text: /*
   * Copyright 2019-2020 The OpenSSL Project Authors. All Rights Reserved.
   *
   * 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 "e_os.h"                /* strcasecmp */
  #include "internal/namemap.h"
  #include <openssl/lhash.h>
  #include "crypto/lhash.h"      /* openssl_lh_strcasehash */
  #include "internal/tsan_assist.h"
  
  /*-
   * The namenum entry
   * =================
   */
  typedef struct {
      char *name;
      int number;
  } NAMENUM_ENTRY;
  
  DEFINE_LHASH_OF(NAMENUM_ENTRY);
  
  /*-
   * The namemap itself
   * ==================
   */
  
  struct ossl_namemap_st {
      /* Flags */
      unsigned int stored:1; /* If 1, it's stored in a library context */
  
      CRYPTO_RWLOCK *lock;
      LHASH_OF(NAMENUM_ENTRY) *namenum;  /* Name->number mapping */
  
  #ifdef tsan_ld_acq
      TSAN_QUALIFIER int max_number;     /* Current max number TSAN version */
  #else
      int max_number;                    /* Current max number plain version */
  #endif
  };
  
  /* LHASH callbacks */
  
  static unsigned long namenum_hash(const NAMENUM_ENTRY *n)
  {
      return openssl_lh_strcasehash(n->name);
  }
  
  static int namenum_cmp(const NAMENUM_ENTRY *a, const NAMENUM_ENTRY *b)
  {
      return strcasecmp(a->name, b->name);
  }
  
  static void namenum_free(NAMENUM_ENTRY *n)
  {
      if (n != NULL)
          OPENSSL_free(n->name);
      OPENSSL_free(n);
  }
  
  /* OSSL_LIB_CTX_METHOD functions for a namemap stored in a library context */
  
  static void *stored_namemap_new(OSSL_LIB_CTX *libctx)
  {
      OSSL_NAMEMAP *namemap = ossl_namemap_new();
  
      if (namemap != NULL)
          namemap->stored = 1;
  
      return namemap;
  }
  
  static void stored_namemap_free(void *vnamemap)
  {
      OSSL_NAMEMAP *namemap = vnamemap;
  
      if (namemap != NULL) {
          /* Pretend it isn't stored, or ossl_namemap_free() will do nothing */
          namemap->stored = 0;
          ossl_namemap_free(namemap);
      }
  }
  
  static const OSSL_LIB_CTX_METHOD stored_namemap_method = {
      stored_namemap_new,
      stored_namemap_free,
  };
  
  /*-
   * API functions
   * =============
   */
  
  int ossl_namemap_empty(OSSL_NAMEMAP *namemap)
  {
  #ifdef tsan_ld_acq
      /* Have TSAN support */
      return namemap == NULL || tsan_load(&namemap->max_number) == 0;
  #else
      /* No TSAN support */
      int rv;
  
      if (namemap == NULL)
          return 1;
  
      CRYPTO_THREAD_read_lock(namemap->lock);
      rv = namemap->max_number == 0;
      CRYPTO_THREAD_unlock(namemap->lock);
      return rv;
  #endif
  }
  
  typedef struct doall_names_data_st {
      int number;
      const char **names;
      int found;
  } DOALL_NAMES_DATA;
  
  static void do_name(const NAMENUM_ENTRY *namenum, DOALL_NAMES_DATA *data)
  {
      if (namenum->number == data->number)
          data->names[data->found++] = namenum->name;
  }
  
  IMPLEMENT_LHASH_DOALL_ARG_CONST(NAMENUM_ENTRY, DOALL_NAMES_DATA);
  
  /*
   * Call the callback for all names in the namemap with the given number.
   * A return value 1 means that the callback was called for all names. A
   * return value of 0 means that the callback was not called for any names.
   */
  int ossl_namemap_doall_names(const OSSL_NAMEMAP *namemap, int number,
                               void (*fn)(const char *name, void *data),
                               void *data)
  {
      DOALL_NAMES_DATA cbdata;
      size_t num_names;
      int i;
  
      cbdata.number = number;
      cbdata.found = 0;
  
      /*
       * We collect all the names first under a read lock. Subsequently we call
       * the user function, so that we're not holding the read lock when in user
       * code. This could lead to deadlocks.
       */
      CRYPTO_THREAD_read_lock(namemap->lock);
      num_names = lh_NAMENUM_ENTRY_num_items(namemap->namenum);
  
      if (num_names == 0) {
          CRYPTO_THREAD_unlock(namemap->lock);
          return 0;
      }
      cbdata.names = OPENSSL_malloc(sizeof(*cbdata.names) * num_names);
      if (cbdata.names == NULL) {
          CRYPTO_THREAD_unlock(namemap->lock);
          return 0;
      }
      lh_NAMENUM_ENTRY_doall_DOALL_NAMES_DATA(namemap->namenum, do_name,
                                              &cbdata);
      CRYPTO_THREAD_unlock(namemap->lock);
  
      for (i = 0; i < cbdata.found; i++)
          fn(cbdata.names[i], data);
  
      OPENSSL_free(cbdata.names);
      return 1;
  }
  
  static int namemap_name2num_n(const OSSL_NAMEMAP *namemap,
                                const char *name, size_t name_len)
  {
      NAMENUM_ENTRY *namenum_entry, namenum_tmpl;
  
      if ((namenum_tmpl.name = OPENSSL_strndup(name, name_len)) == NULL)
          return 0;
      namenum_tmpl.number = 0;
      namenum_entry =
          lh_NAMENUM_ENTRY_retrieve(namemap->namenum, &namenum_tmpl);
      OPENSSL_free(namenum_tmpl.name);
      return namenum_entry != NULL ? namenum_entry->number : 0;
  }
  
  int ossl_namemap_name2num_n(const OSSL_NAMEMAP *namemap,
                              const char *name, size_t name_len)
  {
      int number;
  
  #ifndef FIPS_MODULE
      if (namemap == NULL)
          namemap = ossl_namemap_stored(NULL);
  #endif
  
      if (namemap == NULL)
          return 0;
  
      CRYPTO_THREAD_read_lock(namemap->lock);
      number = namemap_name2num_n(namemap, name, name_len);
      CRYPTO_THREAD_unlock(namemap->lock);
  
      return number;
  }
  
  int ossl_namemap_name2num(const OSSL_NAMEMAP *namemap, const char *name)
  {
      if (name == NULL)
          return 0;
  
      return ossl_namemap_name2num_n(namemap, name, strlen(name));
  }
  
  struct num2name_data_st {
      size_t idx;                  /* Countdown */
      const char *name;            /* Result */
  };
  
  static void do_num2name(const char *name, void *vdata)
  {
      struct num2name_data_st *data = vdata;
  
      if (data->idx > 0)
          data->idx--;
      else if (data->name == NULL)
          data->name = name;
  }
  
  const char *ossl_namemap_num2name(const OSSL_NAMEMAP *namemap, int number,
                                    size_t idx)
  {
      struct num2name_data_st data;
  
      data.idx = idx;
      data.name = NULL;
      if (!ossl_namemap_doall_names(namemap, number, do_num2name, &data))
          return NULL;
      return data.name;
  }
  
  static int namemap_add_name_n(OSSL_NAMEMAP *namemap, int number,
                                const char *name, size_t name_len)
  {
      NAMENUM_ENTRY *namenum = NULL;
      int tmp_number;
  
      /* If it already exists, we don't add it */
      if ((tmp_number = namemap_name2num_n(namemap, name, name_len)) != 0)
          return tmp_number;
  
      if ((namenum = OPENSSL_zalloc(sizeof(*namenum))) == NULL
          || (namenum->name = OPENSSL_strndup(name, name_len)) == NULL)
          goto err;
  
      namenum->number =
          number != 0 ? number : 1 + tsan_counter(&namemap->max_number);
      (void)lh_NAMENUM_ENTRY_insert(namemap->namenum, namenum);
  
      if (lh_NAMENUM_ENTRY_error(namemap->namenum))
          goto err;
      return namenum->number;
  
   err:
      namenum_free(namenum);
      return 0;
  }
  
  int ossl_namemap_add_name_n(OSSL_NAMEMAP *namemap, int number,
                              const char *name, size_t name_len)
  {
      int tmp_number;
  
  #ifndef FIPS_MODULE
      if (namemap == NULL)
          namemap = ossl_namemap_stored(NULL);
  #endif
  
      if (name == NULL || name_len == 0 || namemap == NULL)
          return 0;
  
      CRYPTO_THREAD_write_lock(namemap->lock);
      tmp_number = namemap_add_name_n(namemap, number, name, name_len);
      CRYPTO_THREAD_unlock(namemap->lock);
      return tmp_number;
  }
  
  int ossl_namemap_add_name(OSSL_NAMEMAP *namemap, int number, const char *name)
  {
      if (name == NULL)
          return 0;
  
      return ossl_namemap_add_name_n(namemap, number, name, strlen(name));
  }
  
  int ossl_namemap_add_names(OSSL_NAMEMAP *namemap, int number,
                             const char *names, const char separator)
  {
      const char *p, *q;
      size_t l;
  
      /* Check that we have a namemap */
      if (!ossl_assert(namemap != NULL)) {
          ERR_raise(ERR_LIB_CRYPTO, ERR_R_PASSED_NULL_PARAMETER);
          return 0;
      }
  
      CRYPTO_THREAD_write_lock(namemap->lock);
      /*
       * Check that no name is an empty string, and that all names have at
       * most one numeric identity together.
       */
      for (p = names; *p != '\0'; p = (q == NULL ? p + l : q + 1)) {
          int this_number;
  
          if ((q = strchr(p, separator)) == NULL)
              l = strlen(p);       /* offset to \0 */
          else
              l = q - p;           /* offset to the next separator */
  
          this_number = namemap_name2num_n(namemap, p, l);
  
          if (*p == '\0' || *p == separator) {
              ERR_raise(ERR_LIB_CRYPTO, CRYPTO_R_BAD_ALGORITHM_NAME);
              goto err;
          }
          if (number == 0) {
              number = this_number;
          } else if (this_number != 0 && this_number != number) {
              ERR_raise_data(ERR_LIB_CRYPTO, CRYPTO_R_CONFLICTING_NAMES,
                             "\"%.*s\" has an existing different identity %d (from \"%s\")",
                             l, p, this_number, names);
              goto err;
          }
      }
  
      /* Now that we have checked, register all names */
      for (p = names; *p != '\0'; p = (q == NULL ? p + l : q + 1)) {
          int this_number;
  
          if ((q = strchr(p, separator)) == NULL)
              l = strlen(p);       /* offset to \0 */
          else
              l = q - p;           /* offset to the next separator */
  
          this_number = namemap_add_name_n(namemap, number, p, l);
          if (number == 0) {
              number = this_number;
          } else if (this_number != number) {
              ERR_raise_data(ERR_LIB_CRYPTO, ERR_R_INTERNAL_ERROR,
                             "Got number %d when expecting %d",
                             this_number, number);
              goto err;
          }
      }
  
      CRYPTO_THREAD_unlock(namemap->lock);
      return number;
  
   err:
      CRYPTO_THREAD_unlock(namemap->lock);
      return 0;
  }
  
  /*-
   * Pre-population
   * ==============
   */
  
  #ifndef FIPS_MODULE
  #include <openssl/evp.h>
  
  /* Creates an initial namemap with names found in the legacy method db */
  static void get_legacy_evp_names(const char *main_name, const char *alias,
                                   void *arg)
  {
      int main_id = ossl_namemap_add_name(arg, 0, main_name);
  
      /*
       * We could check that the returned value is the same as main_id,
       * but since this is a void function, there's no sane way to report
       * the error.  The best we can do is trust ourselve to keep the legacy
       * method database conflict free.
       *
       * This registers any alias with the same number as the main name.
       * Should it be that the current |on| *has* the main name, this is
       * simply a no-op.
       */
      if (alias != NULL) {
          (void)ossl_namemap_add_name(arg, main_id, alias);
      }
  }
  
  static void get_legacy_cipher_names(const OBJ_NAME *on, void *arg)
  {
      const EVP_CIPHER *cipher = (void *)OBJ_NAME_get(on->name, on->type);
  
      get_legacy_evp_names(EVP_CIPHER_name(cipher), on->name, arg);
  }
  
  static void get_legacy_md_names(const OBJ_NAME *on, void *arg)
  {
      const EVP_MD *md = (void *)OBJ_NAME_get(on->name, on->type);
      /* We don't want the pkey_type names, so we need some extra care */
      int snid, lnid;
  
      snid = OBJ_sn2nid(on->name);
      lnid = OBJ_ln2nid(on->name);
      if (snid != EVP_MD_pkey_type(md) && lnid != EVP_MD_pkey_type(md))
          get_legacy_evp_names(EVP_MD_name(md), on->name, arg);
      else
          get_legacy_evp_names(EVP_MD_name(md), NULL, arg);
  }
  #endif
  
  /*-
   * Constructors / destructors
   * ==========================
   */
  
  OSSL_NAMEMAP *ossl_namemap_stored(OSSL_LIB_CTX *libctx)
  {
      OSSL_NAMEMAP *namemap =
          ossl_lib_ctx_get_data(libctx, OSSL_LIB_CTX_NAMEMAP_INDEX,
                                &stored_namemap_method);
  
  #ifndef FIPS_MODULE
      if (namemap != NULL && ossl_namemap_empty(namemap)) {
          /* Before pilfering, we make sure the legacy database is populated */
          OPENSSL_init_crypto(OPENSSL_INIT_ADD_ALL_CIPHERS
                              | OPENSSL_INIT_ADD_ALL_DIGESTS, NULL);
  
          OBJ_NAME_do_all(OBJ_NAME_TYPE_CIPHER_METH,
                          get_legacy_cipher_names, namemap);
          OBJ_NAME_do_all(OBJ_NAME_TYPE_MD_METH,
                          get_legacy_md_names, namemap);
      }
  #endif
  
      return namemap;
  }
  
  OSSL_NAMEMAP *ossl_namemap_new(void)
  {
      OSSL_NAMEMAP *namemap;
  
      if ((namemap = OPENSSL_zalloc(sizeof(*namemap))) != NULL
          && (namemap->lock = CRYPTO_THREAD_lock_new()) != NULL
          && (namemap->namenum =
              lh_NAMENUM_ENTRY_new(namenum_hash, namenum_cmp)) != NULL)
          return namemap;
  
      ossl_namemap_free(namemap);
      return NULL;
  }
  
  void ossl_namemap_free(OSSL_NAMEMAP *namemap)
  {
      if (namemap == NULL || namemap->stored)
          return;
  
      lh_NAMENUM_ENTRY_doall(namemap->namenum, namenum_free);
      lh_NAMENUM_ENTRY_free(namemap->namenum);
  
      CRYPTO_THREAD_lock_free(namemap->lock);
      OPENSSL_free(namemap);
  }
  