evp_enc.c revision 68651 
1/* crypto/evp/evp_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 "cryptlib.h"
61#include <openssl/evp.h>
62#include <openssl/err.h>
63#include "evp_locl.h"
64
65const char *EVP_version="EVP" OPENSSL_VERSION_PTEXT;
66
67void EVP_CIPHER_CTX_init(EVP_CIPHER_CTX *ctx)
68	{
69	memset(ctx,0,sizeof(EVP_CIPHER_CTX));
70	/* ctx->cipher=NULL; */
71	}
72
73int EVP_CipherInit(EVP_CIPHER_CTX *ctx, const EVP_CIPHER *cipher,
74	     unsigned char *key, unsigned char *iv, int enc)
75	{
76	if(enc && (enc != -1)) enc = 1;
77	if (cipher) {
78		ctx->cipher=cipher;
79		ctx->key_len = cipher->key_len;
80		if(ctx->cipher->flags & EVP_CIPH_CTRL_INIT) {
81			if(!EVP_CIPHER_CTX_ctrl(ctx, EVP_CTRL_INIT, 0, NULL)) {
82				EVPerr(EVP_F_EVP_CIPHERINIT, EVP_R_INITIALIZATION_ERROR);
83				return 0;
84			}
85		}
86	} else if(!ctx->cipher) {
87		EVPerr(EVP_F_EVP_CIPHERINIT, EVP_R_NO_CIPHER_SET);
88		return 0;
89	}
90	if(!(EVP_CIPHER_CTX_flags(ctx) & EVP_CIPH_CUSTOM_IV)) {
91		switch(EVP_CIPHER_CTX_mode(ctx)) {
92
93			case EVP_CIPH_STREAM_CIPHER:
94			case EVP_CIPH_ECB_MODE:
95			break;
96
97			case EVP_CIPH_CFB_MODE:
98			case EVP_CIPH_OFB_MODE:
99
100			ctx->num = 0;
101
102			case EVP_CIPH_CBC_MODE:
103
104			if(iv) memcpy(ctx->oiv, iv, EVP_CIPHER_CTX_iv_length(ctx));
105			memcpy(ctx->iv, ctx->oiv, EVP_CIPHER_CTX_iv_length(ctx));
106			break;
107
108			default:
109			return 0;
110			break;
111		}
112	}
113
114	if(key || (ctx->cipher->flags & EVP_CIPH_ALWAYS_CALL_INIT)) {
115		if(!ctx->cipher->init(ctx,key,iv,enc)) return 0;
116	}
117	if(enc != -1) ctx->encrypt=enc;
118	ctx->buf_len=0;
119	return 1;
120	}
121
122int EVP_CipherUpdate(EVP_CIPHER_CTX *ctx, unsigned char *out, int *outl,
123	     unsigned char *in, int inl)
124	{
125	if (ctx->encrypt)
126		return EVP_EncryptUpdate(ctx,out,outl,in,inl);
127	else	return EVP_DecryptUpdate(ctx,out,outl,in,inl);
128	}
129
130int EVP_CipherFinal(EVP_CIPHER_CTX *ctx, unsigned char *out, int *outl)
131	{
132	if (ctx->encrypt)
133		return EVP_EncryptFinal(ctx,out,outl);
134	else	return(EVP_DecryptFinal(ctx,out,outl));
135	}
136
137int EVP_EncryptInit(EVP_CIPHER_CTX *ctx, const EVP_CIPHER *cipher,
138	     unsigned char *key, unsigned char *iv)
139	{
140	return EVP_CipherInit(ctx, cipher, key, iv, 1);
141	}
142
143int EVP_DecryptInit(EVP_CIPHER_CTX *ctx, const EVP_CIPHER *cipher,
144	     unsigned char *key, unsigned char *iv)
145	{
146	return EVP_CipherInit(ctx, cipher, key, iv, 0);
147	}
148
149
150int EVP_EncryptUpdate(EVP_CIPHER_CTX *ctx, unsigned char *out, int *outl,
151	     unsigned char *in, int inl)
152	{
153	int i,j,bl;
154
155	i=ctx->buf_len;
156	bl=ctx->cipher->block_size;
157	*outl=0;
158	if ((inl == 0) && (i != bl)) return 1;
159	if (i != 0)
160		{
161		if (i+inl < bl)
162			{
163			memcpy(&(ctx->buf[i]),in,inl);
164			ctx->buf_len+=inl;
165			return 1;
166			}
167		else
168			{
169			j=bl-i;
170			if (j != 0) memcpy(&(ctx->buf[i]),in,j);
171			if(!ctx->cipher->do_cipher(ctx,out,ctx->buf,bl)) return 0;
172			inl-=j;
173			in+=j;
174			out+=bl;
175			*outl+=bl;
176			}
177		}
178	i=inl%bl; /* how much is left */
179	inl-=i;
180	if (inl > 0)
181		{
182		if(!ctx->cipher->do_cipher(ctx,out,in,inl)) return 0;
183		*outl+=inl;
184		}
185
186	if (i != 0)
187		memcpy(ctx->buf,&(in[inl]),i);
188	ctx->buf_len=i;
189	return 1;
190	}
191
192int EVP_EncryptFinal(EVP_CIPHER_CTX *ctx, unsigned char *out, int *outl)
193	{
194	int i,n,b,bl;
195
196	b=ctx->cipher->block_size;
197	if (b == 1)
198		{
199		*outl=0;
200		return 1;
201		}
202	bl=ctx->buf_len;
203	n=b-bl;
204	for (i=bl; i<b; i++)
205		ctx->buf[i]=n;
206	if(!ctx->cipher->do_cipher(ctx,out,ctx->buf,b)) return 0;
207	*outl=b;
208	return 1;
209	}
210
211int EVP_DecryptUpdate(EVP_CIPHER_CTX *ctx, unsigned char *out, int *outl,
212	     unsigned char *in, int inl)
213	{
214	int b,bl,n;
215	int keep_last=0;
216
217	*outl=0;
218	if (inl == 0) return 1;
219
220	b=ctx->cipher->block_size;
221	if (b > 1)
222		{
223		/* Is the input a multiple of the block size? */
224		bl=ctx->buf_len;
225		n=inl+bl;
226		if (n%b == 0)
227			{
228			if (inl < b) /* must be 'just one' buff */
229				{
230				memcpy(&(ctx->buf[bl]),in,inl);
231				ctx->buf_len=b;
232				*outl=0;
233				return 1;
234				}
235			keep_last=1;
236			inl-=b; /* don't do the last block */
237			}
238		}
239	if(!EVP_EncryptUpdate(ctx,out,outl,in,inl)) return 0;
240
241	/* if we have 'decrypted' a multiple of block size, make sure
242	 * we have a copy of this last block */
243	if (keep_last)
244		{
245		memcpy(&(ctx->buf[0]),&(in[inl]),b);
246#ifdef DEBUG
247		if (ctx->buf_len != 0)
248			{
249			abort();
250			}
251#endif
252		ctx->buf_len=b;
253		}
254	return 1;
255	}
256
257int EVP_DecryptFinal(EVP_CIPHER_CTX *ctx, unsigned char *out, int *outl)
258	{
259	int i,b;
260	int n;
261
262	*outl=0;
263	b=ctx->cipher->block_size;
264	if (b > 1)
265		{
266		if (ctx->buf_len != b)
267			{
268			EVPerr(EVP_F_EVP_DECRYPTFINAL,EVP_R_WRONG_FINAL_BLOCK_LENGTH);
269			return(0);
270			}
271		if(!EVP_EncryptUpdate(ctx,ctx->buf,&n,ctx->buf,0)) return 0;
272		if (n != b)
273			return(0);
274		n=ctx->buf[b-1];
275		if (n > b)
276			{
277			EVPerr(EVP_F_EVP_DECRYPTFINAL,EVP_R_BAD_DECRYPT);
278			return(0);
279			}
280		for (i=0; i<n; i++)
281			{
282			if (ctx->buf[--b] != n)
283				{
284				EVPerr(EVP_F_EVP_DECRYPTFINAL,EVP_R_BAD_DECRYPT);
285				return(0);
286				}
287			}
288		n=ctx->cipher->block_size-n;
289		for (i=0; i<n; i++)
290			out[i]=ctx->buf[i];
291		*outl=n;
292		}
293	else
294		*outl=0;
295	return(1);
296	}
297
298int EVP_CIPHER_CTX_cleanup(EVP_CIPHER_CTX *c)
299	{
300	if ((c->cipher != NULL) && (c->cipher->cleanup != NULL))
301		{
302		if(!c->cipher->cleanup(c)) return 0;
303		}
304	memset(c,0,sizeof(EVP_CIPHER_CTX));
305	return 1;
306	}
307
308int EVP_CIPHER_CTX_set_key_length(EVP_CIPHER_CTX *c, int keylen)
309	{
310	if(c->cipher->flags & EVP_CIPH_CUSTOM_KEY_LENGTH)
311		return EVP_CIPHER_CTX_ctrl(c, EVP_CTRL_SET_KEY_LENGTH, keylen, NULL);
312	if(c->key_len == keylen) return 1;
313	if((keylen > 0) && (c->cipher->flags & EVP_CIPH_VARIABLE_LENGTH))
314		{
315		c->key_len = keylen;
316		return 1;
317		}
318	EVPerr(EVP_F_EVP_CIPHER_CTX_SET_KEY_LENGTH,EVP_R_INVALID_KEY_LENGTH);
319	return 0;
320	}
321
322int EVP_CIPHER_CTX_ctrl(EVP_CIPHER_CTX *ctx, int type, int arg, void *ptr)
323{
324	int ret;
325	if(!ctx->cipher) {
326		EVPerr(EVP_F_EVP_CIPHER_CTX_CTRL, EVP_R_NO_CIPHER_SET);
327		return 0;
328	}
329
330	if(!ctx->cipher->ctrl) {
331		EVPerr(EVP_F_EVP_CIPHER_CTX_CTRL, EVP_R_CTRL_NOT_IMPLEMENTED);
332		return 0;
333	}
334
335	ret = ctx->cipher->ctrl(ctx, type, arg, ptr);
336	if(ret == -1) {
337		EVPerr(EVP_F_EVP_CIPHER_CTX_CTRL, EVP_R_CTRL_OPERATION_NOT_IMPLEMENTED);
338		return 0;
339	}
340	return ret;
341}
342