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comparison random.c @ 694:c85bb68e1db6

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add loadavg and entropy_avail as sources
author Matt Johnston <matt@ucc.asn.au>
date Sat, 23 Feb 2013 10:27:49 +0800
parents c3de235d9506
children 5f2d16d3e598
comparison
equal deleted inserted replaced
692:c58a15983808 694:c85bb68e1db6
71 if (readfd < 0) { 71 if (readfd < 0) {
72 goto out; 72 goto out;
73 } 73 }
74 74
75 readcount = 0; 75 readcount = 0;
76 while (readcount < len) 76 while (len == 0 || readcount < len)
77 { 77 {
78 int readlen, wantread; 78 int readlen, wantread;
79 unsigned char readbuf[128]; 79 unsigned char readbuf[2048];
80 if (!already_blocked) 80 if (!already_blocked)
81 { 81 {
82 int ret; 82 int ret;
83 struct timeval timeout = { .tv_sec = 2, .tv_usec = 0}; 83 struct timeval timeout = { .tv_sec = 2, .tv_usec = 0};
84 fd_set read_fds; 84 fd_set read_fds;
91 dropbear_log(LOG_WARNING, "Warning: Reading the randomness source '%s' seems to have blocked.\nYou may need to find a better entropy source.", filename); 91 dropbear_log(LOG_WARNING, "Warning: Reading the randomness source '%s' seems to have blocked.\nYou may need to find a better entropy source.", filename);
92 already_blocked = 1; 92 already_blocked = 1;
93 } 93 }
94 } 94 }
95 95
96 wantread = MIN(sizeof(readbuf), len-readcount); 96 if (len == 0)
97 {
98 wantread = sizeof(readbuf);
99 }
100 else
101 {
102 wantread = MIN(sizeof(readbuf), len-readcount);
103 }
97 104
98 #ifdef DROPBEAR_PRNGD_SOCKET 105 #ifdef DROPBEAR_PRNGD_SOCKET
99 if (prngd) 106 if (prngd)
100 { 107 {
101 char egdcmd[2]; 108 char egdcmd[2];
183 dropbear_exit("Failure reading random device %s", 190 dropbear_exit("Failure reading random device %s",
184 DROPBEAR_URANDOM_DEV); 191 DROPBEAR_URANDOM_DEV);
185 } 192 }
186 #endif 193 #endif
187 194
188 /* A few other sources to fall back on. Add more here for other platforms */ 195 /* A few other sources to fall back on.
196 * Add more here for other platforms */
189 #ifdef __linux__ 197 #ifdef __linux__
190 /* Seems to be a reasonable source of entropy from timers. Possibly hard 198 /* Seems to be a reasonable source of entropy from timers. Possibly hard
191 * for even local attackers to reproduce */ 199 * for even local attackers to reproduce */
192 process_file(&hs, "/proc/timer_list", 0, 0); 200 process_file(&hs, "/proc/timer_list", 0, 0);
193 /* Might help on systems with wireless */ 201 /* Might help on systems with wireless */
194 process_file(&hs, "/proc/interrupts", 0, 0); 202 process_file(&hs, "/proc/interrupts", 0, 0);
195 203
204 process_file(&hs, "/proc/loadavg", 0, 0);
205 process_file(&hs, "/proc/sys/kernel/random/entropy_avail", 0, 0);
206
196 /* Mostly network visible but useful in some situations */ 207 /* Mostly network visible but useful in some situations */
197 process_file(&hs, "/proc/net/netstat", 0, 0); 208 process_file(&hs, "/proc/net/netstat", 0, 0);
198 process_file(&hs, "/proc/net/dev", 0, 0); 209 process_file(&hs, "/proc/net/dev", 0, 0);
199 process_file(&hs, "/proc/net/tcp", 0, 0); 210 process_file(&hs, "/proc/net/tcp", 0, 0);
200 /* Also includes interface lo */ 211 /* Also includes interface lo */