From 6e5714eaf77d79ae1c8b47e3e040ff5411b717ec Mon Sep 17 00:00:00 2001 From: "David S. Miller" Date: Wed, 3 Aug 2011 20:50:44 -0700 Subject: net: Compute protocol sequence numbers and fragment IDs using MD5. Computers have become a lot faster since we compromised on the partial MD4 hash which we use currently for performance reasons. MD5 is a much safer choice, and is inline with both RFC1948 and other ISS generators (OpenBSD, Solaris, etc.) Furthermore, only having 24-bits of the sequence number be truly unpredictable is a very serious limitation. So the periodic regeneration and 8-bit counter have been removed. We compute and use a full 32-bit sequence number. For ipv6, DCCP was found to use a 32-bit truncated initial sequence number (it needs 43-bits) and that is fixed here as well. Reported-by: Dan Kaminsky Tested-by: Willy Tarreau Signed-off-by: David S. Miller --- include/linux/random.h | 12 ------------ include/net/secure_seq.h | 20 ++++++++++++++++++++ 2 files changed, 20 insertions(+), 12 deletions(-) create mode 100644 include/net/secure_seq.h (limited to 'include') diff --git a/include/linux/random.h b/include/linux/random.h index ce29a040c8d..d13059f3ea3 100644 --- a/include/linux/random.h +++ b/include/linux/random.h @@ -57,18 +57,6 @@ extern void add_interrupt_randomness(int irq); extern void get_random_bytes(void *buf, int nbytes); void generate_random_uuid(unsigned char uuid_out[16]); -extern __u32 secure_ip_id(__be32 daddr); -extern __u32 secure_ipv6_id(const __be32 daddr[4]); -extern u32 secure_ipv4_port_ephemeral(__be32 saddr, __be32 daddr, __be16 dport); -extern u32 secure_ipv6_port_ephemeral(const __be32 *saddr, const __be32 *daddr, - __be16 dport); -extern __u32 secure_tcp_sequence_number(__be32 saddr, __be32 daddr, - __be16 sport, __be16 dport); -extern __u32 secure_tcpv6_sequence_number(__be32 *saddr, __be32 *daddr, - __be16 sport, __be16 dport); -extern u64 secure_dccp_sequence_number(__be32 saddr, __be32 daddr, - __be16 sport, __be16 dport); - #ifndef MODULE extern const struct file_operations random_fops, urandom_fops; #endif diff --git a/include/net/secure_seq.h b/include/net/secure_seq.h new file mode 100644 index 00000000000..d97f6892c01 --- /dev/null +++ b/include/net/secure_seq.h @@ -0,0 +1,20 @@ +#ifndef _NET_SECURE_SEQ +#define _NET_SECURE_SEQ + +#include + +extern __u32 secure_ip_id(__be32 daddr); +extern __u32 secure_ipv6_id(const __be32 daddr[4]); +extern u32 secure_ipv4_port_ephemeral(__be32 saddr, __be32 daddr, __be16 dport); +extern u32 secure_ipv6_port_ephemeral(const __be32 *saddr, const __be32 *daddr, + __be16 dport); +extern __u32 secure_tcp_sequence_number(__be32 saddr, __be32 daddr, + __be16 sport, __be16 dport); +extern __u32 secure_tcpv6_sequence_number(__be32 *saddr, __be32 *daddr, + __be16 sport, __be16 dport); +extern u64 secure_dccp_sequence_number(__be32 saddr, __be32 daddr, + __be16 sport, __be16 dport); +extern u64 secure_dccpv6_sequence_number(__be32 *saddr, __be32 *daddr, + __be16 sport, __be16 dport); + +#endif /* _NET_SECURE_SEQ */ -- cgit v1.2.3