/* 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 "apr_lib.h"
#include "apu.h"
#include "apu_errno.h"
#include <ctype.h>
#include <assert.h>
#include <stdlib.h>
#include "apr_strings.h"
#include "apr_time.h"
#include "apr_buckets.h"
#include "apr_crypto_internal.h"
#if APU_HAVE_CRYPTO
#include <openssl/evp.h>
#include <openssl/engine.h>
#define LOG_PREFIX "apr_crypto_openssl: "
struct apr_crypto_t {
apr_pool_t *pool;
const apr_crypto_driver_t *provider;
apu_err_t *result;
apr_array_header_t *keys;
apr_crypto_config_t *config;
apr_hash_t *types;
apr_hash_t *modes;
};
struct apr_crypto_config_t {
ENGINE *engine;
};
struct apr_crypto_key_t {
apr_pool_t *pool;
const apr_crypto_driver_t *provider;
const apr_crypto_t *f;
const EVP_CIPHER * cipher;
unsigned char *key;
int keyLen;
int doPad;
int ivSize;
};
struct apr_crypto_block_t {
apr_pool_t *pool;
const apr_crypto_driver_t *provider;
const apr_crypto_t *f;
EVP_CIPHER_CTX cipherCtx;
int initialised;
int ivSize;
int blockSize;
int doPad;
};
static int key_3des_192 = APR_KEY_3DES_192;
static int key_aes_128 = APR_KEY_AES_128;
static int key_aes_192 = APR_KEY_AES_192;
static int key_aes_256 = APR_KEY_AES_256;
static int mode_ecb = APR_MODE_ECB;
static int mode_cbc = APR_MODE_CBC;
/**
* Fetch the most recent error from this driver.
*/
static apr_status_t crypto_error(const apu_err_t **result,
const apr_crypto_t *f)
{
*result = f->result;
return APR_SUCCESS;
}
/**
* Shutdown the crypto library and release resources.
*/
static apr_status_t crypto_shutdown(void)
{
ERR_free_strings();
EVP_cleanup();
ENGINE_cleanup();
return APR_SUCCESS;
}
static apr_status_t crypto_shutdown_helper(void *data)
{
return crypto_shutdown();
}
/**
* Initialise the crypto library and perform one time initialisation.
*/
static apr_status_t crypto_init(apr_pool_t *pool, const char *params,
const apu_err_t **result)
{
CRYPTO_malloc_init();
ERR_load_crypto_strings();
/* SSL_load_error_strings(); */
OpenSSL_add_all_algorithms();
ENGINE_load_builtin_engines();
ENGINE_register_all_complete();
apr_pool_cleanup_register(pool, pool, crypto_shutdown_helper,
apr_pool_cleanup_null);
return APR_SUCCESS;
}
/**
* @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.
*/
static apr_status_t crypto_block_cleanup(apr_crypto_block_t *ctx)
{
if (ctx->initialised) {
EVP_CIPHER_CTX_cleanup(&ctx->cipherCtx);
ctx->initialised = 0;
}
return APR_SUCCESS;
}
static apr_status_t crypto_block_cleanup_helper(void *data)
{
apr_crypto_block_t *block = (apr_crypto_block_t *) data;
return crypto_block_cleanup(block);
}
/**
* @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.
*/
static apr_status_t crypto_cleanup(apr_crypto_t *f)
{
if (f->config->engine) {
ENGINE_finish(f->config->engine);
ENGINE_free(f->config->engine);
f->config->engine = NULL;
}
return APR_SUCCESS;
}
static apr_status_t crypto_cleanup_helper(void *data)
{
apr_crypto_t *f = (apr_crypto_t *) data;
return crypto_cleanup(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 provider - provider 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.
*/
static apr_status_t crypto_make(apr_crypto_t **ff,
const apr_crypto_driver_t *provider, const char *params,
apr_pool_t *pool)
{
apr_crypto_config_t *config = NULL;
apr_crypto_t *f = apr_pcalloc(pool, sizeof(apr_crypto_t));
const char *engine = NULL;
struct {
const char *field;
const char *value;
int set;
} fields[] = {
{ "engine", NULL, 0 },
{ NULL, NULL, 0 }
};
const char *ptr;
size_t klen;
char **elts = NULL;
char *elt;
int i = 0, j;
apr_status_t status;
if (params) {
if (APR_SUCCESS != (status = apr_tokenize_to_argv(params, &elts, pool))) {
return status;
}
while ((elt = elts[i])) {
ptr = strchr(elt, '=');
if (ptr) {
for (klen = ptr - elt; klen && apr_isspace(elt[klen - 1]); --klen)
;
ptr++;
}
else {
for (klen = strlen(elt); klen && apr_isspace(elt[klen - 1]); --klen)
;
}
elt[klen] = 0;
for (j = 0; fields[j].field != NULL; ++j) {
if (!strcasecmp(fields[j].field, elt)) {
fields[j].set = 1;
if (ptr) {
fields[j].value = ptr;
}
break;
}
}
i++;
}
engine = fields[0].value;
}
if (!f) {
return APR_ENOMEM;
}
*ff = f;
f->pool = pool;
f->provider = provider;
config = f->config = apr_pcalloc(pool, sizeof(apr_crypto_config_t));
if (!config) {
return APR_ENOMEM;
}
f->result = apr_pcalloc(pool, sizeof(apu_err_t));
if (!f->result) {
return APR_ENOMEM;
}
f->keys = apr_array_make(pool, 10, sizeof(apr_crypto_key_t));
if (!f->keys) {
return APR_ENOMEM;
}
f->types = apr_hash_make(pool);
if (!f->types) {
return APR_ENOMEM;
}
apr_hash_set(f->types, "3des192", APR_HASH_KEY_STRING, &(key_3des_192));
apr_hash_set(f->types, "aes128", APR_HASH_KEY_STRING, &(key_aes_128));
apr_hash_set(f->types, "aes192", APR_HASH_KEY_STRING, &(key_aes_192));
apr_hash_set(f->types, "aes256", APR_HASH_KEY_STRING, &(key_aes_256));
f->modes = apr_hash_make(pool);
if (!f->modes) {
return APR_ENOMEM;
}
apr_hash_set(f->modes, "ecb", APR_HASH_KEY_STRING, &(mode_ecb));
apr_hash_set(f->modes, "cbc", APR_HASH_KEY_STRING, &(mode_cbc));
apr_pool_cleanup_register(pool, f, crypto_cleanup_helper,
apr_pool_cleanup_null);
if (engine) {
config->engine = ENGINE_by_id(engine);
if (!config->engine) {
return APR_ENOENGINE;
}
if (!ENGINE_init(config->engine)) {
ENGINE_free(config->engine);
config->engine = NULL;
return APR_EINITENGINE;
}
}
return APR_SUCCESS;
}
/**
* @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
*/
static apr_status_t crypto_get_block_key_types(apr_hash_t **types,
const apr_crypto_t *f)
{
*types = f->types;
return APR_SUCCESS;
}
/**
* @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
*/
static apr_status_t crypto_get_block_key_modes(apr_hash_t **modes,
const apr_crypto_t *f)
{
*modes = f->modes;
return APR_SUCCESS;
}
/**
* @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 Iteration count
* @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.
*/
static apr_status_t crypto_passphrase(apr_crypto_key_t **k, 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)
{
apr_crypto_key_t *key = *k;
if (!key) {
*k = key = apr_array_push(f->keys);
}
if (!key) {
return APR_ENOMEM;
}
key->f = f;
key->provider = f->provider;
/* determine the cipher to be used */
switch (type) {
case (APR_KEY_3DES_192):
/* A 3DES key */
if (mode == APR_MODE_CBC) {
key->cipher = EVP_des_ede3_cbc();
}
else {
key->cipher = EVP_des_ede3_ecb();
}
break;
case (APR_KEY_AES_128):
if (mode == APR_MODE_CBC) {
key->cipher = EVP_aes_128_cbc();
}
else {
key->cipher = EVP_aes_128_ecb();
}
break;
case (APR_KEY_AES_192):
if (mode == APR_MODE_CBC) {
key->cipher = EVP_aes_192_cbc();
}
else {
key->cipher = EVP_aes_192_ecb();
}
break;
case (APR_KEY_AES_256):
if (mode == APR_MODE_CBC) {
key->cipher = EVP_aes_256_cbc();
}
else {
key->cipher = EVP_aes_256_ecb();
}
break;
default:
/* unknown key type, give up */
return APR_EKEYTYPE;
}
/* find the length of the key we need */
key->keyLen = EVP_CIPHER_key_length(key->cipher);
/* make space for the key */
key->key = apr_pcalloc(p, key->keyLen);
if (!key->key) {
return APR_ENOMEM;
}
apr_crypto_clear(p, key->key, key->keyLen);
/* generate the key */
if (PKCS5_PBKDF2_HMAC_SHA1(pass, passLen, (unsigned char *) salt, saltLen,
iterations, key->keyLen, key->key) == 0) {
return APR_ENOKEY;
}
key->doPad = doPad;
/* note: openssl incorrectly returns non zero IV size values for ECB
* algorithms, so work around this by ignoring the IV size.
*/
if (APR_MODE_ECB != mode) {
key->ivSize = EVP_CIPHER_iv_length(key->cipher);
}
if (ivSize) {
*ivSize = key->ivSize;
}
return APR_SUCCESS;
}
/**
* @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.
* @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.
*/
static apr_status_t 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)
{
unsigned char *usedIv;
apr_crypto_config_t *config = key->f->config;
apr_crypto_block_t *block = *ctx;
if (!block) {
*ctx = block = apr_pcalloc(p, sizeof(apr_crypto_block_t));
}
if (!block) {
return APR_ENOMEM;
}
block->f = key->f;
block->pool = p;
block->provider = key->provider;
apr_pool_cleanup_register(p, block, crypto_block_cleanup_helper,
apr_pool_cleanup_null);
/* create a new context for encryption */
EVP_CIPHER_CTX_init(&block->cipherCtx);
block->initialised = 1;
/* generate an IV, if necessary */
usedIv = NULL;
if (key->ivSize) {
if (iv == NULL) {
return APR_ENOIV;
}
if (*iv == NULL) {
usedIv = apr_pcalloc(p, key->ivSize);
if (!usedIv) {
return APR_ENOMEM;
}
apr_crypto_clear(p, usedIv, key->ivSize);
if (!((RAND_status() == 1)
&& (RAND_bytes(usedIv, key->ivSize) == 1))) {
return APR_ENOIV;
}
*iv = usedIv;
}
else {
usedIv = (unsigned char *) *iv;
}
}
/* set up our encryption context */
#if CRYPTO_OPENSSL_CONST_BUFFERS
if (!EVP_EncryptInit_ex(&block->cipherCtx, key->cipher, config->engine,
key->key, usedIv)) {
#else
if (!EVP_EncryptInit_ex(&block->cipherCtx, key->cipher, config->engine, (unsigned char *) key->key, (unsigned char *) usedIv)) {
#endif
return APR_EINIT;
}
/* Clear up any read padding */
if (!EVP_CIPHER_CTX_set_padding(&block->cipherCtx, key->doPad)) {
return APR_EPADDING;
}
if (blockSize) {
*blockSize = EVP_CIPHER_block_size(key->cipher);
}
return APR_SUCCESS;
}
/**
* @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.
*/
static apr_status_t crypto_block_encrypt(unsigned char **out,
apr_size_t *outlen, const unsigned char *in, apr_size_t inlen,
apr_crypto_block_t *ctx)
{
int outl = *outlen;
unsigned char *buffer;
/* are we after the maximum size of the out buffer? */
if (!out) {
*outlen = inlen + EVP_MAX_BLOCK_LENGTH;
return APR_SUCCESS;
}
/* must we allocate the output buffer from a pool? */
if (!*out) {
buffer = apr_palloc(ctx->pool, inlen + EVP_MAX_BLOCK_LENGTH);
if (!buffer) {
return APR_ENOMEM;
}
apr_crypto_clear(ctx->pool, buffer, inlen + EVP_MAX_BLOCK_LENGTH);
*out = buffer;
}
#if CRYPT_OPENSSL_CONST_BUFFERS
if (!EVP_EncryptUpdate(&ctx->cipherCtx, (*out), &outl, in, inlen)) {
#else
if (!EVP_EncryptUpdate(&ctx->cipherCtx, (*out), &outl,
(unsigned char *) in, inlen)) {
#endif
return APR_ECRYPT;
}
*outlen = outl;
return APR_SUCCESS;
}
/**
* @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.
*/
static apr_status_t crypto_block_encrypt_finish(unsigned char *out,
apr_size_t *outlen, apr_crypto_block_t *ctx)
{
int len = *outlen;
if (EVP_EncryptFinal_ex(&ctx->cipherCtx, out, &len) == 0) {
return APR_EPADDING;
}
*outlen = len;
return APR_SUCCESS;
}
/**
* @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. If the buffer pointed to is NULL,
* an IV will be created at random, in space allocated from the pool.
* If the buffer is not NULL, the IV in the buffer will be used.
* @param key The key structure.
* @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.
*/
static apr_status_t 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)
{
apr_crypto_config_t *config = key->f->config;
apr_crypto_block_t *block = *ctx;
if (!block) {
*ctx = block = apr_pcalloc(p, sizeof(apr_crypto_block_t));
}
if (!block) {
return APR_ENOMEM;
}
block->f = key->f;
block->pool = p;
block->provider = key->provider;
apr_pool_cleanup_register(p, block, crypto_block_cleanup_helper,
apr_pool_cleanup_null);
/* create a new context for encryption */
EVP_CIPHER_CTX_init(&block->cipherCtx);
block->initialised = 1;
/* generate an IV, if necessary */
if (key->ivSize) {
if (iv == NULL) {
return APR_ENOIV;
}
}
/* set up our encryption context */
#if CRYPTO_OPENSSL_CONST_BUFFERS
if (!EVP_DecryptInit_ex(&block->cipherCtx, key->cipher, config->engine,
key->key, iv)) {
#else
if (!EVP_DecryptInit_ex(&block->cipherCtx, key->cipher, config->engine, (unsigned char *) key->key, (unsigned char *) iv)) {
#endif
return APR_EINIT;
}
/* Clear up any read padding */
if (!EVP_CIPHER_CTX_set_padding(&block->cipherCtx, key->doPad)) {
return APR_EPADDING;
}
if (blockSize) {
*blockSize = EVP_CIPHER_block_size(key->cipher);
}
return APR_SUCCESS;
}
/**
* @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.
*/
static apr_status_t crypto_block_decrypt(unsigned char **out,
apr_size_t *outlen, const unsigned char *in, apr_size_t inlen,
apr_crypto_block_t *ctx)
{
int outl = *outlen;
unsigned char *buffer;
/* are we after the maximum size of the out buffer? */
if (!out) {
*outlen = inlen + EVP_MAX_BLOCK_LENGTH;
return APR_SUCCESS;
}
/* must we allocate the output buffer from a pool? */
if (!(*out)) {
buffer = apr_palloc(ctx->pool, inlen + EVP_MAX_BLOCK_LENGTH);
if (!buffer) {
return APR_ENOMEM;
}
apr_crypto_clear(ctx->pool, buffer, inlen + EVP_MAX_BLOCK_LENGTH);
*out = buffer;
}
#if CRYPT_OPENSSL_CONST_BUFFERS
if (!EVP_DecryptUpdate(&ctx->cipherCtx, *out, &outl, in, inlen)) {
#else
if (!EVP_DecryptUpdate(&ctx->cipherCtx, *out, &outl, (unsigned char *) in,
inlen)) {
#endif
return APR_ECRYPT;
}
*outlen = outl;
return APR_SUCCESS;
}
/**
* @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.
*/
static apr_status_t crypto_block_decrypt_finish(unsigned char *out,
apr_size_t *outlen, apr_crypto_block_t *ctx)
{
int len = *outlen;
if (EVP_DecryptFinal_ex(&ctx->cipherCtx, out, &len) == 0) {
return APR_EPADDING;
}
*outlen = len;
return APR_SUCCESS;
}
/**
* OpenSSL module.
*/
APU_MODULE_DECLARE_DATA const apr_crypto_driver_t apr_crypto_openssl_driver = {
"openssl", crypto_init, crypto_make, crypto_get_block_key_types,
crypto_get_block_key_modes, crypto_passphrase,
crypto_block_encrypt_init, crypto_block_encrypt,
crypto_block_encrypt_finish, crypto_block_decrypt_init,
crypto_block_decrypt, crypto_block_decrypt_finish,
crypto_block_cleanup, crypto_cleanup, crypto_shutdown, crypto_error
};
#endif