contrib/credential/libsecret/git-credential-libsecret.c

   1 /*
   2  * Copyright (C) 2011 John Szakmeister <john@szakmeister.net>
   3  *               2012 Philipp A. Hartmann <pah@qo.cx>
   4  *               2016 Mantas Mikulėnas <grawity@gmail.com>
   5  *
   6  *  This program is free software; you can redistribute it and/or modify
   7  *  it under the terms of the GNU General Public License as published by
   8  *  the Free Software Foundation; either version 2 of the License, or
   9  *  (at your option) any later version.
  10  *
  11  *  This program is distributed in the hope that it will be useful,
  12  *  but WITHOUT ANY WARRANTY; without even the implied warranty of
  13  *  MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
  14  *  GNU General Public License for more details.
  15  *
  16  *  You should have received a copy of the GNU General Public License
  17  *  along with this program; if not, see <http://www.gnu.org/licenses/>.
  18  */
  19
  20 /*
  21  * Credits:
  22  * - GNOME Keyring API handling originally written by John Szakmeister
  23  * - ported to credential helper API by Philipp A. Hartmann
  24  */
  25
  26 #include <stdio.h>
  27 #include <string.h>
  28 #include <stdlib.h>
  29 #include <glib.h>
  30 #include <libsecret/secret.h>
  31
  32 /*
  33  * This credential struct and API is simplified from git's credential.{h,c}
  34  */
  35 struct credential {
  36         char *protocol;
  37         char *host;
  38         unsigned short port;
  39         char *path;
  40         char *username;
  41         char *password;
  42 };
  43
  44 #define CREDENTIAL_INIT { NULL, NULL, 0, NULL, NULL, NULL }
  45
  46 typedef int (*credential_op_cb)(struct credential *);
  47
  48 struct credential_operation {
  49         char *name;
  50         credential_op_cb op;
  51 };
  52
  53 #define CREDENTIAL_OP_END { NULL, NULL }
  54
  55 /* ----------------- Secret Service functions ----------------- */
  56
  57 static char *make_label(struct credential *c)
  58 {
  59         if (c->port)
  60                 return g_strdup_printf("Git: %s://%s:%hu/%s",
  61                                         c->protocol, c->host, c->port, c->path ? c->path : "");
  62         else
  63                 return g_strdup_printf("Git: %s://%s/%s",
  64                                         c->protocol, c->host, c->path ? c->path : "");
  65 }
  66
  67 static GHashTable *make_attr_list(struct credential *c)
  68 {
  69         GHashTable *al = g_hash_table_new_full(g_str_hash, g_str_equal, NULL, g_free);
  70
  71         if (c->username)
  72                 g_hash_table_insert(al, "user", g_strdup(c->username));
  73         if (c->protocol)
  74                 g_hash_table_insert(al, "protocol", g_strdup(c->protocol));
  75         if (c->host)
  76                 g_hash_table_insert(al, "server", g_strdup(c->host));
  77         if (c->port)
  78                 g_hash_table_insert(al, "port", g_strdup_printf("%hu", c->port));
  79         if (c->path)
  80                 g_hash_table_insert(al, "object", g_strdup(c->path));
  81
  82         return al;
  83 }
  84
  85 static int keyring_get(struct credential *c)
  86 {
  87         SecretService *service = NULL;
  88         GHashTable *attributes = NULL;
  89         GError *error = NULL;
  90         GList *items = NULL;
  91
  92         if (!c->protocol || !(c->host || c->path))
  93                 return EXIT_FAILURE;
  94
  95         service = secret_service_get_sync(0, NULL, &error);
  96         if (error != NULL) {
  97                 g_critical("could not connect to Secret Service: %s", error->message);
  98                 g_error_free(error);
  99                 return EXIT_FAILURE;
 100         }
 101
 102         attributes = make_attr_list(c);
 103         items = secret_service_search_sync(service,
 104                                            SECRET_SCHEMA_COMPAT_NETWORK,
 105                                            attributes,
 106                                            SECRET_SEARCH_LOAD_SECRETS | SECRET_SEARCH_UNLOCK,
 107                                            NULL,
 108                                            &error);
 109         g_hash_table_unref(attributes);
 110         if (error != NULL) {
 111                 g_critical("lookup failed: %s", error->message);
 112                 g_error_free(error);
 113                 return EXIT_FAILURE;
 114         }
 115
 116         if (items != NULL) {
 117                 SecretItem *item;
 118                 SecretValue *secret;
 119                 const char *s;
 120
 121                 item = items->data;
 122                 secret = secret_item_get_secret(item);
 123                 attributes = secret_item_get_attributes(item);
 124
 125                 s = g_hash_table_lookup(attributes, "user");
 126                 if (s) {
 127                         g_free(c->username);
 128                         c->username = g_strdup(s);
 129                 }
 130
 131                 s = secret_value_get_text(secret);
 132                 if (s) {
 133                         g_free(c->password);
 134                         c->password = g_strdup(s);
 135                 }
 136
 137                 g_hash_table_unref(attributes);
 138                 secret_value_unref(secret);
 139                 g_list_free_full(items, g_object_unref);
 140         }
 141
 142         return EXIT_SUCCESS;
 143 }
 144
 145
 146 static int keyring_store(struct credential *c)
 147 {
 148         char *label = NULL;
 149         GHashTable *attributes = NULL;
 150         GError *error = NULL;
 151
 152         /*
 153          * Sanity check that what we are storing is actually sensible.
 154          * In particular, we can't make a URL without a protocol field.
 155          * Without either a host or pathname (depending on the scheme),
 156          * we have no primary key. And without a username and password,
 157          * we are not actually storing a credential.
 158          */
 159         if (!c->protocol || !(c->host || c->path) ||
 160             !c->username || !c->password)
 161                 return EXIT_FAILURE;
 162
 163         label = make_label(c);
 164         attributes = make_attr_list(c);
 165         secret_password_storev_sync(SECRET_SCHEMA_COMPAT_NETWORK,
 166                                     attributes,
 167                                     NULL,
 168                                     label,
 169                                     c->password,
 170                                     NULL,
 171                                     &error);
 172         g_free(label);
 173         g_hash_table_unref(attributes);
 174
 175         if (error != NULL) {
 176                 g_critical("store failed: %s", error->message);
 177                 g_error_free(error);
 178                 return EXIT_FAILURE;
 179         }
 180
 181         return EXIT_SUCCESS;
 182 }
 183
 184 static int keyring_erase(struct credential *c)
 185 {
 186         GHashTable *attributes = NULL;
 187         GError *error = NULL;
 188
 189         /*
 190          * Sanity check that we actually have something to match
 191          * against. The input we get is a restrictive pattern,
 192          * so technically a blank credential means "erase everything".
 193          * But it is too easy to accidentally send this, since it is equivalent
 194          * to empty input. So explicitly disallow it, and require that the
 195          * pattern have some actual content to match.
 196          */
 197         if (!c->protocol && !c->host && !c->path && !c->username)
 198                 return EXIT_FAILURE;
 199
 200         attributes = make_attr_list(c);
 201         secret_password_clearv_sync(SECRET_SCHEMA_COMPAT_NETWORK,
 202                                     attributes,
 203                                     NULL,
 204                                     &error);
 205         g_hash_table_unref(attributes);
 206
 207         if (error != NULL) {
 208                 g_critical("erase failed: %s", error->message);
 209                 g_error_free(error);
 210                 return EXIT_FAILURE;
 211         }
 212
 213         return EXIT_SUCCESS;
 214 }
 215
 216 /*
 217  * Table with helper operation callbacks, used by generic
 218  * credential helper main function.
 219  */
 220 static struct credential_operation const credential_helper_ops[] = {
 221         { "get",   keyring_get },
 222         { "store", keyring_store },
 223         { "erase", keyring_erase },
 224         CREDENTIAL_OP_END
 225 };
 226
 227 /* ------------------ credential functions ------------------ */
 228
 229 static void credential_init(struct credential *c)
 230 {
 231         memset(c, 0, sizeof(*c));
 232 }
 233
 234 static void credential_clear(struct credential *c)
 235 {
 236         g_free(c->protocol);
 237         g_free(c->host);
 238         g_free(c->path);
 239         g_free(c->username);
 240         g_free(c->password);
 241
 242         credential_init(c);
 243 }
 244
 245 static int credential_read(struct credential *c)
 246 {
 247         char *buf;
 248         size_t line_len;
 249         char *key;
 250         char *value;
 251
 252         key = buf = g_malloc(1024);
 253
 254         while (fgets(buf, 1024, stdin)) {
 255                 line_len = strlen(buf);
 256
 257                 if (line_len && buf[line_len-1] == '\n')
 258                         buf[--line_len] = '\0';
 259
 260                 if (!line_len)
 261                         break;
 262
 263                 value = strchr(buf, '=');
 264                 if (!value) {
 265                         g_warning("invalid credential line: %s", key);
 266                         g_free(buf);
 267                         return -1;
 268                 }
 269                 *value++ = '\0';
 270
 271                 if (!strcmp(key, "protocol")) {
 272                         g_free(c->protocol);
 273                         c->protocol = g_strdup(value);
 274                 } else if (!strcmp(key, "host")) {
 275                         g_free(c->host);
 276                         c->host = g_strdup(value);
 277                         value = strrchr(c->host, ':');
 278                         if (value) {
 279                                 *value++ = '\0';
 280                                 c->port = atoi(value);
 281                         }
 282                 } else if (!strcmp(key, "path")) {
 283                         g_free(c->path);
 284                         c->path = g_strdup(value);
 285                 } else if (!strcmp(key, "username")) {
 286                         g_free(c->username);
 287                         c->username = g_strdup(value);
 288                 } else if (!strcmp(key, "password")) {
 289                         g_free(c->password);
 290                         c->password = g_strdup(value);
 291                         while (*value)
 292                                 *value++ = '\0';
 293                 }
 294                 /*
 295                  * Ignore other lines; we don't know what they mean, but
 296                  * this future-proofs us when later versions of git do
 297                  * learn new lines, and the helpers are updated to match.
 298                  */
 299         }
 300
 301         g_free(buf);
 302
 303         return 0;
 304 }
 305
 306 static void credential_write_item(FILE *fp, const char *key, const char *value)
 307 {
 308         if (!value)
 309                 return;
 310         fprintf(fp, "%s=%s\n", key, value);
 311 }
 312
 313 static void credential_write(const struct credential *c)
 314 {
 315         /* only write username/password, if set */
 316         credential_write_item(stdout, "username", c->username);
 317         credential_write_item(stdout, "password", c->password);
 318 }
 319
 320 static void usage(const char *name)
 321 {
 322         struct credential_operation const *try_op = credential_helper_ops;
 323         const char *basename = strrchr(name, '/');
 324
 325         basename = (basename) ? basename + 1 : name;
 326         fprintf(stderr, "usage: %s <", basename);
 327         while (try_op->name) {
 328                 fprintf(stderr, "%s", (try_op++)->name);
 329                 if (try_op->name)
 330                         fprintf(stderr, "%s", "|");
 331         }
 332         fprintf(stderr, "%s", ">\n");
 333 }
 334
 335 int main(int argc, char *argv[])
 336 {
 337         int ret = EXIT_SUCCESS;
 338
 339         struct credential_operation const *try_op = credential_helper_ops;
 340         struct credential cred = CREDENTIAL_INIT;
 341
 342         if (!argv[1]) {
 343                 usage(argv[0]);
 344                 exit(EXIT_FAILURE);
 345         }
 346
 347         g_set_application_name("Git Credential Helper");
 348
 349         /* lookup operation callback */
 350         while (try_op->name && strcmp(argv[1], try_op->name))
 351                 try_op++;
 352
 353         /* unsupported operation given -- ignore silently */
 354         if (!try_op->name || !try_op->op)
 355                 goto out;
 356
 357         ret = credential_read(&cred);
 358         if (ret)
 359                 goto out;
 360
 361         /* perform credential operation */
 362         ret = (*try_op->op)(&cred);
 363
 364         credential_write(&cred);
 365
 366 out:
 367         credential_clear(&cred);
 368         return ret;
 369 }