Andrew's git / gitweb.git / credential.c
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credential.con commit transport-helper: barf when user tries old:new (67c9c78)
   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
   8void credential_init(struct credential *c)
   9{
  10        memset(c, 0, sizeof(*c));
  11        c->helpers.strdup_strings = 1;
  12}
  13
  14void 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
  26int 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
  37static 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
  79static int proto_is_http(const char *s)
  80{
  81        if (!s)
  82                return 0;
  83        return !strcmp(s, "https") || !strcmp(s, "http");
  84}
  85
  86static 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
  99static 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
 112static 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
 132static 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
 142int 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
 189static 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
 196void 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
 205static 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
 246static 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
 266void 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
 286void 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
 302void 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
 318void 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}