xref: /aosp_15_r20/external/boringssl/src/include/openssl/cipher.h (revision 8fb009dc861624b67b6cdb62ea21f0f22d0c584b)
1 /* Copyright (C) 1995-1998 Eric Young ([email protected])
2  * All rights reserved.
3  *
4  * This package is an SSL implementation written
5  * by Eric Young ([email protected]).
6  * The implementation was written so as to conform with Netscapes SSL.
7  *
8  * This library is free for commercial and non-commercial use as long as
9  * the following conditions are aheared to.  The following conditions
10  * apply to all code found in this distribution, be it the RC4, RSA,
11  * lhash, DES, etc., code; not just the SSL code.  The SSL documentation
12  * included with this distribution is covered by the same copyright terms
13  * except that the holder is Tim Hudson ([email protected]).
14  *
15  * Copyright remains Eric Young's, and as such any Copyright notices in
16  * the code are not to be removed.
17  * If this package is used in a product, Eric Young should be given attribution
18  * as the author of the parts of the library used.
19  * This can be in the form of a textual message at program startup or
20  * in documentation (online or textual) provided with the package.
21  *
22  * Redistribution and use in source and binary forms, with or without
23  * modification, are permitted provided that the following conditions
24  * are met:
25  * 1. Redistributions of source code must retain the copyright
26  *    notice, this list of conditions and the following disclaimer.
27  * 2. Redistributions in binary form must reproduce the above copyright
28  *    notice, this list of conditions and the following disclaimer in the
29  *    documentation and/or other materials provided with the distribution.
30  * 3. All advertising materials mentioning features or use of this software
31  *    must display the following acknowledgement:
32  *    "This product includes cryptographic software written by
33  *     Eric Young ([email protected])"
34  *    The word 'cryptographic' can be left out if the rouines from the library
35  *    being used are not cryptographic related :-).
36  * 4. If you include any Windows specific code (or a derivative thereof) from
37  *    the apps directory (application code) you must include an acknowledgement:
38  *    "This product includes software written by Tim Hudson ([email protected])"
39  *
40  * THIS SOFTWARE IS PROVIDED BY ERIC YOUNG ``AS IS'' AND
41  * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
42  * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
43  * ARE DISCLAIMED.  IN NO EVENT SHALL THE AUTHOR OR CONTRIBUTORS BE LIABLE
44  * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
45  * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
46  * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
47  * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
48  * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
49  * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
50  * SUCH DAMAGE.
51  *
52  * The licence and distribution terms for any publically available version or
53  * derivative of this code cannot be changed.  i.e. this code cannot simply be
54  * copied and put under another distribution licence
55  * [including the GNU Public Licence.] */
56 
57 #ifndef OPENSSL_HEADER_CIPHER_H
58 #define OPENSSL_HEADER_CIPHER_H
59 
60 #include <openssl/base.h>
61 
62 #if defined(__cplusplus)
63 extern "C" {
64 #endif
65 
66 
67 // Ciphers.
68 
69 
70 // Cipher primitives.
71 //
72 // The following functions return |EVP_CIPHER| objects that implement the named
73 // cipher algorithm.
74 
75 OPENSSL_EXPORT const EVP_CIPHER *EVP_rc4(void);
76 
77 OPENSSL_EXPORT const EVP_CIPHER *EVP_des_cbc(void);
78 OPENSSL_EXPORT const EVP_CIPHER *EVP_des_ecb(void);
79 OPENSSL_EXPORT const EVP_CIPHER *EVP_des_ede(void);
80 OPENSSL_EXPORT const EVP_CIPHER *EVP_des_ede3(void);
81 OPENSSL_EXPORT const EVP_CIPHER *EVP_des_ede_cbc(void);
82 OPENSSL_EXPORT const EVP_CIPHER *EVP_des_ede3_cbc(void);
83 
84 OPENSSL_EXPORT const EVP_CIPHER *EVP_aes_128_ecb(void);
85 OPENSSL_EXPORT const EVP_CIPHER *EVP_aes_128_cbc(void);
86 OPENSSL_EXPORT const EVP_CIPHER *EVP_aes_128_ctr(void);
87 OPENSSL_EXPORT const EVP_CIPHER *EVP_aes_128_ofb(void);
88 
89 OPENSSL_EXPORT const EVP_CIPHER *EVP_aes_256_ecb(void);
90 OPENSSL_EXPORT const EVP_CIPHER *EVP_aes_256_cbc(void);
91 OPENSSL_EXPORT const EVP_CIPHER *EVP_aes_256_ctr(void);
92 OPENSSL_EXPORT const EVP_CIPHER *EVP_aes_256_ofb(void);
93 OPENSSL_EXPORT const EVP_CIPHER *EVP_aes_256_xts(void);
94 
95 // EVP_enc_null returns a 'cipher' that passes plaintext through as
96 // ciphertext.
97 OPENSSL_EXPORT const EVP_CIPHER *EVP_enc_null(void);
98 
99 // EVP_rc2_cbc returns a cipher that implements 128-bit RC2 in CBC mode.
100 OPENSSL_EXPORT const EVP_CIPHER *EVP_rc2_cbc(void);
101 
102 // EVP_rc2_40_cbc returns a cipher that implements 40-bit RC2 in CBC mode. This
103 // is obviously very, very weak and is included only in order to read PKCS#12
104 // files, which often encrypt the certificate chain using this cipher. It is
105 // deliberately not exported.
106 const EVP_CIPHER *EVP_rc2_40_cbc(void);
107 
108 // EVP_get_cipherbynid returns the cipher corresponding to the given NID, or
109 // NULL if no such cipher is known. Note using this function links almost every
110 // cipher implemented by BoringSSL into the binary, whether the caller uses them
111 // or not. Size-conscious callers, such as client software, should not use this
112 // function.
113 OPENSSL_EXPORT const EVP_CIPHER *EVP_get_cipherbynid(int nid);
114 
115 
116 // Cipher context allocation.
117 //
118 // An |EVP_CIPHER_CTX| represents the state of an encryption or decryption in
119 // progress.
120 
121 // EVP_CIPHER_CTX_init initialises an, already allocated, |EVP_CIPHER_CTX|.
122 OPENSSL_EXPORT void EVP_CIPHER_CTX_init(EVP_CIPHER_CTX *ctx);
123 
124 // EVP_CIPHER_CTX_new allocates a fresh |EVP_CIPHER_CTX|, calls
125 // |EVP_CIPHER_CTX_init| and returns it, or NULL on allocation failure.
126 OPENSSL_EXPORT EVP_CIPHER_CTX *EVP_CIPHER_CTX_new(void);
127 
128 // EVP_CIPHER_CTX_cleanup frees any memory referenced by |ctx|. It returns
129 // one.
130 OPENSSL_EXPORT int EVP_CIPHER_CTX_cleanup(EVP_CIPHER_CTX *ctx);
131 
132 // EVP_CIPHER_CTX_free calls |EVP_CIPHER_CTX_cleanup| on |ctx| and then frees
133 // |ctx| itself.
134 OPENSSL_EXPORT void EVP_CIPHER_CTX_free(EVP_CIPHER_CTX *ctx);
135 
136 // EVP_CIPHER_CTX_copy sets |out| to be a duplicate of the current state of
137 // |in|. The |out| argument must have been previously initialised.
138 OPENSSL_EXPORT int EVP_CIPHER_CTX_copy(EVP_CIPHER_CTX *out,
139                                        const EVP_CIPHER_CTX *in);
140 
141 // EVP_CIPHER_CTX_reset calls |EVP_CIPHER_CTX_cleanup| followed by
142 // |EVP_CIPHER_CTX_init| and returns one.
143 OPENSSL_EXPORT int EVP_CIPHER_CTX_reset(EVP_CIPHER_CTX *ctx);
144 
145 
146 // Cipher context configuration.
147 
148 // EVP_CipherInit_ex configures |ctx| for a fresh encryption (or decryption, if
149 // |enc| is zero) operation using |cipher|. If |ctx| has been previously
150 // configured with a cipher then |cipher|, |key| and |iv| may be |NULL| and
151 // |enc| may be -1 to reuse the previous values. The operation will use |key|
152 // as the key and |iv| as the IV (if any). These should have the correct
153 // lengths given by |EVP_CIPHER_key_length| and |EVP_CIPHER_iv_length|. It
154 // returns one on success and zero on error.
155 OPENSSL_EXPORT int EVP_CipherInit_ex(EVP_CIPHER_CTX *ctx,
156                                      const EVP_CIPHER *cipher, ENGINE *engine,
157                                      const uint8_t *key, const uint8_t *iv,
158                                      int enc);
159 
160 // EVP_EncryptInit_ex calls |EVP_CipherInit_ex| with |enc| equal to one.
161 OPENSSL_EXPORT int EVP_EncryptInit_ex(EVP_CIPHER_CTX *ctx,
162                                       const EVP_CIPHER *cipher, ENGINE *impl,
163                                       const uint8_t *key, const uint8_t *iv);
164 
165 // EVP_DecryptInit_ex calls |EVP_CipherInit_ex| with |enc| equal to zero.
166 OPENSSL_EXPORT int EVP_DecryptInit_ex(EVP_CIPHER_CTX *ctx,
167                                       const EVP_CIPHER *cipher, ENGINE *impl,
168                                       const uint8_t *key, const uint8_t *iv);
169 
170 
171 // Cipher operations.
172 
173 // EVP_EncryptUpdate encrypts |in_len| bytes from |in| to |out|. The number
174 // of output bytes may be up to |in_len| plus the block length minus one and
175 // |out| must have sufficient space. The number of bytes actually output is
176 // written to |*out_len|. It returns one on success and zero otherwise.
177 //
178 // If |ctx| is an AEAD cipher, e.g. |EVP_aes_128_gcm|, and |out| is NULL, this
179 // function instead adds |in_len| bytes from |in| to the AAD and sets |*out_len|
180 // to |in_len|. The AAD must be fully specified in this way before this function
181 // is used to encrypt plaintext.
182 OPENSSL_EXPORT int EVP_EncryptUpdate(EVP_CIPHER_CTX *ctx, uint8_t *out,
183                                      int *out_len, const uint8_t *in,
184                                      int in_len);
185 
186 // EVP_EncryptFinal_ex writes at most a block of ciphertext to |out| and sets
187 // |*out_len| to the number of bytes written. If padding is enabled (the
188 // default) then standard padding is applied to create the final block. If
189 // padding is disabled (with |EVP_CIPHER_CTX_set_padding|) then any partial
190 // block remaining will cause an error. The function returns one on success and
191 // zero otherwise.
192 OPENSSL_EXPORT int EVP_EncryptFinal_ex(EVP_CIPHER_CTX *ctx, uint8_t *out,
193                                        int *out_len);
194 
195 // EVP_DecryptUpdate decrypts |in_len| bytes from |in| to |out|. The number of
196 // output bytes may be up to |in_len| plus the block length minus one and |out|
197 // must have sufficient space. The number of bytes actually output is written
198 // to |*out_len|. It returns one on success and zero otherwise.
199 //
200 // If |ctx| is an AEAD cipher, e.g. |EVP_aes_128_gcm|, and |out| is NULL, this
201 // function instead adds |in_len| bytes from |in| to the AAD and sets |*out_len|
202 // to |in_len|. The AAD must be fully specified in this way before this function
203 // is used to decrypt ciphertext.
204 OPENSSL_EXPORT int EVP_DecryptUpdate(EVP_CIPHER_CTX *ctx, uint8_t *out,
205                                      int *out_len, const uint8_t *in,
206                                      int in_len);
207 
208 // EVP_DecryptFinal_ex writes at most a block of ciphertext to |out| and sets
209 // |*out_len| to the number of bytes written. If padding is enabled (the
210 // default) then padding is removed from the final block.
211 //
212 // WARNING: it is unsafe to call this function with unauthenticated
213 // ciphertext if padding is enabled.
214 OPENSSL_EXPORT int EVP_DecryptFinal_ex(EVP_CIPHER_CTX *ctx, uint8_t *out,
215                                        int *out_len);
216 
217 // EVP_CipherUpdate calls either |EVP_EncryptUpdate| or |EVP_DecryptUpdate|
218 // depending on how |ctx| has been setup.
219 OPENSSL_EXPORT int EVP_CipherUpdate(EVP_CIPHER_CTX *ctx, uint8_t *out,
220                                     int *out_len, const uint8_t *in,
221                                     int in_len);
222 
223 // EVP_CipherFinal_ex calls either |EVP_EncryptFinal_ex| or
224 // |EVP_DecryptFinal_ex| depending on how |ctx| has been setup.
225 OPENSSL_EXPORT int EVP_CipherFinal_ex(EVP_CIPHER_CTX *ctx, uint8_t *out,
226                                       int *out_len);
227 
228 
229 // Cipher context accessors.
230 
231 // EVP_CIPHER_CTX_cipher returns the |EVP_CIPHER| underlying |ctx|, or NULL if
232 // none has been set.
233 OPENSSL_EXPORT const EVP_CIPHER *EVP_CIPHER_CTX_cipher(
234     const EVP_CIPHER_CTX *ctx);
235 
236 // EVP_CIPHER_CTX_nid returns a NID identifying the |EVP_CIPHER| underlying
237 // |ctx| (e.g. |NID_aes_128_gcm|). It will crash if no cipher has been
238 // configured.
239 OPENSSL_EXPORT int EVP_CIPHER_CTX_nid(const EVP_CIPHER_CTX *ctx);
240 
241 // EVP_CIPHER_CTX_encrypting returns one if |ctx| is configured for encryption
242 // and zero otherwise.
243 OPENSSL_EXPORT int EVP_CIPHER_CTX_encrypting(const EVP_CIPHER_CTX *ctx);
244 
245 // EVP_CIPHER_CTX_block_size returns the block size, in bytes, of the cipher
246 // underlying |ctx|, or one if the cipher is a stream cipher. It will crash if
247 // no cipher has been configured.
248 OPENSSL_EXPORT unsigned EVP_CIPHER_CTX_block_size(const EVP_CIPHER_CTX *ctx);
249 
250 // EVP_CIPHER_CTX_key_length returns the key size, in bytes, of the cipher
251 // underlying |ctx| or zero if no cipher has been configured.
252 OPENSSL_EXPORT unsigned EVP_CIPHER_CTX_key_length(const EVP_CIPHER_CTX *ctx);
253 
254 // EVP_CIPHER_CTX_iv_length returns the IV size, in bytes, of the cipher
255 // underlying |ctx|. It will crash if no cipher has been configured.
256 OPENSSL_EXPORT unsigned EVP_CIPHER_CTX_iv_length(const EVP_CIPHER_CTX *ctx);
257 
258 // EVP_CIPHER_CTX_get_app_data returns the opaque, application data pointer for
259 // |ctx|, or NULL if none has been set.
260 OPENSSL_EXPORT void *EVP_CIPHER_CTX_get_app_data(const EVP_CIPHER_CTX *ctx);
261 
262 // EVP_CIPHER_CTX_set_app_data sets the opaque, application data pointer for
263 // |ctx| to |data|.
264 OPENSSL_EXPORT void EVP_CIPHER_CTX_set_app_data(EVP_CIPHER_CTX *ctx,
265                                                 void *data);
266 
267 // EVP_CIPHER_CTX_flags returns a value which is the OR of zero or more
268 // |EVP_CIPH_*| flags. It will crash if no cipher has been configured.
269 OPENSSL_EXPORT uint32_t EVP_CIPHER_CTX_flags(const EVP_CIPHER_CTX *ctx);
270 
271 // EVP_CIPHER_CTX_mode returns one of the |EVP_CIPH_*| cipher mode values
272 // enumerated below. It will crash if no cipher has been configured.
273 OPENSSL_EXPORT uint32_t EVP_CIPHER_CTX_mode(const EVP_CIPHER_CTX *ctx);
274 
275 // EVP_CIPHER_CTX_ctrl is an |ioctl| like function. The |command| argument
276 // should be one of the |EVP_CTRL_*| values. The |arg| and |ptr| arguments are
277 // specific to the command in question.
278 OPENSSL_EXPORT int EVP_CIPHER_CTX_ctrl(EVP_CIPHER_CTX *ctx, int command,
279                                        int arg, void *ptr);
280 
281 // EVP_CIPHER_CTX_set_padding sets whether padding is enabled for |ctx| and
282 // returns one. Pass a non-zero |pad| to enable padding (the default) or zero
283 // to disable.
284 OPENSSL_EXPORT int EVP_CIPHER_CTX_set_padding(EVP_CIPHER_CTX *ctx, int pad);
285 
286 // EVP_CIPHER_CTX_set_key_length sets the key length for |ctx|. This is only
287 // valid for ciphers that can take a variable length key. It returns one on
288 // success and zero on error.
289 OPENSSL_EXPORT int EVP_CIPHER_CTX_set_key_length(EVP_CIPHER_CTX *ctx,
290                                                  unsigned key_len);
291 
292 
293 // Cipher accessors.
294 
295 // EVP_CIPHER_nid returns a NID identifying |cipher|. (For example,
296 // |NID_aes_128_gcm|.)
297 OPENSSL_EXPORT int EVP_CIPHER_nid(const EVP_CIPHER *cipher);
298 
299 // EVP_CIPHER_block_size returns the block size, in bytes, for |cipher|, or one
300 // if |cipher| is a stream cipher.
301 OPENSSL_EXPORT unsigned EVP_CIPHER_block_size(const EVP_CIPHER *cipher);
302 
303 // EVP_CIPHER_key_length returns the key size, in bytes, for |cipher|. If
304 // |cipher| can take a variable key length then this function returns the
305 // default key length and |EVP_CIPHER_flags| will return a value with
306 // |EVP_CIPH_VARIABLE_LENGTH| set.
307 OPENSSL_EXPORT unsigned EVP_CIPHER_key_length(const EVP_CIPHER *cipher);
308 
309 // EVP_CIPHER_iv_length returns the IV size, in bytes, of |cipher|, or zero if
310 // |cipher| doesn't take an IV.
311 OPENSSL_EXPORT unsigned EVP_CIPHER_iv_length(const EVP_CIPHER *cipher);
312 
313 // EVP_CIPHER_flags returns a value which is the OR of zero or more
314 // |EVP_CIPH_*| flags.
315 OPENSSL_EXPORT uint32_t EVP_CIPHER_flags(const EVP_CIPHER *cipher);
316 
317 // EVP_CIPHER_mode returns one of the cipher mode values enumerated below.
318 OPENSSL_EXPORT uint32_t EVP_CIPHER_mode(const EVP_CIPHER *cipher);
319 
320 
321 // Key derivation.
322 
323 // EVP_BytesToKey generates a key and IV for the cipher |type| by iterating
324 // |md| |count| times using |data| and |salt|. On entry, the |key| and |iv|
325 // buffers must have enough space to hold a key and IV for |type|. It returns
326 // the length of the key on success or zero on error.
327 OPENSSL_EXPORT int EVP_BytesToKey(const EVP_CIPHER *type, const EVP_MD *md,
328                                   const uint8_t *salt, const uint8_t *data,
329                                   size_t data_len, unsigned count, uint8_t *key,
330                                   uint8_t *iv);
331 
332 
333 // Cipher modes (for |EVP_CIPHER_mode|).
334 
335 #define EVP_CIPH_STREAM_CIPHER 0x0
336 #define EVP_CIPH_ECB_MODE 0x1
337 #define EVP_CIPH_CBC_MODE 0x2
338 #define EVP_CIPH_CFB_MODE 0x3
339 #define EVP_CIPH_OFB_MODE 0x4
340 #define EVP_CIPH_CTR_MODE 0x5
341 #define EVP_CIPH_GCM_MODE 0x6
342 #define EVP_CIPH_XTS_MODE 0x7
343 
344 // The following values are never returned from |EVP_CIPHER_mode| and are
345 // included only to make it easier to compile code with BoringSSL.
346 #define EVP_CIPH_CCM_MODE 0x8
347 #define EVP_CIPH_OCB_MODE 0x9
348 #define EVP_CIPH_WRAP_MODE 0xa
349 
350 
351 // Cipher flags (for |EVP_CIPHER_flags|).
352 
353 // EVP_CIPH_VARIABLE_LENGTH indicates that the cipher takes a variable length
354 // key.
355 #define EVP_CIPH_VARIABLE_LENGTH 0x40
356 
357 // EVP_CIPH_ALWAYS_CALL_INIT indicates that the |init| function for the cipher
358 // should always be called when initialising a new operation, even if the key
359 // is NULL to indicate that the same key is being used.
360 #define EVP_CIPH_ALWAYS_CALL_INIT 0x80
361 
362 // EVP_CIPH_CUSTOM_IV indicates that the cipher manages the IV itself rather
363 // than keeping it in the |iv| member of |EVP_CIPHER_CTX|.
364 #define EVP_CIPH_CUSTOM_IV 0x100
365 
366 // EVP_CIPH_CTRL_INIT indicates that EVP_CTRL_INIT should be used when
367 // initialising an |EVP_CIPHER_CTX|.
368 #define EVP_CIPH_CTRL_INIT 0x200
369 
370 // EVP_CIPH_FLAG_CUSTOM_CIPHER indicates that the cipher manages blocking
371 // itself. This causes EVP_(En|De)crypt_ex to be simple wrapper functions.
372 #define EVP_CIPH_FLAG_CUSTOM_CIPHER 0x400
373 
374 // EVP_CIPH_FLAG_AEAD_CIPHER specifies that the cipher is an AEAD. This is an
375 // older version of the proper AEAD interface. See aead.h for the current
376 // one.
377 #define EVP_CIPH_FLAG_AEAD_CIPHER 0x800
378 
379 // EVP_CIPH_CUSTOM_COPY indicates that the |ctrl| callback should be called
380 // with |EVP_CTRL_COPY| at the end of normal |EVP_CIPHER_CTX_copy|
381 // processing.
382 #define EVP_CIPH_CUSTOM_COPY 0x1000
383 
384 // EVP_CIPH_FLAG_NON_FIPS_ALLOW is meaningless. In OpenSSL it permits non-FIPS
385 // algorithms in FIPS mode. But BoringSSL FIPS mode doesn't prohibit algorithms
386 // (it's up the the caller to use the FIPS module in a fashion compliant with
387 // their needs). Thus this exists only to allow code to compile.
388 #define EVP_CIPH_FLAG_NON_FIPS_ALLOW 0
389 
390 
391 // Deprecated functions
392 
393 // EVP_CipherInit acts like EVP_CipherInit_ex except that |EVP_CIPHER_CTX_init|
394 // is called on |cipher| first, if |cipher| is not NULL.
395 OPENSSL_EXPORT int EVP_CipherInit(EVP_CIPHER_CTX *ctx, const EVP_CIPHER *cipher,
396                                   const uint8_t *key, const uint8_t *iv,
397                                   int enc);
398 
399 // EVP_EncryptInit calls |EVP_CipherInit| with |enc| equal to one.
400 OPENSSL_EXPORT int EVP_EncryptInit(EVP_CIPHER_CTX *ctx,
401                                    const EVP_CIPHER *cipher, const uint8_t *key,
402                                    const uint8_t *iv);
403 
404 // EVP_DecryptInit calls |EVP_CipherInit| with |enc| equal to zero.
405 OPENSSL_EXPORT int EVP_DecryptInit(EVP_CIPHER_CTX *ctx,
406                                    const EVP_CIPHER *cipher, const uint8_t *key,
407                                    const uint8_t *iv);
408 
409 // EVP_CipherFinal calls |EVP_CipherFinal_ex|.
410 OPENSSL_EXPORT int EVP_CipherFinal(EVP_CIPHER_CTX *ctx, uint8_t *out,
411                                    int *out_len);
412 
413 // EVP_EncryptFinal calls |EVP_EncryptFinal_ex|.
414 OPENSSL_EXPORT int EVP_EncryptFinal(EVP_CIPHER_CTX *ctx, uint8_t *out,
415                                     int *out_len);
416 
417 // EVP_DecryptFinal calls |EVP_DecryptFinal_ex|.
418 OPENSSL_EXPORT int EVP_DecryptFinal(EVP_CIPHER_CTX *ctx, uint8_t *out,
419                                     int *out_len);
420 
421 // EVP_Cipher historically exposed an internal implementation detail of |ctx|
422 // and should not be used. Use |EVP_CipherUpdate| and |EVP_CipherFinal_ex|
423 // instead.
424 //
425 // If |ctx|'s cipher does not have the |EVP_CIPH_FLAG_CUSTOM_CIPHER| flag, it
426 // encrypts or decrypts |in_len| bytes from |in| and writes the resulting
427 // |in_len| bytes to |out|. It returns one on success and zero on error.
428 // |in_len| must be a multiple of the cipher's block size, or the behavior is
429 // undefined.
430 //
431 // TODO(davidben): Rather than being undefined (it'll often round the length up
432 // and likely read past the buffer), just fail the operation.
433 //
434 // If |ctx|'s cipher has the |EVP_CIPH_FLAG_CUSTOM_CIPHER| flag, it runs in one
435 // of two modes: If |in| is non-NULL, it behaves like |EVP_CipherUpdate|. If
436 // |in| is NULL, it behaves like |EVP_CipherFinal_ex|. In both cases, it returns
437 // |*out_len| on success and -1 on error.
438 //
439 // WARNING: The two possible calling conventions of this function signal errors
440 // incompatibly. In the first, zero indicates an error. In the second, zero
441 // indicates success with zero bytes of output.
442 OPENSSL_EXPORT int EVP_Cipher(EVP_CIPHER_CTX *ctx, uint8_t *out,
443                               const uint8_t *in, size_t in_len);
444 
445 // EVP_add_cipher_alias does nothing and returns one.
446 OPENSSL_EXPORT int EVP_add_cipher_alias(const char *a, const char *b);
447 
448 // EVP_get_cipherbyname returns an |EVP_CIPHER| given a human readable name in
449 // |name|, or NULL if the name is unknown. Note using this function links almost
450 // every cipher implemented by BoringSSL into the binary, not just the ones the
451 // caller requests. Size-conscious callers, such as client software, should not
452 // use this function.
453 OPENSSL_EXPORT const EVP_CIPHER *EVP_get_cipherbyname(const char *name);
454 
455 // These AEADs are deprecated AES-GCM implementations that set
456 // |EVP_CIPH_FLAG_CUSTOM_CIPHER|. Use |EVP_aead_aes_128_gcm| and
457 // |EVP_aead_aes_256_gcm| instead.
458 //
459 // WARNING: Although these APIs allow streaming an individual AES-GCM operation,
460 // this is not secure. Until calling |EVP_DecryptFinal_ex|, the tag has not yet
461 // been checked and output released by |EVP_DecryptUpdate| is unauthenticated
462 // and easily manipulated by attackers. Callers must buffer the output and may
463 // not act on it until the entire operation is complete.
464 OPENSSL_EXPORT const EVP_CIPHER *EVP_aes_128_gcm(void);
465 OPENSSL_EXPORT const EVP_CIPHER *EVP_aes_256_gcm(void);
466 
467 // These are deprecated, 192-bit version of AES.
468 OPENSSL_EXPORT const EVP_CIPHER *EVP_aes_192_ecb(void);
469 OPENSSL_EXPORT const EVP_CIPHER *EVP_aes_192_cbc(void);
470 OPENSSL_EXPORT const EVP_CIPHER *EVP_aes_192_ctr(void);
471 OPENSSL_EXPORT const EVP_CIPHER *EVP_aes_192_gcm(void);
472 OPENSSL_EXPORT const EVP_CIPHER *EVP_aes_192_ofb(void);
473 
474 // EVP_des_ede3_ecb is an alias for |EVP_des_ede3|. Use the former instead.
475 OPENSSL_EXPORT const EVP_CIPHER *EVP_des_ede3_ecb(void);
476 
477 // EVP_aes_128_cfb128 is only available in decrepit.
478 OPENSSL_EXPORT const EVP_CIPHER *EVP_aes_128_cfb128(void);
479 
480 // EVP_aes_128_cfb is an alias for |EVP_aes_128_cfb128| and is only available in
481 // decrepit.
482 OPENSSL_EXPORT const EVP_CIPHER *EVP_aes_128_cfb(void);
483 
484 // EVP_aes_192_cfb128 is only available in decrepit.
485 OPENSSL_EXPORT const EVP_CIPHER *EVP_aes_192_cfb128(void);
486 
487 // EVP_aes_192_cfb is an alias for |EVP_aes_192_cfb128| and is only available in
488 // decrepit.
489 OPENSSL_EXPORT const EVP_CIPHER *EVP_aes_192_cfb(void);
490 
491 // EVP_aes_256_cfb128 is only available in decrepit.
492 OPENSSL_EXPORT const EVP_CIPHER *EVP_aes_256_cfb128(void);
493 
494 // EVP_aes_256_cfb is an alias for |EVP_aes_256_cfb128| and is only available in
495 // decrepit.
496 OPENSSL_EXPORT const EVP_CIPHER *EVP_aes_256_cfb(void);
497 
498 // EVP_bf_ecb is Blowfish in ECB mode and is only available in decrepit.
499 OPENSSL_EXPORT const EVP_CIPHER *EVP_bf_ecb(void);
500 
501 // EVP_bf_cbc is Blowfish in CBC mode and is only available in decrepit.
502 OPENSSL_EXPORT const EVP_CIPHER *EVP_bf_cbc(void);
503 
504 // EVP_bf_cfb is Blowfish in 64-bit CFB mode and is only available in decrepit.
505 OPENSSL_EXPORT const EVP_CIPHER *EVP_bf_cfb(void);
506 
507 // EVP_cast5_ecb is CAST5 in ECB mode and is only available in decrepit.
508 OPENSSL_EXPORT const EVP_CIPHER *EVP_cast5_ecb(void);
509 
510 // EVP_cast5_cbc is CAST5 in CBC mode and is only available in decrepit.
511 OPENSSL_EXPORT const EVP_CIPHER *EVP_cast5_cbc(void);
512 
513 // The following flags do nothing and are included only to make it easier to
514 // compile code with BoringSSL.
515 #define EVP_CIPHER_CTX_FLAG_WRAP_ALLOW 0
516 
517 // EVP_CIPHER_CTX_set_flags does nothing.
518 OPENSSL_EXPORT void EVP_CIPHER_CTX_set_flags(const EVP_CIPHER_CTX *ctx,
519                                              uint32_t flags);
520 
521 
522 // Private functions.
523 
524 // EVP_CIPH_NO_PADDING disables padding in block ciphers.
525 #define EVP_CIPH_NO_PADDING 0x800
526 
527 // The following are |EVP_CIPHER_CTX_ctrl| commands.
528 #define EVP_CTRL_INIT 0x0
529 #define EVP_CTRL_SET_KEY_LENGTH 0x1
530 #define EVP_CTRL_GET_RC2_KEY_BITS 0x2
531 #define EVP_CTRL_SET_RC2_KEY_BITS 0x3
532 #define EVP_CTRL_GET_RC5_ROUNDS 0x4
533 #define EVP_CTRL_SET_RC5_ROUNDS 0x5
534 #define EVP_CTRL_RAND_KEY 0x6
535 #define EVP_CTRL_PBE_PRF_NID 0x7
536 #define EVP_CTRL_COPY 0x8
537 #define EVP_CTRL_AEAD_SET_IVLEN 0x9
538 #define EVP_CTRL_AEAD_GET_TAG 0x10
539 #define EVP_CTRL_AEAD_SET_TAG 0x11
540 #define EVP_CTRL_AEAD_SET_IV_FIXED 0x12
541 #define EVP_CTRL_GCM_IV_GEN 0x13
542 #define EVP_CTRL_AEAD_SET_MAC_KEY 0x17
543 // EVP_CTRL_GCM_SET_IV_INV sets the GCM invocation field, decrypt only
544 #define EVP_CTRL_GCM_SET_IV_INV 0x18
545 #define EVP_CTRL_GET_IVLEN 0x19
546 
547 // The following constants are unused.
548 #define EVP_GCM_TLS_FIXED_IV_LEN 4
549 #define EVP_GCM_TLS_EXPLICIT_IV_LEN 8
550 #define EVP_GCM_TLS_TAG_LEN 16
551 
552 // The following are legacy aliases for AEAD |EVP_CIPHER_CTX_ctrl| values.
553 #define EVP_CTRL_GCM_SET_IVLEN EVP_CTRL_AEAD_SET_IVLEN
554 #define EVP_CTRL_GCM_GET_TAG EVP_CTRL_AEAD_GET_TAG
555 #define EVP_CTRL_GCM_SET_TAG EVP_CTRL_AEAD_SET_TAG
556 #define EVP_CTRL_GCM_SET_IV_FIXED EVP_CTRL_AEAD_SET_IV_FIXED
557 
558 #define EVP_MAX_KEY_LENGTH 64
559 #define EVP_MAX_IV_LENGTH 16
560 #define EVP_MAX_BLOCK_LENGTH 32
561 
562 struct evp_cipher_ctx_st {
563   // cipher contains the underlying cipher for this context.
564   const EVP_CIPHER *cipher;
565 
566   // app_data is a pointer to opaque, user data.
567   void *app_data;      // application stuff
568 
569   // cipher_data points to the |cipher| specific state.
570   void *cipher_data;
571 
572   // key_len contains the length of the key, which may differ from
573   // |cipher->key_len| if the cipher can take a variable key length.
574   unsigned key_len;
575 
576   // encrypt is one if encrypting and zero if decrypting.
577   int encrypt;
578 
579   // flags contains the OR of zero or more |EVP_CIPH_*| flags, above.
580   uint32_t flags;
581 
582   // oiv contains the original IV value.
583   uint8_t oiv[EVP_MAX_IV_LENGTH];
584 
585   // iv contains the current IV value, which may have been updated.
586   uint8_t iv[EVP_MAX_IV_LENGTH];
587 
588   // buf contains a partial block which is used by, for example, CTR mode to
589   // store unused keystream bytes.
590   uint8_t buf[EVP_MAX_BLOCK_LENGTH];
591 
592   // buf_len contains the number of bytes of a partial block contained in
593   // |buf|.
594   int buf_len;
595 
596   // num contains the number of bytes of |iv| which are valid for modes that
597   // manage partial blocks themselves.
598   unsigned num;
599 
600   // final_used is non-zero if the |final| buffer contains plaintext.
601   int final_used;
602 
603   uint8_t final[EVP_MAX_BLOCK_LENGTH];  // possible final block
604 
605   // Has this structure been rendered unusable by a failure.
606   int poisoned;
607 } /* EVP_CIPHER_CTX */;
608 
609 typedef struct evp_cipher_info_st {
610   const EVP_CIPHER *cipher;
611   unsigned char iv[EVP_MAX_IV_LENGTH];
612 } EVP_CIPHER_INFO;
613 
614 
615 #if defined(__cplusplus)
616 }  // extern C
617 
618 #if !defined(BORINGSSL_NO_CXX)
619 extern "C++" {
620 
621 BSSL_NAMESPACE_BEGIN
622 
623 BORINGSSL_MAKE_DELETER(EVP_CIPHER_CTX, EVP_CIPHER_CTX_free)
624 
625 using ScopedEVP_CIPHER_CTX =
626     internal::StackAllocated<EVP_CIPHER_CTX, int, EVP_CIPHER_CTX_init,
627                              EVP_CIPHER_CTX_cleanup>;
628 
629 BSSL_NAMESPACE_END
630 
631 }  // extern C++
632 #endif
633 
634 #endif
635 
636 #define CIPHER_R_AES_KEY_SETUP_FAILED 100
637 #define CIPHER_R_BAD_DECRYPT 101
638 #define CIPHER_R_BAD_KEY_LENGTH 102
639 #define CIPHER_R_BUFFER_TOO_SMALL 103
640 #define CIPHER_R_CTRL_NOT_IMPLEMENTED 104
641 #define CIPHER_R_CTRL_OPERATION_NOT_IMPLEMENTED 105
642 #define CIPHER_R_DATA_NOT_MULTIPLE_OF_BLOCK_LENGTH 106
643 #define CIPHER_R_INITIALIZATION_ERROR 107
644 #define CIPHER_R_INPUT_NOT_INITIALIZED 108
645 #define CIPHER_R_INVALID_AD_SIZE 109
646 #define CIPHER_R_INVALID_KEY_LENGTH 110
647 #define CIPHER_R_INVALID_NONCE_SIZE 111
648 #define CIPHER_R_INVALID_OPERATION 112
649 #define CIPHER_R_IV_TOO_LARGE 113
650 #define CIPHER_R_NO_CIPHER_SET 114
651 #define CIPHER_R_OUTPUT_ALIASES_INPUT 115
652 #define CIPHER_R_TAG_TOO_LARGE 116
653 #define CIPHER_R_TOO_LARGE 117
654 #define CIPHER_R_UNSUPPORTED_AD_SIZE 118
655 #define CIPHER_R_UNSUPPORTED_INPUT_SIZE 119
656 #define CIPHER_R_UNSUPPORTED_KEY_SIZE 120
657 #define CIPHER_R_UNSUPPORTED_NONCE_SIZE 121
658 #define CIPHER_R_UNSUPPORTED_TAG_SIZE 122
659 #define CIPHER_R_WRONG_FINAL_BLOCK_LENGTH 123
660 #define CIPHER_R_NO_DIRECTION_SET 124
661 #define CIPHER_R_INVALID_NONCE 125
662 
663 #endif  // OPENSSL_HEADER_CIPHER_H
664