/*

   +----------------------------------------------------------------------+

   | Copyright © The PHP Group and Contributors.                          |

   +----------------------------------------------------------------------+

   | This source file is subject to the Modified BSD License that is      |

   | bundled with this package in the file LICENSE, and is available      |

   | through the World Wide Web at <https://www.php.net/license/>.        |

   |                                                                      |

   | SPDX-License-Identifier: BSD-3-Clause                                |

   +----------------------------------------------------------------------+

   | Authors: Anthony Ferrara <ircmaxell@php.net>                         |

   |          Charles R. Portwood II <charlesportwoodii@erianna.com>      |

   +----------------------------------------------------------------------+

*/

#include <stdlib.h>

#include "php.h"

#include "fcntl.h"

#include "php_password.h"

#include "php_crypt.h"

#include "base64.h"

#include "zend_interfaces.h"

#include "info.h"

#include "ext/random/php_random_csprng.h"

#include "password_arginfo.h"

#ifdef HAVE_ARGON2LIB

#include "argon2.h"

#endif

#ifdef PHP_WIN32

#include "win32/winutil.h"

#endif

static zend_array php_password_algos;

int php_password_algo_register(const char *ident, const php_password_algo *algo) {

  zend_string *key = zend_string_init_interned(ident, strlen(ident), 1);

  return zend_hash_add_ptr(&php_password_algos, key, (void *) algo) ? SUCCESS : FAILURE;

}

void php_password_algo_unregister(const char *ident) {

  zend_hash_str_del(&php_password_algos, ident, strlen(ident));

}

static int php_password_salt_to64(const char *str, const size_t str_len, const size_t out_len, char *ret) /* {{{ */

{

  size_t pos = 0;

  zend_string *buffer;

  if ((int) str_len < 0) {

    return FAILURE;

  }

  buffer = php_base64_encode((unsigned char*) str, str_len);

  if (ZSTR_LEN(buffer) < out_len) {

    /* Too short of an encoded string generated */

    zend_string_release_ex(buffer, 0);

    return FAILURE;

  }

  for (pos = 0; pos < out_len; pos++) {

    if (ZSTR_VAL(buffer)[pos] == '+') {

      ret[pos] = '.';

    } else if (ZSTR_VAL(buffer)[pos] == '=') {

      zend_string_free(buffer);

      return FAILURE;

    } else {

      ret[pos] = ZSTR_VAL(buffer)[pos];

    }

  }

  zend_string_free(buffer);

  return SUCCESS;

}

/* }}} */

static zend_string* php_password_make_salt(size_t length) /* {{{ */

{

  zend_string *ret, *buffer;

  if (length > (INT_MAX / 3)) {

    zend_value_error("Length is too large to safely generate");

    return NULL;

  }

  buffer = zend_string_alloc(length * 3 / 4 + 1, 0);

  if (FAILURE == php_random_bytes_throw(ZSTR_VAL(buffer), ZSTR_LEN(buffer))) {

    zend_value_error("Unable to generate salt");

    zend_string_efree(buffer);

    return NULL;

  }

  ret = zend_string_alloc(length, 0);

  if (php_password_salt_to64(ZSTR_VAL(buffer), ZSTR_LEN(buffer), length, ZSTR_VAL(ret)) == FAILURE) {

    zend_value_error("Generated salt too short");

    zend_string_efree(buffer);

    zend_string_efree(ret);

    return NULL;

  }

  zend_string_efree(buffer);

  ZSTR_VAL(ret)[length] = 0;

  return ret;

}

/* }}} */

static zend_string* php_password_get_salt(zval *unused_, size_t required_salt_len, HashTable *options) {

  if (options && zend_hash_str_exists(options, "salt", sizeof("salt") - 1)) {

    php_error_docref(NULL, E_WARNING, "The \"salt\" option has been ignored, since providing a custom salt is no longer supported");

  }

  return php_password_make_salt(required_salt_len);

}

/* bcrypt implementation */

static bool php_password_bcrypt_get_cost(const zend_string *hash, zend_long *cost) {

  const char *h = ZSTR_VAL(hash);

  if ((ZSTR_LEN(hash) != 60) ||

    (h[0] != '$') || (h[1] != '2') || (h[2] != 'y') || (h[3] != '$') ||

    !ZEND_IS_DIGIT(h[4]) || !ZEND_IS_DIGIT(h[5]) || (h[6] != '$')) {

    return false;

  }

  *cost = (h[4] - '0') * 10 + (h[5] - '0');

  return *cost >= 4 && *cost <= 31;

}

static bool php_password_bcrypt_valid(const zend_string *hash) {

  zend_long cost;

  return php_password_bcrypt_get_cost(hash, &cost);

}

static int php_password_bcrypt_get_info(zval *return_value, const zend_string *hash) {

  zend_long cost;

  if (!php_password_bcrypt_get_cost(hash, &cost)) {

    /* Should never get called this way. */

    return FAILURE;

  }

  add_assoc_long(return_value, "cost", cost);

  return SUCCESS;

}

static bool php_password_bcrypt_needs_rehash(const zend_string *hash, zend_array *options) {

  zval *znew_cost;

  zend_long old_cost;

  zend_long new_cost = PHP_PASSWORD_BCRYPT_COST;

  if (!php_password_bcrypt_get_cost(hash, &old_cost)) {

    /* Should never get called this way. */

    return true;

  }

  if (options && (znew_cost = zend_hash_str_find(options, "cost", sizeof("cost")-1)) != NULL) {

    new_cost = zval_get_long(znew_cost);

  }

  return old_cost != new_cost;

}

static bool php_password_bcrypt_verify(const zend_string *password, const zend_string *hash) {

  int status = 0;

  zend_string *ret = php_crypt(ZSTR_VAL(password), (int)ZSTR_LEN(password), ZSTR_VAL(hash), (int)ZSTR_LEN(hash), 1);

  if (!ret) {

    return false;

  }

  if (ZSTR_LEN(hash) < 13) {

    zend_string_free(ret);

    return false;

  }

  /* We're using this method instead of == in order to provide

   * resistance towards timing attacks. This is a constant time

   * equality check that will always check every byte of both

   * values. */

  status = php_safe_bcmp(ret, hash);

  zend_string_free(ret);

  return status == 0;

}

static zend_string* php_password_bcrypt_hash(const zend_string *password, zend_array *options) {

  char hash_format[10];

  size_t hash_format_len;

  zend_string *result, *hash, *salt;

  zval *zcost;

  zend_long cost = PHP_PASSWORD_BCRYPT_COST;

  if (memchr(ZSTR_VAL(password), '\0', ZSTR_LEN(password))) {

    zend_value_error("Bcrypt password must not contain null character");

    return NULL;

  }

  if (options && (zcost = zend_hash_str_find(options, "cost", sizeof("cost")-1)) != NULL) {

    cost = zval_get_long(zcost);

  }

  if (cost < 4 || cost > 31) {

    zend_value_error("Invalid bcrypt cost parameter specified: " ZEND_LONG_FMT, cost);

    return NULL;

  }

  hash_format_len = snprintf(hash_format, sizeof(hash_format), "$2y$%02" ZEND_LONG_FMT_SPEC "$", cost);

  if (!(salt = php_password_get_salt(NULL, Z_UL(22), options))) {

    return NULL;

  }

  ZSTR_VAL(salt)[ZSTR_LEN(salt)] = 0;

  hash = zend_string_concat2(hash_format, hash_format_len, ZSTR_VAL(salt), ZSTR_LEN(salt));

  zend_string_release_ex(salt, 0);

  /* This cast is safe, since both values are defined here in code and cannot overflow */

  result = php_crypt(ZSTR_VAL(password), (int)ZSTR_LEN(password), ZSTR_VAL(hash), (int)ZSTR_LEN(hash), 1);

  zend_string_release_ex(hash, 0);

  if (!result) {

    return NULL;

  }

  if (ZSTR_LEN(result) < 13) {

    zend_string_free(result);

    return NULL;

  }

  return result;

}

const php_password_algo php_password_algo_bcrypt = {

  "bcrypt",

  php_password_bcrypt_hash,

  php_password_bcrypt_verify,

  php_password_bcrypt_needs_rehash,

  php_password_bcrypt_get_info,

  php_password_bcrypt_valid,

};

#ifdef HAVE_ARGON2LIB

/* argon2i/argon2id shared implementation */

static int extract_argon2_parameters(const zend_string *hash,

                    zend_long *v, zend_long *memory_cost,

                    zend_long *time_cost, zend_long *threads) /* {{{ */

{

  const char *p = ZSTR_VAL(hash);

  if (!hash || (ZSTR_LEN(hash) < sizeof("$argon2id$"))) {

    return FAILURE;

  }

  if (!memcmp(p, "$argon2i$", sizeof("$argon2i$") - 1)) {

    p += sizeof("$argon2i$") - 1;

  } else if (!memcmp(p, "$argon2id$", sizeof("$argon2id$") - 1)) {

    p += sizeof("$argon2id$") - 1;

  } else {

    return FAILURE;

  }

  sscanf(p, "v=" ZEND_LONG_FMT "$m=" ZEND_LONG_FMT ",t=" ZEND_LONG_FMT ",p=" ZEND_LONG_FMT,

         v, memory_cost, time_cost, threads);

  return SUCCESS;

}

/* }}} */

static int php_password_argon2_get_info(zval *return_value, const zend_string *hash) {

  zend_long v = 0;

  zend_long memory_cost = PHP_PASSWORD_ARGON2_MEMORY_COST;

  zend_long time_cost = PHP_PASSWORD_ARGON2_TIME_COST;

  zend_long threads = PHP_PASSWORD_ARGON2_THREADS;

  extract_argon2_parameters(hash, &v, &memory_cost, &time_cost, &threads);

  add_assoc_long(return_value, "memory_cost", memory_cost);

  add_assoc_long(return_value, "time_cost", time_cost);

  add_assoc_long(return_value, "threads", threads);

  return SUCCESS;

}

static bool php_password_argon2_needs_rehash(const zend_string *hash, zend_array *options) {

  zend_long v = 0;

  zend_long new_memory_cost = PHP_PASSWORD_ARGON2_MEMORY_COST, memory_cost = 0;

  zend_long new_time_cost = PHP_PASSWORD_ARGON2_TIME_COST, time_cost = 0;

  zend_long new_threads = PHP_PASSWORD_ARGON2_THREADS, threads = 0;

  zval *option_buffer;

  if (options && (option_buffer = zend_hash_str_find(options, "memory_cost", sizeof("memory_cost")-1)) != NULL) {

    new_memory_cost = zval_get_long(option_buffer);

  }

  if (options && (option_buffer = zend_hash_str_find(options, "time_cost", sizeof("time_cost")-1)) != NULL) {

    new_time_cost = zval_get_long(option_buffer);

  }

  if (options && (option_buffer = zend_hash_str_find(options, "threads", sizeof("threads")-1)) != NULL) {

    new_threads = zval_get_long(option_buffer);

  }

  extract_argon2_parameters(hash, &v, &memory_cost, &time_cost, &threads);

  return (new_time_cost != time_cost) ||

      (new_memory_cost != memory_cost) ||

      (new_threads != threads);

}

static zend_string *php_password_argon2_hash(const zend_string *password, zend_array *options, argon2_type type) {

  zval *option_buffer;

  zend_string *salt, *out, *encoded;

  size_t time_cost = PHP_PASSWORD_ARGON2_TIME_COST;

  size_t memory_cost = PHP_PASSWORD_ARGON2_MEMORY_COST;

  size_t threads = PHP_PASSWORD_ARGON2_THREADS;

  size_t encoded_len;

  int status = 0;

  if (options && (option_buffer = zend_hash_str_find(options, "memory_cost", sizeof("memory_cost")-1)) != NULL) {

    memory_cost = zval_get_long(option_buffer);

  }

  if (memory_cost > ARGON2_MAX_MEMORY || memory_cost < ARGON2_MIN_MEMORY) {

    zend_value_error("Memory cost is outside of allowed memory range");

    return NULL;

  }

  if (options && (option_buffer = zend_hash_str_find(options, "time_cost", sizeof("time_cost")-1)) != NULL) {

    time_cost = zval_get_long(option_buffer);

  }

  if (time_cost > ARGON2_MAX_TIME || time_cost < ARGON2_MIN_TIME) {

    zend_value_error("Time cost is outside of allowed time range");

    return NULL;

  }

  if (options && (option_buffer = zend_hash_str_find(options, "threads", sizeof("threads")-1)) != NULL) {

    threads = zval_get_long(option_buffer);

  }

  if (threads > ARGON2_MAX_LANES || threads == 0) {

    zend_value_error("Invalid number of threads");

    return NULL;

  }

  if (!(salt = php_password_get_salt(NULL, Z_UL(16), options))) {

    return NULL;

  }

  out = zend_string_alloc(32, 0);

  encoded_len = argon2_encodedlen(

    time_cost,

    memory_cost,

    threads,

    (uint32_t)ZSTR_LEN(salt),

    ZSTR_LEN(out),

    type

  );

  encoded = zend_string_alloc(encoded_len - 1, 0);

  status = argon2_hash(

    time_cost,

    memory_cost,

    threads,

    ZSTR_VAL(password),

    ZSTR_LEN(password),

    ZSTR_VAL(salt),

    ZSTR_LEN(salt),

    ZSTR_VAL(out),

    ZSTR_LEN(out),

    ZSTR_VAL(encoded),

    encoded_len,

    type,

    ARGON2_VERSION_NUMBER

  );

  zend_string_release_ex(out, 0);

  zend_string_release_ex(salt, 0);

  if (status != ARGON2_OK) {

    zend_string_efree(encoded);

    zend_value_error("%s", argon2_error_message(status));

    return NULL;

  }

  ZSTR_VAL(encoded)[ZSTR_LEN(encoded)] = 0;

  return encoded;

}

/* argon2i specific methods */

static bool php_password_argon2i_verify(const zend_string *password, const zend_string *hash) {

  return ARGON2_OK == argon2_verify(ZSTR_VAL(hash), ZSTR_VAL(password), ZSTR_LEN(password), Argon2_i);

}

static zend_string *php_password_argon2i_hash(const zend_string *password, zend_array *options) {

  return php_password_argon2_hash(password, options, Argon2_i);

}

const php_password_algo php_password_algo_argon2i = {

  "argon2i",

  php_password_argon2i_hash,

  php_password_argon2i_verify,

  php_password_argon2_needs_rehash,

  php_password_argon2_get_info,

  NULL,

};

/* argon2id specific methods */

static bool php_password_argon2id_verify(const zend_string *password, const zend_string *hash) {

  return ARGON2_OK == argon2_verify(ZSTR_VAL(hash), ZSTR_VAL(password), ZSTR_LEN(password), Argon2_id);

}

static zend_string *php_password_argon2id_hash(const zend_string *password, zend_array *options) {

  return php_password_argon2_hash(password, options, Argon2_id);

}

const php_password_algo php_password_algo_argon2id = {

  "argon2id",

  php_password_argon2id_hash,

  php_password_argon2id_verify,

  php_password_argon2_needs_rehash,

  php_password_argon2_get_info,

  NULL,

};

#endif

PHP_MINIT_FUNCTION(password) /* {{{ */

{

  zend_hash_init(&php_password_algos, 4, NULL, ZVAL_PTR_DTOR, 1);

  register_password_symbols(module_number);

  if (FAILURE == php_password_algo_register("2y", &php_password_algo_bcrypt)) {

    return FAILURE;

  }

#ifdef HAVE_ARGON2LIB

  if (FAILURE == php_password_algo_register("argon2i", &php_password_algo_argon2i)) {

    return FAILURE;

  }

  if (FAILURE == php_password_algo_register("argon2id", &php_password_algo_argon2id)) {

    return FAILURE;

  }

#endif

  return SUCCESS;

}

/* }}} */

PHP_MSHUTDOWN_FUNCTION(password) /* {{{ */

{

#ifdef ZTS

  if (!tsrm_is_main_thread()) {

    return SUCCESS;

  }

#endif

  zend_hash_destroy(&php_password_algos);

  return SUCCESS;

}

/* }}} */

const php_password_algo* php_password_algo_default(void) {

  return &php_password_algo_bcrypt;

}

const php_password_algo* php_password_algo_find(const zend_string *ident) {

  zval *tmp;

  if (!ident) {

    return NULL;

  }

  tmp = zend_hash_find(&php_password_algos, (zend_string*)ident);

  if (!tmp || (Z_TYPE_P(tmp) != IS_PTR)) {

    return NULL;

  }

  return Z_PTR_P(tmp);

}

static const php_password_algo* php_password_algo_find_zval(zend_string *arg_str, zend_long arg_long, bool arg_is_null) {

  if (arg_is_null) {

    return php_password_algo_default();

  }

  if (arg_str) {

    return php_password_algo_find(arg_str);

  }

  switch (arg_long) {

    case 0: return php_password_algo_default();

    case 1: return &php_password_algo_bcrypt;

#ifdef HAVE_ARGON2LIB

    case 2: return &php_password_algo_argon2i;

    case 3: return &php_password_algo_argon2id;

#else

    case 2:

      {

      zend_string *n = ZSTR_INIT_LITERAL("argon2i", 0);

      const php_password_algo* ret = php_password_algo_find(n);

      zend_string_release(n);

      return ret;

      }

    case 3:

      {

      zend_string *n = ZSTR_INIT_LITERAL("argon2id", 0);

      const php_password_algo* ret = php_password_algo_find(n);

      zend_string_release(n);

      return ret;

      }

#endif

  }

  return NULL;

}

zend_string *php_password_algo_extract_ident(const zend_string* hash) {

  const char *ident, *ident_end;

  if (!hash || ZSTR_LEN(hash) < 3) {

    /* Minimum prefix: "$x$" */

    return NULL;

  }

  ident = ZSTR_VAL(hash) + 1;

  ident_end = strchr(ident, '$');

  if (!ident_end) {

    /* No terminating '$' */

    return NULL;

  }

  return zend_string_init(ident, ident_end - ident, 0);

}

const php_password_algo* php_password_algo_identify_ex(const zend_string* hash, const php_password_algo *default_algo) {

  const php_password_algo *algo;

  zend_string *ident = php_password_algo_extract_ident(hash);

  if (!ident) {

    return default_algo;

  }

  algo = php_password_algo_find(ident);

  zend_string_release(ident);

  return (!algo || (algo->valid && !algo->valid(hash))) ? default_algo : algo;

}

/* {{{ Retrieves information about a given hash */

PHP_FUNCTION(password_get_info)

{

  const php_password_algo *algo;

  zend_string *hash, *ident;

  zval options;

  ZEND_PARSE_PARAMETERS_START(1, 1)

    Z_PARAM_STR(hash)

  ZEND_PARSE_PARAMETERS_END();

  array_init(return_value);

  array_init(&options);

  ident = php_password_algo_extract_ident(hash);

  algo = php_password_algo_find(ident);

  if (!algo || (algo->valid && !algo->valid(hash))) {

    if (ident) {

      zend_string_release(ident);

    }

    add_assoc_null(return_value, "algo");

    add_assoc_string(return_value, "algoName", "unknown");

    add_assoc_zval(return_value, "options", &options);

    return;

  }

  add_assoc_str(return_value, "algo", php_password_algo_extract_ident(hash));

  zend_string_release(ident);

  add_assoc_string(return_value, "algoName", algo->name);

  if (algo->get_info) {

    algo->get_info(&options, hash);

  }

  add_assoc_zval(return_value, "options", &options);

}

/** }}} */

/* {{{ Determines if a given hash requires re-hashing based upon parameters */

PHP_FUNCTION(password_needs_rehash)

{

  const php_password_algo *old_algo, *new_algo;

  zend_string *hash;

  zend_string *new_algo_str;

  zend_long new_algo_long = 0;

  bool new_algo_is_null;

  zend_array *options = NULL;

  ZEND_PARSE_PARAMETERS_START(2, 3)

    Z_PARAM_STR(hash)

    Z_PARAM_STR_OR_LONG_OR_NULL(new_algo_str, new_algo_long, new_algo_is_null)

    Z_PARAM_OPTIONAL

    Z_PARAM_ARRAY_HT(options)

  ZEND_PARSE_PARAMETERS_END();

  new_algo = php_password_algo_find_zval(new_algo_str, new_algo_long, new_algo_is_null);

  if (!new_algo) {

    /* Unknown new algorithm, never prompt to rehash. */

    RETURN_FALSE;

  }

  old_algo = php_password_algo_identify_ex(hash, NULL);

  if (old_algo != new_algo) {

    /* Different algorithm preferred, always rehash. */

    RETURN_TRUE;

  }

  RETURN_BOOL(old_algo->needs_rehash(hash, options));

}

/* }}} */

/* {{{ Verify a hash created using crypt() or password_hash() */

PHP_FUNCTION(password_verify)

{

  zend_string *password, *hash;

  const php_password_algo *algo;

  ZEND_PARSE_PARAMETERS_START(2, 2)

    Z_PARAM_STR(password)

    Z_PARAM_STR(hash)

  ZEND_PARSE_PARAMETERS_END();

  algo = php_password_algo_identify(hash);

  RETURN_BOOL(algo && (!algo->verify || algo->verify(password, hash)));

}

/* }}} */

/* {{{ Hash a password */

PHP_FUNCTION(password_hash)

{

  zend_string *password, *digest = NULL;

  zend_string *algo_str;

  zend_long algo_long = 0;

  bool algo_is_null;

  const php_password_algo *algo;

  zend_array *options = NULL;

  ZEND_PARSE_PARAMETERS_START(2, 3)

    Z_PARAM_STR(password)

    Z_PARAM_STR_OR_LONG_OR_NULL(algo_str, algo_long, algo_is_null)

    Z_PARAM_OPTIONAL

    Z_PARAM_ARRAY_HT(options)

  ZEND_PARSE_PARAMETERS_END();

  algo = php_password_algo_find_zval(algo_str, algo_long, algo_is_null);

  if (!algo) {

    zend_argument_value_error(2, "must be a valid password hashing algorithm");

    RETURN_THROWS();

  }

  digest = algo->hash(password, options);

  if (!digest) {

    if (!EG(exception)) {

      zend_throw_error(NULL, "Password hashing failed for unknown reason");

    }

    RETURN_THROWS();

  }

  RETURN_NEW_STR(digest);

}

/* }}} */

/* {{{ */

PHP_FUNCTION(password_algos) {

  zend_string *algo;

  ZEND_PARSE_PARAMETERS_NONE();

  array_init(return_value);

  ZEND_HASH_MAP_FOREACH_STR_KEY(&php_password_algos, algo) {

    add_next_index_str(return_value, zend_string_copy(algo));

  } ZEND_HASH_FOREACH_END();

}

/* }}} */