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         if (!skip_prefix(var, "credential.", &key))
  44                 return 0;
  45
  46         if (!value)
  47                 return config_error_nonbool(var);
  48
  49         dot = strrchr(key, '.');
  50         if (dot) {
  51                 struct credential want = CREDENTIAL_INIT;
  52                 char *url = xmemdupz(key, dot - key);
  53                 int matched;
  54
  55                 credential_from_url(&want, url);
  56                 matched = credential_match(&want, c);
  57
  58                 credential_clear(&want);
  59                 free(url);
  60
  61                 if (!matched)
  62                         return 0;
  63                 key = dot + 1;
  64         }
  65
  66         if (!strcmp(key, "helper")) {
  67                 if (*value)
  68                         string_list_append(&c->helpers, value);
  69                 else
  70                         string_list_clear(&c->helpers, 0);
  71         } else if (!strcmp(key, "username")) {
  72                 if (!c->username)
  73                         c->username = xstrdup(value);
  74         }
  75         else if (!strcmp(key, "usehttppath"))
  76                 c->use_http_path = git_config_bool(var, value);
  77
  78         return 0;
  79 }
  80
  81 static int proto_is_http(const char *s)
  82 {
  83         if (!s)
  84                 return 0;
  85         return !strcmp(s, "https") || !strcmp(s, "http");
  86 }
  87
  88 static void credential_apply_config(struct credential *c)
  89 {
  90         if (c->configured)
  91                 return;
  92         git_config(credential_config_callback, c);
  93         c->configured = 1;
  94
  95         if (!c->use_http_path && proto_is_http(c->protocol)) {
  96                 FREE_AND_NULL(c->path);
  97         }
  98 }
  99
 100 static void credential_describe(struct credential *c, struct strbuf *out)
 101 {
 102         if (!c->protocol)
 103                 return;
 104         strbuf_addf(out, "%s://", c->protocol);
 105         if (c->username && *c->username)
 106                 strbuf_addf(out, "%s@", c->username);
 107         if (c->host)
 108                 strbuf_addstr(out, c->host);
 109         if (c->path)
 110                 strbuf_addf(out, "/%s", c->path);
 111 }
 112
 113 static char *credential_ask_one(const char *what, struct credential *c,
 114                                 int flags)
 115 {
 116         struct strbuf desc = STRBUF_INIT;
 117         struct strbuf prompt = STRBUF_INIT;
 118         char *r;
 119
 120         credential_describe(c, &desc);
 121         if (desc.len)
 122                 strbuf_addf(&prompt, "%s for '%s': ", what, desc.buf);
 123         else
 124                 strbuf_addf(&prompt, "%s: ", what);
 125
 126         r = git_prompt(prompt.buf, flags);
 127
 128         strbuf_release(&desc);
 129         strbuf_release(&prompt);
 130         return xstrdup(r);
 131 }
 132
 133 static void credential_getpass(struct credential *c)
 134 {
 135         if (!c->username)
 136                 c->username = credential_ask_one("Username", c,
 137                                                  PROMPT_ASKPASS|PROMPT_ECHO);
 138         if (!c->password)
 139                 c->password = credential_ask_one("Password", c,
 140                                                  PROMPT_ASKPASS);
 141 }
 142
 143 int credential_read(struct credential *c, FILE *fp)
 144 {
 145         struct strbuf line = STRBUF_INIT;
 146
 147         while (strbuf_getline_lf(&line, fp) != EOF) {
 148                 char *key = line.buf;
 149                 char *value = strchr(key, '=');
 150
 151                 if (!line.len)
 152                         break;
 153
 154                 if (!value) {
 155                         warning("invalid credential line: %s", key);
 156                         strbuf_release(&line);
 157                         return -1;
 158                 }
 159                 *value++ = '\0';
 160
 161                 if (!strcmp(key, "username")) {
 162                         free(c->username);
 163                         c->username = xstrdup(value);
 164                 } else if (!strcmp(key, "password")) {
 165                         free(c->password);
 166                         c->password = xstrdup(value);
 167                 } else if (!strcmp(key, "protocol")) {
 168                         free(c->protocol);
 169                         c->protocol = xstrdup(value);
 170                 } else if (!strcmp(key, "host")) {
 171                         free(c->host);
 172                         c->host = xstrdup(value);
 173                 } else if (!strcmp(key, "path")) {
 174                         free(c->path);
 175                         c->path = xstrdup(value);
 176                 } else if (!strcmp(key, "url")) {
 177                         credential_from_url(c, value);
 178                 } else if (!strcmp(key, "quit")) {
 179                         c->quit = !!git_config_bool("quit", value);
 180                 }
 181                 /*
 182                  * Ignore other lines; we don't know what they mean, but
 183                  * this future-proofs us when later versions of git do
 184                  * learn new lines, and the helpers are updated to match.
 185                  */
 186         }
 187
 188         strbuf_release(&line);
 189         return 0;
 190 }
 191
 192 static void credential_write_item(FILE *fp, const char *key, const char *value)
 193 {
 194         if (!value)
 195                 return;
 196         fprintf(fp, "%s=%s\n", key, value);
 197 }
 198
 199 void credential_write(const struct credential *c, FILE *fp)
 200 {
 201         credential_write_item(fp, "protocol", c->protocol);
 202         credential_write_item(fp, "host", c->host);
 203         credential_write_item(fp, "path", c->path);
 204         credential_write_item(fp, "username", c->username);
 205         credential_write_item(fp, "password", c->password);
 206 }
 207
 208 static int run_credential_helper(struct credential *c,
 209                                  const char *cmd,
 210                                  int want_output)
 211 {
 212         struct child_process helper = CHILD_PROCESS_INIT;
 213         const char *argv[] = { NULL, NULL };
 214         FILE *fp;
 215
 216         argv[0] = cmd;
 217         helper.argv = argv;
 218         helper.use_shell = 1;
 219         helper.in = -1;
 220         if (want_output)
 221                 helper.out = -1;
 222         else
 223                 helper.no_stdout = 1;
 224
 225         if (start_command(&helper) < 0)
 226                 return -1;
 227
 228         fp = xfdopen(helper.in, "w");
 229         credential_write(c, fp);
 230         fclose(fp);
 231
 232         if (want_output) {
 233                 int r;
 234                 fp = xfdopen(helper.out, "r");
 235                 r = credential_read(c, fp);
 236                 fclose(fp);
 237                 if (r < 0) {
 238                         finish_command(&helper);
 239                         return -1;
 240                 }
 241         }
 242
 243         if (finish_command(&helper))
 244                 return -1;
 245         return 0;
 246 }
 247
 248 static int credential_do(struct credential *c, const char *helper,
 249                          const char *operation)
 250 {
 251         struct strbuf cmd = STRBUF_INIT;
 252         int r;
 253
 254         if (helper[0] == '!')
 255                 strbuf_addstr(&cmd, helper + 1);
 256         else if (is_absolute_path(helper))
 257                 strbuf_addstr(&cmd, helper);
 258         else
 259                 strbuf_addf(&cmd, "git credential-%s", helper);
 260
 261         strbuf_addf(&cmd, " %s", operation);
 262         r = run_credential_helper(c, cmd.buf, !strcmp(operation, "get"));
 263
 264         strbuf_release(&cmd);
 265         return r;
 266 }
 267
 268 void credential_fill(struct credential *c)
 269 {
 270         int i;
 271
 272         if (c->username && c->password)
 273                 return;
 274
 275         credential_apply_config(c);
 276
 277         for (i = 0; i < c->helpers.nr; i++) {
 278                 credential_do(c, c->helpers.items[i].string, "get");
 279                 if (c->username && c->password)
 280                         return;
 281                 if (c->quit)
 282                         die("credential helper '%s' told us to quit",
 283                             c->helpers.items[i].string);
 284         }
 285
 286         credential_getpass(c);
 287         if (!c->username && !c->password)
 288                 die("unable to get password from user");
 289 }
 290
 291 void credential_approve(struct credential *c)
 292 {
 293         int i;
 294
 295         if (c->approved)
 296                 return;
 297         if (!c->username || !c->password)
 298                 return;
 299
 300         credential_apply_config(c);
 301
 302         for (i = 0; i < c->helpers.nr; i++)
 303                 credential_do(c, c->helpers.items[i].string, "store");
 304         c->approved = 1;
 305 }
 306
 307 void credential_reject(struct credential *c)
 308 {
 309         int i;
 310
 311         credential_apply_config(c);
 312
 313         for (i = 0; i < c->helpers.nr; i++)
 314                 credential_do(c, c->helpers.items[i].string, "erase");
 315
 316         FREE_AND_NULL(c->username);
 317         FREE_AND_NULL(c->password);
 318         c->approved = 0;
 319 }
 320
 321 void credential_from_url(struct credential *c, const char *url)
 322 {
 323         const char *at, *colon, *cp, *slash, *host, *proto_end;
 324
 325         credential_clear(c);
 326
 327         /*
 328          * Match one of:
 329          *   (1) proto://<host>/...
 330          *   (2) proto://<user>@<host>/...
 331          *   (3) proto://<user>:<pass>@<host>/...
 332          */
 333         proto_end = strstr(url, "://");
 334         if (!proto_end)
 335                 return;
 336         cp = proto_end + 3;
 337         at = strchr(cp, '@');
 338         colon = strchr(cp, ':');
 339         slash = strchrnul(cp, '/');
 340
 341         if (!at || slash <= at) {
 342                 /* Case (1) */
 343                 host = cp;
 344         }
 345         else if (!colon || at <= colon) {
 346                 /* Case (2) */
 347                 c->username = url_decode_mem(cp, at - cp);
 348                 host = at + 1;
 349         } else {
 350                 /* Case (3) */
 351                 c->username = url_decode_mem(cp, colon - cp);
 352                 c->password = url_decode_mem(colon + 1, at - (colon + 1));
 353                 host = at + 1;
 354         }
 355
 356         if (proto_end - url > 0)
 357                 c->protocol = xmemdupz(url, proto_end - url);
 358         if (slash - host > 0)
 359                 c->host = url_decode_mem(host, slash - host);
 360         /* Trim leading and trailing slashes from path */
 361         while (*slash == '/')
 362                 slash++;
 363         if (*slash) {
 364                 char *p;
 365                 c->path = url_decode(slash);
 366                 p = c->path + strlen(c->path) - 1;
 367                 while (p > c->path && *p == '/')
 368                         *p-- = '\0';
 369         }
 370 }