summaryrefslogtreecommitdiff
path: root/thirdparty/openssl/crypto/evp/evp_enc.c
blob: be577bac767fe9cf2c163be6967b20d1f6cc9014 (plain)
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81
82
83
84
85
86
87
88
89
90
91
92
93
94
95
96
97
98
99
100
101
102
103
104
105
106
107
108
109
110
111
112
113
114
115
116
117
118
119
120
121
122
123
124
125
126
127
128
129
130
131
132
133
134
135
136
137
138
139
140
141
142
143
144
145
146
147
148
149
150
151
152
153
154
155
156
157
158
159
160
161
162
163
164
165
166
167
168
169
170
171
172
173
174
175
176
177
178
179
180
181
182
183
184
185
186
187
188
189
190
191
192
193
194
195
196
197
198
199
200
201
202
203
204
205
206
207
208
209
210
211
212
213
214
215
216
217
218
219
220
221
222
223
224
225
226
227
228
229
230
231
232
233
234
235
236
237
238
239
240
241
242
243
244
245
246
247
248
249
250
251
252
253
254
255
256
257
258
259
260
261
262
263
264
265
266
267
268
269
270
271
272
273
274
275
276
277
278
279
280
281
282
283
284
285
286
287
288
289
290
291
292
293
294
295
296
297
298
299
300
301
302
303
304
305
306
307
308
309
310
311
312
313
314
315
316
317
318
319
320
321
322
323
324
325
326
327
328
329
330
331
332
333
334
335
336
337
338
339
340
341
342
343
344
345
346
347
348
349
350
351
352
353
354
355
356
357
358
359
360
361
362
363
364
365
366
367
368
369
370
371
372
373
374
375
376
377
378
379
380
381
382
383
384
385
386
387
388
389
390
391
392
393
394
395
396
397
398
399
400
401
402
403
404
405
406
407
408
409
410
411
412
413
414
415
416
417
418
419
420
421
422
423
424
425
426
427
428
429
430
431
432
433
434
435
436
437
438
439
440
441
442
443
444
445
446
447
448
449
450
451
452
453
454
455
456
457
458
459
460
461
462
463
464
465
466
467
468
469
470
471
472
473
474
475
476
477
478
479
480
481
482
483
484
485
486
487
488
489
490
491
492
493
494
495
496
497
498
499
500
501
502
503
504
505
506
507
508
509
510
511
512
513
514
515
516
517
518
519
520
521
522
523
524
525
526
527
528
529
530
531
532
533
534
535
536
537
538
539
540
541
542
543
544
545
546
547
548
549
550
551
552
553
554
555
556
557
558
559
560
561
562
563
564
565
566
567
568
569
570
571
572
573
574
575
576
577
578
579
580
581
582
583
584
585
586
587
588
589
590
591
592
593
594
595
596
597
598
599
600
601
602
603
604
605
606
607
608
609
610
611
612
613
614
615
616
617
618
619
620
621
622
623
624
625
626
627
628
629
630
631
632
633
634
635
636
637
638
639
640
641
642
643
644
645
646
647
648
649
650
651
652
653
654
655
656
657
658
659
660
661
662
663
664
665
666
667
668
669
670
671
672
673
/* crypto/evp/evp_enc.c */
/* Copyright (C) 1995-1998 Eric Young (eay@cryptsoft.com)
 * All rights reserved.
 *
 * This package is an SSL implementation written
 * by Eric Young (eay@cryptsoft.com).
 * The implementation was written so as to conform with Netscapes SSL.
 *
 * This library is free for commercial and non-commercial use as long as
 * the following conditions are aheared to.  The following conditions
 * apply to all code found in this distribution, be it the RC4, RSA,
 * lhash, DES, etc., code; not just the SSL code.  The SSL documentation
 * included with this distribution is covered by the same copyright terms
 * except that the holder is Tim Hudson (tjh@cryptsoft.com).
 *
 * Copyright remains Eric Young's, and as such any Copyright notices in
 * the code are not to be removed.
 * If this package is used in a product, Eric Young should be given attribution
 * as the author of the parts of the library used.
 * This can be in the form of a textual message at program startup or
 * in documentation (online or textual) provided with the package.
 *
 * Redistribution and use in source and binary forms, with or without
 * modification, are permitted provided that the following conditions
 * are met:
 * 1. Redistributions of source code must retain the copyright
 *    notice, this list of conditions and the following disclaimer.
 * 2. Redistributions in binary form must reproduce the above copyright
 *    notice, this list of conditions and the following disclaimer in the
 *    documentation and/or other materials provided with the distribution.
 * 3. All advertising materials mentioning features or use of this software
 *    must display the following acknowledgement:
 *    "This product includes cryptographic software written by
 *     Eric Young (eay@cryptsoft.com)"
 *    The word 'cryptographic' can be left out if the rouines from the library
 *    being used are not cryptographic related :-).
 * 4. If you include any Windows specific code (or a derivative thereof) from
 *    the apps directory (application code) you must include an acknowledgement:
 *    "This product includes software written by Tim Hudson (tjh@cryptsoft.com)"
 *
 * THIS SOFTWARE IS PROVIDED BY ERIC YOUNG ``AS IS'' AND
 * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
 * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
 * ARE DISCLAIMED.  IN NO EVENT SHALL THE AUTHOR OR CONTRIBUTORS BE LIABLE
 * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
 * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
 * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
 * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
 * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
 * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
 * SUCH DAMAGE.
 *
 * The licence and distribution terms for any publically available version or
 * derivative of this code cannot be changed.  i.e. this code cannot simply be
 * copied and put under another distribution licence
 * [including the GNU Public Licence.]
 */

#include <stdio.h>
#include "cryptlib.h"
#include <openssl/evp.h>
#include <openssl/err.h>
#include <openssl/rand.h>
#ifndef OPENSSL_NO_ENGINE
# include <openssl/engine.h>
#endif
#ifdef OPENSSL_FIPS
# include <openssl/fips.h>
#endif
#include "evp_locl.h"

#ifdef OPENSSL_FIPS
# define M_do_cipher(ctx, out, in, inl) FIPS_cipher(ctx, out, in, inl)
#else
# define M_do_cipher(ctx, out, in, inl) ctx->cipher->do_cipher(ctx, out, in, inl)
#endif

const char EVP_version[] = "EVP" OPENSSL_VERSION_PTEXT;

void EVP_CIPHER_CTX_init(EVP_CIPHER_CTX *ctx)
{
    memset(ctx, 0, sizeof(EVP_CIPHER_CTX));
    /* ctx->cipher=NULL; */
}

EVP_CIPHER_CTX *EVP_CIPHER_CTX_new(void)
{
    EVP_CIPHER_CTX *ctx = OPENSSL_malloc(sizeof *ctx);
    if (ctx)
        EVP_CIPHER_CTX_init(ctx);
    return ctx;
}

int EVP_CipherInit(EVP_CIPHER_CTX *ctx, const EVP_CIPHER *cipher,
                   const unsigned char *key, const unsigned char *iv, int enc)
{
    if (cipher)
        EVP_CIPHER_CTX_init(ctx);
    return EVP_CipherInit_ex(ctx, cipher, NULL, key, iv, enc);
}

int EVP_CipherInit_ex(EVP_CIPHER_CTX *ctx, const EVP_CIPHER *cipher,
                      ENGINE *impl, const unsigned char *key,
                      const unsigned char *iv, int enc)
{
    if (enc == -1)
        enc = ctx->encrypt;
    else {
        if (enc)
            enc = 1;
        ctx->encrypt = enc;
    }
#ifndef OPENSSL_NO_ENGINE
    /*
     * Whether it's nice or not, "Inits" can be used on "Final"'d contexts so
     * this context may already have an ENGINE! Try to avoid releasing the
     * previous handle, re-querying for an ENGINE, and having a
     * reinitialisation, when it may all be unecessary.
     */
    if (ctx->engine && ctx->cipher && (!cipher ||
                                       (cipher
                                        && (cipher->nid ==
                                            ctx->cipher->nid))))
        goto skip_to_init;
#endif
    if (cipher) {
        /*
         * Ensure a context left lying around from last time is cleared (the
         * previous check attempted to avoid this if the same ENGINE and
         * EVP_CIPHER could be used).
         */
        if (ctx->cipher) {
            unsigned long flags = ctx->flags;
            EVP_CIPHER_CTX_cleanup(ctx);
            /* Restore encrypt and flags */
            ctx->encrypt = enc;
            ctx->flags = flags;
        }
#ifndef OPENSSL_NO_ENGINE
        if (impl) {
            if (!ENGINE_init(impl)) {
                EVPerr(EVP_F_EVP_CIPHERINIT_EX, EVP_R_INITIALIZATION_ERROR);
                return 0;
            }
        } else
            /* Ask if an ENGINE is reserved for this job */
            impl = ENGINE_get_cipher_engine(cipher->nid);
        if (impl) {
            /* There's an ENGINE for this job ... (apparently) */
            const EVP_CIPHER *c = ENGINE_get_cipher(impl, cipher->nid);
            if (!c) {
                /*
                 * One positive side-effect of US's export control history,
                 * is that we should at least be able to avoid using US
                 * mispellings of "initialisation"?
                 */
                EVPerr(EVP_F_EVP_CIPHERINIT_EX, EVP_R_INITIALIZATION_ERROR);
                return 0;
            }
            /* We'll use the ENGINE's private cipher definition */
            cipher = c;
            /*
             * Store the ENGINE functional reference so we know 'cipher' came
             * from an ENGINE and we need to release it when done.
             */
            ctx->engine = impl;
        } else
            ctx->engine = NULL;
#endif

#ifdef OPENSSL_FIPS
        if (FIPS_mode()) {
            const EVP_CIPHER *fcipher = NULL;
            if (cipher)
                fcipher = evp_get_fips_cipher(cipher);
            if (fcipher)
                cipher = fcipher;
            return FIPS_cipherinit(ctx, cipher, key, iv, enc);
        }
#endif
        ctx->cipher = cipher;
        if (ctx->cipher->ctx_size) {
            ctx->cipher_data = OPENSSL_malloc(ctx->cipher->ctx_size);
            if (!ctx->cipher_data) {
                ctx->cipher = NULL;
                EVPerr(EVP_F_EVP_CIPHERINIT_EX, ERR_R_MALLOC_FAILURE);
                return 0;
            }
        } else {
            ctx->cipher_data = NULL;
        }
        ctx->key_len = cipher->key_len;
        /* Preserve wrap enable flag, zero everything else */
        ctx->flags &= EVP_CIPHER_CTX_FLAG_WRAP_ALLOW;
        if (ctx->cipher->flags & EVP_CIPH_CTRL_INIT) {
            if (!EVP_CIPHER_CTX_ctrl(ctx, EVP_CTRL_INIT, 0, NULL)) {
                ctx->cipher = NULL;
                EVPerr(EVP_F_EVP_CIPHERINIT_EX, EVP_R_INITIALIZATION_ERROR);
                return 0;
            }
        }
    } else if (!ctx->cipher) {
        EVPerr(EVP_F_EVP_CIPHERINIT_EX, EVP_R_NO_CIPHER_SET);
        return 0;
    }
#ifndef OPENSSL_NO_ENGINE
 skip_to_init:
#endif
#ifdef OPENSSL_FIPS
    if (FIPS_mode())
        return FIPS_cipherinit(ctx, cipher, key, iv, enc);
#endif
    /* we assume block size is a power of 2 in *cryptUpdate */
    OPENSSL_assert(ctx->cipher->block_size == 1
                   || ctx->cipher->block_size == 8
                   || ctx->cipher->block_size == 16);

    if (!(ctx->flags & EVP_CIPHER_CTX_FLAG_WRAP_ALLOW)
        && EVP_CIPHER_CTX_mode(ctx) == EVP_CIPH_WRAP_MODE) {
        EVPerr(EVP_F_EVP_CIPHERINIT_EX, EVP_R_WRAP_MODE_NOT_ALLOWED);
        return 0;
    }

    if (!(EVP_CIPHER_CTX_flags(ctx) & EVP_CIPH_CUSTOM_IV)) {
        switch (EVP_CIPHER_CTX_mode(ctx)) {

        case EVP_CIPH_STREAM_CIPHER:
        case EVP_CIPH_ECB_MODE:
            break;

        case EVP_CIPH_CFB_MODE:
        case EVP_CIPH_OFB_MODE:

            ctx->num = 0;
            /* fall-through */

        case EVP_CIPH_CBC_MODE:

            OPENSSL_assert(EVP_CIPHER_CTX_iv_length(ctx) <=
                           (int)sizeof(ctx->iv));
            if (iv)
                memcpy(ctx->oiv, iv, EVP_CIPHER_CTX_iv_length(ctx));
            memcpy(ctx->iv, ctx->oiv, EVP_CIPHER_CTX_iv_length(ctx));
            break;

        case EVP_CIPH_CTR_MODE:
            ctx->num = 0;
            /* Don't reuse IV for CTR mode */
            if (iv)
                memcpy(ctx->iv, iv, EVP_CIPHER_CTX_iv_length(ctx));
            break;

        default:
            return 0;
            break;
        }
    }

    if (key || (ctx->cipher->flags & EVP_CIPH_ALWAYS_CALL_INIT)) {
        if (!ctx->cipher->init(ctx, key, iv, enc))
            return 0;
    }
    ctx->buf_len = 0;
    ctx->final_used = 0;
    ctx->block_mask = ctx->cipher->block_size - 1;
    return 1;
}

int EVP_CipherUpdate(EVP_CIPHER_CTX *ctx, unsigned char *out, int *outl,
                     const unsigned char *in, int inl)
{
    if (ctx->encrypt)
        return EVP_EncryptUpdate(ctx, out, outl, in, inl);
    else
        return EVP_DecryptUpdate(ctx, out, outl, in, inl);
}

int EVP_CipherFinal_ex(EVP_CIPHER_CTX *ctx, unsigned char *out, int *outl)
{
    if (ctx->encrypt)
        return EVP_EncryptFinal_ex(ctx, out, outl);
    else
        return EVP_DecryptFinal_ex(ctx, out, outl);
}

int EVP_CipherFinal(EVP_CIPHER_CTX *ctx, unsigned char *out, int *outl)
{
    if (ctx->encrypt)
        return EVP_EncryptFinal(ctx, out, outl);
    else
        return EVP_DecryptFinal(ctx, out, outl);
}

int EVP_EncryptInit(EVP_CIPHER_CTX *ctx, const EVP_CIPHER *cipher,
                    const unsigned char *key, const unsigned char *iv)
{
    return EVP_CipherInit(ctx, cipher, key, iv, 1);
}

int EVP_EncryptInit_ex(EVP_CIPHER_CTX *ctx, const EVP_CIPHER *cipher,
                       ENGINE *impl, const unsigned char *key,
                       const unsigned char *iv)
{
    return EVP_CipherInit_ex(ctx, cipher, impl, key, iv, 1);
}

int EVP_DecryptInit(EVP_CIPHER_CTX *ctx, const EVP_CIPHER *cipher,
                    const unsigned char *key, const unsigned char *iv)
{
    return EVP_CipherInit(ctx, cipher, key, iv, 0);
}

int EVP_DecryptInit_ex(EVP_CIPHER_CTX *ctx, const EVP_CIPHER *cipher,
                       ENGINE *impl, const unsigned char *key,
                       const unsigned char *iv)
{
    return EVP_CipherInit_ex(ctx, cipher, impl, key, iv, 0);
}

int EVP_EncryptUpdate(EVP_CIPHER_CTX *ctx, unsigned char *out, int *outl,
                      const unsigned char *in, int inl)
{
    int i, j, bl;

    if (ctx->cipher->flags & EVP_CIPH_FLAG_CUSTOM_CIPHER) {
        i = M_do_cipher(ctx, out, in, inl);
        if (i < 0)
            return 0;
        else
            *outl = i;
        return 1;
    }

    if (inl <= 0) {
        *outl = 0;
        return inl == 0;
    }

    if (ctx->buf_len == 0 && (inl & (ctx->block_mask)) == 0) {
        if (M_do_cipher(ctx, out, in, inl)) {
            *outl = inl;
            return 1;
        } else {
            *outl = 0;
            return 0;
        }
    }
    i = ctx->buf_len;
    bl = ctx->cipher->block_size;
    OPENSSL_assert(bl <= (int)sizeof(ctx->buf));
    if (i != 0) {
        if (bl - i > inl) {
            memcpy(&(ctx->buf[i]), in, inl);
            ctx->buf_len += inl;
            *outl = 0;
            return 1;
        } else {
            j = bl - i;
            memcpy(&(ctx->buf[i]), in, j);
            if (!M_do_cipher(ctx, out, ctx->buf, bl))
                return 0;
            inl -= j;
            in += j;
            out += bl;
            *outl = bl;
        }
    } else
        *outl = 0;
    i = inl & (bl - 1);
    inl -= i;
    if (inl > 0) {
        if (!M_do_cipher(ctx, out, in, inl))
            return 0;
        *outl += inl;
    }

    if (i != 0)
        memcpy(ctx->buf, &(in[inl]), i);
    ctx->buf_len = i;
    return 1;
}

int EVP_EncryptFinal(EVP_CIPHER_CTX *ctx, unsigned char *out, int *outl)
{
    int ret;
    ret = EVP_EncryptFinal_ex(ctx, out, outl);
    return ret;
}

int EVP_EncryptFinal_ex(EVP_CIPHER_CTX *ctx, unsigned char *out, int *outl)
{
    int n, ret;
    unsigned int i, b, bl;

    if (ctx->cipher->flags & EVP_CIPH_FLAG_CUSTOM_CIPHER) {
        ret = M_do_cipher(ctx, out, NULL, 0);
        if (ret < 0)
            return 0;
        else
            *outl = ret;
        return 1;
    }

    b = ctx->cipher->block_size;
    OPENSSL_assert(b <= sizeof ctx->buf);
    if (b == 1) {
        *outl = 0;
        return 1;
    }
    bl = ctx->buf_len;
    if (ctx->flags & EVP_CIPH_NO_PADDING) {
        if (bl) {
            EVPerr(EVP_F_EVP_ENCRYPTFINAL_EX,
                   EVP_R_DATA_NOT_MULTIPLE_OF_BLOCK_LENGTH);
            return 0;
        }
        *outl = 0;
        return 1;
    }

    n = b - bl;
    for (i = bl; i < b; i++)
        ctx->buf[i] = n;
    ret = M_do_cipher(ctx, out, ctx->buf, b);

    if (ret)
        *outl = b;

    return ret;
}

int EVP_DecryptUpdate(EVP_CIPHER_CTX *ctx, unsigned char *out, int *outl,
                      const unsigned char *in, int inl)
{
    int fix_len;
    unsigned int b;

    if (ctx->cipher->flags & EVP_CIPH_FLAG_CUSTOM_CIPHER) {
        fix_len = M_do_cipher(ctx, out, in, inl);
        if (fix_len < 0) {
            *outl = 0;
            return 0;
        } else
            *outl = fix_len;
        return 1;
    }

    if (inl <= 0) {
        *outl = 0;
        return inl == 0;
    }

    if (ctx->flags & EVP_CIPH_NO_PADDING)
        return EVP_EncryptUpdate(ctx, out, outl, in, inl);

    b = ctx->cipher->block_size;
    OPENSSL_assert(b <= sizeof ctx->final);

    if (ctx->final_used) {
        memcpy(out, ctx->final, b);
        out += b;
        fix_len = 1;
    } else
        fix_len = 0;

    if (!EVP_EncryptUpdate(ctx, out, outl, in, inl))
        return 0;

    /*
     * if we have 'decrypted' a multiple of block size, make sure we have a
     * copy of this last block
     */
    if (b > 1 && !ctx->buf_len) {
        *outl -= b;
        ctx->final_used = 1;
        memcpy(ctx->final, &out[*outl], b);
    } else
        ctx->final_used = 0;

    if (fix_len)
        *outl += b;

    return 1;
}

int EVP_DecryptFinal(EVP_CIPHER_CTX *ctx, unsigned char *out, int *outl)
{
    int ret;
    ret = EVP_DecryptFinal_ex(ctx, out, outl);
    return ret;
}

int EVP_DecryptFinal_ex(EVP_CIPHER_CTX *ctx, unsigned char *out, int *outl)
{
    int i, n;
    unsigned int b;
    *outl = 0;

    if (ctx->cipher->flags & EVP_CIPH_FLAG_CUSTOM_CIPHER) {
        i = M_do_cipher(ctx, out, NULL, 0);
        if (i < 0)
            return 0;
        else
            *outl = i;
        return 1;
    }

    b = ctx->cipher->block_size;
    if (ctx->flags & EVP_CIPH_NO_PADDING) {
        if (ctx->buf_len) {
            EVPerr(EVP_F_EVP_DECRYPTFINAL_EX,
                   EVP_R_DATA_NOT_MULTIPLE_OF_BLOCK_LENGTH);
            return 0;
        }
        *outl = 0;
        return 1;
    }
    if (b > 1) {
        if (ctx->buf_len || !ctx->final_used) {
            EVPerr(EVP_F_EVP_DECRYPTFINAL_EX, EVP_R_WRONG_FINAL_BLOCK_LENGTH);
            return (0);
        }
        OPENSSL_assert(b <= sizeof ctx->final);

        /*
         * The following assumes that the ciphertext has been authenticated.
         * Otherwise it provides a padding oracle.
         */
        n = ctx->final[b - 1];
        if (n == 0 || n > (int)b) {
            EVPerr(EVP_F_EVP_DECRYPTFINAL_EX, EVP_R_BAD_DECRYPT);
            return (0);
        }
        for (i = 0; i < n; i++) {
            if (ctx->final[--b] != n) {
                EVPerr(EVP_F_EVP_DECRYPTFINAL_EX, EVP_R_BAD_DECRYPT);
                return (0);
            }
        }
        n = ctx->cipher->block_size - n;
        for (i = 0; i < n; i++)
            out[i] = ctx->final[i];
        *outl = n;
    } else
        *outl = 0;
    return (1);
}

void EVP_CIPHER_CTX_free(EVP_CIPHER_CTX *ctx)
{
    if (ctx) {
        EVP_CIPHER_CTX_cleanup(ctx);
        OPENSSL_free(ctx);
    }
}

int EVP_CIPHER_CTX_cleanup(EVP_CIPHER_CTX *c)
{
#ifndef OPENSSL_FIPS
    if (c->cipher != NULL) {
        if (c->cipher->cleanup && !c->cipher->cleanup(c))
            return 0;
        /* Cleanse cipher context data */
        if (c->cipher_data)
            OPENSSL_cleanse(c->cipher_data, c->cipher->ctx_size);
    }
    if (c->cipher_data)
        OPENSSL_free(c->cipher_data);
#endif
#ifndef OPENSSL_NO_ENGINE
    if (c->engine)
        /*
         * The EVP_CIPHER we used belongs to an ENGINE, release the
         * functional reference we held for this reason.
         */
        ENGINE_finish(c->engine);
#endif
#ifdef OPENSSL_FIPS
    FIPS_cipher_ctx_cleanup(c);
#endif
    memset(c, 0, sizeof(EVP_CIPHER_CTX));
    return 1;
}

int EVP_CIPHER_CTX_set_key_length(EVP_CIPHER_CTX *c, int keylen)
{
    if (c->cipher->flags & EVP_CIPH_CUSTOM_KEY_LENGTH)
        return EVP_CIPHER_CTX_ctrl(c, EVP_CTRL_SET_KEY_LENGTH, keylen, NULL);
    if (c->key_len == keylen)
        return 1;
    if ((keylen > 0) && (c->cipher->flags & EVP_CIPH_VARIABLE_LENGTH)) {
        c->key_len = keylen;
        return 1;
    }
    EVPerr(EVP_F_EVP_CIPHER_CTX_SET_KEY_LENGTH, EVP_R_INVALID_KEY_LENGTH);
    return 0;
}

int EVP_CIPHER_CTX_set_padding(EVP_CIPHER_CTX *ctx, int pad)
{
    if (pad)
        ctx->flags &= ~EVP_CIPH_NO_PADDING;
    else
        ctx->flags |= EVP_CIPH_NO_PADDING;
    return 1;
}

int EVP_CIPHER_CTX_ctrl(EVP_CIPHER_CTX *ctx, int type, int arg, void *ptr)
{
    int ret;
    if (!ctx->cipher) {
        EVPerr(EVP_F_EVP_CIPHER_CTX_CTRL, EVP_R_NO_CIPHER_SET);
        return 0;
    }

    if (!ctx->cipher->ctrl) {
        EVPerr(EVP_F_EVP_CIPHER_CTX_CTRL, EVP_R_CTRL_NOT_IMPLEMENTED);
        return 0;
    }

    ret = ctx->cipher->ctrl(ctx, type, arg, ptr);
    if (ret == -1) {
        EVPerr(EVP_F_EVP_CIPHER_CTX_CTRL,
               EVP_R_CTRL_OPERATION_NOT_IMPLEMENTED);
        return 0;
    }
    return ret;
}

int EVP_CIPHER_CTX_rand_key(EVP_CIPHER_CTX *ctx, unsigned char *key)
{
    if (ctx->cipher->flags & EVP_CIPH_RAND_KEY)
        return EVP_CIPHER_CTX_ctrl(ctx, EVP_CTRL_RAND_KEY, 0, key);
    if (RAND_bytes(key, ctx->key_len) <= 0)
        return 0;
    return 1;
}

int EVP_CIPHER_CTX_copy(EVP_CIPHER_CTX *out, const EVP_CIPHER_CTX *in)
{
    if ((in == NULL) || (in->cipher == NULL)) {
        EVPerr(EVP_F_EVP_CIPHER_CTX_COPY, EVP_R_INPUT_NOT_INITIALIZED);
        return 0;
    }
#ifndef OPENSSL_NO_ENGINE
    /* Make sure it's safe to copy a cipher context using an ENGINE */
    if (in->engine && !ENGINE_init(in->engine)) {
        EVPerr(EVP_F_EVP_CIPHER_CTX_COPY, ERR_R_ENGINE_LIB);
        return 0;
    }
#endif

    EVP_CIPHER_CTX_cleanup(out);
    memcpy(out, in, sizeof *out);

    if (in->cipher_data && in->cipher->ctx_size) {
        out->cipher_data = OPENSSL_malloc(in->cipher->ctx_size);
        if (!out->cipher_data) {
            out->cipher = NULL;
            EVPerr(EVP_F_EVP_CIPHER_CTX_COPY, ERR_R_MALLOC_FAILURE);
            return 0;
        }
        memcpy(out->cipher_data, in->cipher_data, in->cipher->ctx_size);
    }

    if (in->cipher->flags & EVP_CIPH_CUSTOM_COPY)
        if (!in->cipher->ctrl((EVP_CIPHER_CTX *)in, EVP_CTRL_COPY, 0, out)) {
            out->cipher = NULL;
            EVPerr(EVP_F_EVP_CIPHER_CTX_COPY, EVP_R_INITIALIZATION_ERROR);
            return 0;
        }
    return 1;
}