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Diffstat (limited to 'libraries/irrlicht-1.8/source/Irrlicht/aesGladman/prng.cpp')
-rw-r--r-- | libraries/irrlicht-1.8/source/Irrlicht/aesGladman/prng.cpp | 292 |
1 files changed, 146 insertions, 146 deletions
diff --git a/libraries/irrlicht-1.8/source/Irrlicht/aesGladman/prng.cpp b/libraries/irrlicht-1.8/source/Irrlicht/aesGladman/prng.cpp index d5800b3..708cb08 100644 --- a/libraries/irrlicht-1.8/source/Irrlicht/aesGladman/prng.cpp +++ b/libraries/irrlicht-1.8/source/Irrlicht/aesGladman/prng.cpp | |||
@@ -1,146 +1,146 @@ | |||
1 | /* | 1 | /* |
2 | --------------------------------------------------------------------------- | 2 | --------------------------------------------------------------------------- |
3 | Copyright (c) 2002, Dr Brian Gladman < >, Worcester, UK. | 3 | Copyright (c) 2002, Dr Brian Gladman < >, Worcester, UK. |
4 | All rights reserved. | 4 | All rights reserved. |
5 | 5 | ||
6 | LICENSE TERMS | 6 | LICENSE TERMS |
7 | 7 | ||
8 | The free distribution and use of this software in both source and binary | 8 | The free distribution and use of this software in both source and binary |
9 | form is allowed (with or without changes) provided that: | 9 | form is allowed (with or without changes) provided that: |
10 | 10 | ||
11 | 1. distributions of this source code include the above copyright | 11 | 1. distributions of this source code include the above copyright |
12 | notice, this list of conditions and the following disclaimer; | 12 | notice, this list of conditions and the following disclaimer; |
13 | 13 | ||
14 | 2. distributions in binary form include the above copyright | 14 | 2. distributions in binary form include the above copyright |
15 | notice, this list of conditions and the following disclaimer | 15 | notice, this list of conditions and the following disclaimer |
16 | in the documentation and/or other associated materials; | 16 | in the documentation and/or other associated materials; |
17 | 17 | ||
18 | 3. the copyright holder's name is not used to endorse products | 18 | 3. the copyright holder's name is not used to endorse products |
19 | built using this software without specific written permission. | 19 | built using this software without specific written permission. |
20 | 20 | ||
21 | ALTERNATIVELY, provided that this notice is retained in full, this product | 21 | ALTERNATIVELY, provided that this notice is retained in full, this product |
22 | may be distributed under the terms of the GNU General Public License (GPL), | 22 | may be distributed under the terms of the GNU General Public License (GPL), |
23 | in which case the provisions of the GPL apply INSTEAD OF those given above. | 23 | in which case the provisions of the GPL apply INSTEAD OF those given above. |
24 | 24 | ||
25 | DISCLAIMER | 25 | DISCLAIMER |
26 | 26 | ||
27 | This software is provided 'as is' with no explicit or implied warranties | 27 | This software is provided 'as is' with no explicit or implied warranties |
28 | in respect of its properties, including, but not limited to, correctness | 28 | in respect of its properties, including, but not limited to, correctness |
29 | and/or fitness for purpose. | 29 | and/or fitness for purpose. |
30 | --------------------------------------------------------------------------- | 30 | --------------------------------------------------------------------------- |
31 | Issue Date: 24/01/2003 | 31 | Issue Date: 24/01/2003 |
32 | 32 | ||
33 | This file implements a random data pool based on the use of an external | 33 | This file implements a random data pool based on the use of an external |
34 | entropy function. It is based on the ideas advocated by Peter Gutmann in | 34 | entropy function. It is based on the ideas advocated by Peter Gutmann in |
35 | his work on pseudo random sequence generators. It is not a 'paranoid' | 35 | his work on pseudo random sequence generators. It is not a 'paranoid' |
36 | random sequence generator and no attempt is made to protect the pool | 36 | random sequence generator and no attempt is made to protect the pool |
37 | from prying eyes either by memory locking or by techniques to obscure | 37 | from prying eyes either by memory locking or by techniques to obscure |
38 | its location in memory. | 38 | its location in memory. |
39 | */ | 39 | */ |
40 | 40 | ||
41 | #include <memory.h> | 41 | #include <memory.h> |
42 | #include "prng.h" | 42 | #include "prng.h" |
43 | 43 | ||
44 | /* mix a random data pool using the SHA1 compression function (as */ | 44 | /* mix a random data pool using the SHA1 compression function (as */ |
45 | /* suggested by Peter Gutmann in his paper on random pools) */ | 45 | /* suggested by Peter Gutmann in his paper on random pools) */ |
46 | 46 | ||
47 | static void prng_mix(unsigned char buf[]) | 47 | static void prng_mix(unsigned char buf[]) |
48 | { unsigned int i, len; | 48 | { unsigned int i, len; |
49 | sha1_ctx ctx[1]; | 49 | sha1_ctx ctx[1]; |
50 | 50 | ||
51 | /*lint -e{663} unusual array to pointer conversion */ | 51 | /*lint -e{663} unusual array to pointer conversion */ |
52 | for(i = 0; i < PRNG_POOL_SIZE; i += SHA1_DIGEST_SIZE) | 52 | for(i = 0; i < PRNG_POOL_SIZE; i += SHA1_DIGEST_SIZE) |
53 | { | 53 | { |
54 | /* copy digest size pool block into SHA1 hash block */ | 54 | /* copy digest size pool block into SHA1 hash block */ |
55 | memcpy(ctx->hash, buf + (i ? i : PRNG_POOL_SIZE) | 55 | memcpy(ctx->hash, buf + (i ? i : PRNG_POOL_SIZE) |
56 | - SHA1_DIGEST_SIZE, SHA1_DIGEST_SIZE); | 56 | - SHA1_DIGEST_SIZE, SHA1_DIGEST_SIZE); |
57 | 57 | ||
58 | /* copy data from pool into the SHA1 data buffer */ | 58 | /* copy data from pool into the SHA1 data buffer */ |
59 | len = PRNG_POOL_SIZE - i; | 59 | len = PRNG_POOL_SIZE - i; |
60 | memcpy(ctx->wbuf, buf + i, (len > SHA1_BLOCK_SIZE ? SHA1_BLOCK_SIZE : len)); | 60 | memcpy(ctx->wbuf, buf + i, (len > SHA1_BLOCK_SIZE ? SHA1_BLOCK_SIZE : len)); |
61 | 61 | ||
62 | if(len < SHA1_BLOCK_SIZE) | 62 | if(len < SHA1_BLOCK_SIZE) |
63 | memcpy(((char*)ctx->wbuf) + len, buf, SHA1_BLOCK_SIZE - len); | 63 | memcpy(((char*)ctx->wbuf) + len, buf, SHA1_BLOCK_SIZE - len); |
64 | 64 | ||
65 | /* compress using the SHA1 compression function */ | 65 | /* compress using the SHA1 compression function */ |
66 | sha1_compile(ctx); | 66 | sha1_compile(ctx); |
67 | 67 | ||
68 | /* put digest size block back into the random pool */ | 68 | /* put digest size block back into the random pool */ |
69 | memcpy(buf + i, ctx->hash, SHA1_DIGEST_SIZE); | 69 | memcpy(buf + i, ctx->hash, SHA1_DIGEST_SIZE); |
70 | } | 70 | } |
71 | } | 71 | } |
72 | 72 | ||
73 | /* refresh the output buffer and update the random pool by adding */ | 73 | /* refresh the output buffer and update the random pool by adding */ |
74 | /* entropy and remixing */ | 74 | /* entropy and remixing */ |
75 | 75 | ||
76 | static void update_pool(prng_ctx ctx[1]) | 76 | static void update_pool(prng_ctx ctx[1]) |
77 | { unsigned int i = 0; | 77 | { unsigned int i = 0; |
78 | 78 | ||
79 | /* transfer random pool data to the output buffer */ | 79 | /* transfer random pool data to the output buffer */ |
80 | memcpy(ctx->obuf, ctx->rbuf, PRNG_POOL_SIZE); | 80 | memcpy(ctx->obuf, ctx->rbuf, PRNG_POOL_SIZE); |
81 | 81 | ||
82 | /* enter entropy data into the pool */ | 82 | /* enter entropy data into the pool */ |
83 | while(i < PRNG_POOL_SIZE) | 83 | while(i < PRNG_POOL_SIZE) |
84 | i += ctx->entropy(ctx->rbuf + i, PRNG_POOL_SIZE - i); | 84 | i += ctx->entropy(ctx->rbuf + i, PRNG_POOL_SIZE - i); |
85 | 85 | ||
86 | /* invert and xor the original pool data into the pool */ | 86 | /* invert and xor the original pool data into the pool */ |
87 | for(i = 0; i < PRNG_POOL_SIZE; ++i) | 87 | for(i = 0; i < PRNG_POOL_SIZE; ++i) |
88 | ctx->rbuf[i] ^= ~ctx->obuf[i]; | 88 | ctx->rbuf[i] ^= ~ctx->obuf[i]; |
89 | 89 | ||
90 | /* mix the pool and the output buffer */ | 90 | /* mix the pool and the output buffer */ |
91 | prng_mix(ctx->rbuf); | 91 | prng_mix(ctx->rbuf); |
92 | prng_mix(ctx->obuf); | 92 | prng_mix(ctx->obuf); |
93 | } | 93 | } |
94 | 94 | ||
95 | void prng_init(prng_entropy_fn fun, prng_ctx ctx[1]) | 95 | void prng_init(prng_entropy_fn fun, prng_ctx ctx[1]) |
96 | { int i; | 96 | { int i; |
97 | 97 | ||
98 | /* clear the buffers and the counter in the context */ | 98 | /* clear the buffers and the counter in the context */ |
99 | memset(ctx, 0, sizeof(prng_ctx)); | 99 | memset(ctx, 0, sizeof(prng_ctx)); |
100 | 100 | ||
101 | /* set the pointer to the entropy collection function */ | 101 | /* set the pointer to the entropy collection function */ |
102 | ctx->entropy = fun; | 102 | ctx->entropy = fun; |
103 | 103 | ||
104 | /* initialise the random data pool */ | 104 | /* initialise the random data pool */ |
105 | update_pool(ctx); | 105 | update_pool(ctx); |
106 | 106 | ||
107 | /* mix the pool a minimum number of times */ | 107 | /* mix the pool a minimum number of times */ |
108 | for(i = 0; i < PRNG_MIN_MIX; ++i) | 108 | for(i = 0; i < PRNG_MIN_MIX; ++i) |
109 | prng_mix(ctx->rbuf); | 109 | prng_mix(ctx->rbuf); |
110 | 110 | ||
111 | /* update the pool to prime the pool output buffer */ | 111 | /* update the pool to prime the pool output buffer */ |
112 | update_pool(ctx); | 112 | update_pool(ctx); |
113 | } | 113 | } |
114 | 114 | ||
115 | /* provide random bytes from the random data pool */ | 115 | /* provide random bytes from the random data pool */ |
116 | 116 | ||
117 | void prng_rand(unsigned char data[], unsigned int data_len, prng_ctx ctx[1]) | 117 | void prng_rand(unsigned char data[], unsigned int data_len, prng_ctx ctx[1]) |
118 | { unsigned char *rp = data; | 118 | { unsigned char *rp = data; |
119 | unsigned int len, pos = ctx->pos; | 119 | unsigned int len, pos = ctx->pos; |
120 | 120 | ||
121 | while(data_len) | 121 | while(data_len) |
122 | { | 122 | { |
123 | /* transfer 'data_len' bytes (or the number of bytes remaining */ | 123 | /* transfer 'data_len' bytes (or the number of bytes remaining */ |
124 | /* the pool output buffer if less) into the output */ | 124 | /* the pool output buffer if less) into the output */ |
125 | len = (data_len < PRNG_POOL_SIZE - pos ? data_len : PRNG_POOL_SIZE - pos); | 125 | len = (data_len < PRNG_POOL_SIZE - pos ? data_len : PRNG_POOL_SIZE - pos); |
126 | memcpy(rp, ctx->obuf + pos, len); | 126 | memcpy(rp, ctx->obuf + pos, len); |
127 | rp += len; /* update ouput buffer position pointer */ | 127 | rp += len; /* update ouput buffer position pointer */ |
128 | pos += len; /* update pool output buffer pointer */ | 128 | pos += len; /* update pool output buffer pointer */ |
129 | data_len -= len; /* update the remaining data count */ | 129 | data_len -= len; /* update the remaining data count */ |
130 | 130 | ||
131 | /* refresh the random pool if necessary */ | 131 | /* refresh the random pool if necessary */ |
132 | if(pos == PRNG_POOL_SIZE) | 132 | if(pos == PRNG_POOL_SIZE) |
133 | { | 133 | { |
134 | update_pool(ctx); pos = 0; | 134 | update_pool(ctx); pos = 0; |
135 | } | 135 | } |
136 | } | 136 | } |
137 | 137 | ||
138 | ctx->pos = pos; | 138 | ctx->pos = pos; |
139 | } | 139 | } |
140 | 140 | ||
141 | void prng_end(prng_ctx ctx[1]) | 141 | void prng_end(prng_ctx ctx[1]) |
142 | { | 142 | { |
143 | /* ensure the data in the context is destroyed */ | 143 | /* ensure the data in the context is destroyed */ |
144 | memset(ctx, 0, sizeof(prng_ctx)); | 144 | memset(ctx, 0, sizeof(prng_ctx)); |
145 | } | 145 | } |
146 | 146 | ||