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
  
153
  
154
  
155
  
156
  
157
  
158
  
159
  
160
  
161
  
162
  
163
  
164
  
165
  
166
  
167
  
168
  
169
  
170
  
171
  
172
  
/* nettle.cmod -*- c -*- */ 
 
#include "global.h" 
RCSID("$Id: nettle.cmod,v 1.11 2003/08/06 01:13:56 nilsson Exp $"); 
#include "interpret.h" 
#include "svalue.h" 
/* For this_object() */ 
#include "object.h" 
#include "module_support.h" 
 
#include "nettle_config.h" 
 
#ifdef HAVE_LIBNETTLE 
 
#include "nettle/yarrow.h" 
#include "nettle.h" 
 
#include <assert.h> 
#include <stdio.h> 
#include <stdarg.h> 
 
DECLARATIONS 
 
/*! @module Nettle 
 *! Low level crypto functions used by the @[Crypto] module. Unless 
 *! you are doing something very special, you would want to use the 
 *! Crypto module instead. 
 */ 
 
/*! @class Yarrow 
 *! 
 *! Yarrow is a family of pseudo-randomness generators, designed for 
 *! cryptographic use, by John Kelsey, Bruce Schneier and Niels Ferguson. 
 *! Yarrow-160 is described in a paper at 
 *! @url{http://www.counterpane.com/yarrow.html@}, and it uses SHA1 and 
 *! triple-DES, and has a 160-bit internal state. Nettle implements 
 *! Yarrow-256, which is similar, but uses SHA256 and AES to get an 
 *! internal state of 256 bits. 
 */ 
PIKECLASS Yarrow 
{ 
  CVAR struct yarrow256_ctx *ctx; 
  CVAR struct yarrow_source *sources; 
 
  PIKEFUN void create(void|int arg) { 
    INT32 num = 0; 
    THIS->sources = NULL; 
 
    if(arg) { 
      if (arg->type != PIKE_T_INT) 
        Pike_error("Bad argument type.\n"); 
      num = arg->u.integer; 
      if(num < 0) 
        Pike_error("Invalid number of sources.\n"); 
      THIS->sources = xalloc(sizeof(struct yarrow_source)*num); 
    } 
 
    yarrow256_init(THIS->ctx, num, THIS->sources); 
  } 
 
  /*! @decl Yarrow seed(string data) 
   *! The random generator needs to be seeded before 
   *! it can be used. The seed must be at least 32 
   *! characters long. The seed could be stored from 
   *! a previous run by inserting the value returned 
   *! from @[get_seed]. 
   *! @returns 
   *!   Returns the called object. 
   */ 
  PIKEFUN object seed(string data) 
  { 
    if(data->len < YARROW256_SEED_FILE_SIZE) 
      Pike_error( "Seed must be at least 32 characters.\n" ); 
 
    NO_WIDE_STRING(data); 
    yarrow256_seed(THIS->ctx, data->len, data->str); 
    RETURN this_object(); 
  } 
 
  /*! @decl string get_seed() 
   *! Returns part of the internal state so that it can 
   *! be saved for later seeding. 
   */ 
  PIKEFUN string get_seed() 
  { 
    RETURN make_shared_string(THIS->ctx->seed_file); 
  } 
 
  /*! @decl int(0..1) is_seeded() 
   *! Returns 1 if the random generator is seeded and ready 
   *! to generator output. 0 otherwise. 
   */ 
  PIKEFUN int(0..1) is_seeded() 
  { 
    RETURN yarrow256_is_seeded(THIS->ctx); 
  } 
 
  PIKEFUN void force_reseed() 
  { 
    yarrow256_force_reseed(THIS->ctx); 
  } 
 
  PIKEFUN int(0..1) update(string data, int source, int entropy) 
  { 
    NO_WIDE_STRING(data); 
    if( !THIS->ctx->nsources ) 
      Pike_error("This random generator has no sources.\n"); 
    if( source<0 || source>=THIS->ctx->nsources ) 
      Pike_error("Invalid random source.\n"); 
    if( entropy<0 ) 
      Pike_error("Entropy must be positive.\n"); 
    RETURN yarrow256_update(THIS->ctx, source, entropy, data->len, data->str); 
  } 
 
  PIKEFUN int(0..) needed_sources() 
  { 
    RETURN yarrow256_needed_sources(THIS->ctx); 
  } 
 
  /*! @decl string random_string(int length) 
   *! Returns a pseudo-random string of the requested @[length]. 
   */ 
  PIKEFUN string random_string(int length) 
  { 
    struct pike_string *rnd; 
    if(length < 0) 
      Pike_error("Invalid length, must be positive.\n"); 
    if( !yarrow256_is_seeded(THIS->ctx) ) 
      Pike_error("Random generator not seeded.\n"); 
    rnd = begin_shared_string(length); 
    yarrow256_random(THIS->ctx, length, rnd->str); 
    RETURN end_shared_string(rnd); 
  } 
 
  INIT 
  { 
    THIS->ctx = xalloc(sizeof(struct yarrow256_ctx)); 
    THIS->ctx->nsources = 0; 
  } 
  EXIT 
  { 
    if(THIS->ctx->nsources) free(THIS->sources); 
    free(THIS->ctx); 
  } 
} 
 
/*! @endclass 
 */ 
 
/*! @endmodule 
 */ 
 
#endif /* HAVE_LIBNETTLE */ 
 
PIKE_MODULE_INIT 
{ 
  INIT; 
#ifdef HAVE_LIBNETTLE 
  hash_init(); 
  cipher_init(); 
#endif /* HAVE_LIBNETTLE */ 
} 
 
PIKE_MODULE_EXIT 
{ 
#ifdef HAVE_LIBNETTLE 
  cipher_exit(); 
  hash_exit(); 
#endif /* HAVE_LIBNETTLE */ 
  EXIT; 
}