xref: /openbsd/lib/libcrypto/evp/bio_md.c (revision db3296cf)
1 /* crypto/evp/bio_md.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 /* BIO_put and BIO_get both add to the digest,
66  * BIO_gets returns the digest */
67 
68 static int md_write(BIO *h, char const *buf, int num);
69 static int md_read(BIO *h, char *buf, int size);
70 /*static int md_puts(BIO *h, const char *str); */
71 static int md_gets(BIO *h, char *str, int size);
72 static long md_ctrl(BIO *h, int cmd, long arg1, void *arg2);
73 static int md_new(BIO *h);
74 static int md_free(BIO *data);
75 static long md_callback_ctrl(BIO *h,int cmd,bio_info_cb *fp);
76 
77 static BIO_METHOD methods_md=
78 	{
79 	BIO_TYPE_MD,"message digest",
80 	md_write,
81 	md_read,
82 	NULL, /* md_puts, */
83 	md_gets,
84 	md_ctrl,
85 	md_new,
86 	md_free,
87 	md_callback_ctrl,
88 	};
89 
90 BIO_METHOD *BIO_f_md(void)
91 	{
92 	return(&methods_md);
93 	}
94 
95 static int md_new(BIO *bi)
96 	{
97 	EVP_MD_CTX *ctx;
98 
99 	ctx=EVP_MD_CTX_create();
100 	if (ctx == NULL) return(0);
101 
102 	bi->init=0;
103 	bi->ptr=(char *)ctx;
104 	bi->flags=0;
105 	return(1);
106 	}
107 
108 static int md_free(BIO *a)
109 	{
110 	if (a == NULL) return(0);
111 	EVP_MD_CTX_destroy(a->ptr);
112 	a->ptr=NULL;
113 	a->init=0;
114 	a->flags=0;
115 	return(1);
116 	}
117 
118 static int md_read(BIO *b, char *out, int outl)
119 	{
120 	int ret=0;
121 	EVP_MD_CTX *ctx;
122 
123 	if (out == NULL) return(0);
124 	ctx=b->ptr;
125 
126 	if ((ctx == NULL) || (b->next_bio == NULL)) return(0);
127 
128 	ret=BIO_read(b->next_bio,out,outl);
129 	if (b->init)
130 		{
131 		if (ret > 0)
132 			{
133 			EVP_DigestUpdate(ctx,(unsigned char *)out,
134 				(unsigned int)ret);
135 			}
136 		}
137 	BIO_clear_retry_flags(b);
138 	BIO_copy_next_retry(b);
139 	return(ret);
140 	}
141 
142 static int md_write(BIO *b, const char *in, int inl)
143 	{
144 	int ret=0;
145 	EVP_MD_CTX *ctx;
146 
147 	if ((in == NULL) || (inl <= 0)) return(0);
148 	ctx=b->ptr;
149 
150 	if ((ctx != NULL) && (b->next_bio != NULL))
151 		ret=BIO_write(b->next_bio,in,inl);
152 	if (b->init)
153 		{
154 		if (ret > 0)
155 			{
156 			EVP_DigestUpdate(ctx,(unsigned char *)in,
157 				(unsigned int)ret);
158 			}
159 		}
160 	BIO_clear_retry_flags(b);
161 	BIO_copy_next_retry(b);
162 	return(ret);
163 	}
164 
165 static long md_ctrl(BIO *b, int cmd, long num, void *ptr)
166 	{
167 	EVP_MD_CTX *ctx,*dctx,**pctx;
168 	const EVP_MD **ppmd;
169 	EVP_MD *md;
170 	long ret=1;
171 	BIO *dbio;
172 
173 	ctx=b->ptr;
174 
175 	switch (cmd)
176 		{
177 	case BIO_CTRL_RESET:
178 		if (b->init)
179 			EVP_DigestInit_ex(ctx,ctx->digest, NULL);
180 		else
181 			ret=0;
182 		ret=BIO_ctrl(b->next_bio,cmd,num,ptr);
183 		break;
184 	case BIO_C_GET_MD:
185 		if (b->init)
186 			{
187 			ppmd=ptr;
188 			*ppmd=ctx->digest;
189 			}
190 		else
191 			ret=0;
192 		break;
193 	case BIO_C_GET_MD_CTX:
194 		if (b->init)
195 			{
196 			pctx=ptr;
197 			*pctx=ctx;
198 			}
199 		else
200 			ret=0;
201 		break;
202 	case BIO_C_DO_STATE_MACHINE:
203 		BIO_clear_retry_flags(b);
204 		ret=BIO_ctrl(b->next_bio,cmd,num,ptr);
205 		BIO_copy_next_retry(b);
206 		break;
207 
208 	case BIO_C_SET_MD:
209 		md=ptr;
210 		EVP_DigestInit_ex(ctx,md, NULL);
211 		b->init=1;
212 		break;
213 	case BIO_CTRL_DUP:
214 		dbio=ptr;
215 		dctx=dbio->ptr;
216 		EVP_MD_CTX_copy_ex(dctx,ctx);
217 		b->init=1;
218 		break;
219 	default:
220 		ret=BIO_ctrl(b->next_bio,cmd,num,ptr);
221 		break;
222 		}
223 	return(ret);
224 	}
225 
226 static long md_callback_ctrl(BIO *b, int cmd, bio_info_cb *fp)
227 	{
228 	long ret=1;
229 
230 	if (b->next_bio == NULL) return(0);
231 	switch (cmd)
232 		{
233 	default:
234 		ret=BIO_callback_ctrl(b->next_bio,cmd,fp);
235 		break;
236 		}
237 	return(ret);
238 	}
239 
240 static int md_gets(BIO *bp, char *buf, int size)
241 	{
242 	EVP_MD_CTX *ctx;
243 	unsigned int ret;
244 
245 
246 	ctx=bp->ptr;
247 	if (size < ctx->digest->md_size)
248 		return(0);
249 	EVP_DigestFinal_ex(ctx,(unsigned char *)buf,&ret);
250 	return((int)ret);
251 	}
252 
253 /*
254 static int md_puts(bp,str)
255 BIO *bp;
256 char *str;
257 	{
258 	return(-1);
259 	}
260 */
261 
262