Sanitize paths

Use _ instead of . in paths.
This is useful for paths like /.well-known, where the previous subject transformation would be invalid, due to two consecutive dots.

1 files changed, 4 insertions, 3 deletions

diff --git a/main.go b/main.go
index 14e75ae..8ab98dd 100644
--- a/main.go
+++ b/main.go
@@ -99,12 +99,13 @@ func main() {
 		if h, _, err := net.SplitHostPort(host); err == nil {
 			host = h
 		}
-		// Use "-" instead of "." in the domain to make it a single token.
-		domainParts := strings.ReplaceAll(host, ".", "-")
+		// Use "_" instead of "." in the domain to make it a single token.
+		domainParts := strings.ReplaceAll(host, ".", "_")
 
 		// Process path component
 		path := strings.TrimPrefix(r.URL.Path, "/")
-		subjectPath := strings.ReplaceAll(path, "/", ".")
+		// Replace all "." with "_" and then all "/" with ".".
+		subjectPath := strings.ReplaceAll(strings.ReplaceAll(path, ".", "_"), "/", ".")
 
 		// Build final subject
 		subjectBase := "http"