1 /* crypto/evp/evp_enc.c */
2 /* Copyright (C) 1995-1998 Eric Young (eay@cryptsoft.com)
5 * This package is an SSL implementation written
6 * by Eric Young (eay@cryptsoft.com).
7 * The implementation was written so as to conform with Netscapes SSL.
9 * This library is free for commercial and non-commercial use as long as
10 * the following conditions are aheared to. The following conditions
11 * apply to all code found in this distribution, be it the RC4, RSA,
12 * lhash, DES, etc., code; not just the SSL code. The SSL documentation
13 * included with this distribution is covered by the same copyright terms
14 * except that the holder is Tim Hudson (tjh@cryptsoft.com).
16 * Copyright remains Eric Young's, and as such any Copyright notices in
17 * the code are not to be removed.
18 * If this package is used in a product, Eric Young should be given attribution
19 * as the author of the parts of the library used.
20 * This can be in the form of a textual message at program startup or
21 * in documentation (online or textual) provided with the package.
23 * Redistribution and use in source and binary forms, with or without
24 * modification, are permitted provided that the following conditions
26 * 1. Redistributions of source code must retain the copyright
27 * notice, this list of conditions and the following disclaimer.
28 * 2. Redistributions in binary form must reproduce the above copyright
29 * notice, this list of conditions and the following disclaimer in the
30 * documentation and/or other materials provided with the distribution.
31 * 3. All advertising materials mentioning features or use of this software
32 * must display the following acknowledgement:
33 * "This product includes cryptographic software written by
34 * Eric Young (eay@cryptsoft.com)"
35 * The word 'cryptographic' can be left out if the rouines from the library
36 * being used are not cryptographic related :-).
37 * 4. If you include any Windows specific code (or a derivative thereof) from
38 * the apps directory (application code) you must include an acknowledgement:
39 * "This product includes software written by Tim Hudson (tjh@cryptsoft.com)"
41 * THIS SOFTWARE IS PROVIDED BY ERIC YOUNG ``AS IS'' AND
42 * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
43 * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
44 * ARE DISCLAIMED. IN NO EVENT SHALL THE AUTHOR OR CONTRIBUTORS BE LIABLE
45 * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
46 * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
47 * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
48 * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
49 * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
50 * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
53 * The licence and distribution terms for any publically available version or
54 * derivative of this code cannot be changed. i.e. this code cannot simply be
55 * copied and put under another distribution licence
56 * [including the GNU Public Licence.]
61 #include <openssl/evp.h>
62 #include <openssl/err.h>
63 #include <openssl/rand.h>
64 #ifndef OPENSSL_NO_ENGINE
65 #include <openssl/engine.h>
67 #include "../constant_time_locl.h"
71 #define M_do_cipher(ctx, out, in, inl) \
72 EVP_Cipher(ctx,out,in,inl)
74 #define M_do_cipher(ctx, out, in, inl) \
75 ctx->cipher->do_cipher(ctx,out,in,inl)
78 const char EVP_version[]="EVP" OPENSSL_VERSION_PTEXT;
80 EVP_CIPHER_CTX *EVP_CIPHER_CTX_new(void)
82 EVP_CIPHER_CTX *ctx=OPENSSL_malloc(sizeof *ctx);
84 EVP_CIPHER_CTX_init(ctx);
88 int EVP_CipherInit(EVP_CIPHER_CTX *ctx, const EVP_CIPHER *cipher,
89 const unsigned char *key, const unsigned char *iv, int enc)
92 EVP_CIPHER_CTX_init(ctx);
93 return EVP_CipherInit_ex(ctx,cipher,NULL,key,iv,enc);
96 int EVP_CipherUpdate(EVP_CIPHER_CTX *ctx, unsigned char *out, int *outl,
97 const unsigned char *in, int inl)
100 return EVP_EncryptUpdate(ctx,out,outl,in,inl);
101 else return EVP_DecryptUpdate(ctx,out,outl,in,inl);
104 int EVP_CipherFinal_ex(EVP_CIPHER_CTX *ctx, unsigned char *out, int *outl)
107 return EVP_EncryptFinal_ex(ctx,out,outl);
108 else return EVP_DecryptFinal_ex(ctx,out,outl);
111 int EVP_CipherFinal(EVP_CIPHER_CTX *ctx, unsigned char *out, int *outl)
114 return EVP_EncryptFinal(ctx,out,outl);
115 else return EVP_DecryptFinal(ctx,out,outl);
118 int EVP_EncryptInit(EVP_CIPHER_CTX *ctx, const EVP_CIPHER *cipher,
119 const unsigned char *key, const unsigned char *iv)
121 return EVP_CipherInit(ctx, cipher, key, iv, 1);
124 int EVP_EncryptInit_ex(EVP_CIPHER_CTX *ctx,const EVP_CIPHER *cipher, ENGINE *impl,
125 const unsigned char *key, const unsigned char *iv)
127 return EVP_CipherInit_ex(ctx, cipher, impl, key, iv, 1);
130 int EVP_DecryptInit(EVP_CIPHER_CTX *ctx, const EVP_CIPHER *cipher,
131 const unsigned char *key, const unsigned char *iv)
133 return EVP_CipherInit(ctx, cipher, key, iv, 0);
136 int EVP_DecryptInit_ex(EVP_CIPHER_CTX *ctx, const EVP_CIPHER *cipher, ENGINE *impl,
137 const unsigned char *key, const unsigned char *iv)
139 return EVP_CipherInit_ex(ctx, cipher, impl, key, iv, 0);
142 int EVP_EncryptUpdate(EVP_CIPHER_CTX *ctx, unsigned char *out, int *outl,
143 const unsigned char *in, int inl)
153 if(ctx->buf_len == 0 && (inl&(ctx->block_mask)) == 0)
155 if(M_do_cipher(ctx,out,in,inl))
167 bl=ctx->cipher->block_size;
168 OPENSSL_assert(bl <= (int)sizeof(ctx->buf));
173 memcpy(&(ctx->buf[i]),in,inl);
181 memcpy(&(ctx->buf[i]),in,j);
182 if(!M_do_cipher(ctx,out,ctx->buf,bl)) return 0;
195 if(!M_do_cipher(ctx,out,in,inl)) return 0;
200 memcpy(ctx->buf,&(in[inl]),i);
205 int EVP_EncryptFinal(EVP_CIPHER_CTX *ctx, unsigned char *out, int *outl)
208 ret = EVP_EncryptFinal_ex(ctx, out, outl);
212 int EVP_EncryptFinal_ex(EVP_CIPHER_CTX *ctx, unsigned char *out, int *outl)
215 unsigned int i, b, bl;
217 b=ctx->cipher->block_size;
218 OPENSSL_assert(b <= sizeof ctx->buf);
225 if (ctx->flags & EVP_CIPH_NO_PADDING)
229 EVPerr(EVP_F_EVP_ENCRYPTFINAL_EX,EVP_R_DATA_NOT_MULTIPLE_OF_BLOCK_LENGTH);
239 ret=M_do_cipher(ctx,out,ctx->buf,b);
248 int EVP_DecryptUpdate(EVP_CIPHER_CTX *ctx, unsigned char *out, int *outl,
249 const unsigned char *in, int inl)
260 if (ctx->flags & EVP_CIPH_NO_PADDING)
261 return EVP_EncryptUpdate(ctx, out, outl, in, inl);
263 b=ctx->cipher->block_size;
264 OPENSSL_assert(b <= sizeof ctx->final);
268 memcpy(out,ctx->final,b);
276 if(!EVP_EncryptUpdate(ctx,out,outl,in,inl))
279 /* if we have 'decrypted' a multiple of block size, make sure
280 * we have a copy of this last block */
281 if (b > 1 && !ctx->buf_len)
285 memcpy(ctx->final,&out[*outl],b);
296 int EVP_DecryptFinal(EVP_CIPHER_CTX *ctx, unsigned char *out, int *outl)
299 ret = EVP_DecryptFinal_ex(ctx, out, outl);
303 int EVP_DecryptFinal_ex(EVP_CIPHER_CTX *ctx, unsigned char *out, int *outl)
306 unsigned char pad, padding_good;
309 b=(unsigned int)(ctx->cipher->block_size);
310 if (ctx->flags & EVP_CIPH_NO_PADDING)
314 EVPerr(EVP_F_EVP_DECRYPTFINAL_EX,EVP_R_DATA_NOT_MULTIPLE_OF_BLOCK_LENGTH);
322 if (ctx->buf_len || !ctx->final_used)
324 EVPerr(EVP_F_EVP_DECRYPTFINAL_EX,EVP_R_WRONG_FINAL_BLOCK_LENGTH);
327 OPENSSL_assert(b <= sizeof ctx->final);
330 padding_good = (unsigned char)(~constant_time_is_zero_8(pad));
331 padding_good &= constant_time_ge_8(b, pad);
333 for (i = 1; i < b; ++i)
335 unsigned char is_pad_index = constant_time_lt_8(i, pad);
336 unsigned char pad_byte_good = constant_time_eq_8(ctx->final[b-i-1], pad);
337 padding_good &= constant_time_select_8(is_pad_index, pad_byte_good, 0xff);
341 * At least 1 byte is always padding, so we always write b - 1
342 * bytes to avoid a timing leak. The caller is required to have |b|
343 * bytes space in |out| by the API contract.
345 for (i = 0; i < b - 1; ++i)
346 out[i] = ctx->final[i] & padding_good;
347 /* Safe cast: for a good padding, EVP_MAX_IV_LENGTH >= b >= pad */
348 *outl = padding_good & ((unsigned char)(b - pad));
349 return padding_good & 1;
358 void EVP_CIPHER_CTX_free(EVP_CIPHER_CTX *ctx)
362 EVP_CIPHER_CTX_cleanup(ctx);
367 int EVP_CIPHER_CTX_set_key_length(EVP_CIPHER_CTX *c, int keylen)
369 if(c->cipher->flags & EVP_CIPH_CUSTOM_KEY_LENGTH)
370 return EVP_CIPHER_CTX_ctrl(c, EVP_CTRL_SET_KEY_LENGTH, keylen, NULL);
371 if(c->key_len == keylen) return 1;
372 if((keylen > 0) && (c->cipher->flags & EVP_CIPH_VARIABLE_LENGTH))
377 EVPerr(EVP_F_EVP_CIPHER_CTX_SET_KEY_LENGTH,EVP_R_INVALID_KEY_LENGTH);
381 int EVP_CIPHER_CTX_set_padding(EVP_CIPHER_CTX *ctx, int pad)
383 if (pad) ctx->flags &= ~EVP_CIPH_NO_PADDING;
384 else ctx->flags |= EVP_CIPH_NO_PADDING;
388 int EVP_CIPHER_CTX_rand_key(EVP_CIPHER_CTX *ctx, unsigned char *key)
390 if (ctx->cipher->flags & EVP_CIPH_RAND_KEY)
391 return EVP_CIPHER_CTX_ctrl(ctx, EVP_CTRL_RAND_KEY, 0, key);
392 if (RAND_bytes(key, ctx->key_len) <= 0)
397 #ifndef OPENSSL_NO_ENGINE
401 static int do_evp_enc_engine_full(EVP_CIPHER_CTX *ctx, const EVP_CIPHER **pcipher, ENGINE *impl)
405 if (!ENGINE_init(impl))
407 EVPerr(EVP_F_DO_EVP_ENC_ENGINE_FULL, EVP_R_INITIALIZATION_ERROR);
412 /* Ask if an ENGINE is reserved for this job */
413 impl = ENGINE_get_cipher_engine((*pcipher)->nid);
416 /* There's an ENGINE for this job ... (apparently) */
417 const EVP_CIPHER *c = ENGINE_get_cipher(impl, (*pcipher)->nid);
420 /* One positive side-effect of US's export
421 * control history, is that we should at least
422 * be able to avoid using US mispellings of
423 * "initialisation"? */
424 EVPerr(EVP_F_DO_EVP_ENC_ENGINE_FULL, EVP_R_INITIALIZATION_ERROR);
427 /* We'll use the ENGINE's private cipher definition */
429 /* Store the ENGINE functional reference so we know
430 * 'cipher' came from an ENGINE and we need to release
439 void int_EVP_CIPHER_init_engine_callbacks(void)
441 int_EVP_CIPHER_set_engine_callbacks(
442 ENGINE_finish, do_evp_enc_engine_full);