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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 
BIO_f_cipher(void)103 BIO_METHOD *BIO_f_cipher(void)
104 	{
105 	return(&methods_enc);
106 	}
107 
enc_new(BIO * bi)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 
enc_free(BIO * a)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 
enc_read(BIO * b,char * out,int outl)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 
enc_write(BIO * b,const char * in,int inl)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 
enc_ctrl(BIO * b,int cmd,long num,void * ptr)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 
enc_callback_ctrl(BIO * b,int cmd,bio_info_cb * fp)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 
BIO_set_cipher(BIO * b,const EVP_CIPHER * c,const unsigned char * k,const unsigned char * i,int e)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 	}
428 
429