password.c

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/*
   +----------------------------------------------------------------------+
   | Copyright (c) The PHP Group                                          |
   +----------------------------------------------------------------------+
   | This source file is subject to version 3.01 of the PHP license,      |
   | that is bundled with this package in the file LICENSE, and is        |
   | available through the world-wide-web at the following url:           |
   | https://www.php.net/license/3_01.txt                                 |
   | If you did not receive a copy of the PHP license and are unable to   |
   | obtain it through the world-wide-web, please send a note to          |
   | license@php.net so we can mail you a copy immediately.               |
   +----------------------------------------------------------------------+
   | 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_release_ex(buffer, 0);
        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_release_ex(buffer, 0);
        zend_string_release_ex(ret, 0);
        return NULL;
    }
    zend_string_release_ex(buffer, 0);
    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_valid(const zend_string *hash) {
    const char *h = ZSTR_VAL(hash);
    return (ZSTR_LEN(hash) == 60) &&
        (h[0] == '$') && (h[1] == '2') && (h[2] == 'y');
}
 
static int php_password_bcrypt_get_info(zval *return_value, const zend_string *hash) {
    zend_long cost = PHP_PASSWORD_BCRYPT_COST;
 
    if (!php_password_bcrypt_valid(hash)) {
        /* Should never get called this way. */
        return FAILURE;
    }
 
    sscanf(ZSTR_VAL(hash), "$2y$" ZEND_LONG_FMT "$", &cost);
    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 = PHP_PASSWORD_BCRYPT_COST;
    zend_long new_cost = PHP_PASSWORD_BCRYPT_COST;
 
    if (!php_password_bcrypt_valid(hash)) {
        /* Should never get called this way. */
        return 1;
    }
 
    sscanf(ZSTR_VAL(hash), "$2y$" ZEND_LONG_FMT "$", &old_cost);
    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 0;
    }
 
    if (ZSTR_LEN(hash) < 13) {
        zend_string_free(ret);
        return 0;
    }
 
    /* 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();
}
/* }}} */