Tests: Client is at 88.198.53.113.
Test were performed with patch patch-asterisk-trunk-contactdeny.txt
===================================================================

[test]
host=dynamic
type=friend
nat=no
contactdeny=1.2.3.4
secret=test
context=sdaf3r98fh9sdhf9a3

sipsak -U -s sip:test@83.136.32.165 -a test -C "sip:test@88.198.53.113" -vvv
--> 200 OK
--> contact URI is allowed
--> OK
[May 17 19:44:13] DEBUG[3918] chan_sip.c: Store REGISTER's Contact header for call routing.
[May 17 19:44:13] VERBOSE[3918] chan_sip.c:     -- Registered SIP 'test' at 88.198.53.113 port 5060

sipsak -U -s sip:test@83.136.32.165 -a test -C "sip:test@1.2.3.4" -vvv
--> 603
--> contact URI is denied 
--> OK
[May 17 19:45:35] DEBUG[3918] chan_sip.c: Store REGISTER's Contact header for call routing.
[May 17 19:45:35] WARNING[3918] chan_sip.c: Host '1.2.3.4' disallowed by contact ACL (violating IP 1.2.3.4)



[test]
host=dynamic
type=friend
nat=no
contactdeny=88.198.53.113
secret=test
context=sdaf3r98fh9sdhf9a3

sipsak -U -s sip:test@83.136.32.165 -a test -C "sip:test@88.198.53.113" -vvv
--> 603
--> contact URI is denied 
--> OK
[May 17 19:41:31] DEBUG[3843] chan_sip.c: Store REGISTER's Contact header for call routing.
[May 17 19:41:31] WARNING[3843] chan_sip.c: Host '88.198.53.113' disallowed by contact ACL (violating IP 88.198.53.113)

sipsak -U -s sip:test@83.136.32.165 -a test -C "sip:test@1.2.3.4" -vvv
--> 200 OK
--> contact URI is allowed
--> OK
[May 17 19:42:36] DEBUG[3843] chan_sip.c: Store REGISTER's Contact header for call routing.
[May 17 19:42:36] VERBOSE[3843] chan_sip.c:     -- Registered SIP 'test' at 1.2.3.4 port 5060



[test]
host=dynamic
type=friend
nat=yes
contactdeny=1.2.3.4
secret=test
context=sdaf3r98fh9sdhf9a3

sipsak -U -s sip:test@83.136.32.165 -a test -C "sip:test@88.198.53.113" -vvv
--> 200 OK
--> src-IP is allowed to be used as contact address
--> OK
[May 17 19:47:20] DEBUG[4162] chan_sip.c: Store REGISTER's src-IP:port for call routing.
[May 17 19:47:20] VERBOSE[4162] chan_sip.c:     -- Registered SIP 'test' at 88.198.53.113 port 48998

sipsak -U -s sip:test@83.136.32.165 -a test -C "sip:test@1.2.3.4" -vvv
--> 200 OK
--> src-IP is allowed to be used as contact address
--> OK
[May 17 19:48:25] DEBUG[4162] chan_sip.c: Store REGISTER's src-IP:port for call routing.
[May 17 19:48:25] VERBOSE[4162] chan_sip.c:     -- Registered SIP 'test' at 88.198.53.113 port 33216



[test]
host=dynamic
type=friend
nat=yes
contactdeny=88.198.53.113
secret=test
context=sdaf3r98fh9sdhf9a3

sipsak -U -s sip:test@83.136.32.165 -a test -C "sip:test@88.198.53.113" -vvv
--> 603
--> src-IP is denied 
--> OK
[May 17 19:50:38] DEBUG[4419] chan_sip.c: Store REGISTER's src-IP:port for call routing.
[May 17 19:50:38] WARNING[4419] chan_sip.c: Host '88.198.53.113' disallowed by contact ACL (violating IP 88.198.53.113)


sipsak -U -s sip:test@83.136.32.165 -a test -C "sip:test@1.2.3.4" -vvv
--> 603
--> src-IP is denied 
--> OK
[May 17 19:51:51] DEBUG[4419] chan_sip.c: Store REGISTER's src-IP:port for call routing.
[May 17 19:51:51] WARNING[4419] chan_sip.c: Host '1.2.3.4' disallowed by contact ACL (violating IP 88.198.53.113)