certlib/bundler: add support for pemcrt.

certlib/bundler/bundler.go

@@ -422,6 +422,24 @@ func encodeCertsToFiles(
 			name:    baseName + ".pem",
 			content: pemContent,
 		})
+	case "crt":
+		pemContent := encodeCertsToPEM(certs)
+		files = append(files, fileEntry{
+			name:    baseName + ".crt",
+			content: pemContent,
+		})
+	case "pemcrt":
+		pemContent := encodeCertsToPEM(certs)
+		files = append(files, fileEntry{
+			name:    baseName + ".pem",
+			content: pemContent,
+		})
+
+		pemContent = encodeCertsToPEM(certs)
+		files = append(files, fileEntry{
+			name:    baseName + ".crt",
+			content: pemContent,
+		})
 	case "der":
 		if isSingle {
 			// For single file in DER, concatenate all cert DER bytes

cmd/cert-bundler/testdata/bundle.yaml

@@ -12,6 +12,7 @@ chains:
       include_single: true
       include_individual: true
       manifest: true
+      encoding: pemcrt
       formats:
         - zip
         - tgz
@@ -53,4 +54,4 @@ chains:
       manifest: false
       encoding: both
       formats:
-        - zip
+        - zip