1/* Licensed to the Apache Software Foundation (ASF) under one or more
2 * contributor license agreements.  See the NOTICE file distributed with
3 * this work for additional information regarding copyright ownership.
4 * The ASF licenses this file to You under the Apache License, Version 2.0
5 * (the "License"); you may not use this file except in compliance with
6 * the License.  You may obtain a copy of the License at
7 *
8 *     http://www.apache.org/licenses/LICENSE-2.0
9 *
10 * Unless required by applicable law or agreed to in writing, software
11 * distributed under the License is distributed on an "AS IS" BASIS,
12 * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
13 * See the License for the specific language governing permissions and
14 * limitations under the License.
15 */
16
17#ifndef APR_CRYPTO_H
18#define APR_CRYPTO_H
19
20#include "apu.h"
21#include "apr_pools.h"
22#include "apr_tables.h"
23#include "apr_hash.h"
24#include "apu_errno.h"
25
26#ifdef __cplusplus
27extern "C" {
28#endif
29
30/**
31 * @file apr_crypto.h
32 * @brief APR-UTIL Crypto library
33 */
34/**
35 * @defgroup APR_Util_Crypto Crypto routines
36 * @ingroup APR_Util
37 * @{
38 */
39
40#if APU_HAVE_CRYPTO
41
42#ifndef APU_CRYPTO_RECOMMENDED_DRIVER
43#if APU_HAVE_OPENSSL
44#define APU_CRYPTO_RECOMMENDED_DRIVER "openssl"
45#else
46#if APU_HAVE_NSS
47#define APU_CRYPTO_RECOMMENDED_DRIVER "nss"
48#else
49#if APU_HAVE_MSCNG
50#define APU_CRYPTO_RECOMMENDED_DRIVER "mscng"
51#else
52#if APU_HAVE_MSCAPI
53#define APU_CRYPTO_RECOMMENDED_DRIVER "mscapi"
54#else
55#endif
56#endif
57#endif
58#endif
59#endif
60
61/**
62 * Symmetric Key types understood by the library.
63 *
64 * NOTE: It is expected that this list will grow over time.
65 *
66 * Interoperability Matrix:
67 *
68 * The matrix is based on the testcrypto.c unit test, which attempts to
69 * test whether a simple encrypt/decrypt will succeed, as well as testing
70 * whether an encrypted string by one library can be decrypted by the
71 * others.
72 *
73 * Some libraries will successfully encrypt and decrypt their own data,
74 * but won't decrypt data from another library. It is hoped that over
75 * time these anomalies will be found and fixed, but until then it is
76 * recommended that ciphers are chosen that interoperate across platform.
77 *
78 * An X below means the test passes, it does not necessarily mean that
79 * encryption performed is correct or secure. Applications should stick
80 * to ciphers that pass the interoperablity tests on the right hand side
81 * of the table.
82 *
83 * Aligned data is data whose length is a multiple of the block size for
84 * the chosen cipher. Padded data is data that is not aligned by block
85 * size and must be padded by the crypto library.
86 *
87 *                  OpenSSL      NSS      Interop
88 *                 Align Pad  Align Pad  Align Pad
89 * 3DES_192/CBC    X     X    X     X    X     X
90 * 3DES_192/ECB    X     X
91 * AES_256/CBC     X     X    X     X    X     X
92 * AES_256/ECB     X     X    X          X
93 * AES_192/CBC     X     X    X     X
94 * AES_192/ECB     X     X    X
95 * AES_128/CBC     X     X    X     X
96 * AES_128/ECB     X     X    X
97 *
98 * Conclusion: for padded data, use 3DES_192/CBC or AES_256/CBC. For
99 * aligned data, use 3DES_192/CBC, AES_256/CBC or AES_256/ECB.
100 */
101
102typedef enum
103{
104    APR_KEY_NONE, APR_KEY_3DES_192, /** 192 bit (3-Key) 3DES */
105    APR_KEY_AES_128, /** 128 bit AES */
106    APR_KEY_AES_192, /** 192 bit AES */
107    APR_KEY_AES_256
108/** 256 bit AES */
109} apr_crypto_block_key_type_e;
110
111typedef enum
112{
113    APR_MODE_NONE, /** An error condition */
114    APR_MODE_ECB, /** Electronic Code Book */
115    APR_MODE_CBC
116/** Cipher Block Chaining */
117} apr_crypto_block_key_mode_e;
118
119/* These are opaque structs.  Instantiation is up to each backend */
120typedef struct apr_crypto_driver_t apr_crypto_driver_t;
121typedef struct apr_crypto_t apr_crypto_t;
122typedef struct apr_crypto_config_t apr_crypto_config_t;
123typedef struct apr_crypto_key_t apr_crypto_key_t;
124typedef struct apr_crypto_block_t apr_crypto_block_t;
125
126/**
127 * @brief Perform once-only initialisation. Call once only.
128 *
129 * @param pool - pool to register any shutdown cleanups, etc
130 * @return APR_NOTIMPL in case of no crypto support.
131 */
132APU_DECLARE(apr_status_t) apr_crypto_init(apr_pool_t *pool);
133
134/**
135 * @brief Register a cleanup to zero out the buffer provided
136 * when the pool is cleaned up.
137 *
138 * @param pool - pool to register the cleanup
139 * @param buffer - buffer to zero out
140 * @param size - size of the buffer to zero out
141 */
142APU_DECLARE(apr_status_t) apr_crypto_clear(apr_pool_t *pool, void *buffer,
143        apr_size_t size);
144
145/**
146 * @brief Get the driver struct for a name
147 *
148 * @param driver - pointer to driver struct.
149 * @param name - driver name
150 * @param params - array of initialisation parameters
151 * @param result - result and error message on failure
152 * @param pool - (process) pool to register cleanup
153 * @return APR_SUCCESS for success
154 * @return APR_ENOTIMPL for no driver (when DSO not enabled)
155 * @return APR_EDSOOPEN if DSO driver file can't be opened
156 * @return APR_ESYMNOTFOUND if the driver file doesn't contain a driver
157 * @remarks NSS: the params can have "dir", "key3", "cert7" and "secmod"
158 *  keys, each followed by an equal sign and a value. Such key/value pairs can
159 *  be delimited by space or tab. If the value contains a space, surround the
160 *  whole key value pair in quotes: "dir=My Directory".
161 * @remarks OpenSSL: currently no params are supported.
162 */
163APU_DECLARE(apr_status_t) apr_crypto_get_driver(
164        const apr_crypto_driver_t **driver,
165        const char *name, const char *params, const apu_err_t **result,
166        apr_pool_t *pool);
167
168/**
169 * @brief Return the name of the driver.
170 *
171 * @param driver - The driver in use.
172 * @return The name of the driver.
173 */
174APU_DECLARE(const char *) apr_crypto_driver_name(
175        const apr_crypto_driver_t *driver);
176
177/**
178 * @brief Get the result of the last operation on a context. If the result
179 *        is NULL, the operation was successful.
180 * @param result - the result structure
181 * @param f - context pointer
182 * @return APR_SUCCESS for success
183 */
184APU_DECLARE(apr_status_t) apr_crypto_error(const apu_err_t **result,
185        const apr_crypto_t *f);
186
187/**
188 * @brief Create a context for supporting encryption. Keys, certificates,
189 *        algorithms and other parameters will be set per context. More than
190 *        one context can be created at one time. A cleanup will be automatically
191 *        registered with the given pool to guarantee a graceful shutdown.
192 * @param f - context pointer will be written here
193 * @param driver - driver to use
194 * @param params - array of key parameters
195 * @param pool - process pool
196 * @return APR_ENOENGINE when the engine specified does not exist. APR_EINITENGINE
197 * if the engine cannot be initialised.
198 * @remarks NSS: currently no params are supported.
199 * @remarks OpenSSL: the params can have "engine" as a key, followed by an equal
200 *  sign and a value.
201 */
202APU_DECLARE(apr_status_t) apr_crypto_make(apr_crypto_t **f,
203        const apr_crypto_driver_t *driver, const char *params,
204        apr_pool_t *pool);
205
206/**
207 * @brief Get a hash table of key types, keyed by the name of the type against
208 * an integer pointer constant.
209 *
210 * @param types - hashtable of key types keyed to constants.
211 * @param f - encryption context
212 * @return APR_SUCCESS for success
213 */
214APU_DECLARE(apr_status_t) apr_crypto_get_block_key_types(apr_hash_t **types,
215        const apr_crypto_t *f);
216
217/**
218 * @brief Get a hash table of key modes, keyed by the name of the mode against
219 * an integer pointer constant.
220 *
221 * @param modes - hashtable of key modes keyed to constants.
222 * @param f - encryption context
223 * @return APR_SUCCESS for success
224 */
225APU_DECLARE(apr_status_t) apr_crypto_get_block_key_modes(apr_hash_t **modes,
226        const apr_crypto_t *f);
227
228/**
229 * @brief Create a key from the given passphrase. By default, the PBKDF2
230 *        algorithm is used to generate the key from the passphrase. It is expected
231 *        that the same pass phrase will generate the same key, regardless of the
232 *        backend crypto platform used. The key is cleaned up when the context
233 *        is cleaned, and may be reused with multiple encryption or decryption
234 *        operations.
235 * @note If *key is NULL, a apr_crypto_key_t will be created from a pool. If
236 *       *key is not NULL, *key must point at a previously created structure.
237 * @param key The key returned, see note.
238 * @param ivSize The size of the initialisation vector will be returned, based
239 *               on whether an IV is relevant for this type of crypto.
240 * @param pass The passphrase to use.
241 * @param passLen The passphrase length in bytes
242 * @param salt The salt to use.
243 * @param saltLen The salt length in bytes
244 * @param type 3DES_192, AES_128, AES_192, AES_256.
245 * @param mode Electronic Code Book / Cipher Block Chaining.
246 * @param doPad Pad if necessary.
247 * @param iterations Number of iterations to use in algorithm
248 * @param f The context to use.
249 * @param p The pool to use.
250 * @return Returns APR_ENOKEY if the pass phrase is missing or empty, or if a backend
251 *         error occurred while generating the key. APR_ENOCIPHER if the type or mode
252 *         is not supported by the particular backend. APR_EKEYTYPE if the key type is
253 *         not known. APR_EPADDING if padding was requested but is not supported.
254 *         APR_ENOTIMPL if not implemented.
255 */
256APU_DECLARE(apr_status_t) apr_crypto_passphrase(apr_crypto_key_t **key,
257        apr_size_t *ivSize, const char *pass, apr_size_t passLen,
258        const unsigned char * salt, apr_size_t saltLen,
259        const apr_crypto_block_key_type_e type,
260        const apr_crypto_block_key_mode_e mode, const int doPad,
261        const int iterations, const apr_crypto_t *f, apr_pool_t *p);
262
263/**
264 * @brief Initialise a context for encrypting arbitrary data using the given key.
265 * @note If *ctx is NULL, a apr_crypto_block_t will be created from a pool. If
266 *       *ctx is not NULL, *ctx must point at a previously created structure.
267 * @param ctx The block context returned, see note.
268 * @param iv Optional initialisation vector. If the buffer pointed to is NULL,
269 *           an IV will be created at random, in space allocated from the pool.
270 *           If the buffer pointed to is not NULL, the IV in the buffer will be
271 *           used.
272 * @param key The key structure to use.
273 * @param blockSize The block size of the cipher.
274 * @param p The pool to use.
275 * @return Returns APR_ENOIV if an initialisation vector is required but not specified.
276 *         Returns APR_EINIT if the backend failed to initialise the context. Returns
277 *         APR_ENOTIMPL if not implemented.
278 */
279APU_DECLARE(apr_status_t) apr_crypto_block_encrypt_init(
280        apr_crypto_block_t **ctx, const unsigned char **iv,
281        const apr_crypto_key_t *key, apr_size_t *blockSize, apr_pool_t *p);
282
283/**
284 * @brief Encrypt data provided by in, write it to out.
285 * @note The number of bytes written will be written to outlen. If
286 *       out is NULL, outlen will contain the maximum size of the
287 *       buffer needed to hold the data, including any data
288 *       generated by apr_crypto_block_encrypt_finish below. If *out points
289 *       to NULL, a buffer sufficiently large will be created from
290 *       the pool provided. If *out points to a not-NULL value, this
291 *       value will be used as a buffer instead.
292 * @param out Address of a buffer to which data will be written,
293 *        see note.
294 * @param outlen Length of the output will be written here.
295 * @param in Address of the buffer to read.
296 * @param inlen Length of the buffer to read.
297 * @param ctx The block context to use.
298 * @return APR_ECRYPT if an error occurred. Returns APR_ENOTIMPL if
299 *         not implemented.
300 */
301APU_DECLARE(apr_status_t) apr_crypto_block_encrypt(unsigned char **out,
302        apr_size_t *outlen, const unsigned char *in, apr_size_t inlen,
303        apr_crypto_block_t *ctx);
304
305/**
306 * @brief Encrypt final data block, write it to out.
307 * @note If necessary the final block will be written out after being
308 *       padded. Typically the final block will be written to the
309 *       same buffer used by apr_crypto_block_encrypt, offset by the
310 *       number of bytes returned as actually written by the
311 *       apr_crypto_block_encrypt() call. After this call, the context
312 *       is cleaned and can be reused by apr_crypto_block_encrypt_init().
313 * @param out Address of a buffer to which data will be written. This
314 *            buffer must already exist, and is usually the same
315 *            buffer used by apr_evp_crypt(). See note.
316 * @param outlen Length of the output will be written here.
317 * @param ctx The block context to use.
318 * @return APR_ECRYPT if an error occurred.
319 * @return APR_EPADDING if padding was enabled and the block was incorrectly
320 *         formatted.
321 * @return APR_ENOTIMPL if not implemented.
322 */
323APU_DECLARE(apr_status_t) apr_crypto_block_encrypt_finish(unsigned char *out,
324        apr_size_t *outlen, apr_crypto_block_t *ctx);
325
326/**
327 * @brief Initialise a context for decrypting arbitrary data using the given key.
328 * @note If *ctx is NULL, a apr_crypto_block_t will be created from a pool. If
329 *       *ctx is not NULL, *ctx must point at a previously created structure.
330 * @param ctx The block context returned, see note.
331 * @param blockSize The block size of the cipher.
332 * @param iv Optional initialisation vector.
333 * @param key The key structure to use.
334 * @param p The pool to use.
335 * @return Returns APR_ENOIV if an initialisation vector is required but not specified.
336 *         Returns APR_EINIT if the backend failed to initialise the context. Returns
337 *         APR_ENOTIMPL if not implemented.
338 */
339APU_DECLARE(apr_status_t) apr_crypto_block_decrypt_init(
340        apr_crypto_block_t **ctx, apr_size_t *blockSize,
341        const unsigned char *iv, const apr_crypto_key_t *key, apr_pool_t *p);
342
343/**
344 * @brief Decrypt data provided by in, write it to out.
345 * @note The number of bytes written will be written to outlen. If
346 *       out is NULL, outlen will contain the maximum size of the
347 *       buffer needed to hold the data, including any data
348 *       generated by apr_crypto_block_decrypt_finish below. If *out points
349 *       to NULL, a buffer sufficiently large will be created from
350 *       the pool provided. If *out points to a not-NULL value, this
351 *       value will be used as a buffer instead.
352 * @param out Address of a buffer to which data will be written,
353 *        see note.
354 * @param outlen Length of the output will be written here.
355 * @param in Address of the buffer to read.
356 * @param inlen Length of the buffer to read.
357 * @param ctx The block context to use.
358 * @return APR_ECRYPT if an error occurred. Returns APR_ENOTIMPL if
359 *         not implemented.
360 */
361APU_DECLARE(apr_status_t) apr_crypto_block_decrypt(unsigned char **out,
362        apr_size_t *outlen, const unsigned char *in, apr_size_t inlen,
363        apr_crypto_block_t *ctx);
364
365/**
366 * @brief Decrypt final data block, write it to out.
367 * @note If necessary the final block will be written out after being
368 *       padded. Typically the final block will be written to the
369 *       same buffer used by apr_crypto_block_decrypt, offset by the
370 *       number of bytes returned as actually written by the
371 *       apr_crypto_block_decrypt() call. After this call, the context
372 *       is cleaned and can be reused by apr_crypto_block_decrypt_init().
373 * @param out Address of a buffer to which data will be written. This
374 *            buffer must already exist, and is usually the same
375 *            buffer used by apr_evp_crypt(). See note.
376 * @param outlen Length of the output will be written here.
377 * @param ctx The block context to use.
378 * @return APR_ECRYPT if an error occurred.
379 * @return APR_EPADDING if padding was enabled and the block was incorrectly
380 *         formatted.
381 * @return APR_ENOTIMPL if not implemented.
382 */
383APU_DECLARE(apr_status_t) apr_crypto_block_decrypt_finish(unsigned char *out,
384        apr_size_t *outlen, apr_crypto_block_t *ctx);
385
386/**
387 * @brief Clean encryption / decryption context.
388 * @note After cleanup, a context is free to be reused if necessary.
389 * @param ctx The block context to use.
390 * @return Returns APR_ENOTIMPL if not supported.
391 */
392APU_DECLARE(apr_status_t) apr_crypto_block_cleanup(apr_crypto_block_t *ctx);
393
394/**
395 * @brief Clean encryption / decryption context.
396 * @note After cleanup, a context is free to be reused if necessary.
397 * @param f The context to use.
398 * @return Returns APR_ENOTIMPL if not supported.
399 */
400APU_DECLARE(apr_status_t) apr_crypto_cleanup(apr_crypto_t *f);
401
402/**
403 * @brief Shutdown the crypto library.
404 * @note After shutdown, it is expected that the init function can be called again.
405 * @param driver - driver to use
406 * @return Returns APR_ENOTIMPL if not supported.
407 */
408APU_DECLARE(apr_status_t) apr_crypto_shutdown(
409        const apr_crypto_driver_t *driver);
410
411#endif /* APU_HAVE_CRYPTO */
412
413/** @} */
414
415#ifdef __cplusplus
416}
417#endif
418
419#endif
420