Psiphon library is broken with Go 1.25

[fortuna]

I'm getting:

$ go test -C x -tags psiphon -v github.com/Jigsaw-Code/outline-sdk/x/psiphon
panic: tls: ConnectionState is not equal to tls.ConnectionState: struct field count mismatch: 17 vs 16

goroutine 1 [running]:
github.com/Psiphon-Labs/psiphon-tls.init.0()
        /Users/fortuna/go/pkg/mod/github.com/!psiphon-!labs/psiphon-tls@v0.0.0-20250318183125-2a2fae2db378/unsafe.go:44 +0xbc
FAIL    github.com/Jigsaw-Code/outline-sdk/x/psiphon    0.380s
FAIL

Psiphon does some reflection to access internals of the TLS library, and that seems to break. Probably a result of the standard tls library changing.

We need the Psiphon team to make their library work with newer tls library and make it available so we can pull it via go get github.com/Psiphon-Labs/psiphon-tunnel-core@staging-cli

[fortuna]

This is the broken code in psiphon-tls:
https://github.com/Psiphon-Labs/psiphon-tls/blob/2a2fae2db378acefb9615182dccc85f04917f88b/unsafe.go#L41-L46

func init() {
	err := structsEqual(&tls.ConnectionState{}, &ConnectionState{})
	if err != nil {
		panic(fmt.Sprintf("tls: ConnectionState is not equal to tls.ConnectionState: %v", err))
	}
}

[fortuna]

I discovered that the Psiphon library is incompatible with Go 1.25+
This succeeds:

$ GOTOOLCHAIN=go1.24.6 go test -C x -tags psiphon ./...
ok      github.com/Jigsaw-Code/outline-sdk/x/configurl  0.418s
ok      github.com/Jigsaw-Code/outline-sdk/x/connectivity       1.306s
?       github.com/Jigsaw-Code/outline-sdk/x/disorder   [no test files]
?       github.com/Jigsaw-Code/outline-sdk/x/examples/fetch-proxy       [no test files]
?       github.com/Jigsaw-Code/outline-sdk/x/examples/fetch-psiphon     [no test files]
?       github.com/Jigsaw-Code/outline-sdk/x/examples/measure   [no test files]
?       github.com/Jigsaw-Code/outline-sdk/x/examples/outline-cli       [no test files]
?       github.com/Jigsaw-Code/outline-sdk/x/examples/run-mobileproxy   [no test files]
?       github.com/Jigsaw-Code/outline-sdk/x/examples/smart-proxy       [no test files]
?       github.com/Jigsaw-Code/outline-sdk/x/examples/ws2endpoint       [no test files]
ok      github.com/Jigsaw-Code/outline-sdk/x/httpconnect        0.670s
ok      github.com/Jigsaw-Code/outline-sdk/x/httpproxy  0.242s
?       github.com/Jigsaw-Code/outline-sdk/x/mobileproxy        [no test files]
ok      github.com/Jigsaw-Code/outline-sdk/x/psiphon    0.465s
ok      github.com/Jigsaw-Code/outline-sdk/x/report     0.534s
ok      github.com/Jigsaw-Code/outline-sdk/x/smart      0.649s
ok      github.com/Jigsaw-Code/outline-sdk/x/soax       0.449s
ok      github.com/Jigsaw-Code/outline-sdk/x/sockopt    0.794s
ok      github.com/Jigsaw-Code/outline-sdk/x/sysproxy   2.471s
?       github.com/Jigsaw-Code/outline-sdk/x/tools/fetch        [no test files]
?       github.com/Jigsaw-Code/outline-sdk/x/tools/fetch-speed  [no test files]
?       github.com/Jigsaw-Code/outline-sdk/x/tools/http2transport       [no test files]
?       github.com/Jigsaw-Code/outline-sdk/x/tools/resolve      [no test files]
?       github.com/Jigsaw-Code/outline-sdk/x/tools/test-connectivity    [no test files]
ok      github.com/Jigsaw-Code/outline-sdk/x/websocket  0.975s

This fails:

$ GOTOOLCHAIN=go1.25.0 go test -C x -tags psiphon ./...
ok      github.com/Jigsaw-Code/outline-sdk/x/configurl  0.223s
ok      github.com/Jigsaw-Code/outline-sdk/x/connectivity       1.424s
?       github.com/Jigsaw-Code/outline-sdk/x/disorder   [no test files]
?       github.com/Jigsaw-Code/outline-sdk/x/examples/fetch-proxy       [no test files]
?       github.com/Jigsaw-Code/outline-sdk/x/examples/fetch-psiphon     [no test files]
?       github.com/Jigsaw-Code/outline-sdk/x/examples/measure   [no test files]
?       github.com/Jigsaw-Code/outline-sdk/x/examples/outline-cli       [no test files]
?       github.com/Jigsaw-Code/outline-sdk/x/examples/run-mobileproxy   [no test files]
?       github.com/Jigsaw-Code/outline-sdk/x/examples/smart-proxy       [no test files]
?       github.com/Jigsaw-Code/outline-sdk/x/examples/ws2endpoint       [no test files]
ok      github.com/Jigsaw-Code/outline-sdk/x/httpconnect        0.828s
ok      github.com/Jigsaw-Code/outline-sdk/x/httpproxy  0.243s
?       github.com/Jigsaw-Code/outline-sdk/x/mobileproxy        [no test files]
panic: tls: ConnectionState is not equal to tls.ConnectionState: struct field count mismatch: 17 vs 16

goroutine 1 [running]:
github.com/Psiphon-Labs/psiphon-tls.init.0()
        /Users/fortuna/go/pkg/mod/github.com/!psiphon-!labs/psiphon-tls@v0.0.0-20250318183125-2a2fae2db378/unsafe.go:44 +0xbc
FAIL    github.com/Jigsaw-Code/outline-sdk/x/psiphon    0.585s
ok      github.com/Jigsaw-Code/outline-sdk/x/report     0.303s
panic: tls: ConnectionState is not equal to tls.ConnectionState: struct field count mismatch: 17 vs 16

goroutine 1 [running]:
github.com/Psiphon-Labs/psiphon-tls.init.0()
        /Users/fortuna/go/pkg/mod/github.com/!psiphon-!labs/psiphon-tls@v0.0.0-20250318183125-2a2fae2db378/unsafe.go:44 +0xbc
FAIL    github.com/Jigsaw-Code/outline-sdk/x/smart      0.277s
ok      github.com/Jigsaw-Code/outline-sdk/x/soax       0.661s
ok      github.com/Jigsaw-Code/outline-sdk/x/sockopt    0.395s
ok      github.com/Jigsaw-Code/outline-sdk/x/sysproxy   2.220s
?       github.com/Jigsaw-Code/outline-sdk/x/tools/fetch        [no test files]
?       github.com/Jigsaw-Code/outline-sdk/x/tools/fetch-speed  [no test files]
?       github.com/Jigsaw-Code/outline-sdk/x/tools/http2transport       [no test files]
?       github.com/Jigsaw-Code/outline-sdk/x/tools/resolve      [no test files]
?       github.com/Jigsaw-Code/outline-sdk/x/tools/test-connectivity    [no test files]
ok      github.com/Jigsaw-Code/outline-sdk/x/websocket  0.844s
FAIL

[fortuna]

Here is the history of ConnectionState: https://github.com/golang/go/blame/b21867b1a2a8e276257e3cb81f4a1dc7e8f9e2cd/src/crypto/tls/common.go#L235