bio_md.c revision 296341 
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            if (EVP_DigestUpdate(ctx, (unsigned char *)out,
138                                 (unsigned int)ret) <= 0)
139                return (-1);
140        }
141    }
142    BIO_clear_retry_flags(b);
143    BIO_copy_next_retry(b);
144    return (ret);
145}
146
147static int md_write(BIO *b, const char *in, int inl)
148{
149    int ret = 0;
150    EVP_MD_CTX *ctx;
151
152    if ((in == NULL) || (inl <= 0))
153        return (0);
154    ctx = b->ptr;
155
156    if ((ctx != NULL) && (b->next_bio != NULL))
157        ret = BIO_write(b->next_bio, in, inl);
158    if (b->init) {
159        if (ret > 0) {
160            if (!EVP_DigestUpdate(ctx, (const unsigned char *)in,
161                                  (unsigned int)ret)) {
162                BIO_clear_retry_flags(b);
163                return 0;
164            }
165        }
166    }
167    if (b->next_bio != NULL) {
168        BIO_clear_retry_flags(b);
169        BIO_copy_next_retry(b);
170    }
171    return (ret);
172}
173
174static long md_ctrl(BIO *b, int cmd, long num, void *ptr)
175{
176    EVP_MD_CTX *ctx, *dctx, **pctx;
177    const EVP_MD **ppmd;
178    EVP_MD *md;
179    long ret = 1;
180    BIO *dbio;
181
182    ctx = b->ptr;
183
184    switch (cmd) {
185    case BIO_CTRL_RESET:
186        if (b->init)
187            ret = EVP_DigestInit_ex(ctx, ctx->digest, NULL);
188        else
189            ret = 0;
190        if (ret > 0)
191            ret = BIO_ctrl(b->next_bio, cmd, num, ptr);
192        break;
193    case BIO_C_GET_MD:
194        if (b->init) {
195            ppmd = ptr;
196            *ppmd = ctx->digest;
197        } else
198            ret = 0;
199        break;
200    case BIO_C_GET_MD_CTX:
201        pctx = ptr;
202        *pctx = ctx;
203        b->init = 1;
204        break;
205    case BIO_C_SET_MD_CTX:
206        if (b->init)
207            b->ptr = ptr;
208        else
209            ret = 0;
210        break;
211    case BIO_C_DO_STATE_MACHINE:
212        BIO_clear_retry_flags(b);
213        ret = BIO_ctrl(b->next_bio, cmd, num, ptr);
214        BIO_copy_next_retry(b);
215        break;
216
217    case BIO_C_SET_MD:
218        md = ptr;
219        ret = EVP_DigestInit_ex(ctx, md, NULL);
220        if (ret > 0)
221            b->init = 1;
222        break;
223    case BIO_CTRL_DUP:
224        dbio = ptr;
225        dctx = dbio->ptr;
226        if (!EVP_MD_CTX_copy_ex(dctx, ctx))
227            return 0;
228        b->init = 1;
229        break;
230    default:
231        ret = BIO_ctrl(b->next_bio, cmd, num, ptr);
232        break;
233    }
234    return (ret);
235}
236
237static long md_callback_ctrl(BIO *b, int cmd, bio_info_cb *fp)
238{
239    long ret = 1;
240
241    if (b->next_bio == NULL)
242        return (0);
243    switch (cmd) {
244    default:
245        ret = BIO_callback_ctrl(b->next_bio, cmd, fp);
246        break;
247    }
248    return (ret);
249}
250
251static int md_gets(BIO *bp, char *buf, int size)
252{
253    EVP_MD_CTX *ctx;
254    unsigned int ret;
255
256    ctx = bp->ptr;
257    if (size < ctx->digest->md_size)
258        return (0);
259    if (EVP_DigestFinal_ex(ctx, (unsigned char *)buf, &ret) <= 0)
260        return -1;
261
262    return ((int)ret);
263}
264
265/*-
266static int md_puts(bp,str)
267BIO *bp;
268char *str;
269        {
270        return(-1);
271        }
272*/
273