?lang_form? ?lang_select? ?lang_submit? ?lang_endform?
{HEADER END}
{BLAME START}

library

?curdirlinks? -

Blame information for rev 32

Line No. Rev Author Line
1 32 kaklik /*********************************************************************
2 *
3 * Random Number Generator
4 * Library for Microchip TCP/IP Stack
5 * - Provides a cryptographically secure method for generating
6 * random data
7 *
8 *********************************************************************
9 * FileName: Random.c
10 * Dependencies: StackTsk.c
11 * Tick.c
12 * Processor: PIC18, PIC24F, PIC24H, dsPIC30F, dsPIC33F, PIC32
13 * Compiler: Microchip C32 v1.05 or higher
14 * Microchip C30 v3.12 or higher
15 * Microchip C18 v3.30 or higher
16 * HI-TECH PICC-18 PRO 9.63PL2 or higher
17 * Company: Microchip Technology, Inc.
18 *
19 * Software License Agreement
20 *
21 * Copyright (C) 2002-2009 Microchip Technology Inc. All rights
22 * reserved.
23 *
24 * Microchip licenses to you the right to use, modify, copy, and
25 * distribute:
26 * (i) the Software when embedded on a Microchip microcontroller or
27 * digital signal controller product ("Device") which is
28 * integrated into Licensee's product; or
29 * (ii) ONLY the Software driver source files ENC28J60.c, ENC28J60.h,
30 * ENCX24J600.c and ENCX24J600.h ported to a non-Microchip device
31 * used in conjunction with a Microchip ethernet controller for
32 * the sole purpose of interfacing with the ethernet controller.
33 *
34 * You should refer to the license agreement accompanying this
35 * Software for additional information regarding your rights and
36 * obligations.
37 *
38 * THE SOFTWARE AND DOCUMENTATION ARE PROVIDED "AS IS" WITHOUT
39 * WARRANTY OF ANY KIND, EITHER EXPRESS OR IMPLIED, INCLUDING WITHOUT
40 * LIMITATION, ANY WARRANTY OF MERCHANTABILITY, FITNESS FOR A
41 * PARTICULAR PURPOSE, TITLE AND NON-INFRINGEMENT. IN NO EVENT SHALL
42 * MICROCHIP BE LIABLE FOR ANY INCIDENTAL, SPECIAL, INDIRECT OR
43 * CONSEQUENTIAL DAMAGES, LOST PROFITS OR LOST DATA, COST OF
44 * PROCUREMENT OF SUBSTITUTE GOODS, TECHNOLOGY OR SERVICES, ANY CLAIMS
45 * BY THIRD PARTIES (INCLUDING BUT NOT LIMITED TO ANY DEFENSE
46 * THEREOF), ANY CLAIMS FOR INDEMNITY OR CONTRIBUTION, OR OTHER
47 * SIMILAR COSTS, WHETHER ASSERTED ON THE BASIS OF CONTRACT, TORT
48 * (INCLUDING NEGLIGENCE), BREACH OF WARRANTY, OR OTHERWISE.
49 *
50 *
51 * Author Date Comment
52 *~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
53 * Elliott Wood 5/09/07 Original (Rev 1.0)
54 ********************************************************************/
55  
56 #define __RANDOM_C
57  
58 #include "TCPIPConfig.h"
59  
60 #if defined(STACK_USE_SSL_SERVER) || defined(STACK_USE_SSL_CLIENT)
61  
62 #include "TCPIP Stack/TCPIP.h"
63  
64 static HASH_SUM randHash;
65 static BYTE output[20];
66 static BYTE bCount;
67  
68 /*********************************************************************
69 * Function: void RandomInit(void)
70 *
71 * PreCondition: None
72 *
73 * Input: None
74 *
75 * Output: Random number generator is initialized.
76 *
77 * Side Effects: None
78 *
79 * Overview: Sets up the random generator structure.
80 *
81 * Note: Data may not be secure until several packets have
82 * been received.
83 ********************************************************************/
84 void RandomInit(void)
85 {
86 unsigned char i;
87 unsigned long dw;
88  
89 SHA1Initialize(&randHash);
90  
91 // Add some starting entropy to the pool. This is slow.
92 for(i = 0; i < 5; i++)
93 {
94 dw = GenerateRandomDWORD();
95 RandomAdd(((BYTE*)&dw)[0]);
96 RandomAdd(((BYTE*)&dw)[1]);
97 RandomAdd(((BYTE*)&dw)[2]);
98 RandomAdd(((BYTE*)&dw)[3]);
99 }
100  
101 bCount = 20;
102 }
103  
104 /*********************************************************************
105 * Function: BYTE RandomGet(void)
106 *
107 * PreCondition: None
108 *
109 * Input: None
110 *
111 * Output: A random byte is generated
112 *
113 * Side Effects: None
114 *
115 * Overview: None
116 *
117 * Note: None
118 ********************************************************************/
119 BYTE RandomGet(void)
120 {
121 if(bCount >= 20u)
122 {//we need to get new random bytes
123 SHA1Calculate(&randHash, output);
124 RandomAdd(output[0]);
125 bCount = 0;
126 }
127  
128 //return the random byte
129 return output[bCount++];
130 }
131  
132  
133 /*********************************************************************
134 * Function: void RandomAdd(BYTE data)
135 *
136 * PreCondition: None
137 *
138 * Input: a random byte to add to the seed
139 *
140 * Output: None
141 *
142 * Side Effects: None
143 *
144 * Overview: Hashes the byte and an asynchronous timer value
145 *
146 * Note: None
147 ********************************************************************/
148 void RandomAdd(BYTE data)
149 {
150 DWORD dTemp;
151  
152 SHA1AddData(&randHash, &data, 1);
153 dTemp = TickGet();
154 SHA1AddData(&randHash, (BYTE*)&dTemp, 1);
155  
156 bCount = 20;
157 }
158  
159 #endif //#if defined(STACK_USE_SSL_SERVER) || defined(STACK_USE_SSL_CLIENT)
{BLAME END}
{FOOTER START}

Powered by WebSVN v2.8.3