bio_md.c revision 296465 
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/*
66 * BIO_put and BIO_get both add to the digest, BIO_gets returns the digest
67 */
68
69static int md_write(BIO *h, char const *buf, int num);
70static int md_read(BIO *h, char *buf, int size);
71/*
72 * static int md_puts(BIO *h, const char *str);
73 */
74static int md_gets(BIO *h, char *str, int size);
75static long md_ctrl(BIO *h, int cmd, long arg1, void *arg2);
76static int md_new(BIO *h);
77static int md_free(BIO *data);
78static long md_callback_ctrl(BIO *h, int cmd, bio_info_cb *fp);
79
80static BIO_METHOD methods_md = {
81    BIO_TYPE_MD, "message digest",
82    md_write,
83    md_read,
84    NULL,                       /* md_puts, */
85    md_gets,
86    md_ctrl,
87    md_new,
88    md_free,
89    md_callback_ctrl,
90};
91
92BIO_METHOD *BIO_f_md(void)
93{
94    return (&methods_md);
95}
96
97static int md_new(BIO *bi)
98{
99    EVP_MD_CTX *ctx;
100
101    ctx = EVP_MD_CTX_create();
102    if (ctx == NULL)
103        return (0);
104
105    bi->init = 0;
106    bi->ptr = (char *)ctx;
107    bi->flags = 0;
108    return (1);
109}
110
111static int md_free(BIO *a)
112{
113    if (a == NULL)
114        return (0);
115    EVP_MD_CTX_destroy(a->ptr);
116    a->ptr = NULL;
117    a->init = 0;
118    a->flags = 0;
119    return (1);
120}
121
122static int md_read(BIO *b, char *out, int outl)
123{
124    int ret = 0;
125    EVP_MD_CTX *ctx;
126
127    if (out == NULL)
128        return (0);
129    ctx = b->ptr;
130
131    if ((ctx == NULL) || (b->next_bio == NULL))
132        return (0);
133
134    ret = BIO_read(b->next_bio, out, outl);
135    if (b->init) {
136        if (ret > 0) {
137            EVP_DigestUpdate(ctx, (unsigned char *)out, (unsigned int)ret);
138        }
139    }
140    BIO_clear_retry_flags(b);
141    BIO_copy_next_retry(b);
142    return (ret);
143}
144
145static int md_write(BIO *b, const char *in, int inl)
146{
147    int ret = 0;
148    EVP_MD_CTX *ctx;
149
150    if ((in == NULL) || (inl <= 0))
151        return (0);
152    ctx = b->ptr;
153
154    if ((ctx != NULL) && (b->next_bio != NULL))
155        ret = BIO_write(b->next_bio, in, inl);
156    if (b->init) {
157        if (ret > 0) {
158            EVP_DigestUpdate(ctx, (const unsigned char *)in,
159                             (unsigned int)ret);
160        }
161    }
162    BIO_clear_retry_flags(b);
163    BIO_copy_next_retry(b);
164    return (ret);
165}
166
167static long md_ctrl(BIO *b, int cmd, long num, void *ptr)
168{
169    EVP_MD_CTX *ctx, *dctx, **pctx;
170    const EVP_MD **ppmd;
171    EVP_MD *md;
172    long ret = 1;
173    BIO *dbio;
174
175    ctx = b->ptr;
176
177    switch (cmd) {
178    case BIO_CTRL_RESET:
179        if (b->init)
180            ret = EVP_DigestInit_ex(ctx, ctx->digest, NULL);
181        else
182            ret = 0;
183        if (ret > 0)
184            ret = BIO_ctrl(b->next_bio, cmd, num, ptr);
185        break;
186    case BIO_C_GET_MD:
187        if (b->init) {
188            ppmd = ptr;
189            *ppmd = ctx->digest;
190        } else
191            ret = 0;
192        break;
193    case BIO_C_GET_MD_CTX:
194        pctx = ptr;
195        *pctx = ctx;
196        break;
197    case BIO_C_SET_MD_CTX:
198        if (b->init)
199            b->ptr = ptr;
200        else
201            ret = 0;
202        break;
203    case BIO_C_DO_STATE_MACHINE:
204        BIO_clear_retry_flags(b);
205        ret = BIO_ctrl(b->next_bio, cmd, num, ptr);
206        BIO_copy_next_retry(b);
207        break;
208
209    case BIO_C_SET_MD:
210        md = ptr;
211        ret = EVP_DigestInit_ex(ctx, md, NULL);
212        if (ret > 0)
213            b->init = 1;
214        break;
215    case BIO_CTRL_DUP:
216        dbio = ptr;
217        dctx = dbio->ptr;
218        EVP_MD_CTX_copy_ex(dctx, ctx);
219        b->init = 1;
220        break;
221    default:
222        ret = BIO_ctrl(b->next_bio, cmd, num, ptr);
223        break;
224    }
225    return (ret);
226}
227
228static long md_callback_ctrl(BIO *b, int cmd, bio_info_cb *fp)
229{
230    long ret = 1;
231
232    if (b->next_bio == NULL)
233        return (0);
234    switch (cmd) {
235    default:
236        ret = BIO_callback_ctrl(b->next_bio, cmd, fp);
237        break;
238    }
239    return (ret);
240}
241
242static int md_gets(BIO *bp, char *buf, int size)
243{
244    EVP_MD_CTX *ctx;
245    unsigned int ret;
246
247    ctx = bp->ptr;
248    if (size < ctx->digest->md_size)
249        return (0);
250    EVP_DigestFinal_ex(ctx, (unsigned char *)buf, &ret);
251    return ((int)ret);
252}
253
254/*-
255static int md_puts(bp,str)
256BIO *bp;
257char *str;
258        {
259        return(-1);
260        }
261*/
262