Added banner recognition for basic discovery of services

1 files changed, 45 insertions, 0 deletions

diff --git a/src/main/java/com/it_jaros/jscanner/ServiceDetector.java b/src/main/java/com/it_jaros/jscanner/ServiceDetector.java
new file mode 100644
index 0000000..7559b43
--- /dev/null
+++ b/src/main/java/com/it_jaros/jscanner/ServiceDetector.java
@@ -0,0 +1,45 @@
+package com.it_jaros.jscanner;
+
+import java.util.List;
+import java.util.regex.Pattern;
+
+public class ServiceDetector {
+    private static final List<ServicePattern> patterns = List.of(
+            new ServicePattern(ServiceType.SSH, Pattern.compile("(?i)^SSH-")),
+
+            new ServicePattern(ServiceType.HTTP, Pattern.compile("(?i)^HTTP/")),
+            new ServicePattern(ServiceType.HTTP, Pattern.compile("(?i)\\bServer:\\s*")),
+
+            new ServicePattern(ServiceType.FTP, Pattern.compile("(?i)^220.*\\bFTP\\b")),
+
+            new ServicePattern(ServiceType.SMTP, Pattern.compile("(?i)^220.*\\bSMTP\\b")),
+            new ServicePattern(ServiceType.SMTP, Pattern.compile("(?i)^220.*\\bESMTP\\b")),
+
+            new ServicePattern(ServiceType.IMAP, Pattern.compile("(?i)^\\* OK.*\\bIMAP\\b")),
+
+            new ServicePattern(ServiceType.POP3, Pattern.compile("(?i)^\\+OK.*\\bPOP3\\b"))
+    );
+
+    public static ServiceType detect(String banner) {
+        if (banner == null || banner.isBlank()) {
+            return ServiceType.UNKNOWN;
+        }
+
+        for (ServicePattern servicePattern : patterns) {
+            if (servicePattern.matches(banner)) {
+                return servicePattern.serviceType();
+            }
+        }
+
+        return ServiceType.UNKNOWN;
+    }
+
+    private record ServicePattern(
+            ServiceType serviceType,
+            Pattern pattern
+    ) {
+        boolean matches(String banner) {
+            return pattern.matcher(banner).find();
+        }
+    }
+}
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