text: /* Licensed to the Apache Software Foundation (ASF) under one or more
   * contributor license agreements.  See the NOTICE file distributed with
   * this work for additional information regarding copyright ownership.
   * The ASF licenses this file to You under the Apache License, Version 2.0
   * (the "License"); you may not use this file except in compliance with
   * the License.  You may obtain a copy of the License at
   *
   *     http://www.apache.org/licenses/LICENSE-2.0
   *
   * Unless required by applicable law or agreed to in writing, software
   * distributed under the License is distributed on an "AS IS" BASIS,
   * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
   * See the License for the specific language governing permissions and
   * limitations under the License.
   */
  
  #include <ctype.h>
  #include <stdio.h>
  
  #include "apu_config.h"
  #include "apu.h"
  #include "apr_pools.h"
  #include "apr_dso.h"
  #include "apr_strings.h"
  #include "apr_hash.h"
  #include "apr_thread_mutex.h"
  #include "apr_lib.h"
  
  #if APU_HAVE_CRYPTO
  
  #include "apu_internal.h"
  #include "apr_crypto_internal.h"
  #include "apr_crypto.h"
  #include "apu_version.h"
  
  static apr_hash_t *drivers = NULL;
  
  #define ERROR_SIZE 1024
  
  #define CLEANUP_CAST (apr_status_t (*)(void*))
  
  #define APR_TYPEDEF_STRUCT(type, incompletion) \
  struct type { \
     incompletion \
     void *unk[]; \
  };
  
  APR_TYPEDEF_STRUCT(apr_crypto_t,
      apr_pool_t *pool;
      apr_crypto_driver_t *provider;
  )
  
  APR_TYPEDEF_STRUCT(apr_crypto_key_t,
      apr_pool_t *pool;
      apr_crypto_driver_t *provider;
      const apr_crypto_t *f;
  )
  
  APR_TYPEDEF_STRUCT(apr_crypto_block_t,
      apr_pool_t *pool;
      apr_crypto_driver_t *provider;
      const apr_crypto_t *f;
  )
  
  typedef struct apr_crypto_clear_t {
      void *buffer;
      apr_size_t size;
  } apr_crypto_clear_t;
  
  #if !APU_DSO_BUILD
  #define DRIVER_LOAD(name,driver_name,pool,params,rv,result) \
      {   \
          extern const apr_crypto_driver_t driver_name; \
          apr_hash_set(drivers,name,APR_HASH_KEY_STRING,&driver_name); \
          if (driver_name.init) {     \
              rv = driver_name.init(pool, params, result); \
          }  \
          *driver = &driver_name; \
      }
  #endif
  
  static apr_status_t apr_crypto_term(void *ptr)
  {
      /* set drivers to NULL so init can work again */
      drivers = NULL;
  
      /* Everything else we need is handled by cleanups registered
       * when we created mutexes and loaded DSOs
       */
      return APR_SUCCESS;
  }
  
  APU_DECLARE(apr_status_t) apr_crypto_init(apr_pool_t *pool)
  {
      apr_status_t ret = APR_SUCCESS;
      apr_pool_t *parent;
  
      if (drivers != NULL) {
          return APR_SUCCESS;
      }
  
      /* Top level pool scope, need process-scope lifetime */
      for (parent = apr_pool_parent_get(pool);
           parent && parent != pool;
           parent = apr_pool_parent_get(pool))
          pool = parent;
  #if APU_DSO_BUILD
      /* deprecate in 2.0 - permit implicit initialization */
      apu_dso_init(pool);
  #endif
      drivers = apr_hash_make(pool);
  
      apr_pool_cleanup_register(pool, NULL, apr_crypto_term,
              apr_pool_cleanup_null);
  
      return ret;
  }
  
  static apr_status_t crypto_clear(void *ptr)
  {
      apr_crypto_clear_t *clear = (apr_crypto_clear_t *)ptr;
  
      memset(clear->buffer, 0, clear->size);
      clear->buffer = NULL;
      clear->size = 0;
  
      return APR_SUCCESS;
  }
  
  APU_DECLARE(apr_status_t) apr_crypto_clear(apr_pool_t *pool,
          void *buffer, apr_size_t size)
  {
      apr_crypto_clear_t *clear = apr_palloc(pool, sizeof(apr_crypto_clear_t));
  
      clear->buffer = buffer;
      clear->size = size;
  
      apr_pool_cleanup_register(pool, clear, crypto_clear,
              apr_pool_cleanup_null);
  
      return APR_SUCCESS;
  }
  
  APU_DECLARE(apr_status_t) apr_crypto_get_driver(
          const apr_crypto_driver_t **driver, const char *name,
          const char *params, const apu_err_t **result, apr_pool_t *pool)
  {
  #if APU_DSO_BUILD
      char modname[32];
      char symname[34];
      apr_dso_handle_t *dso;
      apr_dso_handle_sym_t symbol;
  #endif
      apr_status_t rv;
  
      if (result) {
          *result = NULL; /* until further notice */
      }
  
  #if APU_DSO_BUILD
      rv = apu_dso_mutex_lock();
      if (rv) {
          return rv;
      }
  #endif
      *driver = apr_hash_get(drivers, name, APR_HASH_KEY_STRING);
      if (*driver) {
  #if APU_DSO_BUILD 
          apu_dso_mutex_unlock();
  #endif
          return APR_SUCCESS;
      }
  
  #if APU_DSO_BUILD
      /* The driver DSO must have exactly the same lifetime as the
       * drivers hash table; ignore the passed-in pool */
      pool = apr_hash_pool_get(drivers);
  
  #if defined(NETWARE)
      apr_snprintf(modname, sizeof(modname), "crypto%s.nlm", name);
  #elif defined(WIN32) || defined(__CYGWIN__)
      apr_snprintf(modname, sizeof(modname),
              "apr_crypto_%s-" APU_STRINGIFY(APU_MAJOR_VERSION) ".dll", name);
  #else
      apr_snprintf(modname, sizeof(modname),
              "apr_crypto_%s-" APU_STRINGIFY(APU_MAJOR_VERSION) ".so", name);
  #endif
      apr_snprintf(symname, sizeof(symname), "apr_crypto_%s_driver", name);
      rv = apu_dso_load(&dso, &symbol, modname, symname, pool);
      if (rv == APR_SUCCESS || rv == APR_EINIT) { /* previously loaded?!? */
          *driver = symbol;
          name = apr_pstrdup(pool, name);
          apr_hash_set(drivers, name, APR_HASH_KEY_STRING, *driver);
          rv = APR_SUCCESS;
          if ((*driver)->init) {
              rv = (*driver)->init(pool, params, result);
          }
      }
      apu_dso_mutex_unlock();
  
      if (APR_SUCCESS != rv && result && !*result) {
          char *buffer = apr_pcalloc(pool, ERROR_SIZE);
          apu_err_t *err = apr_pcalloc(pool, sizeof(apu_err_t));
          if (err && buffer) {
              apr_dso_error(dso, buffer, ERROR_SIZE - 1);
              err->msg = buffer;
              err->reason = modname;
              *result = err;
          }
      }
  
  #else /* not builtin and !APR_HAS_DSO => not implemented */
      rv = APR_ENOTIMPL;
  
      /* Load statically-linked drivers: */
  #if APU_HAVE_OPENSSL
      if (name[0] == 'o' && !strcmp(name, "openssl")) {
          DRIVER_LOAD("openssl", apr_crypto_openssl_driver, pool, params, rv, result);
      }
  #endif
  #if APU_HAVE_NSS
      if (name[0] == 'n' && !strcmp(name, "nss")) {
          DRIVER_LOAD("nss", apr_crypto_nss_driver, pool, params, rv, result);
      }
  #endif
  #if APU_HAVE_MSCAPI
      if (name[0] == 'm' && !strcmp(name, "mscapi")) {
          DRIVER_LOAD("mscapi", apr_crypto_mscapi_driver, pool, params, rv, result);
      }
  #endif
  #if APU_HAVE_MSCNG
      if (name[0] == 'm' && !strcmp(name, "mscng")) {
          DRIVER_LOAD("mscng", apr_crypto_mscng_driver, pool, params, rv, result);
      }
  #endif
  
  #endif
  
      return rv;
  }
  
  /**
   * @brief Return the name of the driver.
   *
   * @param driver - The driver in use.
   * @return The name of the driver.
   */
  APU_DECLARE(const char *)apr_crypto_driver_name (
          const apr_crypto_driver_t *driver)
  {
      return driver->name;
  }
  
  /**
   * @brief Get the result of the last operation on a context. If the result
   *        is NULL, the operation was successful.
   * @param result - the result structure
   * @param f - context pointer
   * @return APR_SUCCESS for success
   */
  APU_DECLARE(apr_status_t) apr_crypto_error(const apu_err_t **result,
          const apr_crypto_t *f)
  {
      return f->provider->error(result, f);
  }
  
  /**
   * @brief Create a context for supporting encryption. Keys, certificates,
   *        algorithms and other parameters will be set per context. More than
   *        one context can be created at one time. A cleanup will be automatically
   *        registered with the given pool to guarantee a graceful shutdown.
   * @param f - context pointer will be written here
   * @param driver - driver to use
   * @param params - array of key parameters
   * @param pool - process pool
   * @return APR_ENOENGINE when the engine specified does not exist. APR_EINITENGINE
   * if the engine cannot be initialised.
   * @remarks NSS: currently no params are supported.
   * @remarks OpenSSL: the params can have "engine" as a key, followed by an equal
   *  sign and a value.
   */
  APU_DECLARE(apr_status_t) apr_crypto_make(apr_crypto_t **f,
          const apr_crypto_driver_t *driver, const char *params, apr_pool_t *pool)
  {
      return driver->make(f, driver, params, pool);
  }
  
  /**
   * @brief Get a hash table of key types, keyed by the name of the type against
   * an integer pointer constant.
   *
   * @param types - hashtable of key types keyed to constants.
   * @param f - encryption context
   * @return APR_SUCCESS for success
   */
  APU_DECLARE(apr_status_t) apr_crypto_get_block_key_types(apr_hash_t **types,
          const apr_crypto_t *f)
  {
      return f->provider->get_block_key_types(types, f);
  }
  
  /**
   * @brief Get a hash table of key modes, keyed by the name of the mode against
   * an integer pointer constant.
   *
   * @param modes - hashtable of key modes keyed to constants.
   * @param f - encryption context
   * @return APR_SUCCESS for success
   */
  APU_DECLARE(apr_status_t) apr_crypto_get_block_key_modes(apr_hash_t **modes,
          const apr_crypto_t *f)
  {
      return f->provider->get_block_key_modes(modes, f);
  }
  
  /**
   * @brief Create a key from the given passphrase. By default, the PBKDF2
   *        algorithm is used to generate the key from the passphrase. It is expected
   *        that the same pass phrase will generate the same key, regardless of the
   *        backend crypto platform used. The key is cleaned up when the context
   *        is cleaned, and may be reused with multiple encryption or decryption
   *        operations.
   * @note If *key is NULL, a apr_crypto_key_t will be created from a pool. If
   *       *key is not NULL, *key must point at a previously created structure.
   * @param key The key returned, see note.
   * @param ivSize The size of the initialisation vector will be returned, based
   *               on whether an IV is relevant for this type of crypto.
   * @param pass The passphrase to use.
   * @param passLen The passphrase length in bytes
   * @param salt The salt to use.
   * @param saltLen The salt length in bytes
   * @param type 3DES_192, AES_128, AES_192, AES_256.
   * @param mode Electronic Code Book / Cipher Block Chaining.
   * @param doPad Pad if necessary.
   * @param iterations Number of iterations to use in algorithm
   * @param f The context to use.
   * @param p The pool to use.
   * @return Returns APR_ENOKEY if the pass phrase is missing or empty, or if a backend
   *         error occurred while generating the key. APR_ENOCIPHER if the type or mode
   *         is not supported by the particular backend. APR_EKEYTYPE if the key type is
   *         not known. APR_EPADDING if padding was requested but is not supported.
   *         APR_ENOTIMPL if not implemented.
   */
  APU_DECLARE(apr_status_t) apr_crypto_passphrase(apr_crypto_key_t **key,
          apr_size_t *ivSize, const char *pass, apr_size_t passLen,
          const unsigned char * salt, apr_size_t saltLen,
          const apr_crypto_block_key_type_e type,
          const apr_crypto_block_key_mode_e mode, const int doPad,
          const int iterations, const apr_crypto_t *f, apr_pool_t *p)
  {
      return f->provider->passphrase(key, ivSize, pass, passLen, salt, saltLen,
              type, mode, doPad, iterations, f, p);
  }
  
  /**
   * @brief Initialise a context for encrypting arbitrary data using the given key.
   * @note If *ctx is NULL, a apr_crypto_block_t will be created from a pool. If
   *       *ctx is not NULL, *ctx must point at a previously created structure.
   * @param ctx The block context returned, see note.
   * @param iv Optional initialisation vector. If the buffer pointed to is NULL,
   *           an IV will be created at random, in space allocated from the pool.
   *           If the buffer pointed to is not NULL, the IV in the buffer will be
   *           used.
   * @param key The key structure to use.
   * @param blockSize The block size of the cipher.
   * @param p The pool to use.
   * @return Returns APR_ENOIV if an initialisation vector is required but not specified.
   *         Returns APR_EINIT if the backend failed to initialise the context. Returns
   *         APR_ENOTIMPL if not implemented.
   */
  APU_DECLARE(apr_status_t) apr_crypto_block_encrypt_init(
          apr_crypto_block_t **ctx, const unsigned char **iv,
          const apr_crypto_key_t *key, apr_size_t *blockSize, apr_pool_t *p)
  {
      return key->provider->block_encrypt_init(ctx, iv, key, blockSize, p);
  }
  
  /**
   * @brief Encrypt data provided by in, write it to out.
   * @note The number of bytes written will be written to outlen. If
   *       out is NULL, outlen will contain the maximum size of the
   *       buffer needed to hold the data, including any data
   *       generated by apr_crypto_block_encrypt_finish below. If *out points
   *       to NULL, a buffer sufficiently large will be created from
   *       the pool provided. If *out points to a not-NULL value, this
   *       value will be used as a buffer instead.
   * @param out Address of a buffer to which data will be written,
   *        see note.
   * @param outlen Length of the output will be written here.
   * @param in Address of the buffer to read.
   * @param inlen Length of the buffer to read.
   * @param ctx The block context to use.
   * @return APR_ECRYPT if an error occurred. Returns APR_ENOTIMPL if
   *         not implemented.
   */
  APU_DECLARE(apr_status_t) apr_crypto_block_encrypt(unsigned char **out,
          apr_size_t *outlen, const unsigned char *in, apr_size_t inlen,
          apr_crypto_block_t *ctx)
  {
      return ctx->provider->block_encrypt(out, outlen, in, inlen, ctx);
  }
  
  /**
   * @brief Encrypt final data block, write it to out.
   * @note If necessary the final block will be written out after being
   *       padded. Typically the final block will be written to the
   *       same buffer used by apr_crypto_block_encrypt, offset by the
   *       number of bytes returned as actually written by the
   *       apr_crypto_block_encrypt() call. After this call, the context
   *       is cleaned and can be reused by apr_crypto_block_encrypt_init().
   * @param out Address of a buffer to which data will be written. This
   *            buffer must already exist, and is usually the same
   *            buffer used by apr_evp_crypt(). See note.
   * @param outlen Length of the output will be written here.
   * @param ctx The block context to use.
   * @return APR_ECRYPT if an error occurred.
   * @return APR_EPADDING if padding was enabled and the block was incorrectly
   *         formatted.
   * @return APR_ENOTIMPL if not implemented.
   */
  APU_DECLARE(apr_status_t) apr_crypto_block_encrypt_finish(unsigned char *out,
          apr_size_t *outlen, apr_crypto_block_t *ctx)
  {
      return ctx->provider->block_encrypt_finish(out, outlen, ctx);
  }
  
  /**
   * @brief Initialise a context for decrypting arbitrary data using the given key.
   * @note If *ctx is NULL, a apr_crypto_block_t will be created from a pool. If
   *       *ctx is not NULL, *ctx must point at a previously created structure.
   * @param ctx The block context returned, see note.
   * @param blockSize The block size of the cipher.
   * @param iv Optional initialisation vector.
   * @param key The key structure to use.
   * @param p The pool to use.
   * @return Returns APR_ENOIV if an initialisation vector is required but not specified.
   *         Returns APR_EINIT if the backend failed to initialise the context. Returns
   *         APR_ENOTIMPL if not implemented.
   */
  APU_DECLARE(apr_status_t) apr_crypto_block_decrypt_init(
          apr_crypto_block_t **ctx, apr_size_t *blockSize,
          const unsigned char *iv, const apr_crypto_key_t *key, apr_pool_t *p)
  {
      return key->provider->block_decrypt_init(ctx, blockSize, iv, key, p);
  }
  
  /**
   * @brief Decrypt data provided by in, write it to out.
   * @note The number of bytes written will be written to outlen. If
   *       out is NULL, outlen will contain the maximum size of the
   *       buffer needed to hold the data, including any data
   *       generated by apr_crypto_block_decrypt_finish below. If *out points
   *       to NULL, a buffer sufficiently large will be created from
   *       the pool provided. If *out points to a not-NULL value, this
   *       value will be used as a buffer instead.
   * @param out Address of a buffer to which data will be written,
   *        see note.
   * @param outlen Length of the output will be written here.
   * @param in Address of the buffer to read.
   * @param inlen Length of the buffer to read.
   * @param ctx The block context to use.
   * @return APR_ECRYPT if an error occurred. Returns APR_ENOTIMPL if
   *         not implemented.
   */
  APU_DECLARE(apr_status_t) apr_crypto_block_decrypt(unsigned char **out,
          apr_size_t *outlen, const unsigned char *in, apr_size_t inlen,
          apr_crypto_block_t *ctx)
  {
      return ctx->provider->block_decrypt(out, outlen, in, inlen, ctx);
  }
  
  /**
   * @brief Decrypt final data block, write it to out.
   * @note If necessary the final block will be written out after being
   *       padded. Typically the final block will be written to the
   *       same buffer used by apr_crypto_block_decrypt, offset by the
   *       number of bytes returned as actually written by the
   *       apr_crypto_block_decrypt() call. After this call, the context
   *       is cleaned and can be reused by apr_crypto_block_decrypt_init().
   * @param out Address of a buffer to which data will be written. This
   *            buffer must already exist, and is usually the same
   *            buffer used by apr_evp_crypt(). See note.
   * @param outlen Length of the output will be written here.
   * @param ctx The block context to use.
   * @return APR_ECRYPT if an error occurred.
   * @return APR_EPADDING if padding was enabled and the block was incorrectly
   *         formatted.
   * @return APR_ENOTIMPL if not implemented.
   */
  APU_DECLARE(apr_status_t) apr_crypto_block_decrypt_finish(unsigned char *out,
          apr_size_t *outlen, apr_crypto_block_t *ctx)
  {
      return ctx->provider->block_decrypt_finish(out, outlen, ctx);
  }
  
  /**
   * @brief Clean encryption / decryption context.
   * @note After cleanup, a context is free to be reused if necessary.
   * @param ctx The block context to use.
   * @return Returns APR_ENOTIMPL if not supported.
   */
  APU_DECLARE(apr_status_t) apr_crypto_block_cleanup(apr_crypto_block_t *ctx)
  {
      return ctx->provider->block_cleanup(ctx);
  }
  
  /**
   * @brief Clean encryption / decryption context.
   * @note After cleanup, a context is free to be reused if necessary.
   * @param f The context to use.
   * @return Returns APR_ENOTIMPL if not supported.
   */
  APU_DECLARE(apr_status_t) apr_crypto_cleanup(apr_crypto_t *f)
  {
      return f->provider->cleanup(f);
  }
  
  /**
   * @brief Shutdown the crypto library.
   * @note After shutdown, it is expected that the init function can be called again.
   * @param driver - driver to use
   * @return Returns APR_ENOTIMPL if not supported.
   */
  APU_DECLARE(apr_status_t) apr_crypto_shutdown(const apr_crypto_driver_t *driver)
  {
      return driver->shutdown();
  }
  
  #endif /* APU_HAVE_CRYPTO */
  