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) {
128 EVPerr(EVP_F_EVP_CIPHERINIT_EX, ERR_R_MALLOC_FAILURE);
132 ctx->cipher_data = NULL;
134 ctx->key_len = cipher->key_len;
135 /* Preserve wrap enable flag, zero everything else */
136 ctx->flags &= EVP_CIPHER_CTX_FLAG_WRAP_ALLOW;
137 if (ctx->cipher->flags & EVP_CIPH_CTRL_INIT) {
138 if (!EVP_CIPHER_CTX_ctrl(ctx, EVP_CTRL_INIT, 0, NULL)) {
139 EVPerr(EVP_F_EVP_CIPHERINIT_EX, EVP_R_INITIALIZATION_ERROR);
143 } else if (!ctx->cipher) {
144 EVPerr(EVP_F_EVP_CIPHERINIT_EX, EVP_R_NO_CIPHER_SET);
147 #ifndef OPENSSL_NO_ENGINE
150 /* we assume block size is a power of 2 in *cryptUpdate */
151 OPENSSL_assert(ctx->cipher->block_size == 1
152 || ctx->cipher->block_size == 8
153 || ctx->cipher->block_size == 16);
155 if (!(ctx->flags & EVP_CIPHER_CTX_FLAG_WRAP_ALLOW)
156 && EVP_CIPHER_CTX_mode(ctx) == EVP_CIPH_WRAP_MODE) {
157 EVPerr(EVP_F_EVP_CIPHERINIT_EX, EVP_R_WRAP_MODE_NOT_ALLOWED);
161 if (!(EVP_CIPHER_flags(EVP_CIPHER_CTX_cipher(ctx)) & EVP_CIPH_CUSTOM_IV)) {
162 switch (EVP_CIPHER_CTX_mode(ctx)) {
164 case EVP_CIPH_STREAM_CIPHER:
165 case EVP_CIPH_ECB_MODE:
168 case EVP_CIPH_CFB_MODE:
169 case EVP_CIPH_OFB_MODE:
174 case EVP_CIPH_CBC_MODE:
176 OPENSSL_assert(EVP_CIPHER_CTX_iv_length(ctx) <=
177 (int)sizeof(ctx->iv));
179 memcpy(ctx->oiv, iv, EVP_CIPHER_CTX_iv_length(ctx));
180 memcpy(ctx->iv, ctx->oiv, EVP_CIPHER_CTX_iv_length(ctx));
183 case EVP_CIPH_CTR_MODE:
185 /* Don't reuse IV for CTR mode */
187 memcpy(ctx->iv, iv, EVP_CIPHER_CTX_iv_length(ctx));
195 if (key || (ctx->cipher->flags & EVP_CIPH_ALWAYS_CALL_INIT)) {
196 if (!ctx->cipher->init(ctx, key, iv, enc))
201 ctx->block_mask = ctx->cipher->block_size - 1;
205 int EVP_CipherUpdate(EVP_CIPHER_CTX *ctx, unsigned char *out, int *outl,
206 const unsigned char *in, int inl)
209 return EVP_EncryptUpdate(ctx, out, outl, in, inl);
211 return EVP_DecryptUpdate(ctx, out, outl, in, inl);
214 int EVP_CipherFinal_ex(EVP_CIPHER_CTX *ctx, unsigned char *out, int *outl)
217 return EVP_EncryptFinal_ex(ctx, out, outl);
219 return EVP_DecryptFinal_ex(ctx, out, outl);
222 int EVP_CipherFinal(EVP_CIPHER_CTX *ctx, unsigned char *out, int *outl)
225 return EVP_EncryptFinal(ctx, out, outl);
227 return EVP_DecryptFinal(ctx, out, outl);
230 int EVP_EncryptInit(EVP_CIPHER_CTX *ctx, const EVP_CIPHER *cipher,
231 const unsigned char *key, const unsigned char *iv)
233 return EVP_CipherInit(ctx, cipher, key, iv, 1);
236 int EVP_EncryptInit_ex(EVP_CIPHER_CTX *ctx, const EVP_CIPHER *cipher,
237 ENGINE *impl, const unsigned char *key,
238 const unsigned char *iv)
240 return EVP_CipherInit_ex(ctx, cipher, impl, key, iv, 1);
243 int EVP_DecryptInit(EVP_CIPHER_CTX *ctx, const EVP_CIPHER *cipher,
244 const unsigned char *key, const unsigned char *iv)
246 return EVP_CipherInit(ctx, cipher, key, iv, 0);
249 int EVP_DecryptInit_ex(EVP_CIPHER_CTX *ctx, const EVP_CIPHER *cipher,
250 ENGINE *impl, const unsigned char *key,
251 const unsigned char *iv)
253 return EVP_CipherInit_ex(ctx, cipher, impl, key, iv, 0);
257 * According to the letter of standard difference between pointers
258 * is specified to be valid only within same object. This makes
259 * it formally challenging to determine if input and output buffers
260 * are not partially overlapping with standard pointer arithmetic.
265 #if defined(OPENSSL_SYS_VMS) && __INITIAL_POINTER_SIZE==64
267 * Then we have VMS that distinguishes itself by adhering to
268 * sizeof(size_t)==4 even in 64-bit builds, which means that
269 * difference between two pointers might be truncated to 32 bits.
270 * In the context one can even wonder how comparison for
271 * equality is implemented. To be on the safe side we adhere to
272 * PTRDIFF_T even for comparison for equality.
274 # define PTRDIFF_T uint64_t
276 # define PTRDIFF_T size_t
279 static int is_partially_overlapping(const void *ptr1, const void *ptr2,
282 PTRDIFF_T diff = (PTRDIFF_T)ptr1-(PTRDIFF_T)ptr2;
284 * Check for partially overlapping buffers. [Binary logical
285 * operations are used instead of boolean to minimize number
286 * of conditional branches.]
288 int overlapped = (len > 0) & (diff != 0) & ((diff < (PTRDIFF_T)len) |
289 (diff > (0 - (PTRDIFF_T)len)));
294 int EVP_EncryptUpdate(EVP_CIPHER_CTX *ctx, unsigned char *out, int *outl,
295 const unsigned char *in, int inl)
299 if (ctx->cipher->flags & EVP_CIPH_FLAG_CUSTOM_CIPHER) {
300 if (is_partially_overlapping(out, in, inl)) {
301 EVPerr(EVP_F_EVP_ENCRYPTUPDATE, EVP_R_PARTIALLY_OVERLAPPING);
305 i = ctx->cipher->do_cipher(ctx, out, in, inl);
317 if (is_partially_overlapping(out, in, inl)) {
318 EVPerr(EVP_F_EVP_ENCRYPTUPDATE, EVP_R_PARTIALLY_OVERLAPPING);
322 if (ctx->buf_len == 0 && (inl & (ctx->block_mask)) == 0) {
323 if (ctx->cipher->do_cipher(ctx, out, in, inl)) {
332 bl = ctx->cipher->block_size;
333 OPENSSL_assert(bl <= (int)sizeof(ctx->buf));
336 memcpy(&(ctx->buf[i]), in, inl);
342 memcpy(&(ctx->buf[i]), in, j);
345 if (is_partially_overlapping(out, in, bl)) {
346 EVPerr(EVP_F_EVP_ENCRYPTUPDATE, EVP_R_PARTIALLY_OVERLAPPING);
349 if (!ctx->cipher->do_cipher(ctx, out, ctx->buf, bl))
359 if (!ctx->cipher->do_cipher(ctx, out, in, inl))
365 memcpy(ctx->buf, &(in[inl]), i);
370 int EVP_EncryptFinal(EVP_CIPHER_CTX *ctx, unsigned char *out, int *outl)
373 ret = EVP_EncryptFinal_ex(ctx, out, outl);
377 int EVP_EncryptFinal_ex(EVP_CIPHER_CTX *ctx, unsigned char *out, int *outl)
380 unsigned int i, b, bl;
382 if (ctx->cipher->flags & EVP_CIPH_FLAG_CUSTOM_CIPHER) {
383 ret = ctx->cipher->do_cipher(ctx, out, NULL, 0);
391 b = ctx->cipher->block_size;
392 OPENSSL_assert(b <= sizeof ctx->buf);
398 if (ctx->flags & EVP_CIPH_NO_PADDING) {
400 EVPerr(EVP_F_EVP_ENCRYPTFINAL_EX,
401 EVP_R_DATA_NOT_MULTIPLE_OF_BLOCK_LENGTH);
409 for (i = bl; i < b; i++)
411 ret = ctx->cipher->do_cipher(ctx, out, ctx->buf, b);
419 int EVP_DecryptUpdate(EVP_CIPHER_CTX *ctx, unsigned char *out, int *outl,
420 const unsigned char *in, int inl)
425 if (ctx->cipher->flags & EVP_CIPH_FLAG_CUSTOM_CIPHER) {
426 if (is_partially_overlapping(out, in, inl)) {
427 EVPerr(EVP_F_EVP_DECRYPTUPDATE, EVP_R_PARTIALLY_OVERLAPPING);
431 fix_len = ctx->cipher->do_cipher(ctx, out, in, inl);
445 if (ctx->flags & EVP_CIPH_NO_PADDING)
446 return EVP_EncryptUpdate(ctx, out, outl, in, inl);
448 b = ctx->cipher->block_size;
449 OPENSSL_assert(b <= sizeof ctx->final);
451 if (ctx->final_used) {
452 /* see comment about PTRDIFF_T comparison above */
453 if (((PTRDIFF_T)out == (PTRDIFF_T)in)
454 || is_partially_overlapping(out, in, b)) {
455 EVPerr(EVP_F_EVP_DECRYPTUPDATE, EVP_R_PARTIALLY_OVERLAPPING);
458 memcpy(out, ctx->final, b);
464 if (!EVP_EncryptUpdate(ctx, out, outl, in, inl))
468 * if we have 'decrypted' a multiple of block size, make sure we have a
469 * copy of this last block
471 if (b > 1 && !ctx->buf_len) {
474 memcpy(ctx->final, &out[*outl], b);
484 int EVP_DecryptFinal(EVP_CIPHER_CTX *ctx, unsigned char *out, int *outl)
487 ret = EVP_DecryptFinal_ex(ctx, out, outl);
491 int EVP_DecryptFinal_ex(EVP_CIPHER_CTX *ctx, unsigned char *out, int *outl)
497 if (ctx->cipher->flags & EVP_CIPH_FLAG_CUSTOM_CIPHER) {
498 i = ctx->cipher->do_cipher(ctx, out, NULL, 0);
506 b = ctx->cipher->block_size;
507 if (ctx->flags & EVP_CIPH_NO_PADDING) {
509 EVPerr(EVP_F_EVP_DECRYPTFINAL_EX,
510 EVP_R_DATA_NOT_MULTIPLE_OF_BLOCK_LENGTH);
517 if (ctx->buf_len || !ctx->final_used) {
518 EVPerr(EVP_F_EVP_DECRYPTFINAL_EX, EVP_R_WRONG_FINAL_BLOCK_LENGTH);
521 OPENSSL_assert(b <= sizeof ctx->final);
524 * The following assumes that the ciphertext has been authenticated.
525 * Otherwise it provides a padding oracle.
527 n = ctx->final[b - 1];
528 if (n == 0 || n > (int)b) {
529 EVPerr(EVP_F_EVP_DECRYPTFINAL_EX, EVP_R_BAD_DECRYPT);
532 for (i = 0; i < n; i++) {
533 if (ctx->final[--b] != n) {
534 EVPerr(EVP_F_EVP_DECRYPTFINAL_EX, EVP_R_BAD_DECRYPT);
538 n = ctx->cipher->block_size - n;
539 for (i = 0; i < n; i++)
540 out[i] = ctx->final[i];
547 int EVP_CIPHER_CTX_set_key_length(EVP_CIPHER_CTX *c, int keylen)
549 if (c->cipher->flags & EVP_CIPH_CUSTOM_KEY_LENGTH)
550 return EVP_CIPHER_CTX_ctrl(c, EVP_CTRL_SET_KEY_LENGTH, keylen, NULL);
551 if (c->key_len == keylen)
553 if ((keylen > 0) && (c->cipher->flags & EVP_CIPH_VARIABLE_LENGTH)) {
557 EVPerr(EVP_F_EVP_CIPHER_CTX_SET_KEY_LENGTH, EVP_R_INVALID_KEY_LENGTH);
561 int EVP_CIPHER_CTX_set_padding(EVP_CIPHER_CTX *ctx, int pad)
564 ctx->flags &= ~EVP_CIPH_NO_PADDING;
566 ctx->flags |= EVP_CIPH_NO_PADDING;
570 int EVP_CIPHER_CTX_ctrl(EVP_CIPHER_CTX *ctx, int type, int arg, void *ptr)
574 EVPerr(EVP_F_EVP_CIPHER_CTX_CTRL, EVP_R_NO_CIPHER_SET);
578 if (!ctx->cipher->ctrl) {
579 EVPerr(EVP_F_EVP_CIPHER_CTX_CTRL, EVP_R_CTRL_NOT_IMPLEMENTED);
583 ret = ctx->cipher->ctrl(ctx, type, arg, ptr);
585 EVPerr(EVP_F_EVP_CIPHER_CTX_CTRL,
586 EVP_R_CTRL_OPERATION_NOT_IMPLEMENTED);
592 int EVP_CIPHER_CTX_rand_key(EVP_CIPHER_CTX *ctx, unsigned char *key)
594 if (ctx->cipher->flags & EVP_CIPH_RAND_KEY)
595 return EVP_CIPHER_CTX_ctrl(ctx, EVP_CTRL_RAND_KEY, 0, key);
596 if (RAND_bytes(key, ctx->key_len) <= 0)
601 int EVP_CIPHER_CTX_copy(EVP_CIPHER_CTX *out, const EVP_CIPHER_CTX *in)
603 if ((in == NULL) || (in->cipher == NULL)) {
604 EVPerr(EVP_F_EVP_CIPHER_CTX_COPY, EVP_R_INPUT_NOT_INITIALIZED);
607 #ifndef OPENSSL_NO_ENGINE
608 /* Make sure it's safe to copy a cipher context using an ENGINE */
609 if (in->engine && !ENGINE_init(in->engine)) {
610 EVPerr(EVP_F_EVP_CIPHER_CTX_COPY, ERR_R_ENGINE_LIB);
615 EVP_CIPHER_CTX_reset(out);
616 memcpy(out, in, sizeof(*out));
618 if (in->cipher_data && in->cipher->ctx_size) {
619 out->cipher_data = OPENSSL_malloc(in->cipher->ctx_size);
620 if (out->cipher_data == NULL) {
621 EVPerr(EVP_F_EVP_CIPHER_CTX_COPY, ERR_R_MALLOC_FAILURE);
624 memcpy(out->cipher_data, in->cipher_data, in->cipher->ctx_size);
627 if (in->cipher->flags & EVP_CIPH_CUSTOM_COPY)
628 return in->cipher->ctrl((EVP_CIPHER_CTX *)in, EVP_CTRL_COPY, 0, out);