text: /*
   * Copyright 2015-2018 The OpenSSL Project Authors. All Rights Reserved.
   * Copyright (c) 2013-2014 Timo Teräs <timo.teras@gmail.com>
   *
   * Licensed under the Apache License 2.0 (the "License").  You may not use
   * this file except in compliance with the License.  You can obtain a copy
   * in the file LICENSE in the source distribution or at
   * https://www.openssl.org/source/license.html
   */
  
  #include "apps.h"
  #include "progs.h"
  
  #if defined(OPENSSL_SYS_UNIX) || defined(__APPLE__) || \
      (defined(__VMS) && defined(__DECC) && __CRTL_VER >= 80300000)
  # include <unistd.h>
  # include <stdio.h>
  # include <limits.h>
  # include <errno.h>
  # include <string.h>
  # include <ctype.h>
  # include <sys/stat.h>
  
  /*
   * Make sure that the processing of symbol names is treated the same as when
   * libcrypto is built.  This is done automatically for public headers (see
   * include/openssl/__DECC_INCLUDE_PROLOGUE.H and __DECC_INCLUDE_EPILOGUE.H),
   * but not for internal headers.
   */
  # ifdef __VMS
  #  pragma names save
  #  pragma names as_is,shortened
  # endif
  
  # include "internal/o_dir.h"
  
  # ifdef __VMS
  #  pragma names restore
  # endif
  
  # include <openssl/evp.h>
  # include <openssl/pem.h>
  # include <openssl/x509.h>
  
  
  # ifndef PATH_MAX
  #  define PATH_MAX 4096
  # endif
  # ifndef NAME_MAX
  #  define NAME_MAX 255
  # endif
  # define MAX_COLLISIONS  256
  
  # if defined(OPENSSL_SYS_VXWORKS)
  /*
   * VxWorks has no symbolic links
   */
  
  #  define lstat(path, buf) stat(path, buf)
  
  int symlink(const char *target, const char *linkpath)
  {
      errno = ENOSYS;
      return -1;
  }
  
  ssize_t readlink(const char *pathname, char *buf, size_t bufsiz)
  {
      errno = ENOSYS;
      return -1;
  }
  # endif
  
  typedef struct hentry_st {
      struct hentry_st *next;
      char *filename;
      unsigned short old_id;
      unsigned char need_symlink;
      unsigned char digest[EVP_MAX_MD_SIZE];
  } HENTRY;
  
  typedef struct bucket_st {
      struct bucket_st *next;
      HENTRY *first_entry, *last_entry;
      unsigned int hash;
      unsigned short type;
      unsigned short num_needed;
  } BUCKET;
  
  enum Type {
      /* Keep in sync with |suffixes|, below. */
      TYPE_CERT=0, TYPE_CRL=1
  };
  
  enum Hash {
      HASH_OLD, HASH_NEW, HASH_BOTH
  };
  
  
  static int evpmdsize;
  static const EVP_MD *evpmd;
  static int remove_links = 1;
  static int verbose = 0;
  static BUCKET *hash_table[257];
  
  static const char *suffixes[] = { "", "r" };
  static const char *extensions[] = { "pem", "crt", "cer", "crl" };
  
  
  static void bit_set(unsigned char *set, unsigned int bit)
  {
      set[bit >> 3] |= 1 << (bit & 0x7);
  }
  
  static int bit_isset(unsigned char *set, unsigned int bit)
  {
      return set[bit >> 3] & (1 << (bit & 0x7));
  }
  
  
  /*
   * Process an entry; return number of errors.
   */
  static int add_entry(enum Type type, unsigned int hash, const char *filename,
                        const unsigned char *digest, int need_symlink,
                        unsigned short old_id)
  {
      static BUCKET nilbucket;
      static HENTRY nilhentry;
      BUCKET *bp;
      HENTRY *ep, *found = NULL;
      unsigned int ndx = (type + hash) % OSSL_NELEM(hash_table);
  
      for (bp = hash_table[ndx]; bp; bp = bp->next)
          if (bp->type == type && bp->hash == hash)
              break;
      if (bp == NULL) {
          bp = app_malloc(sizeof(*bp), "hash bucket");
          *bp = nilbucket;
          bp->next = hash_table[ndx];
          bp->type = type;
          bp->hash = hash;
          hash_table[ndx] = bp;
      }
  
      for (ep = bp->first_entry; ep; ep = ep->next) {
          if (digest && memcmp(digest, ep->digest, evpmdsize) == 0) {
              BIO_printf(bio_err,
                         "%s: warning: skipping duplicate %s in %s\n",
                         opt_getprog(),
                         type == TYPE_CERT ? "certificate" : "CRL", filename);
              return 0;
          }
          if (strcmp(filename, ep->filename) == 0) {
              found = ep;
              if (digest == NULL)
                  break;
          }
      }
      ep = found;
      if (ep == NULL) {
          if (bp->num_needed >= MAX_COLLISIONS) {
              BIO_printf(bio_err,
                         "%s: error: hash table overflow for %s\n",
                         opt_getprog(), filename);
              return 1;
          }
          ep = app_malloc(sizeof(*ep), "collision bucket");
          *ep = nilhentry;
          ep->old_id = ~0;
          ep->filename = OPENSSL_strdup(filename);
          if (bp->last_entry)
              bp->last_entry->next = ep;
          if (bp->first_entry == NULL)
              bp->first_entry = ep;
          bp->last_entry = ep;
      }
  
      if (old_id < ep->old_id)
          ep->old_id = old_id;
      if (need_symlink && !ep->need_symlink) {
          ep->need_symlink = 1;
          bp->num_needed++;
          memcpy(ep->digest, digest, evpmdsize);
      }
      return 0;
  }
  
  /*
   * Check if a symlink goes to the right spot; return 0 if okay.
   * This can be -1 if bad filename, or an error count.
   */
  static int handle_symlink(const char *filename, const char *fullpath)
  {
      unsigned int hash = 0;
      int i, type, id;
      unsigned char ch;
      char linktarget[PATH_MAX], *endptr;
      ossl_ssize_t n;
  
      for (i = 0; i < 8; i++) {
          ch = filename[i];
          if (!isxdigit(ch))
              return -1;
          hash <<= 4;
          hash += OPENSSL_hexchar2int(ch);
      }
      if (filename[i++] != '.')
          return -1;
      for (type = OSSL_NELEM(suffixes) - 1; type > 0; type--) {
          const char *suffix = suffixes[type];
          if (strncasecmp(suffix, &filename[i], strlen(suffix)) == 0)
              break;
      }
      i += strlen(suffixes[type]);
  
      id = strtoul(&filename[i], &endptr, 10);
      if (*endptr != '\0')
          return -1;
  
      n = readlink(fullpath, linktarget, sizeof(linktarget));
      if (n < 0 || n >= (int)sizeof(linktarget))
          return -1;
      linktarget[n] = 0;
  
      return add_entry(type, hash, linktarget, NULL, 0, id);
  }
  
  /*
   * process a file, return number of errors.
   */
  static int do_file(const char *filename, const char *fullpath, enum Hash h)
  {
      STACK_OF (X509_INFO) *inf = NULL;
      X509_INFO *x;
      X509_NAME *name = NULL;
      BIO *b;
      const char *ext;
      unsigned char digest[EVP_MAX_MD_SIZE];
      int type, errs = 0;
      size_t i;
  
      /* Does it end with a recognized extension? */
      if ((ext = strrchr(filename, '.')) == NULL)
          goto end;
      for (i = 0; i < OSSL_NELEM(extensions); i++) {
          if (strcasecmp(extensions[i], ext + 1) == 0)
              break;
      }
      if (i >= OSSL_NELEM(extensions))
          goto end;
  
      /* Does it have X.509 data in it? */
      if ((b = BIO_new_file(fullpath, "r")) == NULL) {
          BIO_printf(bio_err, "%s: error: skipping %s, cannot open file\n",
                     opt_getprog(), filename);
          errs++;
          goto end;
      }
      inf = PEM_X509_INFO_read_bio(b, NULL, NULL, NULL);
      BIO_free(b);
      if (inf == NULL)
          goto end;
  
      if (sk_X509_INFO_num(inf) != 1) {
          BIO_printf(bio_err,
                     "%s: warning: skipping %s,"
                     "it does not contain exactly one certificate or CRL\n",
                     opt_getprog(), filename);
          /* This is not an error. */
          goto end;
      }
      x = sk_X509_INFO_value(inf, 0);
      if (x->x509 != NULL) {
          type = TYPE_CERT;
          name = X509_get_subject_name(x->x509);
          X509_digest(x->x509, evpmd, digest, NULL);
      } else if (x->crl != NULL) {
          type = TYPE_CRL;
          name = X509_CRL_get_issuer(x->crl);
          X509_CRL_digest(x->crl, evpmd, digest, NULL);
      } else {
          ++errs;
          goto end;
      }
      if (name != NULL) {
          if ((h == HASH_NEW) || (h == HASH_BOTH))
              errs += add_entry(type, X509_NAME_hash(name), filename, digest, 1, ~0);
          if ((h == HASH_OLD) || (h == HASH_BOTH))
              errs += add_entry(type, X509_NAME_hash_old(name), filename, digest, 1, ~0);
      }
  
  end:
      sk_X509_INFO_pop_free(inf, X509_INFO_free);
      return errs;
  }
  
  static void str_free(char *s)
  {
      OPENSSL_free(s);
  }
  
  static int ends_with_dirsep(const char *path)
  {
      if (*path != '\0')
          path += strlen(path) - 1;
  # if defined __VMS
      if (*path == ']' || *path == '>' || *path == ':')
          return 1;
  # elif defined _WIN32
      if (*path == '\\')
          return 1;
  # endif
      return *path == '/';
  }
  
  /*
   * Process a directory; return number of errors found.
   */
  static int do_dir(const char *dirname, enum Hash h)
  {
      BUCKET *bp, *nextbp;
      HENTRY *ep, *nextep;
      OPENSSL_DIR_CTX *d = NULL;
      struct stat st;
      unsigned char idmask[MAX_COLLISIONS / 8];
      int n, numfiles, nextid, buflen, errs = 0;
      size_t i;
      const char *pathsep;
      const char *filename;
      char *buf, *copy = NULL;
      STACK_OF(OPENSSL_STRING) *files = NULL;
  
      if (app_access(dirname, W_OK) < 0) {
          BIO_printf(bio_err, "Skipping %s, can't write\n", dirname);
          return 1;
      }
      buflen = strlen(dirname);
      pathsep = (buflen && !ends_with_dirsep(dirname)) ? "/": "";
      buflen += NAME_MAX + 1 + 1;
      buf = app_malloc(buflen, "filename buffer");
  
      if (verbose)
          BIO_printf(bio_out, "Doing %s\n", dirname);
  
      if ((files = sk_OPENSSL_STRING_new_null()) == NULL) {
          BIO_printf(bio_err, "Skipping %s, out of memory\n", dirname);
          errs = 1;
          goto err;
      }
      while ((filename = OPENSSL_DIR_read(&d, dirname)) != NULL) {
          if ((copy = OPENSSL_strdup(filename)) == NULL
                  || sk_OPENSSL_STRING_push(files, copy) == 0) {
              OPENSSL_free(copy);
              BIO_puts(bio_err, "out of memory\n");
              errs = 1;
              goto err;
          }
      }
      OPENSSL_DIR_end(&d);
      sk_OPENSSL_STRING_sort(files);
  
      numfiles = sk_OPENSSL_STRING_num(files);
      for (n = 0; n < numfiles; ++n) {
          filename = sk_OPENSSL_STRING_value(files, n);
          if (BIO_snprintf(buf, buflen, "%s%s%s",
                           dirname, pathsep, filename) >= buflen)
              continue;
          if (lstat(buf, &st) < 0)
              continue;
          if (S_ISLNK(st.st_mode) && handle_symlink(filename, buf) == 0)
              continue;
          errs += do_file(filename, buf, h);
      }
  
      for (i = 0; i < OSSL_NELEM(hash_table); i++) {
          for (bp = hash_table[i]; bp; bp = nextbp) {
              nextbp = bp->next;
              nextid = 0;
              memset(idmask, 0, (bp->num_needed + 7) / 8);
              for (ep = bp->first_entry; ep; ep = ep->next)
                  if (ep->old_id < bp->num_needed)
                      bit_set(idmask, ep->old_id);
  
              for (ep = bp->first_entry; ep; ep = nextep) {
                  nextep = ep->next;
                  if (ep->old_id < bp->num_needed) {
                      /* Link exists, and is used as-is */
                      BIO_snprintf(buf, buflen, "%08x.%s%d", bp->hash,
                                   suffixes[bp->type], ep->old_id);
                      if (verbose)
                          BIO_printf(bio_out, "link %s -> %s\n",
                                     ep->filename, buf);
                  } else if (ep->need_symlink) {
                      /* New link needed (it may replace something) */
                      while (bit_isset(idmask, nextid))
                          nextid++;
  
                      BIO_snprintf(buf, buflen, "%s%s%n%08x.%s%d",
                                   dirname, pathsep, &n, bp->hash,
                                   suffixes[bp->type], nextid);
                      if (verbose)
                          BIO_printf(bio_out, "link %s -> %s\n",
                                     ep->filename, &buf[n]);
                      if (unlink(buf) < 0 && errno != ENOENT) {
                          BIO_printf(bio_err,
                                     "%s: Can't unlink %s, %s\n",
                                     opt_getprog(), buf, strerror(errno));
                          errs++;
                      }
                      if (symlink(ep->filename, buf) < 0) {
                          BIO_printf(bio_err,
                                     "%s: Can't symlink %s, %s\n",
                                     opt_getprog(), ep->filename,
                                     strerror(errno));
                          errs++;
                      }
                      bit_set(idmask, nextid);
                  } else if (remove_links) {
                      /* Link to be deleted */
                      BIO_snprintf(buf, buflen, "%s%s%n%08x.%s%d",
                                   dirname, pathsep, &n, bp->hash,
                                   suffixes[bp->type], ep->old_id);
                      if (verbose)
                          BIO_printf(bio_out, "unlink %s\n",
                                     &buf[n]);
                      if (unlink(buf) < 0 && errno != ENOENT) {
                          BIO_printf(bio_err,
                                     "%s: Can't unlink %s, %s\n",
                                     opt_getprog(), buf, strerror(errno));
                          errs++;
                      }
                  }
                  OPENSSL_free(ep->filename);
                  OPENSSL_free(ep);
              }
              OPENSSL_free(bp);
          }
          hash_table[i] = NULL;
      }
  
   err:
      sk_OPENSSL_STRING_pop_free(files, str_free);
      OPENSSL_free(buf);
      return errs;
  }
  
  typedef enum OPTION_choice {
      OPT_ERR = -1, OPT_EOF = 0, OPT_HELP,
      OPT_COMPAT, OPT_OLD, OPT_N, OPT_VERBOSE
  } OPTION_CHOICE;
  
  const OPTIONS rehash_options[] = {
      {OPT_HELP_STR, 1, '-', "Usage: %s [options] [directory...]\n"},
  
      OPT_SECTION("General"),
      {"help", OPT_HELP, '-', "Display this summary"},
      {"h", OPT_HELP, '-', "Display this summary"},
      {"compat", OPT_COMPAT, '-', "Create both new- and old-style hash links"},
      {"old", OPT_OLD, '-', "Use old-style hash to generate links"},
      {"n", OPT_N, '-', "Do not remove existing links"},
  
      OPT_SECTION("Output"),
      {"v", OPT_VERBOSE, '-', "Verbose output"},
  
      OPT_PARAMETERS(),
      {"directory", 0, 0, "One or more directories to process (optional)"},
      {NULL}
  };
  
  
  int rehash_main(int argc, char **argv)
  {
      const char *env, *prog;
      char *e, *m;
      int errs = 0;
      OPTION_CHOICE o;
      enum Hash h = HASH_NEW;
  
      prog = opt_init(argc, argv, rehash_options);
      while ((o = opt_next()) != OPT_EOF) {
          switch (o) {
          case OPT_EOF:
          case OPT_ERR:
              BIO_printf(bio_err, "%s: Use -help for summary.\n", prog);
              goto end;
          case OPT_HELP:
              opt_help(rehash_options);
              goto end;
          case OPT_COMPAT:
              h = HASH_BOTH;
              break;
          case OPT_OLD:
              h = HASH_OLD;
              break;
          case OPT_N:
              remove_links = 0;
              break;
          case OPT_VERBOSE:
              verbose = 1;
              break;
          }
      }
      argc = opt_num_rest();
      argv = opt_rest();
  
      evpmd = EVP_sha1();
      evpmdsize = EVP_MD_size(evpmd);
  
      if (*argv != NULL) {
          while (*argv != NULL)
              errs += do_dir(*argv++, h);
      } else if ((env = getenv(X509_get_default_cert_dir_env())) != NULL) {
          char lsc[2] = { LIST_SEPARATOR_CHAR, '\0' };
          m = OPENSSL_strdup(env);
          for (e = strtok(m, lsc); e != NULL; e = strtok(NULL, lsc))
              errs += do_dir(e, h);
          OPENSSL_free(m);
      } else {
          errs += do_dir(X509_get_default_cert_dir(), h);
      }
  
   end:
      return errs;
  }
  
  #else
  const OPTIONS rehash_options[] = {
      {NULL}
  };
  
  int rehash_main(int argc, char **argv)
  {
      BIO_printf(bio_err, "Not available; use c_rehash script\n");
      return 1;
  }
  
  #endif /* defined(OPENSSL_SYS_UNIX) || defined(__APPLE__) */
  