1 /*
2 * Copyright 1995-2021 The OpenSSL Project Authors. All Rights Reserved.
3 *
4 * Licensed under the Apache License 2.0 (the "License"). You may not use
5 * this file except in compliance with the License. You can obtain a copy
6 * in the file LICENSE in the source distribution or at
7 * https://www.openssl.org/source/license.html
8 */
9
10 #include <stdio.h>
11 #include <errno.h>
12 #include <openssl/buffer.h>
13 #include <openssl/evp.h>
14 #include "internal/bio.h"
15
16 /*
17 * BIO_put and BIO_get both add to the digest, BIO_gets returns the digest
18 */
19
20 static int md_write(BIO *h, char const *buf, int num);
21 static int md_read(BIO *h, char *buf, int size);
22 static int md_gets(BIO *h, char *str, int size);
23 static long md_ctrl(BIO *h, int cmd, long arg1, void *arg2);
24 static int md_new(BIO *h);
25 static int md_free(BIO *data);
26 static long md_callback_ctrl(BIO *h, int cmd, BIO_info_cb *fp);
27
28 static const BIO_METHOD methods_md = {
29 BIO_TYPE_MD,
30 "message digest",
31 bwrite_conv,
32 md_write,
33 bread_conv,
34 md_read,
35 NULL, /* md_puts, */
36 md_gets,
37 md_ctrl,
38 md_new,
39 md_free,
40 md_callback_ctrl,
41 };
42
BIO_f_md(void)43 const BIO_METHOD *BIO_f_md(void)
44 {
45 return &methods_md;
46 }
47
md_new(BIO * bi)48 static int md_new(BIO *bi)
49 {
50 EVP_MD_CTX *ctx;
51
52 ctx = EVP_MD_CTX_new();
53 if (ctx == NULL)
54 return 0;
55
56 BIO_set_init(bi, 1);
57 BIO_set_data(bi, ctx);
58
59 return 1;
60 }
61
md_free(BIO * a)62 static int md_free(BIO *a)
63 {
64 if (a == NULL)
65 return 0;
66 EVP_MD_CTX_free(BIO_get_data(a));
67 BIO_set_data(a, NULL);
68 BIO_set_init(a, 0);
69
70 return 1;
71 }
72
md_read(BIO * b,char * out,int outl)73 static int md_read(BIO *b, char *out, int outl)
74 {
75 int ret = 0;
76 EVP_MD_CTX *ctx;
77 BIO *next;
78
79 if (out == NULL)
80 return 0;
81
82 ctx = BIO_get_data(b);
83 next = BIO_next(b);
84
85 if ((ctx == NULL) || (next == NULL))
86 return 0;
87
88 ret = BIO_read(next, out, outl);
89 if (BIO_get_init(b)) {
90 if (ret > 0) {
91 if (EVP_DigestUpdate(ctx, (unsigned char *)out,
92 (unsigned int)ret)
93 <= 0)
94 return -1;
95 }
96 }
97 BIO_clear_retry_flags(b);
98 BIO_copy_next_retry(b);
99 return ret;
100 }
101
md_write(BIO * b,const char * in,int inl)102 static int md_write(BIO *b, const char *in, int inl)
103 {
104 int ret = 0;
105 EVP_MD_CTX *ctx;
106 BIO *next;
107
108 if ((in == NULL) || (inl <= 0))
109 return 0;
110
111 ctx = BIO_get_data(b);
112 next = BIO_next(b);
113 if ((ctx != NULL) && (next != NULL))
114 ret = BIO_write(next, in, inl);
115
116 if (BIO_get_init(b)) {
117 if (ret > 0) {
118 if (!EVP_DigestUpdate(ctx, (const unsigned char *)in,
119 (unsigned int)ret)) {
120 BIO_clear_retry_flags(b);
121 return 0;
122 }
123 }
124 }
125 if (next != NULL) {
126 BIO_clear_retry_flags(b);
127 BIO_copy_next_retry(b);
128 }
129 return ret;
130 }
131
md_ctrl(BIO * b,int cmd,long num,void * ptr)132 static long md_ctrl(BIO *b, int cmd, long num, void *ptr)
133 {
134 EVP_MD_CTX *ctx, *dctx, **pctx;
135 const EVP_MD **ppmd;
136 EVP_MD *md;
137 long ret = 1;
138 BIO *dbio, *next;
139
140 ctx = BIO_get_data(b);
141 next = BIO_next(b);
142
143 switch (cmd) {
144 case BIO_CTRL_RESET:
145 if (BIO_get_init(b))
146 ret = EVP_DigestInit_ex(ctx, EVP_MD_CTX_get0_md(ctx), NULL);
147 else
148 ret = 0;
149 if (ret > 0)
150 ret = BIO_ctrl(next, cmd, num, ptr);
151 break;
152 case BIO_C_GET_MD:
153 if (BIO_get_init(b)) {
154 ppmd = ptr;
155 *ppmd = EVP_MD_CTX_get0_md(ctx);
156 } else
157 ret = 0;
158 break;
159 case BIO_C_GET_MD_CTX:
160 pctx = ptr;
161 *pctx = ctx;
162 BIO_set_init(b, 1);
163 break;
164 case BIO_C_SET_MD_CTX:
165 if (BIO_get_init(b))
166 BIO_set_data(b, ptr);
167 else
168 ret = 0;
169 break;
170 case BIO_C_DO_STATE_MACHINE:
171 BIO_clear_retry_flags(b);
172 ret = BIO_ctrl(next, cmd, num, ptr);
173 BIO_copy_next_retry(b);
174 break;
175
176 case BIO_C_SET_MD:
177 md = ptr;
178 ret = EVP_DigestInit_ex(ctx, md, NULL);
179 if (ret > 0)
180 BIO_set_init(b, 1);
181 break;
182 case BIO_CTRL_DUP:
183 dbio = ptr;
184 dctx = BIO_get_data(dbio);
185 if (!EVP_MD_CTX_copy_ex(dctx, ctx))
186 return 0;
187 BIO_set_init(b, 1);
188 break;
189 default:
190 ret = BIO_ctrl(next, cmd, num, ptr);
191 break;
192 }
193 return ret;
194 }
195
md_callback_ctrl(BIO * b,int cmd,BIO_info_cb * fp)196 static long md_callback_ctrl(BIO *b, int cmd, BIO_info_cb *fp)
197 {
198 BIO *next;
199
200 next = BIO_next(b);
201
202 if (next == NULL)
203 return 0;
204
205 return BIO_callback_ctrl(next, cmd, fp);
206 }
207
md_gets(BIO * bp,char * buf,int size)208 static int md_gets(BIO *bp, char *buf, int size)
209 {
210 EVP_MD_CTX *ctx;
211 unsigned int ret;
212
213 ctx = BIO_get_data(bp);
214
215 if (size < EVP_MD_CTX_get_size(ctx))
216 return 0;
217
218 if (EVP_DigestFinal_ex(ctx, (unsigned char *)buf, &ret) <= 0)
219 return -1;
220
221 return (int)ret;
222 }
223