summaryrefslogtreecommitdiff
path: root/lib/ext_max_record.c
blob: 1ffef22004b8e04fa80f2fcabeb2d0a2415c7575 (plain)
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81
82
83
84
85
86
87
88
89
90
91
92
93
94
95
96
97
98
99
100
101
102
103
104
105
106
107
108
109
110
111
112
113
114
115
116
117
118
119
120
121
122
123
124
125
126
127
128
129
130
131
132
133
134
135
136
137
138
139
140
141
142
143
144
145
146
147
148
149
150
151
152
/*
 *      Copyright (C) 2001 Nikos Mavroyanopoulos
 *
 * This file is part of GNUTLS.
 *
 * GNUTLS is free software; you can redistribute it and/or modify
 * it under the terms of the GNU General Public License as published by
 * the Free Software Foundation; either version 2 of the License, or
 * (at your option) any later version.
 *
 * GNUTLS is distributed in the hope that it will be useful,
 * but WITHOUT ANY WARRANTY; without even the implied warranty of
 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
 * GNU General Public License for more details.
 *
 * You should have received a copy of the GNU General Public License
 * along with this program; if not, write to the Free Software
 * Foundation, Inc., 59 Temple Place - Suite 330, Boston, MA 02111-1307, USA
 */

#include "gnutls_int.h"
#include "gnutls_errors.h"
#include "gnutls_num.h"
#include "ext_max_record.h"

/* 
 * In case of a server: if a MAX_RECORD_SIZE extension type is received then it stores
 * into the state the new value. The server may use gnutls_get_max_record_size(),
 * in order to access it.
 *
 * In case of a client: If a different max record size (than the default) has
 * been specified then it sends the extension.
 *
 */

int _gnutls_max_record_recv_params( GNUTLS_STATE state, const opaque* data, int data_size) {
	size_t new_size;
	
	if (state->security_parameters.entity == GNUTLS_SERVER) {
		if (data_size > 0) {
			if ( data_size != 1) {
				gnutls_assert();
				return GNUTLS_E_UNEXPECTED_PACKET_LENGTH;
			}
			
			new_size = _gnutls_mre_num2record(data[0]);

			if (new_size < 0) {
				gnutls_assert();
				return new_size;
			}

			state->security_parameters.max_record_size = new_size;
		}
	} else { /* CLIENT SIDE - we must check if the sent record size is the right one 
	          */
		if (data_size > 0) {

			if ( data_size != 1) {
				gnutls_assert();
				return GNUTLS_E_UNEXPECTED_PACKET_LENGTH;
			}

			new_size = _gnutls_mre_num2record(data[0]);

			if (new_size < 0 || new_size != state->gnutls_internals.proposed_record_size) {
				gnutls_assert();
				return GNUTLS_E_ILLEGAL_PARAMETER;
			} else 
				state->security_parameters.max_record_size = state->gnutls_internals.proposed_record_size;

		}
	
	
	}
	
	return 0;
}

/* returns data_size or a negative number on failure
 * data is allocated localy
 */
int _gnutls_max_record_send_params( GNUTLS_STATE state, opaque** data) {
	uint16 len;
	/* this function sends the client extension data (dnsname) */
	if (state->security_parameters.entity == GNUTLS_CLIENT) {

		if (state->gnutls_internals.proposed_record_size != DEFAULT_MAX_RECORD_SIZE) {
			gnutls_assert();
			
			len = 1;
			(*data) = gnutls_malloc(len); /* hold the size and the type also */
			if (*data==NULL) return GNUTLS_E_MEMORY_ERROR;
			
			(*data)[0] = _gnutls_mre_record2num( state->gnutls_internals.proposed_record_size);
			return len;
		}

	} else { /* server side */

		if (state->security_parameters.max_record_size != DEFAULT_MAX_RECORD_SIZE) {
			len = 1;
			(*data) = gnutls_malloc(len); 
			if (*data==NULL) return GNUTLS_E_MEMORY_ERROR;
			
			(*data)[0] = _gnutls_mre_record2num( state->security_parameters.max_record_size);
			return len;
		}	
	
	
	}

	*data = NULL;
	return 0;
}

/* Maps numbers to record sizes according to the
 * extensions draft.
 */
int _gnutls_mre_num2record( int num) {
	switch( num) {
	case 1:
		return 512;
	case 2:
		return 1024;
	case 3:
		return 2048;
	case 4:
		return 4096;
	default:
		return GNUTLS_E_ILLEGAL_PARAMETER;
	}
}

/* Maps record size to numbers according to the
 * extensions draft.
 */
int _gnutls_mre_record2num( int record_size) {
	switch(record_size) {
	case 512:
		return 1;
	case 1024:
		return 2;
	case 2048:
		return 3;
	case 4096:
		return 4;
	default:
		return GNUTLS_E_ILLEGAL_PARAMETER;
	}

}