This is a SIP call, not HTTP, I am assuming this is the same in either or.
I will look at the RFC. Pasting or placing items here is tough as I get warned I cant
the SIP RFC 3261 states pretty much the same thing. Anyway to point below is the sequence from Phone | Asterisk | ISP
As a clarification to the calculation of the A2 value for message integrity assurance in the Digest authentication scheme, implementers should assume, when the entity-body is empty (that is, when SIP messages have no body) that the hash of the entity-body resolves to the MD5 hash of an empty
string, or: H(entity-body) = MD5(“”) = “d41d8cd98f00b204e9800998ecf8427e”
#############
From Phone
#############
Via: SIP/2.0/UDP 10.10.50.11;rport=5060;received=172.16.1.3;branch=z9hG4bK507c1b92A8BFFDBC
Call-ID: 149ff4c418630b6798f71b476e4452ac
From: "Motoman 393" <sip:[email protected]>;tag=AC30F192-1085320B
To: <sip:[email protected];user=phone>;tag=z9hG4bK507c1b92A8BFFDBC
CSeq: 1 INVITE
WWW-Authenticate: Digest realm="asterisk",nonce="1682939633/f329881416f76f219da24fc8464a3dfb",opaque="34073f3f708403ed",algorithm=MD5,qop="auth"
Server: FPBX-16.0.40(18.16.0)
Content-Length: 0
Via: SIP/2.0/UDP 10.10.50.11;branch=z9hG4bKaa23741a3746D421
From: "Motoman 393" <sip:[email protected]>;tag=AC30F192-1085320B
To: <sip:[email protected];user=phone>
CSeq: 2 INVITE
Call-ID: 149ff4c418630b6798f71b476e4452ac
Contact: <sip:[email protected]>
Allow: INVITE,ACK,BYE,CANCEL,OPTIONS,INFO,MESSAGE,SUBSCRIBE,NOTIFY,PRACK,UPDATE,REFER
User-Agent: PolycomVVX-VVX_411-UA/6.4.3.5156
Accept-Language: en
Supported: replaces,100rel
Allow-Events: conference,talk,hold
Authorization: Digest username="393", realm="asterisk", nonce="1682939633/f329881416f76f219da24fc8464a3dfb", qop=auth, cnonce="HPkJM3OgTieFFzA", nc=00000001, opaque="34073f3f708403ed", uri="sip:[email protected];user=phone", response="145d2ea3d11ec0272b92e2ff17b49e47", algorithm=MD5
Max-Forwards: 70
Content-Type: application/sdp
Content-Length: 348
################
From Asterisk
################
<--- Received SIP request (956 bytes) from UDP:172.16.1.3:5060 --->
INVITE sip:[email protected];user=phone SIP/2.0
Via: SIP/2.0/UDP 10.10.50.11;branch=z9hG4bK507c1b92A8BFFDBC
From: "Motoman 393" <sip:[email protected]>;tag=AC30F192-1085320B
To: <sip:[email protected];user=phone>
CSeq: 1 INVITE
Call-ID: 149ff4c418630b6798f71b476e4452ac
Contact: <sip:[email protected]>
Allow: INVITE,ACK,BYE,CANCEL,OPTIONS,INFO,MESSAGE,SUBSCRIBE,NOTIFY,PRACK,UPDATE,REFER
User-Agent: PolycomVVX-VVX_411-UA/6.4.3.5156
Accept-Language: en
Supported: replaces,100rel
Allow-Events: conference,talk,hold
Max-Forwards: 70
Content-Type: application/sdp
Content-Length: 348
<--- Transmitting SIP response (515 bytes) to UDP:172.16.1.3:5060 --->
SIP/2.0 401 Unauthorized
Via: SIP/2.0/UDP 10.10.50.11;rport=5060;received=172.16.1.3;branch=z9hG4bK507c1b92A8BFFDBC
Call-ID: 149ff4c418630b6798f71b476e4452ac
From: "Motoman 393" <sip:[email protected]>;tag=AC30F192-1085320B
To: <sip:[email protected];user=phone>;tag=z9hG4bK507c1b92A8BFFDBC
CSeq: 1 INVITE
WWW-Authenticate: Digest realm="asterisk",nonce="1682939633/f329881416f76f219da24fc8464a3dfb",opaque="34073f3f708403ed",algorithm=MD5,qop="auth"
Server: FPBX-16.0.40(18.16.0)
Content-Length: 0
<--- Received SIP request (1247 bytes) from UDP:172.16.1.3:5060 --->
INVITE sip:[email protected];user=phone SIP/2.0
Via: SIP/2.0/UDP 10.10.50.11;branch=z9hG4bKaa23741a3746D421
From: "Motoman 393" <sip:[email protected]>;tag=AC30F192-1085320B
To: <sip:[email protected];user=phone>
CSeq: 2 INVITE
Call-ID: 149ff4c418630b6798f71b476e4452ac
Contact: <sip:[email protected]>
Allow: INVITE,ACK,BYE,CANCEL,OPTIONS,INFO,MESSAGE,SUBSCRIBE,NOTIFY,PRACK,UPDATE,REFER
User-Agent: PolycomVVX-VVX_411-UA/6.4.3.5156
Accept-Language: en
Supported: replaces,100rel
Allow-Events: conference,talk,hold
Authorization: Digest username="393", realm="asterisk", nonce="1682939633/f329881416f76f219da24fc8464a3dfb", qop=auth, cnonce="HPkJM3OgTieFFzA", nc=00000001, opaque="34073f3f708403ed", uri="sip:[email protected];user=phone", response="145d2ea3d11ec0272b92e2ff17b49e47", algorithm=MD5
Max-Forwards: 70
Content-Type: application/sdp
Content-Length: 348
#############
Sent to ISP
#############
2023/05/01 11:13:53.597 FINE com._FQDNISP.sip.transport.udp [[send: /192.xxx.xxx.18:5060-->/162.xxx.xxx.119:6466
|INVITE sip:[email protected] SIP/2.0
v: SIP/2.0/UDP 192.xxx.xxx.18:5060;branch=z9hG4bKatofTSKthQZ52680fc5f53f53fb85610ac12b692b596, SIP/2.0/UDP 47.xxx.xxx.225:5060;rport=5060;branch=z9hG4bKPj17f88b25-7349-4a2e-884e-c63172fab94c;received=47.xxx.xxx.225
f: <sip:166xxxxxx40@FQDNISP>;tag=b0367d57-5bef-4b0b-bcec-0f90206186d3
t: <sip:166xxxxx56@FQDNISP>
m: <sip:[email protected]:5060>
i: ab3612d6-c0ce-48ee-8a42-c2e2c2f4689a
CSeq: 16330 INVITE
Allow: OPTIONS, INVITE, ACK, BYE, CANCEL, UPDATE, PRACK, REGISTER, SUBSCRIBE, NOTIFY, PUBLISH, MESSAGE, REFER
k: 100rel, timer, replaces, norefersub, histinfo
x: 1800
Min-SE: 90
Max-Forwards: 69
User-Agent: FPBX-16.0.40(18.16.0)
Proxy-Authorization: Digest username="24xxxxxxxxxxx39", realm="FQDNISP.net", nonce="ZE+e8YkcgK89aVdC6Y7tA6DbDEQA", uri="sip:166xxxxxx56@FQDNISP:5060", response="45ab7d80e5295625c3871e872c01c8c7"
Remote-Party-ID: <sip:[email protected]>;party=calling;privacy=off;screen=no
c: application/sdp
l: 239
Record-Route: <sip:[email protected]:5060;lr;id=7193577892bc1ab7daa356a932d9a378>
History-Info: <sip:[email protected]>;index=1