Percent characters (%) in Via parameters are unescaped

[seanbright]

Describe the bug

The branch parameter (and others) in the Via header are tokens according to RFC 3261 but we unescape them anyway. Percent encoded hex pairs are decoded into their binary representations and subsequently printed incorrectly. For example, the log below is a request/response from Asterisk 16 (bundled with pjproject 2.10).

Steps to reproduce

Parse a request that contains the % character followed by 2 hex digits which should be stored literally and see that they are decoded instead.

PJSIP version

2.10 (Asterisk bundled)

Context

Asterisk 16 from Git on Linux.

Log, call stack, etc

Request:

INVITE sip:8675309@192.168.26.150 SIP/2.0
Via: SIP/2.0/UDP 192.168.26.1:62128;branch=z9hG4bKa524287%00%01%02%03%04%05%06%07%08%09%0A%0B%0C%0D%0E%0F%10%11%12%13%14%15%16%17%18%19%1A%1B%1C%1D%1E%1F%20%21%22%23%24%25%26%27%28%29%2A%2B%2C%2D%2E%2F%30%31%32%33%34%35%36%37%38%39%3A%3B%3C%3D%3E%3F%40%41%42%43%44%45%46%47%48%49%4A%4B%4C%4D%4E%4F%50%51%52%53%54%55%56%57%58%59%5A%5B%5C%5D%5E%5F%60%61%62%63%64%65%66%67%68%69%6A%6B%6C%6D%6E%6F%70%71%72%73%74%75%76%77%78%79%7A%7B%7C%7D%7E%7F%80%81%82%83%84%85%86%87%88%89%8A%8B%8C%8D%8E%8F%90%91%92%93%94%95%96%97%98%99%9A%9B%9C%9D%9E%9F%A0%A1%A2%A3%A4%A5%A6%A7%A8%A9%AA%AB%AC%AD%AE%AF%B0%B1%B2%B3%B4%B5%B6%B7%B8%B9%BA%BB%BC%BD%BE%BF%C0%C1%C2%C3%C4%C5%C6%C7%C8%C9%CA%CB%CC%CD%CE%CF%D0%D1%D2%D3%D4%D5%D6%D7%D8%D9%DA%DB%DC%DD%DE%DF%E0%E1%E2%E3%E4%E5%E6%E7%E8%E9%EA%EB%EC%ED%EE%EF%F0%F1%F2%F3%F4%F5%F6%F7%F8%F9%FA%FB%FC%FD%FE%FF;rport
Max-Forwards: 70
Contact: <sip:acct-206@192.168.26.1:62128;rinstance=7c73d8637ff8be32>
To: <sip:8675309@192.168.26.150>
From: "Gerrit"<sip:acct-206@192.168.26.150>;tag=d8edbb40
Call-ID: 84929ZGJkMjBiYTIwMWYzZGFiMDg0ZThiYmU4NWI2Zjg1NmQ
CSeq: 1 INVITE
Allow: SUBSCRIBE, NOTIFY, INVITE, ACK, CANCEL, BYE, REFER, INFO, OPTIONS, MESSAGE
Content-Type: application/sdp
Supported: replaces
User-Agent: Bria 4 release 4.8.1 stamp 84929
Content-Length: 211

v=0
o=- 13276799035054824 1 IN IP4 192.168.26.1
s=Bria 4 release 4.8.1 stamp 84929
c=IN IP4 192.168.26.1
t=0 0
m=audio 64192 RTP/AVP 9 0 101
a=rtpmap:101 telephone-event/8000
a=fmtp:101 0-15
a=sendrecv

Response:

SIP/2.0 401 Unauthorized
Via: SIP/2.0/UDP 192.168.26.1:62128;rport=40850;received=127.0.0.1;branch=z9hG4bKa524287%00%01%02%03%04%05%06%07%08%09%0a%0b%0c%0d%0e%0f%10%11%12%13%14%15%16%17%18%19%1a%1b%1c%1d%1e%1f%20!%22%23%24%%26'%28%29*+%2c-.%2f0123456789%3a%3b%3c%3d%3e%3f%40ABCDEFGHIJKLMNOPQRSTUVWXYZ%5b%5c%5d%5e_`abcdefghijklmnopqrstuvwxyz%7b%7c%7d~%7f%80%81%82%83%84%85%86%87%88%89%8a%8b%8c%8d%8e%8f%90%91%92%93%94%95%96%97%98%99%9a%9b%9c%9d%9e%9f%a0%a1%a2%a3%a4%a5%a6%a7%a8%a9%aa%ab%ac%ad%ae%af%b0%b1%b2%b3%b4%b5%b6%b7%b8%b9%ba%bb%bc%bd%be%bf%c0%c1%c2%c3%c4%c5%c6%c7%c8%c9%ca%cb%cc%cd%ce%cf%d0%d1%d2%d3%d4%d5%d6%d7%d8%d9%da%db%dc%dd%de%df%e0%e1%e2%e3%e4%e5%e6%e7%e8%e9%ea%eb%ec%ed%ee%ef%f0%f1%f2%f3%f4%f5%f6%f7%f8%f9%fa%fb%fc%fd%fe%ff
Call-ID: 84929ZGJkMjBiYTIwMWYzZGFiMDg0ZThiYmU4NWI2Zjg1NmQ
From: "Gerrit" <sip:acct-206@192.168.26.150>;tag=d8edbb40
To: <sip:8675309@192.168.26.150>;tag=z9hG4bKa524287%00%01%02%03%04%05%06%07%08%09%0a%0b%0c%0d%0e%0f%10%11%12%13%14%15%16%17%18%19%1a%1b%1c%1d%1e%1f%20!%22%23%24%%26'%28%29*+%2c-.%2f0123456789%3a%3b%3c%3d%3e%3f%40ABCDEFGHIJKLMNOPQRSTUVWXYZ%5b%5c%5d%5e_`abcdefghijklmnopqrstuvwxyz%7b%7c%7d~%7f%80%81%82%83%84%85%86%87%88%89%8a%8b%8c%8d%8e%8f%90%91%92%93%94%95%96%97%98%99%9a%9b%9c%9d%9e%9f%a0%a1%a2%a3%a4%a5%a6%a7%a8%a9%aa%ab%ac%ad%ae%af%b0%b1%b2%b3%b4%b5%b6%b7%b8%b9%ba%bb%bc%bd%be%bf%c0%c1%c2%c3%c4%c5%c6%c7%c8%c9%ca%cb%cc%cd%ce%cf%d0%d1%d2%d3%d4%d5%d6%d7%d8%d9%da%db%dc%dd%de%df%e0%e1%e2%e3%e4%e5%e6%e7%e8%e9%ea%eb%ec%ed%ee%ef%f0%f1%f2%f3%f4%f5%f6%f7%f8%f9%fa%fb%fc%fd%fe%ff
CSeq: 1 INVITE
WWW-Authenticate: Digest realm="asterisk",nonce="1632330882/7a9dd893a589fc0bfee733218f9d99af",opaque="3a3ba3ac56e6322c",algorithm=md5,qop="auth"
Server: Asterisk PBX GIT-16-97ce647afd
Content-Length:  0

[silentindark]

@sauwming @trengginas @nanangizz Maybe add this patch to master branch?