1 /* crypto/evp/bio_enc.c */
2 /* Copyright (C) 1995-1998 Eric Young (eay@cryptsoft.com)
3 * All rights reserved.
4 *
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.
8 *
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).
15 *
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.
22 *
23 * Redistribution and use in source and binary forms, with or without
24 * modification, are permitted provided that the following conditions
25 * are met:
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)"
40 *
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
51 * SUCH DAMAGE.
52 *
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.]
57 */
58
59 #include <stdio.h>
60 #include <errno.h>
61 #include "cryptlib.h"
62 #include <openssl/buffer.h>
63 #include <openssl/evp.h>
64
65 static int enc_write(BIO *h, const char *buf, int num);
66 static int enc_read(BIO *h, char *buf, int size);
67 /*static int enc_puts(BIO *h, const char *str); */
68 /*static int enc_gets(BIO *h, char *str, int size); */
69 static long enc_ctrl(BIO *h, int cmd, long arg1, void *arg2);
70 static int enc_new(BIO *h);
71 static int enc_free(BIO *data);
72 static long enc_callback_ctrl(BIO *h, int cmd, bio_info_cb *fps);
73 #define ENC_BLOCK_SIZE (1024*4)
74 #define BUF_OFFSET (EVP_MAX_BLOCK_LENGTH*2)
75
76 typedef struct enc_struct
77 {
78 int buf_len;
79 int buf_off;
80 int cont; /* <= 0 when finished */
81 int finished;
82 int ok; /* bad decrypt */
83 EVP_CIPHER_CTX cipher;
84 /* buf is larger than ENC_BLOCK_SIZE because EVP_DecryptUpdate
85 * can return up to a block more data than is presented to it
86 */
87 char buf[ENC_BLOCK_SIZE+BUF_OFFSET+2];
88 } BIO_ENC_CTX;
89
90 static BIO_METHOD methods_enc=
91 {
92 BIO_TYPE_CIPHER,"cipher",
93 enc_write,
94 enc_read,
95 NULL, /* enc_puts, */
96 NULL, /* enc_gets, */
97 enc_ctrl,
98 enc_new,
99 enc_free,
100 enc_callback_ctrl,
101 };
102
103 BIO_METHOD *BIO_f_cipher(void)
104 {
105 return(&methods_enc);
106 }
107
108 static int enc_new(BIO *bi)
109 {
110 BIO_ENC_CTX *ctx;
111
112 ctx=(BIO_ENC_CTX *)OPENSSL_malloc(sizeof(BIO_ENC_CTX));
113 if (ctx == NULL) return(0);
114 EVP_CIPHER_CTX_init(&ctx->cipher);
115
116 ctx->buf_len=0;
117 ctx->buf_off=0;
118 ctx->cont=1;
119 ctx->finished=0;
120 ctx->ok=1;
121
122 bi->init=0;
123 bi->ptr=(char *)ctx;
124 bi->flags=0;
125 return(1);
126 }
127
128 static int enc_free(BIO *a)
129 {
130 BIO_ENC_CTX *b;
131
132 if (a == NULL) return(0);
133 b=(BIO_ENC_CTX *)a->ptr;
134 EVP_CIPHER_CTX_cleanup(&(b->cipher));
135 OPENSSL_cleanse(a->ptr,sizeof(BIO_ENC_CTX));
136 OPENSSL_free(a->ptr);
137 a->ptr=NULL;
138 a->init=0;
139 a->flags=0;
140 return(1);
141 }
142
143 static int enc_read(BIO *b, char *out, int outl)
144 {
145 int ret=0,i;
146 BIO_ENC_CTX *ctx;
147
148 if (out == NULL) return(0);
149 ctx=(BIO_ENC_CTX *)b->ptr;
150
151 if ((ctx == NULL) || (b->next_bio == NULL)) return(0);
152
153 /* First check if there are bytes decoded/encoded */
154 if (ctx->buf_len > 0)
155 {
156 i=ctx->buf_len-ctx->buf_off;
157 if (i > outl) i=outl;
158 memcpy(out,&(ctx->buf[ctx->buf_off]),i);
159 ret=i;
160 out+=i;
161 outl-=i;
162 ctx->buf_off+=i;
163 if (ctx->buf_len == ctx->buf_off)
164 {
165 ctx->buf_len=0;
166 ctx->buf_off=0;
167 }
168 }
169
170 /* At this point, we have room of outl bytes and an empty
171 * buffer, so we should read in some more. */
172
173 while (outl > 0)
174 {
175 if (ctx->cont <= 0) break;
176
177 /* read in at IV offset, read the EVP_Cipher
178 * documentation about why */
179 i=BIO_read(b->next_bio,&(ctx->buf[BUF_OFFSET]),ENC_BLOCK_SIZE);
180
181 if (i <= 0)
182 {
183 /* Should be continue next time we are called? */
184 if (!BIO_should_retry(b->next_bio))
185 {
186 ctx->cont=i;
187 i=EVP_CipherFinal_ex(&(ctx->cipher),
188 (unsigned char *)ctx->buf,
189 &(ctx->buf_len));
190 ctx->ok=i;
191 ctx->buf_off=0;
192 }
193 else
194 {
195 ret=(ret == 0)?i:ret;
196 break;
197 }
198 }
199 else
200 {
201 EVP_CipherUpdate(&(ctx->cipher),
202 (unsigned char *)ctx->buf,&ctx->buf_len,
203 (unsigned char *)&(ctx->buf[BUF_OFFSET]),i);
204 ctx->cont=1;
205 /* Note: it is possible for EVP_CipherUpdate to
206 * decrypt zero bytes because this is or looks like
207 * the final block: if this happens we should retry
208 * and either read more data or decrypt the final
209 * block
210 */
211 if(ctx->buf_len == 0) continue;
212 }
213
214 if (ctx->buf_len <= outl)
215 i=ctx->buf_len;
216 else
217 i=outl;
218 if (i <= 0) break;
219 memcpy(out,ctx->buf,i);
220 ret+=i;
221 ctx->buf_off=i;
222 outl-=i;
223 out+=i;
224 }
225
226 BIO_clear_retry_flags(b);
227 BIO_copy_next_retry(b);
228 return((ret == 0)?ctx->cont:ret);
229 }
230
231 static int enc_write(BIO *b, const char *in, int inl)
232 {
233 int ret=0,n,i;
234 BIO_ENC_CTX *ctx;
235
236 ctx=(BIO_ENC_CTX *)b->ptr;
237 ret=inl;
238
239 BIO_clear_retry_flags(b);
240 n=ctx->buf_len-ctx->buf_off;
241 while (n > 0)
242 {
243 i=BIO_write(b->next_bio,&(ctx->buf[ctx->buf_off]),n);
244 if (i <= 0)
245 {
246 BIO_copy_next_retry(b);
247 return(i);
248 }
249 ctx->buf_off+=i;
250 n-=i;
251 }
252 /* at this point all pending data has been written */
253
254 if ((in == NULL) || (inl <= 0)) return(0);
255
256 ctx->buf_off=0;
257 while (inl > 0)
258 {
259 n=(inl > ENC_BLOCK_SIZE)?ENC_BLOCK_SIZE:inl;
260 EVP_CipherUpdate(&(ctx->cipher),
261 (unsigned char *)ctx->buf,&ctx->buf_len,
262 (unsigned char *)in,n);
263 inl-=n;
264 in+=n;
265
266 ctx->buf_off=0;
267 n=ctx->buf_len;
268 while (n > 0)
269 {
270 i=BIO_write(b->next_bio,&(ctx->buf[ctx->buf_off]),n);
271 if (i <= 0)
272 {
273 BIO_copy_next_retry(b);
274 return (ret == inl) ? i : ret - inl;
275 }
276 n-=i;
277 ctx->buf_off+=i;
278 }
279 ctx->buf_len=0;
280 ctx->buf_off=0;
281 }
282 BIO_copy_next_retry(b);
283 return(ret);
284 }
285
286 static long enc_ctrl(BIO *b, int cmd, long num, void *ptr)
287 {
288 BIO *dbio;
289 BIO_ENC_CTX *ctx,*dctx;
290 long ret=1;
291 int i;
292 EVP_CIPHER_CTX **c_ctx;
293
294 ctx=(BIO_ENC_CTX *)b->ptr;
295
296 switch (cmd)
297 {
298 case BIO_CTRL_RESET:
299 ctx->ok=1;
300 ctx->finished=0;
301 EVP_CipherInit_ex(&(ctx->cipher),NULL,NULL,NULL,NULL,
302 ctx->cipher.encrypt);
303 ret=BIO_ctrl(b->next_bio,cmd,num,ptr);
304 break;
305 case BIO_CTRL_EOF: /* More to read */
306 if (ctx->cont <= 0)
307 ret=1;
308 else
309 ret=BIO_ctrl(b->next_bio,cmd,num,ptr);
310 break;
311 case BIO_CTRL_WPENDING:
312 ret=ctx->buf_len-ctx->buf_off;
313 if (ret <= 0)
314 ret=BIO_ctrl(b->next_bio,cmd,num,ptr);
315 break;
316 case BIO_CTRL_PENDING: /* More to read in buffer */
317 ret=ctx->buf_len-ctx->buf_off;
318 if (ret <= 0)
319 ret=BIO_ctrl(b->next_bio,cmd,num,ptr);
320 break;
321 case BIO_CTRL_FLUSH:
322 /* do a final write */
323 again:
324 while (ctx->buf_len != ctx->buf_off)
325 {
326 i=enc_write(b,NULL,0);
327 if (i < 0)
328 return i;
329 }
330
331 if (!ctx->finished)
332 {
333 ctx->finished=1;
334 ctx->buf_off=0;
335 ret=EVP_CipherFinal_ex(&(ctx->cipher),
336 (unsigned char *)ctx->buf,
337 &(ctx->buf_len));
338 ctx->ok=(int)ret;
339 if (ret <= 0) break;
340
341 /* push out the bytes */
342 goto again;
343 }
344
345 /* Finally flush the underlying BIO */
346 ret=BIO_ctrl(b->next_bio,cmd,num,ptr);
347 break;
348 case BIO_C_GET_CIPHER_STATUS:
349 ret=(long)ctx->ok;
350 break;
351 case BIO_C_DO_STATE_MACHINE:
352 BIO_clear_retry_flags(b);
353 ret=BIO_ctrl(b->next_bio,cmd,num,ptr);
354 BIO_copy_next_retry(b);
355 break;
356 case BIO_C_GET_CIPHER_CTX:
357 c_ctx=(EVP_CIPHER_CTX **)ptr;
358 (*c_ctx)= &(ctx->cipher);
359 b->init=1;
360 break;
361 case BIO_CTRL_DUP:
362 dbio=(BIO *)ptr;
363 dctx=(BIO_ENC_CTX *)dbio->ptr;
364 EVP_CIPHER_CTX_init(&dctx->cipher);
365 ret = EVP_CIPHER_CTX_copy(&dctx->cipher,&ctx->cipher);
366 if (ret)
367 dbio->init=1;
368 break;
369 default:
370 ret=BIO_ctrl(b->next_bio,cmd,num,ptr);
371 break;
372 }
373 return(ret);
374 }
375
376 static long enc_callback_ctrl(BIO *b, int cmd, bio_info_cb *fp)
377 {
378 long ret=1;
379
380 if (b->next_bio == NULL) return(0);
381 switch (cmd)
382 {
383 default:
384 ret=BIO_callback_ctrl(b->next_bio,cmd,fp);
385 break;
386 }
387 return(ret);
388 }
389
390 /*
391 void BIO_set_cipher_ctx(b,c)
392 BIO *b;
393 EVP_CIPHER_ctx *c;
394 {
395 if (b == NULL) return;
396
397 if ((b->callback != NULL) &&
398 (b->callback(b,BIO_CB_CTRL,(char *)c,BIO_CTRL_SET,e,0L) <= 0))
399 return;
400
401 b->init=1;
402 ctx=(BIO_ENC_CTX *)b->ptr;
403 memcpy(ctx->cipher,c,sizeof(EVP_CIPHER_CTX));
404
405 if (b->callback != NULL)
406 b->callback(b,BIO_CB_CTRL,(char *)c,BIO_CTRL_SET,e,1L);
407 }
408 */
409
410 void BIO_set_cipher(BIO *b, const EVP_CIPHER *c, const unsigned char *k,
411 const unsigned char *i, int e)
412 {
413 BIO_ENC_CTX *ctx;
414
415 if (b == NULL) return;
416
417 if ((b->callback != NULL) &&
418 (b->callback(b,BIO_CB_CTRL,(const char *)c,BIO_CTRL_SET,e,0L) <= 0))
419 return;
420
421 b->init=1;
422 ctx=(BIO_ENC_CTX *)b->ptr;
423 EVP_CipherInit_ex(&(ctx->cipher),c,NULL, k,i,e);
424
425 if (b->callback != NULL)
426 b->callback(b,BIO_CB_CTRL,(const char *)c,BIO_CTRL_SET,e,1L);
427 }