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Commit | Line | Data |
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8efc0c15 | 1 | /* |
5260325f | 2 | * |
3 | * bufaux.c | |
4 | * | |
5 | * Author: Tatu Ylonen <ylo@cs.hut.fi> | |
6 | * | |
7 | * Copyright (c) 1995 Tatu Ylonen <ylo@cs.hut.fi>, Espoo, Finland | |
8 | * All rights reserved | |
9 | * | |
10 | * Created: Wed Mar 29 02:24:47 1995 ylo | |
11 | * | |
12 | * Auxiliary functions for storing and retrieving various data types to/from | |
13 | * Buffers. | |
14 | * | |
15 | */ | |
8efc0c15 | 16 | |
17 | #include "includes.h" | |
18 | RCSID("$Id$"); | |
19 | ||
20 | #include "ssh.h" | |
5881cd60 | 21 | |
22 | #ifdef HAVE_OPENSSL | |
8efc0c15 | 23 | #include <openssl/bn.h> |
5881cd60 | 24 | #endif |
25 | #ifdef HAVE_SSL | |
26 | #include <ssl/bn.h> | |
27 | #endif | |
28 | ||
8efc0c15 | 29 | #include "bufaux.h" |
30 | #include "xmalloc.h" | |
31 | #include "getput.h" | |
32 | ||
5260325f | 33 | /* |
34 | * Stores an BIGNUM in the buffer with a 2-byte msb first bit count, followed | |
35 | * by (bits+7)/8 bytes of binary data, msb first. | |
36 | */ | |
8efc0c15 | 37 | void |
38 | buffer_put_bignum(Buffer *buffer, BIGNUM *value) | |
39 | { | |
5260325f | 40 | int bits = BN_num_bits(value); |
41 | int bin_size = (bits + 7) / 8; | |
42 | char *buf = xmalloc(bin_size); | |
43 | int oi; | |
44 | char msg[2]; | |
45 | ||
46 | /* Get the value of in binary */ | |
47 | oi = BN_bn2bin(value, buf); | |
48 | if (oi != bin_size) | |
49 | fatal("buffer_put_bignum: BN_bn2bin() failed: oi %d != bin_size %d", | |
50 | oi, bin_size); | |
51 | ||
52 | /* Store the number of bits in the buffer in two bytes, msb first. */ | |
53 | PUT_16BIT(msg, bits); | |
54 | buffer_append(buffer, msg, 2); | |
55 | /* Store the binary data. */ | |
56 | buffer_append(buffer, buf, oi); | |
aa3378df | 57 | |
5260325f | 58 | memset(buf, 0, bin_size); |
59 | xfree(buf); | |
8efc0c15 | 60 | } |
61 | ||
5260325f | 62 | /* |
63 | * Retrieves an BIGNUM from the buffer. | |
64 | */ | |
8efc0c15 | 65 | int |
66 | buffer_get_bignum(Buffer *buffer, BIGNUM *value) | |
67 | { | |
5260325f | 68 | int bits, bytes; |
69 | unsigned char buf[2], *bin; | |
70 | ||
71 | /* Get the number for bits. */ | |
72 | buffer_get(buffer, (char *) buf, 2); | |
73 | bits = GET_16BIT(buf); | |
74 | /* Compute the number of binary bytes that follow. */ | |
75 | bytes = (bits + 7) / 8; | |
76 | if (buffer_len(buffer) < bytes) | |
77 | fatal("buffer_get_bignum: input buffer too small"); | |
78 | bin = buffer_ptr(buffer); | |
79 | BN_bin2bn(bin, bytes, value); | |
80 | buffer_consume(buffer, bytes); | |
81 | ||
82 | return 2 + bytes; | |
8efc0c15 | 83 | } |
84 | ||
5260325f | 85 | /* |
86 | * Returns an integer from the buffer (4 bytes, msb first). | |
87 | */ | |
88 | unsigned int | |
89 | buffer_get_int(Buffer *buffer) | |
8efc0c15 | 90 | { |
5260325f | 91 | unsigned char buf[4]; |
92 | buffer_get(buffer, (char *) buf, 4); | |
93 | return GET_32BIT(buf); | |
8efc0c15 | 94 | } |
95 | ||
5260325f | 96 | /* |
97 | * Stores an integer in the buffer in 4 bytes, msb first. | |
98 | */ | |
99 | void | |
100 | buffer_put_int(Buffer *buffer, unsigned int value) | |
8efc0c15 | 101 | { |
5260325f | 102 | char buf[4]; |
103 | PUT_32BIT(buf, value); | |
104 | buffer_append(buffer, buf, 4); | |
8efc0c15 | 105 | } |
106 | ||
5260325f | 107 | /* |
108 | * Returns an arbitrary binary string from the buffer. The string cannot | |
109 | * be longer than 256k. The returned value points to memory allocated | |
110 | * with xmalloc; it is the responsibility of the calling function to free | |
111 | * the data. If length_ptr is non-NULL, the length of the returned data | |
112 | * will be stored there. A null character will be automatically appended | |
113 | * to the returned string, and is not counted in length. | |
114 | */ | |
115 | char * | |
116 | buffer_get_string(Buffer *buffer, unsigned int *length_ptr) | |
8efc0c15 | 117 | { |
5260325f | 118 | unsigned int len; |
119 | char *value; | |
120 | /* Get the length. */ | |
121 | len = buffer_get_int(buffer); | |
122 | if (len > 256 * 1024) | |
123 | fatal("Received packet with bad string length %d", len); | |
124 | /* Allocate space for the string. Add one byte for a null character. */ | |
125 | value = xmalloc(len + 1); | |
126 | /* Get the string. */ | |
127 | buffer_get(buffer, value, len); | |
128 | /* Append a null character to make processing easier. */ | |
129 | value[len] = 0; | |
130 | /* Optionally return the length of the string. */ | |
131 | if (length_ptr) | |
132 | *length_ptr = len; | |
133 | return value; | |
8efc0c15 | 134 | } |
135 | ||
5260325f | 136 | /* |
137 | * Stores and arbitrary binary string in the buffer. | |
138 | */ | |
139 | void | |
140 | buffer_put_string(Buffer *buffer, const void *buf, unsigned int len) | |
8efc0c15 | 141 | { |
5260325f | 142 | buffer_put_int(buffer, len); |
143 | buffer_append(buffer, buf, len); | |
8efc0c15 | 144 | } |
145 | ||
5260325f | 146 | /* |
147 | * Returns a character from the buffer (0 - 255). | |
148 | */ | |
149 | int | |
150 | buffer_get_char(Buffer *buffer) | |
8efc0c15 | 151 | { |
5260325f | 152 | char ch; |
153 | buffer_get(buffer, &ch, 1); | |
154 | return (unsigned char) ch; | |
8efc0c15 | 155 | } |
156 | ||
5260325f | 157 | /* |
158 | * Stores a character in the buffer. | |
159 | */ | |
160 | void | |
161 | buffer_put_char(Buffer *buffer, int value) | |
8efc0c15 | 162 | { |
5260325f | 163 | char ch = value; |
164 | buffer_append(buffer, &ch, 1); | |
8efc0c15 | 165 | } |