xref: /openbsd/lib/libcrypto/evp/bio_md.c (revision 9bac3682)
1 /* $OpenBSD: bio_md.c,v 1.22 2024/04/09 13:52:41 beck Exp $ */
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 
62 #include <openssl/buffer.h>
63 #include <openssl/evp.h>
64 
65 #include "bio_local.h"
66 #include "evp_local.h"
67 
68 /* BIO_put and BIO_get both add to the digest,
69  * BIO_gets returns the digest */
70 
71 static int md_write(BIO *h, char const *buf, int num);
72 static int md_read(BIO *h, char *buf, int size);
73 /*static int md_puts(BIO *h, const char *str); */
74 static int md_gets(BIO *h, char *str, int size);
75 static long md_ctrl(BIO *h, int cmd, long arg1, void *arg2);
76 static int md_new(BIO *h);
77 static int md_free(BIO *data);
78 static long md_callback_ctrl(BIO *h, int cmd, BIO_info_cb *fp);
79 
80 static const BIO_METHOD methods_md = {
81 	.type = BIO_TYPE_MD,
82 	.name = "message digest",
83 	.bwrite = md_write,
84 	.bread = md_read,
85 	.bgets = md_gets,
86 	.ctrl = md_ctrl,
87 	.create = md_new,
88 	.destroy = md_free,
89 	.callback_ctrl = md_callback_ctrl
90 };
91 
92 const BIO_METHOD *
BIO_f_md(void)93 BIO_f_md(void)
94 {
95 	return (&methods_md);
96 }
97 LCRYPTO_ALIAS(BIO_f_md);
98 
99 static int
md_new(BIO * bi)100 md_new(BIO *bi)
101 {
102 	EVP_MD_CTX *ctx;
103 
104 	ctx = EVP_MD_CTX_create();
105 	if (ctx == NULL)
106 		return (0);
107 
108 	bi->init = 0;
109 	bi->ptr = (char *)ctx;
110 	bi->flags = 0;
111 	return (1);
112 }
113 
114 static int
md_free(BIO * a)115 md_free(BIO *a)
116 {
117 	if (a == NULL)
118 		return (0);
119 	EVP_MD_CTX_destroy(a->ptr);
120 	a->ptr = NULL;
121 	a->init = 0;
122 	a->flags = 0;
123 	return (1);
124 }
125 
126 static int
md_read(BIO * b,char * out,int outl)127 md_read(BIO *b, char *out, int outl)
128 {
129 	int ret = 0;
130 	EVP_MD_CTX *ctx;
131 
132 	if (out == NULL)
133 		return (0);
134 	ctx = b->ptr;
135 
136 	if ((ctx == NULL) || (b->next_bio == NULL))
137 		return (0);
138 
139 	ret = BIO_read(b->next_bio, out, outl);
140 	if (b->init) {
141 		if (ret > 0) {
142 			if (EVP_DigestUpdate(ctx, (unsigned char *)out,
143 			    (unsigned int)ret) <= 0)
144 				return (-1);
145 		}
146 	}
147 	BIO_clear_retry_flags(b);
148 	BIO_copy_next_retry(b);
149 	return (ret);
150 }
151 
152 static int
md_write(BIO * b,const char * in,int inl)153 md_write(BIO *b, const char *in, int inl)
154 {
155 	int ret = 0;
156 	EVP_MD_CTX *ctx;
157 
158 	if ((in == NULL) || (inl <= 0))
159 		return (0);
160 	ctx = b->ptr;
161 
162 	if ((ctx != NULL) && (b->next_bio != NULL))
163 		ret = BIO_write(b->next_bio, in, inl);
164 	if (b->init) {
165 		if (ret > 0) {
166 			if (!EVP_DigestUpdate(ctx, (const unsigned char *)in,
167 			    (unsigned int)ret)) {
168 				BIO_clear_retry_flags(b);
169 				return 0;
170 			}
171 		}
172 	}
173 	if (b->next_bio != NULL) {
174 		BIO_clear_retry_flags(b);
175 		BIO_copy_next_retry(b);
176 	}
177 	return (ret);
178 }
179 
180 static long
md_ctrl(BIO * b,int cmd,long num,void * ptr)181 md_ctrl(BIO *b, int cmd, long num, void *ptr)
182 {
183 	EVP_MD_CTX *ctx, *dctx, **pctx;
184 	const EVP_MD **ppmd;
185 	EVP_MD *md;
186 	long ret = 1;
187 	BIO *dbio;
188 
189 	ctx = b->ptr;
190 
191 	switch (cmd) {
192 	case BIO_CTRL_RESET:
193 		if (b->init)
194 			ret = EVP_DigestInit_ex(ctx, ctx->digest, NULL);
195 		else
196 			ret = 0;
197 		if (ret > 0)
198 			ret = BIO_ctrl(b->next_bio, cmd, num, ptr);
199 		break;
200 	case BIO_C_GET_MD:
201 		if (b->init) {
202 			ppmd = ptr;
203 			*ppmd = ctx->digest;
204 		} else
205 			ret = 0;
206 		break;
207 	case BIO_C_GET_MD_CTX:
208 		pctx = ptr;
209 		*pctx = ctx;
210 		b->init = 1;
211 		break;
212 	case BIO_C_SET_MD_CTX:
213 		if (b->init)
214 			b->ptr = ptr;
215 		else
216 			ret = 0;
217 		break;
218 	case BIO_C_DO_STATE_MACHINE:
219 		BIO_clear_retry_flags(b);
220 		ret = BIO_ctrl(b->next_bio, cmd, num, ptr);
221 		BIO_copy_next_retry(b);
222 		break;
223 
224 	case BIO_C_SET_MD:
225 		md = ptr;
226 		ret = EVP_DigestInit_ex(ctx, md, NULL);
227 		if (ret > 0)
228 			b->init = 1;
229 		break;
230 	case BIO_CTRL_DUP:
231 		dbio = ptr;
232 		dctx = dbio->ptr;
233 		if (!EVP_MD_CTX_copy_ex(dctx, ctx))
234 			return 0;
235 		b->init = 1;
236 		break;
237 	default:
238 		ret = BIO_ctrl(b->next_bio, cmd, num, ptr);
239 		break;
240 	}
241 	return (ret);
242 }
243 
244 static long
md_callback_ctrl(BIO * b,int cmd,BIO_info_cb * fp)245 md_callback_ctrl(BIO *b, int cmd, BIO_info_cb *fp)
246 {
247 	long ret = 1;
248 
249 	if (b->next_bio == NULL)
250 		return (0);
251 	switch (cmd) {
252 	default:
253 		ret = BIO_callback_ctrl(b->next_bio, cmd, fp);
254 		break;
255 	}
256 	return (ret);
257 }
258 
259 static int
md_gets(BIO * bp,char * buf,int size)260 md_gets(BIO *bp, char *buf, int size)
261 {
262 	EVP_MD_CTX *ctx;
263 	unsigned int ret;
264 
265 	ctx = bp->ptr;
266 	if (size < ctx->digest->md_size)
267 		return (0);
268 	if (EVP_DigestFinal_ex(ctx, (unsigned char *)buf, &ret) <= 0)
269 		return -1;
270 
271 	return ((int)ret);
272 }
273 
274 /*
275 static int md_puts(bp,str)
276 BIO *bp;
277 char *str;
278 	{
279 	return(-1);
280 	}
281 */
282