NethVoice CTI: WebRTC registration fails when the user display name starts with *

[edospadoni]

The NethVoice CTI phone (phone-island) registers its WebRTC extension through Janus. The user's display name, taken from /user/me, is sent as display_name in the Janus SIP register request. Janus hands it to sofia-sip, which puts it in the Contact header unquoted when it only contains SIP token characters. If the name starts with *, Asterisk (PJSIP) parses the header as the wildcard contact (Contact: *), drops the whole message and never answers: the REGISTER times out after 32 seconds (408), phone-island raises the webrtc_down alert ("Connection error"), reloads and loops every 30-40 seconds. The CTI is unusable for that user. Names containing " make sofia-sip fail immediately with error 900.

Some customers name their users *<extension> - Name to show the extension in the CTI, so every user of the tenant is affected.

Steps to reproduce:

1. In the user domain, set a user's display name to *140 - John Doe.
2. Apply the configuration in the NethVoice admin, so that FreePBX regenerates users.json for nethcti-server (the new name reaches the CTI only after this step).
3. Log in to NethVoice CTI with that user.

Expected behavior:
The WebRTC extension registers regardless of the characters in the display name. The display name is cosmetic: Asterisk uses the caller id configured on the endpoint, so it has no functional value.

Actual behavior:
"Connection error" is shown every ~30 seconds and the phone-island reloads in a loop. Browser console:

[REGISTER] Sending registration request {sipExten: '92140', ...}
[JANUS-GUARD] Initialization timeout (30s) - resetting isInitializing flag
Alert detected (webrtc_down or socket_down), triggering automatic reload

Janus log:

Registering user sip:92140@127.0.0.1 (auth=..., secret 127.0.0.1) @ sip:92140@127.0.0.1 through sip:127.0.0.1:20221
[92140][nua_r_register]: 408 Request Timeout

Asterisk full log (11 lines per attempt, one per retransmission):

WARNING[144] pjproject: sip_transport.c Dropping 538 bytes packet from UDP 172.16.10.70:42308 : PJSIP syntax error exception when parsing 'Contact' header on line 8 col 1

REGISTER captured on the loopback interface:

Contact: *140 - John Doe <sip:92140@172.16.10.70:54993;transport=udp>

The same happens with the Janus HTTP API alone: a register request with display_name: "*140 - John Doe" ends with registration_failed 408, the same request with display_name: "John Doe" ends with registered in less than a second. Quoting the name on the client side does not work: sofia-sip does not escape double quotes and fails with registration_failed 900.

Only the web CTI and NethLink are affected, since both embed phone-island. The mobile app registers directly through the SIP proxy and never goes through Janus.

Suggested fix:
Sanitize the display name in phone-island before sending it to Janus: strip ", \, control characters and any leading *. Workaround for affected tenants: remove the leading * from the users' display names and apply the configuration in the NethVoice admin.

Components:

• nethesis/phone-island 1.0.14, src/lib/webrtc/messages.ts (register() sends display_name: name || '')
• NethVoice 1.7.8 (nethvoice-cti 0.15.28), Janus 1.4.2, Asterisk 18.26.3