apps/rehash.c

   1 /*
   2  * Copyright 2015-2016 The OpenSSL Project Authors. All Rights Reserved.
   3  *
   4  * Licensed under the OpenSSL license (the "License").  You may not use
   5  * this file except in compliance with the License.  You can obtain a copy
   6  * in the file LICENSE in the source distribution or at
   7  * https://www.openssl.org/source/license.html
   8  */
   9
  10 /*
  11  * C implementation based on the original Perl and shell versions
  12  *
  13  * Copyright (c) 2013-2014 Timo Teräs <timo.teras@iki.fi>
  14  */
  15
  16 #include "apps.h"
  17
  18 #if defined(OPENSSL_SYS_UNIX) || defined(__APPLE__) || \
  19     (defined(__VMS) && defined(__DECC) && __CTRL_VER >= 80300000)
  20 # include <unistd.h>
  21 # include <stdio.h>
  22 # include <limits.h>
  23 # include <errno.h>
  24 # include <string.h>
  25 # include <ctype.h>
  26 # include <sys/stat.h>
  27
  28 # include "internal/o_dir.h"
  29 # include <openssl/evp.h>
  30 # include <openssl/pem.h>
  31 # include <openssl/x509.h>
  32
  33
  34 # ifndef PATH_MAX
  35 #  define PATH_MAX 4096
  36 # endif
  37 # ifndef NAME_MAX
  38 #  define NAME_MAX 255
  39 # endif
  40 # define MAX_COLLISIONS  256
  41
  42 typedef struct hentry_st {
  43     struct hentry_st *next;
  44     char *filename;
  45     unsigned short old_id;
  46     unsigned char need_symlink;
  47     unsigned char digest[EVP_MAX_MD_SIZE];
  48 } HENTRY;
  49
  50 typedef struct bucket_st {
  51     struct bucket_st *next;
  52     HENTRY *first_entry, *last_entry;
  53     unsigned int hash;
  54     unsigned short type;
  55     unsigned short num_needed;
  56 } BUCKET;
  57
  58 enum Type {
  59     /* Keep in sync with |suffixes|, below. */
  60     TYPE_CERT=0, TYPE_CRL=1
  61 };
  62
  63 enum Hash {
  64     HASH_OLD, HASH_NEW, HASH_BOTH
  65 };
  66
  67
  68 static int evpmdsize;
  69 static const EVP_MD *evpmd;
  70 static int remove_links = 1;
  71 static int verbose = 0;
  72 static BUCKET *hash_table[257];
  73
  74 static const char *suffixes[] = { "", "r" };
  75 static const char *extensions[] = { "pem", "crt", "cer", "crl" };
  76
  77
  78 static void bit_set(unsigned char *set, unsigned int bit)
  79 {
  80     set[bit >> 3] |= 1 << (bit & 0x7);
  81 }
  82
  83 static int bit_isset(unsigned char *set, unsigned int bit)
  84 {
  85     return set[bit >> 3] & (1 << (bit & 0x7));
  86 }
  87
  88
  89 /*
  90  * Process an entry; return number of errors.
  91  */
  92 static int add_entry(enum Type type, unsigned int hash, const char *filename,
  93                       const unsigned char *digest, int need_symlink,
  94                       unsigned short old_id)
  95 {
  96     static BUCKET nilbucket;
  97     static HENTRY nilhentry;
  98     BUCKET *bp;
  99     HENTRY *ep, *found = NULL;
 100     unsigned int ndx = (type + hash) % OSSL_NELEM(hash_table);
 101
 102     for (bp = hash_table[ndx]; bp; bp = bp->next)
 103         if (bp->type == type && bp->hash == hash)
 104             break;
 105     if (bp == NULL) {
 106         bp = app_malloc(sizeof(*bp), "hash bucket");
 107         *bp = nilbucket;
 108         bp->next = hash_table[ndx];
 109         bp->type = type;
 110         bp->hash = hash;
 111         hash_table[ndx] = bp;
 112     }
 113
 114     for (ep = bp->first_entry; ep; ep = ep->next) {
 115         if (digest && memcmp(digest, ep->digest, evpmdsize) == 0) {
 116             BIO_printf(bio_err,
 117                        "%s: skipping duplicate %s in %s\n", opt_getprog(),
 118                        type == TYPE_CERT ? "certificate" : "CRL", filename);
 119             return 1;
 120         }
 121         if (strcmp(filename, ep->filename) == 0) {
 122             found = ep;
 123             if (digest == NULL)
 124                 break;
 125         }
 126     }
 127     ep = found;
 128     if (ep == NULL) {
 129         if (bp->num_needed >= MAX_COLLISIONS) {
 130             BIO_printf(bio_err,
 131                        "%s: hash table overflow for %s\n",
 132                        opt_getprog(), filename);
 133             return 1;
 134         }
 135         ep = app_malloc(sizeof(*ep), "collision bucket");
 136         *ep = nilhentry;
 137         ep->old_id = ~0;
 138         ep->filename = OPENSSL_strdup(filename);
 139         if (bp->last_entry)
 140             bp->last_entry->next = ep;
 141         if (bp->first_entry == NULL)
 142             bp->first_entry = ep;
 143         bp->last_entry = ep;
 144     }
 145
 146     if (old_id < ep->old_id)
 147         ep->old_id = old_id;
 148     if (need_symlink && !ep->need_symlink) {
 149         ep->need_symlink = 1;
 150         bp->num_needed++;
 151         memcpy(ep->digest, digest, evpmdsize);
 152     }
 153     return 0;
 154 }
 155
 156 /*
 157  * Check if a symlink goes to the right spot; return 0 if okay.
 158  * This can be -1 if bad filename, or an error count.
 159  */
 160 static int handle_symlink(const char *filename, const char *fullpath)
 161 {
 162     unsigned int hash = 0;
 163     int i, type, id;
 164     unsigned char ch;
 165     char linktarget[PATH_MAX], *endptr;
 166     ossl_ssize_t n;
 167
 168     for (i = 0; i < 8; i++) {
 169         ch = filename[i];
 170         if (!isxdigit(ch))
 171             return -1;
 172         hash <<= 4;
 173         hash += OPENSSL_hexchar2int(ch);
 174     }
 175     if (filename[i++] != '.')
 176         return -1;
 177     for (type = OSSL_NELEM(suffixes) - 1; type > 0; type--)
 178         if (strcasecmp(suffixes[type], &filename[i]) == 0)
 179             break;
 180     i += strlen(suffixes[type]);
 181
 182     id = strtoul(&filename[i], &endptr, 10);
 183     if (*endptr != '\0')
 184         return -1;
 185
 186     n = readlink(fullpath, linktarget, sizeof(linktarget));
 187     if (n < 0 || n >= (int)sizeof(linktarget))
 188         return -1;
 189     linktarget[n] = 0;
 190
 191     return add_entry(type, hash, linktarget, NULL, 0, id);
 192 }
 193
 194 /*
 195  * process a file, return number of errors.
 196  */
 197 static int do_file(const char *filename, const char *fullpath, enum Hash h)
 198 {
 199     STACK_OF (X509_INFO) *inf = NULL;
 200     X509_INFO *x;
 201     X509_NAME *name = NULL;
 202     BIO *b;
 203     const char *ext;
 204     unsigned char digest[EVP_MAX_MD_SIZE];
 205     int type, errs = 0;
 206     size_t i;
 207
 208     /* Does it end with a recognized extension? */
 209     if ((ext = strrchr(filename, '.')) == NULL)
 210         goto end;
 211     for (i = 0; i < OSSL_NELEM(extensions); i++) {
 212         if (strcasecmp(extensions[i], ext + 1) == 0)
 213             break;
 214     }
 215     if (i >= OSSL_NELEM(extensions))
 216         goto end;
 217
 218     /* Does it have X.509 data in it? */
 219     if ((b = BIO_new_file(fullpath, "r")) == NULL) {
 220         BIO_printf(bio_err, "%s: skipping %s, cannot open file\n",
 221                    opt_getprog(), filename);
 222         errs++;
 223         goto end;
 224     }
 225     inf = PEM_X509_INFO_read_bio(b, NULL, NULL, NULL);
 226     BIO_free(b);
 227     if (inf == NULL)
 228         goto end;
 229
 230     if (sk_X509_INFO_num(inf) != 1) {
 231         BIO_printf(bio_err,
 232                    "%s: skipping %s,"
 233                    "it does not contain exactly one certificate or CRL\n",
 234                    opt_getprog(), filename);
 235         /* This is not an error. */
 236         goto end;
 237     }
 238     x = sk_X509_INFO_value(inf, 0);
 239     if (x->x509) {
 240         type = TYPE_CERT;
 241         name = X509_get_subject_name(x->x509);
 242         X509_digest(x->x509, evpmd, digest, NULL);
 243     } else if (x->crl) {
 244         type = TYPE_CRL;
 245         name = X509_CRL_get_issuer(x->crl);
 246         X509_CRL_digest(x->crl, evpmd, digest, NULL);
 247     } else {
 248         ++errs;
 249         goto end;
 250     }
 251     if (name) {
 252         if ((h == HASH_NEW) || (h == HASH_BOTH))
 253             errs += add_entry(type, X509_NAME_hash(name), filename, digest, 1, ~0);
 254         if ((h == HASH_OLD) || (h == HASH_BOTH))
 255             errs += add_entry(type, X509_NAME_hash_old(name), filename, digest, 1, ~0);
 256     }
 257
 258 end:
 259     sk_X509_INFO_pop_free(inf, X509_INFO_free);
 260     return errs;
 261 }
 262
 263 static void str_free(char *s)
 264 {
 265     OPENSSL_free(s);
 266 }
 267
 268 /*
 269  * Process a directory; return number of errors found.
 270  */
 271 static int do_dir(const char *dirname, enum Hash h)
 272 {
 273     BUCKET *bp, *nextbp;
 274     HENTRY *ep, *nextep;
 275     OPENSSL_DIR_CTX *d = NULL;
 276     struct stat st;
 277     unsigned char idmask[MAX_COLLISIONS / 8];
 278     int n, numfiles, nextid, buflen, errs = 0;
 279     size_t i;
 280     const char *pathsep;
 281     const char *filename;
 282     char *buf, *copy;
 283     STACK_OF(OPENSSL_STRING) *files = NULL;
 284
 285     if (app_access(dirname, W_OK) < 0) {
 286         BIO_printf(bio_err, "Skipping %s, can't write\n", dirname);
 287         return 1;
 288     }
 289     buflen = strlen(dirname);
 290     pathsep = (buflen && dirname[buflen - 1] == '/') ? "" : "/";
 291     buflen += NAME_MAX + 1 + 1;
 292     buf = app_malloc(buflen, "filename buffer");
 293
 294     if (verbose)
 295         BIO_printf(bio_out, "Doing %s\n", dirname);
 296
 297     if ((files = sk_OPENSSL_STRING_new_null()) == NULL) {
 298         BIO_printf(bio_err, "Skipping %s, out of memory\n", dirname);
 299         exit(1);
 300     }
 301     while ((filename = OPENSSL_DIR_read(&d, dirname)) != NULL) {
 302         if ((copy = strdup(filename)) == NULL
 303                 || sk_OPENSSL_STRING_push(files, copy) == 0) {
 304             BIO_puts(bio_err, "out of memory\n");
 305             exit(1);
 306         }
 307     }
 308     OPENSSL_DIR_end(&d);
 309     sk_OPENSSL_STRING_sort(files);
 310
 311     numfiles = sk_OPENSSL_STRING_num(files);
 312     for (n = 0; n < numfiles; ++n) {
 313         filename = sk_OPENSSL_STRING_value(files, n);
 314         if (snprintf(buf, buflen, "%s%s%s",
 315                     dirname, pathsep, filename) >= buflen)
 316             continue;
 317         if (lstat(buf, &st) < 0)
 318             continue;
 319         if (S_ISLNK(st.st_mode) && handle_symlink(filename, buf) == 0)
 320             continue;
 321         errs += do_file(filename, buf, h);
 322     }
 323     sk_OPENSSL_STRING_pop_free(files, str_free);
 324
 325     for (i = 0; i < OSSL_NELEM(hash_table); i++) {
 326         for (bp = hash_table[i]; bp; bp = nextbp) {
 327             nextbp = bp->next;
 328             nextid = 0;
 329             memset(idmask, 0, (bp->num_needed + 7) / 8);
 330             for (ep = bp->first_entry; ep; ep = ep->next)
 331                 if (ep->old_id < bp->num_needed)
 332                     bit_set(idmask, ep->old_id);
 333
 334             for (ep = bp->first_entry; ep; ep = nextep) {
 335                 nextep = ep->next;
 336                 if (ep->old_id < bp->num_needed) {
 337                     /* Link exists, and is used as-is */
 338                     snprintf(buf, buflen, "%08x.%s%d", bp->hash,
 339                              suffixes[bp->type], ep->old_id);
 340                     if (verbose)
 341                         BIO_printf(bio_out, "link %s -> %s\n",
 342                                    ep->filename, buf);
 343                 } else if (ep->need_symlink) {
 344                     /* New link needed (it may replace something) */
 345                     while (bit_isset(idmask, nextid))
 346                         nextid++;
 347
 348                     snprintf(buf, buflen, "%s%s%n%08x.%s%d",
 349                              dirname, pathsep, &n, bp->hash,
 350                              suffixes[bp->type], nextid);
 351                     if (verbose)
 352                         BIO_printf(bio_out, "link %s -> %s\n",
 353                                    ep->filename, &buf[n]);
 354                     if (unlink(buf) < 0 && errno != ENOENT) {
 355                         BIO_printf(bio_err,
 356                                    "%s: Can't unlink %s, %s\n",
 357                                    opt_getprog(), buf, strerror(errno));
 358                         errs++;
 359                     }
 360                     if (symlink(ep->filename, buf) < 0) {
 361                         BIO_printf(bio_err,
 362                                    "%s: Can't symlink %s, %s\n",
 363                                    opt_getprog(), ep->filename,
 364                                    strerror(errno));
 365                         errs++;
 366                     }
 367                 } else if (remove_links) {
 368                     /* Link to be deleted */
 369                     snprintf(buf, buflen, "%s%s%n%08x.%s%d",
 370                              dirname, pathsep, &n, bp->hash,
 371                              suffixes[bp->type], ep->old_id);
 372                     if (verbose)
 373                         BIO_printf(bio_out, "unlink %s\n",
 374                                    &buf[n]);
 375                     if (unlink(buf) < 0 && errno != ENOENT) {
 376                         BIO_printf(bio_err,
 377                                    "%s: Can't unlink %s, %s\n",
 378                                    opt_getprog(), buf, strerror(errno));
 379                         errs++;
 380                     }
 381                 }
 382                 OPENSSL_free(ep->filename);
 383                 OPENSSL_free(ep);
 384             }
 385             OPENSSL_free(bp);
 386         }
 387         hash_table[i] = NULL;
 388     }
 389
 390     OPENSSL_free(buf);
 391     return errs;
 392 }
 393
 394 typedef enum OPTION_choice {
 395     OPT_ERR = -1, OPT_EOF = 0, OPT_HELP,
 396     OPT_COMPAT, OPT_OLD, OPT_N, OPT_VERBOSE
 397 } OPTION_CHOICE;
 398
 399 OPTIONS rehash_options[] = {
 400     {OPT_HELP_STR, 1, '-', "Usage: %s [options] [cert-directory...]\n"},
 401     {OPT_HELP_STR, 1, '-', "Valid options are:\n"},
 402     {"help", OPT_HELP, '-', "Display this summary"},
 403     {"compat", OPT_COMPAT, '-', "Create both new- and old-style hash links"},
 404     {"old", OPT_OLD, '-', "Use old-style hash to generate links"},
 405     {"n", OPT_N, '-', "Do not remove existing links"},
 406     {"v", OPT_VERBOSE, '-', "Verbose output"},
 407     {NULL}
 408 };
 409
 410
 411 int rehash_main(int argc, char **argv)
 412 {
 413     const char *env, *prog;
 414     char *e, *m;
 415     int errs = 0;
 416     OPTION_CHOICE o;
 417     enum Hash h = HASH_NEW;
 418
 419     prog = opt_init(argc, argv, rehash_options);
 420     while ((o = opt_next()) != OPT_EOF) {
 421         switch (o) {
 422         case OPT_EOF:
 423         case OPT_ERR:
 424             BIO_printf(bio_err, "%s: Use -help for summary.\n", prog);
 425             goto end;
 426         case OPT_HELP:
 427             opt_help(rehash_options);
 428             goto end;
 429         case OPT_COMPAT:
 430             h = HASH_BOTH;
 431             break;
 432         case OPT_OLD:
 433             h = HASH_OLD;
 434             break;
 435         case OPT_N:
 436             remove_links = 0;
 437             break;
 438         case OPT_VERBOSE:
 439             verbose = 1;
 440             break;
 441         }
 442     }
 443     argc = opt_num_rest();
 444     argv = opt_rest();
 445
 446     evpmd = EVP_sha1();
 447     evpmdsize = EVP_MD_size(evpmd);
 448
 449     if (*argv) {
 450         while (*argv)
 451             errs += do_dir(*argv++, h);
 452     } else if ((env = getenv("SSL_CERT_DIR")) != NULL) {
 453         m = OPENSSL_strdup(env);
 454         for (e = strtok(m, ":"); e != NULL; e = strtok(NULL, ":"))
 455             errs += do_dir(e, h);
 456         OPENSSL_free(m);
 457     } else {
 458         errs += do_dir("/etc/ssl/certs", h);
 459     }
 460
 461  end:
 462     return errs;
 463 }
 464
 465 #else
 466 OPTIONS rehash_options[] = {
 467     {NULL}
 468 };
 469
 470 int rehash_main(int argc, char **argv)
 471 {
 472     BIO_printf(bio_err, "Not available; use c_rehash script\n");
 473     return (1);
 474 }
 475
 476 #endif /* defined(OPENSSL_SYS_UNIX) || defined(__APPLE__) */