[BUG] Userpass doesn't work if username contains uppercase letters

[haruue]

reported-by: @codetang-2417
ref: #1174 (comment) #1174 (comment)

Reproduce

Server

listen: :8443

tls:
  cert: /etc/hysteria/server.crt
  key: /etc/hysteria/server.key
  sniGuard: disable

auth:
  type: userpass
  userpass:
    user1: pass
    User2: pass

Client

server: 127.0.0.1:8443

#auth: user1:pass
auth: User2:pass

tls:
  insecure: true

socks5:
  listen: 127.0.0.1:21080

When using auth: user1:pass, the Hysteria connection can be established, but it fails when using auth: User2:pass.

2025-01-09T21:40:54+09:00       FATAL   failed to initialize client     {"error": "authentication error, HTTP status code: 404"}

Why?

Simply add a log here

diff --git a/app/cmd/server.go b/app/cmd/server.go
index 5f2d562..c4bf656 100644
--- a/app/cmd/server.go
+++ b/app/cmd/server.go
@@ -755,6 +755,7 @@ func (c *serverConfig) fillAuthenticator(hyConfig *server.Config) error {
                if len(c.Auth.UserPass) == 0 {
                        return configError{Field: "auth.userpass", Err: errors.New("empty auth userpass")}
                }
+               logger.Info("parsed userpass", zap.Any("userpass", c.Auth.UserPass))
                hyConfig.Authenticator = &auth.UserPassAuthenticator{Users: c.Auth.UserPass}
                return nil
        case "http", "https":

We will get

2025-01-09T21:44:58+09:00       INFO    parsed userpass {"userpass": {"user1":"pass","user2":"pass"}}

This issue is caused by viper, which silently converts all map keys to lower case (spf13/viper#373), and there is still no option to disable this behavior.

[codetang-2417]

感谢您的努力！