gpg-interface: introduce an abstraction for multiple gpg formats

diff --git a/gpg-interface.c b/gpg-interface.c
index b39a27980b536b8176a8c4dbdb2c610bfa9aa455..a02db765807dfdcd14054b3641040e0e77256516 100644 (file)
--- a/gpg-interface.c
+++ b/gpg-interface.c
@@ -7,11 +7,52 @@
 #include "tempfile.h"
 
 static char *configured_signing_key;
-static const char *gpg_format = "openpgp";
-static const char *gpg_program = "gpg";
+struct gpg_format {
+       const char *name;
+       const char *program;
+       const char **verify_args;
+       const char **sigs;
+};
+
+static const char *openpgp_verify_args[] = {
+       "--keyid-format=long",
+       NULL
+};
+static const char *openpgp_sigs[] = {
+       "-----BEGIN PGP SIGNATURE-----",
+       "-----BEGIN PGP MESSAGE-----",
+       NULL
+};
+
+static struct gpg_format gpg_format[] = {
+       { .name = "openpgp", .program = "gpg",
+         .verify_args = openpgp_verify_args,
+         .sigs = openpgp_sigs
+       },
+};
+
+static struct gpg_format *use_format = &gpg_format[0];
 
-#define PGP_SIGNATURE "-----BEGIN PGP SIGNATURE-----"
-#define PGP_MESSAGE "-----BEGIN PGP MESSAGE-----"
+static struct gpg_format *get_format_by_name(const char *str)
+{
+       int i;
+
+       for (i = 0; i < ARRAY_SIZE(gpg_format); i++)
+               if (!strcmp(gpg_format[i].name, str))
+                       return gpg_format + i;
+       return NULL;
+}
+
+static struct gpg_format *get_format_by_sig(const char *sig)
+{
+       int i, j;
+
+       for (i = 0; i < ARRAY_SIZE(gpg_format); i++)
+               for (j = 0; gpg_format[i].sigs[j]; j++)
+                       if (starts_with(sig, gpg_format[i].sigs[j]))
+                               return gpg_format + i;
+       return NULL;
+}
 
 void signature_check_clear(struct signature_check *sigc)
 {
@@ -102,12 +143,6 @@ void print_signature_buffer(const struct signature_check *sigc, unsigned flags)
                fputs(output, stderr);
 }
 
-static int is_gpg_start(const char *line)
-{
-       return starts_with(line, PGP_SIGNATURE) ||
-               starts_with(line, PGP_MESSAGE);
-}
-
 size_t parse_signature(const char *buf, size_t size)
 {
        size_t len = 0;
@@ -115,7 +150,7 @@ size_t parse_signature(const char *buf, size_t size)
        while (len < size) {
                const char *eol;
 
-               if (is_gpg_start(buf + len))
+               if (get_format_by_sig(buf + len))
                        match = len;
 
                eol = memchr(buf + len, '\n', size - len);
@@ -132,6 +167,9 @@ void set_signing_key(const char *key)
 
 int git_gpg_config(const char *var, const char *value, void *cb)
 {
+       struct gpg_format *fmt = NULL;
+       char *fmtname = NULL;
+
        if (!strcmp(var, "user.signingkey")) {
                if (!value)
                        return config_error_nonbool(var);
@@ -142,17 +180,20 @@ int git_gpg_config(const char *var, const char *value, void *cb)
        if (!strcmp(var, "gpg.format")) {
                if (!value)
                        return config_error_nonbool(var);
-               if (strcmp(value, "openpgp"))
+               fmt = get_format_by_name(value);
+               if (!fmt)
                        return error("unsupported value for %s: %s",
                                     var, value);
-               return git_config_string(&gpg_format, var, value);
+               use_format = fmt;
+               return 0;
        }
 
-       if (!strcmp(var, "gpg.program")) {
-               if (!value)
-                       return config_error_nonbool(var);
-               gpg_program = xstrdup(value);
-               return 0;
+       if (!strcmp(var, "gpg.program"))
+               fmtname = "openpgp";
+
+       if (fmtname) {
+               fmt = get_format_by_name(fmtname);
+               return git_config_string(&fmt->program, var, value);
        }
 
        return 0;
@@ -173,7 +214,7 @@ int sign_buffer(struct strbuf *buffer, struct strbuf *signature, const char *sig
        struct strbuf gpg_status = STRBUF_INIT;
 
        argv_array_pushl(&gpg.args,
-                        gpg_program,
+                        use_format->program,
                         "--status-fd=2",
                         "-bsau", signing_key,
                         NULL);
@@ -211,6 +252,7 @@ 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 *fmt;
        struct tempfile *temp;
        int ret;
        struct strbuf buf = STRBUF_INIT;
@@ -226,10 +268,14 @@ int verify_signed_buffer(const char *payload, size_t payload_size,
                return -1;
        }
 
+       fmt = get_format_by_sig(signature);
+       if (!fmt)
+               BUG("bad signature '%s'", signature);
+
+       argv_array_push(&gpg.args, fmt->program);
+       argv_array_pushv(&gpg.args, fmt->verify_args);
        argv_array_pushl(&gpg.args,
-                        gpg_program,
                         "--status-fd=1",
-                        "--keyid-format=long",
                         "--verify", temp->filename.buf, "-",
                         NULL);