2 * Copyright 1995-2016 The OpenSSL Project Authors. All Rights Reserved.
4 * Licensed under the OpenSSL license (the "License"). You may not use
5 * this file except in compliance with the License. You can obtain a copy
6 * in the file LICENSE in the source distribution or at
7 * https://www.openssl.org/source/license.html
12 #include "internal/cryptlib.h"
13 #include <openssl/evp.h>
14 #include <openssl/err.h>
15 #include <openssl/rand.h>
16 #include <openssl/engine.h>
17 #include "internal/evp_int.h"
20 int EVP_CIPHER_CTX_reset(EVP_CIPHER_CTX
*c
)
24 if (c
->cipher
!= NULL
) {
25 if (c
->cipher
->cleanup
&& !c
->cipher
->cleanup(c
))
27 /* Cleanse cipher context data */
28 if (c
->cipher_data
&& c
->cipher
->ctx_size
)
29 OPENSSL_cleanse(c
->cipher_data
, c
->cipher
->ctx_size
);
31 OPENSSL_free(c
->cipher_data
);
32 #ifndef OPENSSL_NO_ENGINE
33 ENGINE_finish(c
->engine
);
35 memset(c
, 0, sizeof(*c
));
39 EVP_CIPHER_CTX
*EVP_CIPHER_CTX_new(void)
41 return OPENSSL_zalloc(sizeof(EVP_CIPHER_CTX
));
44 void EVP_CIPHER_CTX_free(EVP_CIPHER_CTX
*ctx
)
46 EVP_CIPHER_CTX_reset(ctx
);
50 int EVP_CipherInit(EVP_CIPHER_CTX
*ctx
, const EVP_CIPHER
*cipher
,
51 const unsigned char *key
, const unsigned char *iv
, int enc
)
53 EVP_CIPHER_CTX_reset(ctx
);
54 return EVP_CipherInit_ex(ctx
, cipher
, NULL
, key
, iv
, enc
);
57 int EVP_CipherInit_ex(EVP_CIPHER_CTX
*ctx
, const EVP_CIPHER
*cipher
,
58 ENGINE
*impl
, const unsigned char *key
,
59 const unsigned char *iv
, int enc
)
68 #ifndef OPENSSL_NO_ENGINE
70 * Whether it's nice or not, "Inits" can be used on "Final"'d contexts so
71 * this context may already have an ENGINE! Try to avoid releasing the
72 * previous handle, re-querying for an ENGINE, and having a
73 * reinitialisation, when it may all be unnecessary.
75 if (ctx
->engine
&& ctx
->cipher
76 && (cipher
== NULL
|| cipher
->nid
== ctx
->cipher
->nid
))
81 * Ensure a context left lying around from last time is cleared (the
82 * previous check attempted to avoid this if the same ENGINE and
83 * EVP_CIPHER could be used).
86 unsigned long flags
= ctx
->flags
;
87 EVP_CIPHER_CTX_reset(ctx
);
88 /* Restore encrypt and flags */
92 #ifndef OPENSSL_NO_ENGINE
94 if (!ENGINE_init(impl
)) {
95 EVPerr(EVP_F_EVP_CIPHERINIT_EX
, EVP_R_INITIALIZATION_ERROR
);
99 /* Ask if an ENGINE is reserved for this job */
100 impl
= ENGINE_get_cipher_engine(cipher
->nid
);
102 /* There's an ENGINE for this job ... (apparently) */
103 const EVP_CIPHER
*c
= ENGINE_get_cipher(impl
, cipher
->nid
);
106 * One positive side-effect of US's export control history,
107 * is that we should at least be able to avoid using US
108 * misspellings of "initialisation"?
110 EVPerr(EVP_F_EVP_CIPHERINIT_EX
, EVP_R_INITIALIZATION_ERROR
);
113 /* We'll use the ENGINE's private cipher definition */
116 * Store the ENGINE functional reference so we know 'cipher' came
117 * from an ENGINE and we need to release it when done.
124 ctx
->cipher
= cipher
;
125 if (ctx
->cipher
->ctx_size
) {
126 ctx
->cipher_data
= OPENSSL_zalloc(ctx
->cipher
->ctx_size
);
127 if (ctx
->cipher_data
== NULL
) {
129 EVPerr(EVP_F_EVP_CIPHERINIT_EX
, ERR_R_MALLOC_FAILURE
);
133 ctx
->cipher_data
= NULL
;
135 ctx
->key_len
= cipher
->key_len
;
136 /* Preserve wrap enable flag, zero everything else */
137 ctx
->flags
&= EVP_CIPHER_CTX_FLAG_WRAP_ALLOW
;
138 if (ctx
->cipher
->flags
& EVP_CIPH_CTRL_INIT
) {
139 if (!EVP_CIPHER_CTX_ctrl(ctx
, EVP_CTRL_INIT
, 0, NULL
)) {
141 EVPerr(EVP_F_EVP_CIPHERINIT_EX
, EVP_R_INITIALIZATION_ERROR
);
145 } else if (!ctx
->cipher
) {
146 EVPerr(EVP_F_EVP_CIPHERINIT_EX
, EVP_R_NO_CIPHER_SET
);
149 #ifndef OPENSSL_NO_ENGINE
152 /* we assume block size is a power of 2 in *cryptUpdate */
153 OPENSSL_assert(ctx
->cipher
->block_size
== 1
154 || ctx
->cipher
->block_size
== 8
155 || ctx
->cipher
->block_size
== 16);
157 if (!(ctx
->flags
& EVP_CIPHER_CTX_FLAG_WRAP_ALLOW
)
158 && EVP_CIPHER_CTX_mode(ctx
) == EVP_CIPH_WRAP_MODE
) {
159 EVPerr(EVP_F_EVP_CIPHERINIT_EX
, EVP_R_WRAP_MODE_NOT_ALLOWED
);
163 if (!(EVP_CIPHER_flags(EVP_CIPHER_CTX_cipher(ctx
)) & EVP_CIPH_CUSTOM_IV
)) {
164 switch (EVP_CIPHER_CTX_mode(ctx
)) {
166 case EVP_CIPH_STREAM_CIPHER
:
167 case EVP_CIPH_ECB_MODE
:
170 case EVP_CIPH_CFB_MODE
:
171 case EVP_CIPH_OFB_MODE
:
176 case EVP_CIPH_CBC_MODE
:
178 OPENSSL_assert(EVP_CIPHER_CTX_iv_length(ctx
) <=
179 (int)sizeof(ctx
->iv
));
181 memcpy(ctx
->oiv
, iv
, EVP_CIPHER_CTX_iv_length(ctx
));
182 memcpy(ctx
->iv
, ctx
->oiv
, EVP_CIPHER_CTX_iv_length(ctx
));
185 case EVP_CIPH_CTR_MODE
:
187 /* Don't reuse IV for CTR mode */
189 memcpy(ctx
->iv
, iv
, EVP_CIPHER_CTX_iv_length(ctx
));
197 if (key
|| (ctx
->cipher
->flags
& EVP_CIPH_ALWAYS_CALL_INIT
)) {
198 if (!ctx
->cipher
->init(ctx
, key
, iv
, enc
))
203 ctx
->block_mask
= ctx
->cipher
->block_size
- 1;
207 int EVP_CipherUpdate(EVP_CIPHER_CTX
*ctx
, unsigned char *out
, int *outl
,
208 const unsigned char *in
, int inl
)
211 return EVP_EncryptUpdate(ctx
, out
, outl
, in
, inl
);
213 return EVP_DecryptUpdate(ctx
, out
, outl
, in
, inl
);
216 int EVP_CipherFinal_ex(EVP_CIPHER_CTX
*ctx
, unsigned char *out
, int *outl
)
219 return EVP_EncryptFinal_ex(ctx
, out
, outl
);
221 return EVP_DecryptFinal_ex(ctx
, out
, outl
);
224 int EVP_CipherFinal(EVP_CIPHER_CTX
*ctx
, unsigned char *out
, int *outl
)
227 return EVP_EncryptFinal(ctx
, out
, outl
);
229 return EVP_DecryptFinal(ctx
, out
, outl
);
232 int EVP_EncryptInit(EVP_CIPHER_CTX
*ctx
, const EVP_CIPHER
*cipher
,
233 const unsigned char *key
, const unsigned char *iv
)
235 return EVP_CipherInit(ctx
, cipher
, key
, iv
, 1);
238 int EVP_EncryptInit_ex(EVP_CIPHER_CTX
*ctx
, const EVP_CIPHER
*cipher
,
239 ENGINE
*impl
, const unsigned char *key
,
240 const unsigned char *iv
)
242 return EVP_CipherInit_ex(ctx
, cipher
, impl
, key
, iv
, 1);
245 int EVP_DecryptInit(EVP_CIPHER_CTX
*ctx
, const EVP_CIPHER
*cipher
,
246 const unsigned char *key
, const unsigned char *iv
)
248 return EVP_CipherInit(ctx
, cipher
, key
, iv
, 0);
251 int EVP_DecryptInit_ex(EVP_CIPHER_CTX
*ctx
, const EVP_CIPHER
*cipher
,
252 ENGINE
*impl
, const unsigned char *key
,
253 const unsigned char *iv
)
255 return EVP_CipherInit_ex(ctx
, cipher
, impl
, key
, iv
, 0);
259 * According to the letter of standard difference between pointers
260 * is specified to be valid only within same object. This makes
261 * it formally challenging to determine if input and output buffers
262 * are not partially overlapping with standard pointer arithmetic.
267 #if defined(OPENSSL_SYS_VMS) && __INITIAL_POINTER_SIZE==64
269 * Then we have VMS that distinguishes itself by adhering to
270 * sizeof(size_t)==4 even in 64-bit builds, which means that
271 * difference between two pointers might be truncated to 32 bits.
272 * In the context one can even wonder how comparison for
273 * equality is implemented. To be on the safe side we adhere to
274 * PTRDIFF_T even for comparison for equality.
276 # define PTRDIFF_T uint64_t
278 # define PTRDIFF_T size_t
281 int is_partially_overlapping(const void *ptr1
, const void *ptr2
, int len
)
283 PTRDIFF_T diff
= (PTRDIFF_T
)ptr1
-(PTRDIFF_T
)ptr2
;
285 * Check for partially overlapping buffers. [Binary logical
286 * operations are used instead of boolean to minimize number
287 * of conditional branches.]
289 int overlapped
= (len
> 0) & (diff
!= 0) & ((diff
< (PTRDIFF_T
)len
) |
290 (diff
> (0 - (PTRDIFF_T
)len
)));
295 int EVP_EncryptUpdate(EVP_CIPHER_CTX
*ctx
, unsigned char *out
, int *outl
,
296 const unsigned char *in
, int inl
)
298 int i
, j
, bl
, cmpl
= inl
;
300 if (EVP_CIPHER_CTX_test_flags(ctx
, EVP_CIPH_FLAG_LENGTH_BITS
))
301 cmpl
= (cmpl
+ 7) / 8;
303 bl
= ctx
->cipher
->block_size
;
305 if (ctx
->cipher
->flags
& EVP_CIPH_FLAG_CUSTOM_CIPHER
) {
306 /* If block size > 1 then the cipher will have to do this check */
307 if (bl
== 1 && is_partially_overlapping(out
, in
, cmpl
)) {
308 EVPerr(EVP_F_EVP_ENCRYPTUPDATE
, EVP_R_PARTIALLY_OVERLAPPING
);
312 i
= ctx
->cipher
->do_cipher(ctx
, out
, in
, inl
);
324 if (is_partially_overlapping(out
+ ctx
->buf_len
, in
, cmpl
)) {
325 EVPerr(EVP_F_EVP_ENCRYPTUPDATE
, EVP_R_PARTIALLY_OVERLAPPING
);
329 if (ctx
->buf_len
== 0 && (inl
& (ctx
->block_mask
)) == 0) {
330 if (ctx
->cipher
->do_cipher(ctx
, out
, in
, inl
)) {
339 OPENSSL_assert(bl
<= (int)sizeof(ctx
->buf
));
342 memcpy(&(ctx
->buf
[i
]), in
, inl
);
348 memcpy(&(ctx
->buf
[i
]), in
, j
);
351 if (!ctx
->cipher
->do_cipher(ctx
, out
, ctx
->buf
, bl
))
361 if (!ctx
->cipher
->do_cipher(ctx
, out
, in
, inl
))
367 memcpy(ctx
->buf
, &(in
[inl
]), i
);
372 int EVP_EncryptFinal(EVP_CIPHER_CTX
*ctx
, unsigned char *out
, int *outl
)
375 ret
= EVP_EncryptFinal_ex(ctx
, out
, outl
);
379 int EVP_EncryptFinal_ex(EVP_CIPHER_CTX
*ctx
, unsigned char *out
, int *outl
)
382 unsigned int i
, b
, bl
;
384 if (ctx
->cipher
->flags
& EVP_CIPH_FLAG_CUSTOM_CIPHER
) {
385 ret
= ctx
->cipher
->do_cipher(ctx
, out
, NULL
, 0);
393 b
= ctx
->cipher
->block_size
;
394 OPENSSL_assert(b
<= sizeof ctx
->buf
);
400 if (ctx
->flags
& EVP_CIPH_NO_PADDING
) {
402 EVPerr(EVP_F_EVP_ENCRYPTFINAL_EX
,
403 EVP_R_DATA_NOT_MULTIPLE_OF_BLOCK_LENGTH
);
411 for (i
= bl
; i
< b
; i
++)
413 ret
= ctx
->cipher
->do_cipher(ctx
, out
, ctx
->buf
, b
);
421 int EVP_DecryptUpdate(EVP_CIPHER_CTX
*ctx
, unsigned char *out
, int *outl
,
422 const unsigned char *in
, int inl
)
424 int fix_len
, cmpl
= inl
;
427 b
= ctx
->cipher
->block_size
;
429 if (EVP_CIPHER_CTX_test_flags(ctx
, EVP_CIPH_FLAG_LENGTH_BITS
))
430 cmpl
= (cmpl
+ 7) / 8;
432 if (ctx
->cipher
->flags
& EVP_CIPH_FLAG_CUSTOM_CIPHER
) {
433 if (b
== 1 && is_partially_overlapping(out
, in
, cmpl
)) {
434 EVPerr(EVP_F_EVP_DECRYPTUPDATE
, EVP_R_PARTIALLY_OVERLAPPING
);
438 fix_len
= ctx
->cipher
->do_cipher(ctx
, out
, in
, inl
);
452 if (ctx
->flags
& EVP_CIPH_NO_PADDING
)
453 return EVP_EncryptUpdate(ctx
, out
, outl
, in
, inl
);
455 OPENSSL_assert(b
<= sizeof ctx
->final
);
457 if (ctx
->final_used
) {
458 /* see comment about PTRDIFF_T comparison above */
459 if (((PTRDIFF_T
)out
== (PTRDIFF_T
)in
)
460 || is_partially_overlapping(out
, in
, b
)) {
461 EVPerr(EVP_F_EVP_DECRYPTUPDATE
, EVP_R_PARTIALLY_OVERLAPPING
);
464 memcpy(out
, ctx
->final
, b
);
470 if (!EVP_EncryptUpdate(ctx
, out
, outl
, in
, inl
))
474 * if we have 'decrypted' a multiple of block size, make sure we have a
475 * copy of this last block
477 if (b
> 1 && !ctx
->buf_len
) {
480 memcpy(ctx
->final
, &out
[*outl
], b
);
490 int EVP_DecryptFinal(EVP_CIPHER_CTX
*ctx
, unsigned char *out
, int *outl
)
493 ret
= EVP_DecryptFinal_ex(ctx
, out
, outl
);
497 int EVP_DecryptFinal_ex(EVP_CIPHER_CTX
*ctx
, unsigned char *out
, int *outl
)
503 if (ctx
->cipher
->flags
& EVP_CIPH_FLAG_CUSTOM_CIPHER
) {
504 i
= ctx
->cipher
->do_cipher(ctx
, out
, NULL
, 0);
512 b
= ctx
->cipher
->block_size
;
513 if (ctx
->flags
& EVP_CIPH_NO_PADDING
) {
515 EVPerr(EVP_F_EVP_DECRYPTFINAL_EX
,
516 EVP_R_DATA_NOT_MULTIPLE_OF_BLOCK_LENGTH
);
523 if (ctx
->buf_len
|| !ctx
->final_used
) {
524 EVPerr(EVP_F_EVP_DECRYPTFINAL_EX
, EVP_R_WRONG_FINAL_BLOCK_LENGTH
);
527 OPENSSL_assert(b
<= sizeof ctx
->final
);
530 * The following assumes that the ciphertext has been authenticated.
531 * Otherwise it provides a padding oracle.
533 n
= ctx
->final
[b
- 1];
534 if (n
== 0 || n
> (int)b
) {
535 EVPerr(EVP_F_EVP_DECRYPTFINAL_EX
, EVP_R_BAD_DECRYPT
);
538 for (i
= 0; i
< n
; i
++) {
539 if (ctx
->final
[--b
] != n
) {
540 EVPerr(EVP_F_EVP_DECRYPTFINAL_EX
, EVP_R_BAD_DECRYPT
);
544 n
= ctx
->cipher
->block_size
- n
;
545 for (i
= 0; i
< n
; i
++)
546 out
[i
] = ctx
->final
[i
];
553 int EVP_CIPHER_CTX_set_key_length(EVP_CIPHER_CTX
*c
, int keylen
)
555 if (c
->cipher
->flags
& EVP_CIPH_CUSTOM_KEY_LENGTH
)
556 return EVP_CIPHER_CTX_ctrl(c
, EVP_CTRL_SET_KEY_LENGTH
, keylen
, NULL
);
557 if (c
->key_len
== keylen
)
559 if ((keylen
> 0) && (c
->cipher
->flags
& EVP_CIPH_VARIABLE_LENGTH
)) {
563 EVPerr(EVP_F_EVP_CIPHER_CTX_SET_KEY_LENGTH
, EVP_R_INVALID_KEY_LENGTH
);
567 int EVP_CIPHER_CTX_set_padding(EVP_CIPHER_CTX
*ctx
, int pad
)
570 ctx
->flags
&= ~EVP_CIPH_NO_PADDING
;
572 ctx
->flags
|= EVP_CIPH_NO_PADDING
;
576 int EVP_CIPHER_CTX_ctrl(EVP_CIPHER_CTX
*ctx
, int type
, int arg
, void *ptr
)
580 EVPerr(EVP_F_EVP_CIPHER_CTX_CTRL
, EVP_R_NO_CIPHER_SET
);
584 if (!ctx
->cipher
->ctrl
) {
585 EVPerr(EVP_F_EVP_CIPHER_CTX_CTRL
, EVP_R_CTRL_NOT_IMPLEMENTED
);
589 ret
= ctx
->cipher
->ctrl(ctx
, type
, arg
, ptr
);
591 EVPerr(EVP_F_EVP_CIPHER_CTX_CTRL
,
592 EVP_R_CTRL_OPERATION_NOT_IMPLEMENTED
);
598 int EVP_CIPHER_CTX_rand_key(EVP_CIPHER_CTX
*ctx
, unsigned char *key
)
600 if (ctx
->cipher
->flags
& EVP_CIPH_RAND_KEY
)
601 return EVP_CIPHER_CTX_ctrl(ctx
, EVP_CTRL_RAND_KEY
, 0, key
);
602 if (RAND_bytes(key
, ctx
->key_len
) <= 0)
607 int EVP_CIPHER_CTX_copy(EVP_CIPHER_CTX
*out
, const EVP_CIPHER_CTX
*in
)
609 if ((in
== NULL
) || (in
->cipher
== NULL
)) {
610 EVPerr(EVP_F_EVP_CIPHER_CTX_COPY
, EVP_R_INPUT_NOT_INITIALIZED
);
613 #ifndef OPENSSL_NO_ENGINE
614 /* Make sure it's safe to copy a cipher context using an ENGINE */
615 if (in
->engine
&& !ENGINE_init(in
->engine
)) {
616 EVPerr(EVP_F_EVP_CIPHER_CTX_COPY
, ERR_R_ENGINE_LIB
);
621 EVP_CIPHER_CTX_reset(out
);
622 memcpy(out
, in
, sizeof(*out
));
624 if (in
->cipher_data
&& in
->cipher
->ctx_size
) {
625 out
->cipher_data
= OPENSSL_malloc(in
->cipher
->ctx_size
);
626 if (out
->cipher_data
== NULL
) {
628 EVPerr(EVP_F_EVP_CIPHER_CTX_COPY
, ERR_R_MALLOC_FAILURE
);
631 memcpy(out
->cipher_data
, in
->cipher_data
, in
->cipher
->ctx_size
);
634 if (in
->cipher
->flags
& EVP_CIPH_CUSTOM_COPY
)
635 if (!in
->cipher
->ctrl((EVP_CIPHER_CTX
*)in
, EVP_CTRL_COPY
, 0, out
)) {
637 EVPerr(EVP_F_EVP_CIPHER_CTX_COPY
, EVP_R_INITIALIZATION_ERROR
);