contrib/credential/gnome-keyring/git-credential-gnome-keyring.c

   1 /*
   2  * Copyright (C) 2011 John Szakmeister <john@szakmeister.net>
   3  *               2012 Philipp A. Hartmann <pah@qo.cx>
   4  *
   5  *  This program is free software; you can redistribute it and/or modify
   6  *  it under the terms of the GNU General Public License as published by
   7  *  the Free Software Foundation; either version 2 of the License, or
   8  *  (at your option) any later version.
   9  *
  10  *  This program is distributed in the hope that it will be useful,
  11  *  but WITHOUT ANY WARRANTY; without even the implied warranty of
  12  *  MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
  13  *  GNU General Public License for more details.
  14  *
  15  *  You should have received a copy of the GNU General Public License
  16  *  along with this program; if not, write to the Free Software
  17  *  Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA  02111-1307  USA
  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 <stdarg.h>
  29 #include <stdlib.h>
  30 #include <errno.h>
  31 #include <gnome-keyring.h>
  32
  33 /*
  34  * This credential struct and API is simplified from git's credential.{h,c}
  35  */
  36 struct credential
  37 {
  38         char          *protocol;
  39         char          *host;
  40         unsigned short port;
  41         char          *path;
  42         char          *username;
  43         char          *password;
  44 };
  45
  46 #define CREDENTIAL_INIT \
  47   { NULL,NULL,0,NULL,NULL,NULL }
  48
  49 void credential_init(struct credential *c);
  50 void credential_clear(struct credential *c);
  51 int  credential_read(struct credential *c);
  52 void credential_write(const struct credential *c);
  53
  54 typedef int (*credential_op_cb)(struct credential*);
  55
  56 struct credential_operation
  57 {
  58         char             *name;
  59         credential_op_cb op;
  60 };
  61
  62 #define CREDENTIAL_OP_END \
  63   { NULL,NULL }
  64
  65 /*
  66  * Table with operation callbacks is defined in concrete
  67  * credential helper implementation and contains entries
  68  * like { "get", function_to_get_credential } terminated
  69  * by CREDENTIAL_OP_END.
  70  */
  71 struct credential_operation const credential_helper_ops[];
  72
  73 /* ---------------- common helper functions ----------------- */
  74
  75 static inline void free_password(char *password)
  76 {
  77         char *c = password;
  78         if (!password)
  79                 return;
  80
  81         while (*c) *c++ = '\0';
  82         free(password);
  83 }
  84
  85 static inline void warning(const char *fmt, ...)
  86 {
  87         va_list ap;
  88
  89         va_start(ap, fmt);
  90         fprintf(stderr, "warning: ");
  91         vfprintf(stderr, fmt, ap);
  92         fprintf(stderr, "\n" );
  93         va_end(ap);
  94 }
  95
  96 static inline void error(const char *fmt, ...)
  97 {
  98         va_list ap;
  99
 100         va_start(ap, fmt);
 101         fprintf(stderr, "error: ");
 102         vfprintf(stderr, fmt, ap);
 103         fprintf(stderr, "\n" );
 104         va_end(ap);
 105 }
 106
 107 static inline void die(const char *fmt, ...)
 108 {
 109         va_list ap;
 110
 111         va_start(ap,fmt);
 112         error(fmt, ap);
 113         va_end(ap);
 114         exit(EXIT_FAILURE);
 115 }
 116
 117 static inline void die_errno(int err)
 118 {
 119         error("%s", strerror(err));
 120         exit(EXIT_FAILURE);
 121 }
 122
 123 static inline char *xstrdup(const char *str)
 124 {
 125         char *ret = strdup(str);
 126         if (!ret)
 127                 die_errno(errno);
 128
 129         return ret;
 130 }
 131
 132 /* ----------------- GNOME Keyring functions ----------------- */
 133
 134 /* create a special keyring option string, if path is given */
 135 static char* keyring_object(struct credential *c)
 136 {
 137         char* object = NULL;
 138
 139         if (!c->path)
 140                 return object;
 141
 142         object = (char*) malloc(strlen(c->host)+strlen(c->path)+8);
 143         if(!object)
 144                 die_errno(errno);
 145
 146         if(c->port)
 147                 sprintf(object,"%s:%hd/%s",c->host,c->port,c->path);
 148         else
 149                 sprintf(object,"%s/%s",c->host,c->path);
 150
 151         return object;
 152 }
 153
 154 int keyring_get(struct credential *c)
 155 {
 156         char* object = NULL;
 157         GList *entries;
 158         GnomeKeyringNetworkPasswordData *password_data;
 159         GnomeKeyringResult result;
 160
 161         if (!c->protocol || !(c->host || c->path))
 162                 return EXIT_FAILURE;
 163
 164         object = keyring_object(c);
 165
 166         result = gnome_keyring_find_network_password_sync(
 167                                 c->username,
 168                                 NULL /* domain */,
 169                                 c->host,
 170                                 object,
 171                                 c->protocol,
 172                                 NULL /* authtype */,
 173                                 c->port,
 174                                 &entries);
 175
 176         free(object);
 177
 178         if (result == GNOME_KEYRING_RESULT_NO_MATCH)
 179                 return EXIT_SUCCESS;
 180
 181         if (result == GNOME_KEYRING_RESULT_CANCELLED)
 182                 return EXIT_SUCCESS;
 183
 184         if (result != GNOME_KEYRING_RESULT_OK) {
 185                 error("%s",gnome_keyring_result_to_message(result));
 186                 return EXIT_FAILURE;
 187         }
 188
 189         /* pick the first one from the list */
 190         password_data = (GnomeKeyringNetworkPasswordData *) entries->data;
 191
 192         free_password(c->password);
 193         c->password = xstrdup(password_data->password);
 194
 195         if (!c->username)
 196                 c->username = xstrdup(password_data->user);
 197
 198         gnome_keyring_network_password_list_free(entries);
 199
 200         return EXIT_SUCCESS;
 201 }
 202
 203
 204 int keyring_store(struct credential *c)
 205 {
 206         guint32 item_id;
 207         char  *object = NULL;
 208
 209         /*
 210          * Sanity check that what we are storing is actually sensible.
 211          * In particular, we can't make a URL without a protocol field.
 212          * Without either a host or pathname (depending on the scheme),
 213          * we have no primary key. And without a username and password,
 214          * we are not actually storing a credential.
 215          */
 216         if (!c->protocol || !(c->host || c->path) ||
 217             !c->username || !c->password)
 218                 return EXIT_FAILURE;
 219
 220         object = keyring_object(c);
 221
 222         gnome_keyring_set_network_password_sync(
 223                                 GNOME_KEYRING_DEFAULT,
 224                                 c->username,
 225                                 NULL /* domain */,
 226                                 c->host,
 227                                 object,
 228                                 c->protocol,
 229                                 NULL /* authtype */,
 230                                 c->port,
 231                                 c->password,
 232                                 &item_id);
 233
 234         free(object);
 235         return EXIT_SUCCESS;
 236 }
 237
 238 int keyring_erase(struct credential *c)
 239 {
 240         char  *object = NULL;
 241         GList *entries;
 242         GnomeKeyringNetworkPasswordData *password_data;
 243         GnomeKeyringResult result;
 244
 245         /*
 246          * Sanity check that we actually have something to match
 247          * against. The input we get is a restrictive pattern,
 248          * so technically a blank credential means "erase everything".
 249          * But it is too easy to accidentally send this, since it is equivalent
 250          * to empty input. So explicitly disallow it, and require that the
 251          * pattern have some actual content to match.
 252          */
 253         if (!c->protocol && !c->host && !c->path && !c->username)
 254                 return EXIT_FAILURE;
 255
 256         object = keyring_object(c);
 257
 258         result = gnome_keyring_find_network_password_sync(
 259                                 c->username,
 260                                 NULL /* domain */,
 261                                 c->host,
 262                                 object,
 263                                 c->protocol,
 264                                 NULL /* authtype */,
 265                                 c->port,
 266                                 &entries);
 267
 268         free(object);
 269
 270         if (result == GNOME_KEYRING_RESULT_NO_MATCH)
 271                 return EXIT_SUCCESS;
 272
 273         if (result == GNOME_KEYRING_RESULT_CANCELLED)
 274                 return EXIT_SUCCESS;
 275
 276         if (result != GNOME_KEYRING_RESULT_OK)
 277         {
 278                 error("%s",gnome_keyring_result_to_message(result));
 279                 return EXIT_FAILURE;
 280         }
 281
 282         /* pick the first one from the list (delete all matches?) */
 283         password_data = (GnomeKeyringNetworkPasswordData *) entries->data;
 284
 285         result = gnome_keyring_item_delete_sync(
 286                 password_data->keyring, password_data->item_id);
 287
 288         gnome_keyring_network_password_list_free(entries);
 289
 290         if (result != GNOME_KEYRING_RESULT_OK)
 291         {
 292                 error("%s",gnome_keyring_result_to_message(result));
 293                 return EXIT_FAILURE;
 294         }
 295
 296         return EXIT_SUCCESS;
 297 }
 298
 299 /*
 300  * Table with helper operation callbacks, used by generic
 301  * credential helper main function.
 302  */
 303 struct credential_operation const credential_helper_ops[] =
 304 {
 305         { "get",   keyring_get   },
 306         { "store", keyring_store },
 307         { "erase", keyring_erase },
 308         CREDENTIAL_OP_END
 309 };
 310
 311 /* ------------------ credential functions ------------------ */
 312
 313 void credential_init(struct credential *c)
 314 {
 315         memset(c, 0, sizeof(*c));
 316 }
 317
 318 void credential_clear(struct credential *c)
 319 {
 320         free(c->protocol);
 321         free(c->host);
 322         free(c->path);
 323         free(c->username);
 324         free_password(c->password);
 325
 326         credential_init(c);
 327 }
 328
 329 int credential_read(struct credential *c)
 330 {
 331         char    buf[1024];
 332         ssize_t line_len = 0;
 333         char   *key      = buf;
 334         char   *value;
 335
 336         while (fgets(buf, sizeof(buf), stdin))
 337         {
 338                 line_len = strlen(buf);
 339
 340                 if(buf[line_len-1]=='\n')
 341                         buf[--line_len]='\0';
 342
 343                 if(!line_len)
 344                         break;
 345
 346                 value = strchr(buf,'=');
 347                 if(!value) {
 348                         warning("invalid credential line: %s", key);
 349                         return -1;
 350                 }
 351                 *value++ = '\0';
 352
 353                 if (!strcmp(key, "protocol")) {
 354                         free(c->protocol);
 355                         c->protocol = xstrdup(value);
 356                 } else if (!strcmp(key, "host")) {
 357                         free(c->host);
 358                         c->host = xstrdup(value);
 359                         value = strrchr(c->host,':');
 360                         if (value) {
 361                                 *value++ = '\0';
 362                                 c->port = atoi(value);
 363                         }
 364                 } else if (!strcmp(key, "path")) {
 365                         free(c->path);
 366                         c->path = xstrdup(value);
 367                 } else if (!strcmp(key, "username")) {
 368                         free(c->username);
 369                         c->username = xstrdup(value);
 370                 } else if (!strcmp(key, "password")) {
 371                         free_password(c->password);
 372                         c->password = xstrdup(value);
 373                         while (*value) *value++ = '\0';
 374                 }
 375                 /*
 376                  * Ignore other lines; we don't know what they mean, but
 377                  * this future-proofs us when later versions of git do
 378                  * learn new lines, and the helpers are updated to match.
 379                  */
 380         }
 381         return 0;
 382 }
 383
 384 void credential_write_item(FILE *fp, const char *key, const char *value)
 385 {
 386         if (!value)
 387                 return;
 388         fprintf(fp, "%s=%s\n", key, value);
 389 }
 390
 391 void credential_write(const struct credential *c)
 392 {
 393         /* only write username/password, if set */
 394         credential_write_item(stdout, "username", c->username);
 395         credential_write_item(stdout, "password", c->password);
 396 }
 397
 398 static void usage(const char *name)
 399 {
 400         struct credential_operation const *try_op = credential_helper_ops;
 401         const char *basename = strrchr(name,'/');
 402
 403         basename = (basename) ? basename + 1 : name;
 404         fprintf(stderr, "Usage: %s <", basename);
 405         while(try_op->name) {
 406                 fprintf(stderr,"%s",(try_op++)->name);
 407                 if(try_op->name)
 408                         fprintf(stderr,"%s","|");
 409         }
 410         fprintf(stderr,"%s",">\n");
 411 }
 412
 413 int main(int argc, char *argv[])
 414 {
 415         int ret = EXIT_SUCCESS;
 416
 417         struct credential_operation const *try_op = credential_helper_ops;
 418         struct credential                  cred   = CREDENTIAL_INIT;
 419
 420         if (!argv[1]) {
 421                 usage(argv[0]);
 422                 goto out;
 423         }
 424
 425         /* lookup operation callback */
 426         while(try_op->name && strcmp(argv[1], try_op->name))
 427                 try_op++;
 428
 429         /* unsupported operation given -- ignore silently */
 430         if(!try_op->name || !try_op->op)
 431                 goto out;
 432
 433         ret = credential_read(&cred);
 434         if(ret)
 435                 goto out;
 436
 437         /* perform credential operation */
 438         ret = (*try_op->op)(&cred);
 439
 440         credential_write(&cred);
 441
 442 out:
 443         credential_clear(&cred);
 444         return ret;
 445 }