2 * Noise generation for PuTTY's cryptographic random number
13 #include <sys/resource.h>
19 static int read_dev_urandom(char *buf
, int len
)
24 fd
= open("/dev/urandom", O_RDONLY
);
30 ret
= read(fd
, buf
+ngot
, len
-ngot
);
42 * This function is called once, at PuTTY startup. It will do some
43 * slightly silly things such as fetching an entire process listing
44 * and scanning /tmp, load the saved random seed from disk, and
45 * also read 32 bytes out of /dev/urandom.
48 void noise_get_heavy(void (*func
) (void *, int))
53 int got_dev_urandom
= 0;
55 if (read_dev_urandom(buf
, 32)) {
60 fp
= popen("ps -axu 2>/dev/null", "r");
62 while ( (ret
= fread(buf
, 1, sizeof(buf
), fp
)) > 0)
65 } else if (!got_dev_urandom
) {
66 fprintf(stderr
, "popen: %s\n"
67 "Unable to access fallback entropy source\n", strerror(errno
));
71 fp
= popen("ls -al /tmp 2>/dev/null", "r");
73 while ( (ret
= fread(buf
, 1, sizeof(buf
), fp
)) > 0)
76 } else if (!got_dev_urandom
) {
77 fprintf(stderr
, "popen: %s\n"
78 "Unable to access fallback entropy source\n", strerror(errno
));
82 read_random_seed(func
);
86 void random_save_seed(void)
92 random_get_savedata(&data
, &len
);
93 write_random_seed(data
, len
);
99 * This function is called every time the random pool needs
100 * stirring, and will acquire the system time.
102 void noise_get_light(void (*func
) (void *, int))
105 gettimeofday(&tv
, NULL
);
106 func(&tv
, sizeof(tv
));
110 * This function is called on a timer, and grabs as much changeable
111 * system data as it can quickly get its hands on.
113 void noise_regular(void)
118 struct rusage rusage
;
120 if ((fd
= open("/proc/meminfo", O_RDONLY
)) >= 0) {
121 while ( (ret
= read(fd
, buf
, sizeof(buf
))) > 0)
122 random_add_noise(buf
, ret
);
125 if ((fd
= open("/proc/stat", O_RDONLY
)) >= 0) {
126 while ( (ret
= read(fd
, buf
, sizeof(buf
))) > 0)
127 random_add_noise(buf
, ret
);
130 getrusage(RUSAGE_SELF
, &rusage
);
131 random_add_noise(&rusage
, sizeof(rusage
));
135 * This function is called on every keypress or mouse move, and
136 * will add the current time to the noise pool. It gets the scan
137 * code or mouse position passed in, and adds that too.
139 void noise_ultralight(unsigned long data
)
142 gettimeofday(&tv
, NULL
);
143 random_add_noise(&tv
, sizeof(tv
));
144 random_add_noise(&data
, sizeof(data
));