5 * Author: Tatu Ylonen <ylo@cs.hut.fi>
7 * Copyright (c) 1995 Tatu Ylonen <ylo@cs.hut.fi>, Espoo, Finland
10 * Created: Wed Mar 29 02:24:47 1995 ylo
12 * Auxiliary functions for storing and retrieving various data types to/from
23 #include <openssl/bn.h>
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.
38 buffer_put_bignum(Buffer *buffer, BIGNUM *value)
40 int bits = BN_num_bits(value);
41 int bin_size = (bits + 7) / 8;
42 char unsigned *buf = xmalloc(bin_size);
46 /* Get the value of in binary */
47 oi = BN_bn2bin(value, buf);
49 fatal("buffer_put_bignum: BN_bn2bin() failed: oi %d != bin_size %d",
52 /* Store the number of bits in the buffer in two bytes, msb first. */
54 buffer_append(buffer, msg, 2);
55 /* Store the binary data. */
56 buffer_append(buffer, (char *)buf, oi);
58 memset(buf, 0, bin_size);
63 * Retrieves an BIGNUM from the buffer.
66 buffer_get_bignum(Buffer *buffer, BIGNUM *value)
69 unsigned char buf[2], *bin;
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 = (unsigned char*) buffer_ptr(buffer);
79 BN_bin2bn(bin, bytes, value);
80 buffer_consume(buffer, bytes);
86 * Returns an integer from the buffer (4 bytes, msb first).
89 buffer_get_int(Buffer *buffer)
92 buffer_get(buffer, (char *) buf, 4);
93 return GET_32BIT(buf);
97 * Stores an integer in the buffer in 4 bytes, msb first.
100 buffer_put_int(Buffer *buffer, unsigned int value)
103 PUT_32BIT(buf, value);
104 buffer_append(buffer, buf, 4);
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.
116 buffer_get_string(Buffer *buffer, unsigned int *length_ptr)
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. */
130 /* Optionally return the length of the string. */
137 * Stores and arbitrary binary string in the buffer.
140 buffer_put_string(Buffer *buffer, const void *buf, unsigned int len)
142 buffer_put_int(buffer, len);
143 buffer_append(buffer, buf, len);
147 * Returns a character from the buffer (0 - 255).
150 buffer_get_char(Buffer *buffer)
153 buffer_get(buffer, &ch, 1);
154 return (unsigned char) ch;
158 * Stores a character in the buffer.
161 buffer_put_char(Buffer *buffer, int value)
164 buffer_append(buffer, &ch, 1);