credential.c

   1 #include "cache.h"
   2 #include "credential.h"
   3 #include "string-list.h"
   4 #include "run-command.h"
   5 #include "url.h"
   6 #include "prompt.h"
   7
   8 void credential_init(struct credential *c)
   9 {
  10         memset(c, 0, sizeof(*c));
  11         c->helpers.strdup_strings = 1;
  12 }
  13
  14 void credential_clear(struct credential *c)
  15 {
  16         free(c->protocol);
  17         free(c->host);
  18         free(c->path);
  19         free(c->username);
  20         free(c->password);
  21         string_list_clear(&c->helpers, 0);
  22
  23         credential_init(c);
  24 }
  25
  26 int credential_match(const struct credential *want,
  27                      const struct credential *have)
  28 {
  29 #define CHECK(x) (!want->x || (have->x && !strcmp(want->x, have->x)))
  30         return CHECK(protocol) &&
  31                CHECK(host) &&
  32                CHECK(path) &&
  33                CHECK(username);
  34 #undef CHECK
  35 }
  36
  37 static int credential_config_callback(const char *var, const char *value,
  38                                       void *data)
  39 {
  40         struct credential *c = data;
  41         const char *key, *dot;
  42
  43         key = skip_prefix(var, "credential.");
  44         if (!key)
  45                 return 0;
  46
  47         if (!value)
  48                 return config_error_nonbool(var);
  49
  50         dot = strrchr(key, '.');
  51         if (dot) {
  52                 struct credential want = CREDENTIAL_INIT;
  53                 char *url = xmemdupz(key, dot - key);
  54                 int matched;
  55
  56                 credential_from_url(&want, url);
  57                 matched = credential_match(&want, c);
  58
  59                 credential_clear(&want);
  60                 free(url);
  61
  62                 if (!matched)
  63                         return 0;
  64                 key = dot + 1;
  65         }
  66
  67         if (!strcmp(key, "helper"))
  68                 string_list_append(&c->helpers, value);
  69         else if (!strcmp(key, "username")) {
  70                 if (!c->username)
  71                         c->username = xstrdup(value);
  72         }
  73         else if (!strcmp(key, "usehttppath"))
  74                 c->use_http_path = git_config_bool(var, value);
  75
  76         return 0;
  77 }
  78
  79 static int proto_is_http(const char *s)
  80 {
  81         if (!s)
  82                 return 0;
  83         return !strcmp(s, "https") || !strcmp(s, "http");
  84 }
  85
  86 static void credential_apply_config(struct credential *c)
  87 {
  88         if (c->configured)
  89                 return;
  90         git_config(credential_config_callback, c);
  91         c->configured = 1;
  92
  93         if (!c->use_http_path && proto_is_http(c->protocol)) {
  94                 free(c->path);
  95                 c->path = NULL;
  96         }
  97 }
  98
  99 static void credential_describe(struct credential *c, struct strbuf *out)
 100 {
 101         if (!c->protocol)
 102                 return;
 103         strbuf_addf(out, "%s://", c->protocol);
 104         if (c->username && *c->username)
 105                 strbuf_addf(out, "%s@", c->username);
 106         if (c->host)
 107                 strbuf_addstr(out, c->host);
 108         if (c->path)
 109                 strbuf_addf(out, "/%s", c->path);
 110 }
 111
 112 static char *credential_ask_one(const char *what, struct credential *c,
 113                                 int flags)
 114 {
 115         struct strbuf desc = STRBUF_INIT;
 116         struct strbuf prompt = STRBUF_INIT;
 117         char *r;
 118
 119         credential_describe(c, &desc);
 120         if (desc.len)
 121                 strbuf_addf(&prompt, "%s for '%s': ", what, desc.buf);
 122         else
 123                 strbuf_addf(&prompt, "%s: ", what);
 124
 125         r = git_prompt(prompt.buf, flags);
 126
 127         strbuf_release(&desc);
 128         strbuf_release(&prompt);
 129         return xstrdup(r);
 130 }
 131
 132 static void credential_getpass(struct credential *c)
 133 {
 134         if (!c->username)
 135                 c->username = credential_ask_one("Username", c,
 136                                                  PROMPT_ASKPASS|PROMPT_ECHO);
 137         if (!c->password)
 138                 c->password = credential_ask_one("Password", c,
 139                                                  PROMPT_ASKPASS);
 140 }
 141
 142 int credential_read(struct credential *c, FILE *fp)
 143 {
 144         struct strbuf line = STRBUF_INIT;
 145
 146         while (strbuf_getline(&line, fp, '\n') != EOF) {
 147                 char *key = line.buf;
 148                 char *value = strchr(key, '=');
 149
 150                 if (!line.len)
 151                         break;
 152
 153                 if (!value) {
 154                         warning("invalid credential line: %s", key);
 155                         strbuf_release(&line);
 156                         return -1;
 157                 }
 158                 *value++ = '\0';
 159
 160                 if (!strcmp(key, "username")) {
 161                         free(c->username);
 162                         c->username = xstrdup(value);
 163                 } else if (!strcmp(key, "password")) {
 164                         free(c->password);
 165                         c->password = xstrdup(value);
 166                 } else if (!strcmp(key, "protocol")) {
 167                         free(c->protocol);
 168                         c->protocol = xstrdup(value);
 169                 } else if (!strcmp(key, "host")) {
 170                         free(c->host);
 171                         c->host = xstrdup(value);
 172                 } else if (!strcmp(key, "path")) {
 173                         free(c->path);
 174                         c->path = xstrdup(value);
 175                 } else if (!strcmp(key, "url")) {
 176                         credential_from_url(c, value);
 177                 }
 178                 /*
 179                  * Ignore other lines; we don't know what they mean, but
 180                  * this future-proofs us when later versions of git do
 181                  * learn new lines, and the helpers are updated to match.
 182                  */
 183         }
 184
 185         strbuf_release(&line);
 186         return 0;
 187 }
 188
 189 static void credential_write_item(FILE *fp, const char *key, const char *value)
 190 {
 191         if (!value)
 192                 return;
 193         fprintf(fp, "%s=%s\n", key, value);
 194 }
 195
 196 void credential_write(const struct credential *c, FILE *fp)
 197 {
 198         credential_write_item(fp, "protocol", c->protocol);
 199         credential_write_item(fp, "host", c->host);
 200         credential_write_item(fp, "path", c->path);
 201         credential_write_item(fp, "username", c->username);
 202         credential_write_item(fp, "password", c->password);
 203 }
 204
 205 static int run_credential_helper(struct credential *c,
 206                                  const char *cmd,
 207                                  int want_output)
 208 {
 209         struct child_process helper;
 210         const char *argv[] = { NULL, NULL };
 211         FILE *fp;
 212
 213         memset(&helper, 0, sizeof(helper));
 214         argv[0] = cmd;
 215         helper.argv = argv;
 216         helper.use_shell = 1;
 217         helper.in = -1;
 218         if (want_output)
 219                 helper.out = -1;
 220         else
 221                 helper.no_stdout = 1;
 222
 223         if (start_command(&helper) < 0)
 224                 return -1;
 225
 226         fp = xfdopen(helper.in, "w");
 227         credential_write(c, fp);
 228         fclose(fp);
 229
 230         if (want_output) {
 231                 int r;
 232                 fp = xfdopen(helper.out, "r");
 233                 r = credential_read(c, fp);
 234                 fclose(fp);
 235                 if (r < 0) {
 236                         finish_command(&helper);
 237                         return -1;
 238                 }
 239         }
 240
 241         if (finish_command(&helper))
 242                 return -1;
 243         return 0;
 244 }
 245
 246 static int credential_do(struct credential *c, const char *helper,
 247                          const char *operation)
 248 {
 249         struct strbuf cmd = STRBUF_INIT;
 250         int r;
 251
 252         if (helper[0] == '!')
 253                 strbuf_addstr(&cmd, helper + 1);
 254         else if (is_absolute_path(helper))
 255                 strbuf_addstr(&cmd, helper);
 256         else
 257                 strbuf_addf(&cmd, "git credential-%s", helper);
 258
 259         strbuf_addf(&cmd, " %s", operation);
 260         r = run_credential_helper(c, cmd.buf, !strcmp(operation, "get"));
 261
 262         strbuf_release(&cmd);
 263         return r;
 264 }
 265
 266 void credential_fill(struct credential *c)
 267 {
 268         int i;
 269
 270         if (c->username && c->password)
 271                 return;
 272
 273         credential_apply_config(c);
 274
 275         for (i = 0; i < c->helpers.nr; i++) {
 276                 credential_do(c, c->helpers.items[i].string, "get");
 277                 if (c->username && c->password)
 278                         return;
 279         }
 280
 281         credential_getpass(c);
 282         if (!c->username && !c->password)
 283                 die("unable to get password from user");
 284 }
 285
 286 void credential_approve(struct credential *c)
 287 {
 288         int i;
 289
 290         if (c->approved)
 291                 return;
 292         if (!c->username || !c->password)
 293                 return;
 294
 295         credential_apply_config(c);
 296
 297         for (i = 0; i < c->helpers.nr; i++)
 298                 credential_do(c, c->helpers.items[i].string, "store");
 299         c->approved = 1;
 300 }
 301
 302 void credential_reject(struct credential *c)
 303 {
 304         int i;
 305
 306         credential_apply_config(c);
 307
 308         for (i = 0; i < c->helpers.nr; i++)
 309                 credential_do(c, c->helpers.items[i].string, "erase");
 310
 311         free(c->username);
 312         c->username = NULL;
 313         free(c->password);
 314         c->password = NULL;
 315         c->approved = 0;
 316 }
 317
 318 void credential_from_url(struct credential *c, const char *url)
 319 {
 320         const char *at, *colon, *cp, *slash, *host, *proto_end;
 321
 322         credential_clear(c);
 323
 324         /*
 325          * Match one of:
 326          *   (1) proto://<host>/...
 327          *   (2) proto://<user>@<host>/...
 328          *   (3) proto://<user>:<pass>@<host>/...
 329          */
 330         proto_end = strstr(url, "://");
 331         if (!proto_end)
 332                 return;
 333         cp = proto_end + 3;
 334         at = strchr(cp, '@');
 335         colon = strchr(cp, ':');
 336         slash = strchrnul(cp, '/');
 337
 338         if (!at || slash <= at) {
 339                 /* Case (1) */
 340                 host = cp;
 341         }
 342         else if (!colon || at <= colon) {
 343                 /* Case (2) */
 344                 c->username = url_decode_mem(cp, at - cp);
 345                 host = at + 1;
 346         } else {
 347                 /* Case (3) */
 348                 c->username = url_decode_mem(cp, colon - cp);
 349                 c->password = url_decode_mem(colon + 1, at - (colon + 1));
 350                 host = at + 1;
 351         }
 352
 353         if (proto_end - url > 0)
 354                 c->protocol = xmemdupz(url, proto_end - url);
 355         if (slash - host > 0)
 356                 c->host = url_decode_mem(host, slash - host);
 357         /* Trim leading and trailing slashes from path */
 358         while (*slash == '/')
 359                 slash++;
 360         if (*slash) {
 361                 char *p;
 362                 c->path = url_decode(slash);
 363                 p = c->path + strlen(c->path) - 1;
 364                 while (p > c->path && *p == '/')
 365                         *p-- = '\0';
 366         }
 367 }