git.distorted.org.uk Git - u/mdw/putty/blob - unix/uxstore.c

   1 /*
   2  * uxstore.c: Unix-specific implementation of the interface defined
   3  * in storage.h.
   4  */
   5
   6 #include <stdio.h>
   7 #include <stdlib.h>
   8 #include <ctype.h>
   9 #include <unistd.h>
  10 #include <fcntl.h>
  11 #include <sys/stat.h>
  12 #include <sys/types.h>
  13 #include "putty.h"
  14 #include "storage.h"
  15 #include "tree234.h"
  16
  17 /*
  18  * For the moment, the only existing Unix utility is pterm and that
  19  * has no GUI configuration at all, so our write routines need do
  20  * nothing. Eventually I suppose these will read and write an rc
  21  * file somewhere or other.
  22  */
  23
  24 void *open_settings_w(char *sessionname)
  25 {
  26     return NULL;
  27 }
  28
  29 void write_setting_s(void *handle, char *key, char *value)
  30 {
  31 }
  32
  33 void write_setting_i(void *handle, char *key, int value)
  34 {
  35 }
  36
  37 void close_settings_w(void *handle)
  38 {
  39 }
  40
  41 /*
  42  * Reading settings, for the moment, is done by retrieving X
  43  * resources from the X display. When we introduce disk files, I
  44  * think what will happen is that the X resources will override
  45  * PuTTY's inbuilt defaults, but that the disk files will then
  46  * override those. This isn't optimal, but it's the best I can
  47  * immediately work out.
  48  */
  49
  50 struct xrm_string {
  51     char *key;
  52     char *value;
  53 };
  54
  55 static tree234 *xrmtree = NULL;
  56
  57 int xrmcmp(void *av, void *bv)
  58 {
  59     struct xrm_string *a = (struct xrm_string *)av;
  60     struct xrm_string *b = (struct xrm_string *)bv;
  61     return strcmp(a->key, b->key);
  62 }
  63
  64 void provide_xrm_string(char *string)
  65 {
  66     char *p, *q;
  67     struct xrm_string *xrms, *ret;
  68
  69     p = q = strchr(string, ':');
  70     if (!q) {
  71         fprintf(stderr, "pterm: expected a colon in resource string"
  72                 " \"%s\"\n", string);
  73         return;
  74     }
  75     q++;
  76     while (p > string && p[-1] != '.' && p[-1] != '*')
  77         p--;
  78     xrms = smalloc(sizeof(struct xrm_string));
  79     xrms->key = smalloc(q-p);
  80     memcpy(xrms->key, p, q-p);
  81     xrms->key[q-p-1] = '\0';
  82     while (*q && isspace(*q))
  83         q++;
  84     xrms->value = dupstr(q);
  85
  86     if (!xrmtree)
  87         xrmtree = newtree234(xrmcmp);
  88
  89     ret = add234(xrmtree, xrms);
  90     if (ret) {
  91         /* Override an existing string. */
  92         del234(xrmtree, ret);
  93         add234(xrmtree, xrms);
  94     }
  95 }
  96
  97 char *get_setting(char *key)
  98 {
  99     struct xrm_string tmp, *ret;
 100     tmp.key = key;
 101     if (xrmtree) {
 102         ret = find234(xrmtree, &tmp, NULL);
 103         if (ret)
 104             return ret->value;
 105     }
 106     return x_get_default(key);
 107 }
 108
 109 void *open_settings_r(char *sessionname)
 110 {
 111     static int thing_to_return_an_arbitrary_non_null_pointer_to;
 112     return &thing_to_return_an_arbitrary_non_null_pointer_to;
 113 }
 114
 115 char *read_setting_s(void *handle, char *key, char *buffer, int buflen)
 116 {
 117     char *val = get_setting(key);
 118     if (!val)
 119         return NULL;
 120     else {
 121         strncpy(buffer, val, buflen);
 122         buffer[buflen-1] = '\0';
 123         return buffer;
 124     }
 125 }
 126
 127 int read_setting_i(void *handle, char *key, int defvalue)
 128 {
 129     char *val = get_setting(key);
 130     if (!val)
 131         return defvalue;
 132     else
 133         return atoi(val);
 134 }
 135
 136 void close_settings_r(void *handle)
 137 {
 138 }
 139
 140 void del_settings(char *sessionname)
 141 {
 142 }
 143
 144 void *enum_settings_start(void)
 145 {
 146     return NULL;
 147 }
 148
 149 char *enum_settings_next(void *handle, char *buffer, int buflen)
 150 {
 151     return NULL;
 152 }
 153
 154 void enum_settings_finish(void *handle)
 155 {
 156 }
 157
 158 enum {
 159     INDEX_DIR, INDEX_HOSTKEYS
 160 };
 161
 162 static void make_filename(char *filename, int index)
 163 {
 164     char *home;
 165     int len;
 166     home = getenv("HOME");
 167     strncpy(filename, home, FILENAME_MAX);
 168     len = strlen(filename);
 169     strncpy(filename + len,
 170             index == INDEX_DIR ? "/.putty" :
 171             index == INDEX_HOSTKEYS ? "/.putty/sshhostkeys" :
 172             "/.putty/ERROR", FILENAME_MAX - len);
 173     filename[FILENAME_MAX-1] = '\0';
 174 }
 175
 176 /*
 177  * Read an entire line of text from a file. Return a buffer
 178  * malloced to be as big as necessary (caller must free).
 179  */
 180 static char *fgetline(FILE *fp)
 181 {
 182     char *ret = smalloc(512);
 183     int size = 512, len = 0;
 184     while (fgets(ret + len, size - len, fp)) {
 185         len += strlen(ret + len);
 186         if (ret[len-1] == '\n')
 187             break;                     /* got a newline, we're done */
 188         size = len + 512;
 189         ret = srealloc(ret, size);
 190     }
 191     if (len == 0) {                    /* first fgets returned NULL */
 192         sfree(ret);
 193         return NULL;
 194     }
 195     ret[len] = '\0';
 196     return ret;
 197 }
 198
 199 /*
 200  * Lines in the host keys file are of the form
 201  *
 202  *   type@port:hostname keydata
 203  *
 204  * e.g.
 205  *
 206  *   rsa@22:foovax.example.org 0x23,0x293487364395345345....2343
 207  */
 208 int verify_host_key(char *hostname, int port, char *keytype, char *key)
 209 {
 210     FILE *fp;
 211     char filename[FILENAME_MAX];
 212     char *line;
 213     int ret;
 214
 215     make_filename(filename, INDEX_HOSTKEYS);
 216     fp = fopen(filename, "r");
 217     if (!fp)
 218         return 1;                      /* key does not exist */
 219
 220     ret = 1;
 221     while ( (line = fgetline(fp)) ) {
 222         int i;
 223         char *p = line;
 224         char porttext[20];
 225
 226         line[strcspn(line, "\n")] = '\0';   /* strip trailing newline */
 227
 228         i = strlen(keytype);
 229         if (strncmp(p, keytype, i))
 230             goto done;
 231         p += i;
 232
 233         if (*p != '@')
 234             goto done;
 235         p++;
 236
 237         sprintf(porttext, "%d", port);
 238         i = strlen(porttext);
 239         if (strncmp(p, porttext, i))
 240             goto done;
 241         p += i;
 242
 243         if (*p != ':')
 244             goto done;
 245         p++;
 246
 247         i = strlen(hostname);
 248         if (strncmp(p, hostname, i))
 249             goto done;
 250         p += i;
 251
 252         if (*p != ' ')
 253             goto done;
 254         p++;
 255
 256         /*
 257          * Found the key. Now just work out whether it's the right
 258          * one or not.
 259          */
 260         if (!strcmp(p, key))
 261             ret = 0;                   /* key matched OK */
 262         else
 263             ret = 2;                   /* key mismatch */
 264
 265         done:
 266         sfree(line);
 267         if (ret != 1)
 268             break;
 269     }
 270
 271     return ret;
 272 }
 273
 274 void store_host_key(char *hostname, int port, char *keytype, char *key)
 275 {
 276     FILE *fp;
 277     int fd;
 278     char filename[FILENAME_MAX];
 279
 280     make_filename(filename, INDEX_HOSTKEYS);
 281     fd = open(filename, O_CREAT | O_APPEND | O_RDWR, 0600);
 282     if (fd < 0) {
 283         char dir[FILENAME_MAX];
 284
 285         make_filename(dir, INDEX_DIR);
 286         mkdir(dir, 0700);
 287         fd = open(filename, O_CREAT | O_APPEND | O_RDWR, 0600);
 288     }
 289     if (fd < 0) {
 290         perror(filename);
 291         exit(1);
 292     }
 293     fp = fdopen(fd, "a");
 294     fprintf(fp, "%s@%d:%s %s\n", keytype, port, hostname, key);
 295     fclose(fp);
 296 }
 297
 298 void read_random_seed(noise_consumer_t consumer)
 299 {
 300 }
 301
 302 void write_random_seed(void *data, int len)
 303 {
 304 }
 305
 306 void cleanup_all(void)
 307 {
 308 }