fix(torsf): update domain fronting (#1531)

This diff updates snowflake's domain fronting such that `torsf` is
working as intended again. I adapted this diff from
#1529, written by @Lanius-collaris
(thank you so much! 🥰 🙌). The original diff contained extra
functionality that it would be very nice to have. I have chosen to drop
this functionality, because I'd like to quickly merge a Snowflake fix. I
will take care of the additional changes in a subsequent diff.

Part of ooni/probe#2692.

---------

Co-authored-by: Lanius-collaris <[email protected]>

Author: bassosimone

internal/experiment/torsf/integration_test.go

@@ -13,7 +13,6 @@ import (
 )
 
 func TestRunWithExistingTor(t *testing.T) {
-	t.Skip("TODO(https://github.com/ooni/probe/issues/2692)")
 	if testing.Short() {
 		t.Skip("skip test in short mode")
 	}

internal/experiment/torsf/torsf.go

@@ -25,7 +25,7 @@ import (
 // We may want to have a single implementation for both nettests in the future.
 
 // testVersion is the experiment version.
-const testVersion = "0.5.0"
+const testVersion = "0.5.1"
 
 // Config contains the experiment config.
 type Config struct {

internal/experiment/torsf/torsf_test.go

@@ -25,7 +25,7 @@ func TestExperimentNameAndVersion(t *testing.T) {
 	if m.ExperimentName() != "torsf" {
 		t.Fatal("invalid experiment name")
 	}
-	if m.ExperimentVersion() != "0.5.0" {
+	if m.ExperimentVersion() != "0.5.1" {
 		t.Fatal("invalid experiment version")
 	}
 }

internal/ptx/snowflake.go

@@ -41,11 +41,11 @@ func (d *snowflakeRendezvousMethodDomainFronting) AMPCacheURL() string {
 }
 
 func (d *snowflakeRendezvousMethodDomainFronting) BrokerURL() string {
-	return "https://snowflake-broker.torproject.net.global.prod.fastly.net/"
+	return "https://1098762253.rsc.cdn77.org/"
 }
 
 func (d *snowflakeRendezvousMethodDomainFronting) FrontDomain() string {
-	return "foursquare.com"
+	return "www.phpmyadmin.net"
 }
 
 // NewSnowflakeRendezvousMethodAMP is a rendezvous method that

internal/ptx/snowflake_test.go

@@ -16,11 +16,11 @@ func TestSnowflakeMethodDomainFronting(t *testing.T) {
 	if meth.AMPCacheURL() != "" {
 		t.Fatal("invalid amp cache URL")
 	}
-	const brokerURL = "https://snowflake-broker.torproject.net.global.prod.fastly.net/"
+	const brokerURL = "https://1098762253.rsc.cdn77.org/"
 	if meth.BrokerURL() != brokerURL {
 		t.Fatal("invalid broker URL")
 	}
-	const frontDomain = "foursquare.com"
+	const frontDomain = "www.phpmyadmin.net"
 	if meth.FrontDomain() != frontDomain {
 		t.Fatal("invalid front domain")
 	}