credential-store.c

   1 #include "cache.h"
   2 #include "lockfile.h"
   3 #include "credential.h"
   4 #include "string-list.h"
   5 #include "parse-options.h"
   6
   7 static struct lock_file credential_lock;
   8
   9 static void parse_credential_file(const char *fn,
  10                                   struct credential *c,
  11                                   void (*match_cb)(struct credential *),
  12                                   void (*other_cb)(struct strbuf *))
  13 {
  14         FILE *fh;
  15         struct strbuf line = STRBUF_INIT;
  16         struct credential entry = CREDENTIAL_INIT;
  17
  18         fh = fopen(fn, "r");
  19         if (!fh) {
  20                 if (errno != ENOENT)
  21                         die_errno("unable to open %s", fn);
  22                 return;
  23         }
  24
  25         while (strbuf_getline(&line, fh, '\n') != EOF) {
  26                 credential_from_url(&entry, line.buf);
  27                 if (entry.username && entry.password &&
  28                     credential_match(c, &entry)) {
  29                         if (match_cb) {
  30                                 match_cb(&entry);
  31                                 break;
  32                         }
  33                 }
  34                 else if (other_cb)
  35                         other_cb(&line);
  36         }
  37
  38         credential_clear(&entry);
  39         strbuf_release(&line);
  40         fclose(fh);
  41 }
  42
  43 static void print_entry(struct credential *c)
  44 {
  45         printf("username=%s\n", c->username);
  46         printf("password=%s\n", c->password);
  47 }
  48
  49 static void print_line(struct strbuf *buf)
  50 {
  51         strbuf_addch(buf, '\n');
  52         write_or_die(credential_lock.fd, buf->buf, buf->len);
  53 }
  54
  55 static void rewrite_credential_file(const char *fn, struct credential *c,
  56                                     struct strbuf *extra)
  57 {
  58         if (hold_lock_file_for_update(&credential_lock, fn, 0) < 0)
  59                 die_errno("unable to get credential storage lock");
  60         if (extra)
  61                 print_line(extra);
  62         parse_credential_file(fn, c, NULL, print_line);
  63         if (commit_lock_file(&credential_lock) < 0)
  64                 die_errno("unable to commit credential store");
  65 }
  66
  67 static void store_credential(const char *fn, struct credential *c)
  68 {
  69         struct strbuf buf = STRBUF_INIT;
  70
  71         /*
  72          * Sanity check that what we are storing is actually sensible.
  73          * In particular, we can't make a URL without a protocol field.
  74          * Without either a host or pathname (depending on the scheme),
  75          * we have no primary key. And without a username and password,
  76          * we are not actually storing a credential.
  77          */
  78         if (!c->protocol || !(c->host || c->path) ||
  79             !c->username || !c->password)
  80                 return;
  81
  82         strbuf_addf(&buf, "%s://", c->protocol);
  83         strbuf_addstr_urlencode(&buf, c->username, 1);
  84         strbuf_addch(&buf, ':');
  85         strbuf_addstr_urlencode(&buf, c->password, 1);
  86         strbuf_addch(&buf, '@');
  87         if (c->host)
  88                 strbuf_addstr_urlencode(&buf, c->host, 1);
  89         if (c->path) {
  90                 strbuf_addch(&buf, '/');
  91                 strbuf_addstr_urlencode(&buf, c->path, 0);
  92         }
  93
  94         rewrite_credential_file(fn, c, &buf);
  95         strbuf_release(&buf);
  96 }
  97
  98 static void remove_credential(const char *fn, struct credential *c)
  99 {
 100         /*
 101          * Sanity check that we actually have something to match
 102          * against. The input we get is a restrictive pattern,
 103          * so technically a blank credential means "erase everything".
 104          * But it is too easy to accidentally send this, since it is equivalent
 105          * to empty input. So explicitly disallow it, and require that the
 106          * pattern have some actual content to match.
 107          */
 108         if (c->protocol || c->host || c->path || c->username)
 109                 rewrite_credential_file(fn, c, NULL);
 110 }
 111
 112 static int lookup_credential(const char *fn, struct credential *c)
 113 {
 114         parse_credential_file(fn, c, print_entry, NULL);
 115         return c->username && c->password;
 116 }
 117
 118 int main(int argc, char **argv)
 119 {
 120         const char * const usage[] = {
 121                 "git credential-store [options] <action>",
 122                 NULL
 123         };
 124         const char *op;
 125         struct credential c = CREDENTIAL_INIT;
 126         char *file = NULL;
 127         struct option options[] = {
 128                 OPT_STRING(0, "file", &file, "path",
 129                            "fetch and store credentials in <path>"),
 130                 OPT_END()
 131         };
 132
 133         umask(077);
 134
 135         argc = parse_options(argc, (const char **)argv, NULL, options, usage, 0);
 136         if (argc != 1)
 137                 usage_with_options(usage, options);
 138         op = argv[0];
 139
 140         if (!file)
 141                 file = expand_user_path("~/.git-credentials");
 142         if (!file)
 143                 die("unable to set up default path; use --file");
 144
 145         if (credential_read(&c, stdin) < 0)
 146                 die("unable to read credential");
 147
 148         if (!strcmp(op, "get"))
 149                 lookup_credential(file, &c);
 150         else if (!strcmp(op, "erase"))
 151                 remove_credential(file, &c);
 152         else if (!strcmp(op, "store"))
 153                 store_credential(file, &c);
 154         else
 155                 ; /* Ignore unknown operation. */
 156
 157         return 0;
 158 }