credential.c

   1 #include "cache.h"
   2 #include "credential.h"
   3 #include "string-list.h"
   4 #include "run-command.h"
   5
   6 void credential_init(struct credential *c)
   7 {
   8         memset(c, 0, sizeof(*c));
   9         c->helpers.strdup_strings = 1;
  10 }
  11
  12 void credential_clear(struct credential *c)
  13 {
  14         free(c->protocol);
  15         free(c->host);
  16         free(c->path);
  17         free(c->username);
  18         free(c->password);
  19         string_list_clear(&c->helpers, 0);
  20
  21         credential_init(c);
  22 }
  23
  24 static void credential_describe(struct credential *c, struct strbuf *out)
  25 {
  26         if (!c->protocol)
  27                 return;
  28         strbuf_addf(out, "%s://", c->protocol);
  29         if (c->username && *c->username)
  30                 strbuf_addf(out, "%s@", c->username);
  31         if (c->host)
  32                 strbuf_addstr(out, c->host);
  33         if (c->path)
  34                 strbuf_addf(out, "/%s", c->path);
  35 }
  36
  37 static char *credential_ask_one(const char *what, struct credential *c)
  38 {
  39         struct strbuf desc = STRBUF_INIT;
  40         struct strbuf prompt = STRBUF_INIT;
  41         char *r;
  42
  43         credential_describe(c, &desc);
  44         if (desc.len)
  45                 strbuf_addf(&prompt, "%s for '%s': ", what, desc.buf);
  46         else
  47                 strbuf_addf(&prompt, "%s: ", what);
  48
  49         /* FIXME: for usernames, we should do something less magical that
  50          * actually echoes the characters. However, we need to read from
  51          * /dev/tty and not stdio, which is not portable (but getpass will do
  52          * it for us). http.c uses the same workaround. */
  53         r = git_getpass(prompt.buf);
  54
  55         strbuf_release(&desc);
  56         strbuf_release(&prompt);
  57         return xstrdup(r);
  58 }
  59
  60 static void credential_getpass(struct credential *c)
  61 {
  62         if (!c->username)
  63                 c->username = credential_ask_one("Username", c);
  64         if (!c->password)
  65                 c->password = credential_ask_one("Password", c);
  66 }
  67
  68 int credential_read(struct credential *c, FILE *fp)
  69 {
  70         struct strbuf line = STRBUF_INIT;
  71
  72         while (strbuf_getline(&line, fp, '\n') != EOF) {
  73                 char *key = line.buf;
  74                 char *value = strchr(key, '=');
  75
  76                 if (!line.len)
  77                         break;
  78
  79                 if (!value) {
  80                         warning("invalid credential line: %s", key);
  81                         strbuf_release(&line);
  82                         return -1;
  83                 }
  84                 *value++ = '\0';
  85
  86                 if (!strcmp(key, "username")) {
  87                         free(c->username);
  88                         c->username = xstrdup(value);
  89                 } else if (!strcmp(key, "password")) {
  90                         free(c->password);
  91                         c->password = xstrdup(value);
  92                 } else if (!strcmp(key, "protocol")) {
  93                         free(c->protocol);
  94                         c->protocol = xstrdup(value);
  95                 } else if (!strcmp(key, "host")) {
  96                         free(c->host);
  97                         c->host = xstrdup(value);
  98                 } else if (!strcmp(key, "path")) {
  99                         free(c->path);
 100                         c->path = xstrdup(value);
 101                 }
 102                 /*
 103                  * Ignore other lines; we don't know what they mean, but
 104                  * this future-proofs us when later versions of git do
 105                  * learn new lines, and the helpers are updated to match.
 106                  */
 107         }
 108
 109         strbuf_release(&line);
 110         return 0;
 111 }
 112
 113 static void credential_write_item(FILE *fp, const char *key, const char *value)
 114 {
 115         if (!value)
 116                 return;
 117         fprintf(fp, "%s=%s\n", key, value);
 118 }
 119
 120 static void credential_write(const struct credential *c, FILE *fp)
 121 {
 122         credential_write_item(fp, "protocol", c->protocol);
 123         credential_write_item(fp, "host", c->host);
 124         credential_write_item(fp, "path", c->path);
 125         credential_write_item(fp, "username", c->username);
 126         credential_write_item(fp, "password", c->password);
 127 }
 128
 129 static int run_credential_helper(struct credential *c,
 130                                  const char *cmd,
 131                                  int want_output)
 132 {
 133         struct child_process helper;
 134         const char *argv[] = { NULL, NULL };
 135         FILE *fp;
 136
 137         memset(&helper, 0, sizeof(helper));
 138         argv[0] = cmd;
 139         helper.argv = argv;
 140         helper.use_shell = 1;
 141         helper.in = -1;
 142         if (want_output)
 143                 helper.out = -1;
 144         else
 145                 helper.no_stdout = 1;
 146
 147         if (start_command(&helper) < 0)
 148                 return -1;
 149
 150         fp = xfdopen(helper.in, "w");
 151         credential_write(c, fp);
 152         fclose(fp);
 153
 154         if (want_output) {
 155                 int r;
 156                 fp = xfdopen(helper.out, "r");
 157                 r = credential_read(c, fp);
 158                 fclose(fp);
 159                 if (r < 0) {
 160                         finish_command(&helper);
 161                         return -1;
 162                 }
 163         }
 164
 165         if (finish_command(&helper))
 166                 return -1;
 167         return 0;
 168 }
 169
 170 static int credential_do(struct credential *c, const char *helper,
 171                          const char *operation)
 172 {
 173         struct strbuf cmd = STRBUF_INIT;
 174         int r;
 175
 176         if (helper[0] == '!')
 177                 strbuf_addstr(&cmd, helper + 1);
 178         else if (is_absolute_path(helper))
 179                 strbuf_addstr(&cmd, helper);
 180         else
 181                 strbuf_addf(&cmd, "git credential-%s", helper);
 182
 183         strbuf_addf(&cmd, " %s", operation);
 184         r = run_credential_helper(c, cmd.buf, !strcmp(operation, "get"));
 185
 186         strbuf_release(&cmd);
 187         return r;
 188 }
 189
 190 void credential_fill(struct credential *c)
 191 {
 192         int i;
 193
 194         if (c->username && c->password)
 195                 return;
 196
 197         for (i = 0; i < c->helpers.nr; i++) {
 198                 credential_do(c, c->helpers.items[i].string, "get");
 199                 if (c->username && c->password)
 200                         return;
 201         }
 202
 203         credential_getpass(c);
 204         if (!c->username && !c->password)
 205                 die("unable to get password from user");
 206 }
 207
 208 void credential_approve(struct credential *c)
 209 {
 210         int i;
 211
 212         if (c->approved)
 213                 return;
 214         if (!c->username || !c->password)
 215                 return;
 216
 217         for (i = 0; i < c->helpers.nr; i++)
 218                 credential_do(c, c->helpers.items[i].string, "store");
 219         c->approved = 1;
 220 }
 221
 222 void credential_reject(struct credential *c)
 223 {
 224         int i;
 225
 226         for (i = 0; i < c->helpers.nr; i++)
 227                 credential_do(c, c->helpers.items[i].string, "erase");
 228
 229         free(c->username);
 230         c->username = NULL;
 231         free(c->password);
 232         c->password = NULL;
 233         c->approved = 0;
 234 }