DeforaNetworks/fwknop
DeforaNetworks/fwknop
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Seed random() at least a bit before using random()

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In fwknop, the values generated using random() are only used for the ID
field of raw IP packets. As indicated in the corresponding comments,
this value does not really matter, and it does not really have to be
random at all.

However, it should not hurt to initialize the entropy pool before
generating random values. arc4random() would be a better choice, but it
is not portable across the range of systems currently supported by
fwknop.
This commit is contained in:
Pierre Pronchery 2018-08-06 19:20:35 +02:00
parent ae089b1bad
commit f00d44deac
1 changed files with 3 additions and 0 deletions
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3
client/spa_comm.c
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@ -250,6 +250,7 @@ send_spa_packet_tcp_raw(const char *spa_data, const int sd_len,
/* Total size is header plus payload */
iph->tot_len = hdrlen + sd_len;
/* The value here does not matter */
srandom(time(NULL) ^ getuid() ^ (getgid() << 16) ^ getpid());
iph->id = random() & 0xffff;
iph->frag_off = 0;
iph->ttl = RAW_SPA_TTL;
@ -363,6 +364,7 @@ send_spa_packet_udp_raw(const char *spa_data, const int sd_len,
/* Total size is header plus payload */
iph->tot_len = hdrlen + sd_len;
/* The value here does not matter */
srandom(time(NULL) ^ getuid() ^ (getgid() << 16) ^ getpid());
iph->id = random() & 0xffff;
iph->frag_off = 0;
iph->ttl = RAW_SPA_TTL;
@ -462,6 +464,7 @@ send_spa_packet_icmp(const char *spa_data, const int sd_len,
/* Total size is header plus payload */
iph->tot_len = hdrlen + sd_len;
/* The value here does not matter */
srandom(time(NULL) ^ getuid() ^ (getgid() << 16) ^ getpid());
iph->id = random() & 0xffff;
iph->frag_off = 0;
iph->ttl = RAW_SPA_TTL;