16.4