Example, register/client SIGSEGV case when Algorithm in lowercase.

[tkang007]

Hi,
I would like to report an issue when register to an Asterisk with the example/register/client/main.go

$  ./client -ip 192.168.219.101:15060 -srv 192.168.219.101:5060 -u 100 -p 100
...
panic: runtime error: invalid memory address or nil pointer dereference
[signal SIGSEGV: segmentation violation code=0x1 addr=0x0 pc=0x648827]

goroutine 1 [running]:
github.com/icholy/digest.(*Credentials).String(0x0)
        /home/vagrant/go/pkg/mod/github.com/icholy/digest@v0.1.22/credentials.go:76 +0x67
main.main()
        /home/vagrant/sipgo/example/register/client/main.go:101 +0xe05

Could be fixed by changing Algorithm to uppercase as it was expected by digest.Digest method.

...
		wwwAuth := res.GetHeader("WWW-Authenticate")
		chal, err := digest.ParseChallenge(wwwAuth.Value())
		if err != nil {
			log.Fatal().Str("wwwauth", wwwAuth.Value()).Err(err).Msg("Fail to parse challenge")
		}
		chal.Algorithm = strings.ToUpper(chal.Algorithm)   //##### fixing
...

Asterisk's WWW-Authenticate parsed challenge:

github.com/icholy/digest.Challenge {Realm: "asterisk", Domain: []string len: 0, cap: 0, nil, Nonce: "1685669327/dfd8ceb694344a6f663b95f91eb48096", Opaque: "2ac5572d63798b56", Stale: false, Algorithm: "md5", QOP: []string len: 1, cap: 1, ["auth"], Charset: "", Userhash: false}

Thanks.

[tkang007]

just for sharing

[emiago]

Hi @tkang007 maybe to create a PR. Not sure is some digest lib issue.

[r4hx]

Yes. It is issue belong digest. I made PR for fix it icholy/digest#11 or you can use my fork https://github.com/r4hx/digest

You need just add to your go.mod

replace github.com/icholy/digest => github.com/r4hx/digest v0.0.1

and run command in terminal

go mod tidy

[emiago]

@r4hx I only noticed this issue couple days ago and it is older version of asterisk (16). I guess they fixed on their end in newer version.
Let me know when your PR merges

[r4hx]

@r4hx I only noticed this issue couple days ago and it is older version of asterisk (16). I guess they fixed on their end in newer version. Let me know when your PR merges

My PR will not be merge, because maintainer reject it. He gave an another solution which more clearly (maybe, i not a golang programmer :D) and simply. But my solution still worked, we have a two tweak how to solve this problem now.

[emiago]

yes he is right about rfc. Still solution he provides seems something related to HTTP?

[r4hx]

Still solution he provides seems something related to HTTP?

No, it’s solution related to udp (header of packet).

[emiago]

hi @r4hx fixed on client.

[r4hx]

hi @r4hx fixed on client.

Nice work. Thank you.