This patch adds hsub support to aamfetch. For details about hsub, see
<http://www.bananasplit.info/nymgrind/news2maildir/hsub.py>.

To use hsub, configure an esub rule, but enter "#" (without the quotes)
as password.

---

diff -u source/esub/Esub.1.1.1.1.java source/esub/Esub.java
--- source/esub/Esub.1.1.1.1.java	Sun Nov 01 20:59:41 2009
+++ source/esub/Esub.java	Sun Nov 01 21:25:16 2009
@@ -31,6 +31,22 @@
     }
   
     public boolean verify(String subject, String password, String esub) {
+	// use hsub if the password is "#"
+	if (password.equals("#")) {
+	    try {	 
+		byte[] esubBytes = unhex(esub);
+		if (esubBytes.length != 24) return false;
+		MessageDigest sha1 = MessageDigest.getInstance
+		    ("SHA-256", "BC");
+		sha1.update(esubBytes, 0, 8);
+		sha1.update(subject.getBytes("ISO-8859-1"));
+		byte[] hash = sha1.digest();
+		return hex(hash).substring(0,32).equals
+		    (hex(esubBytes).substring(16));
+	    } catch (Exception ex) {
+		ex.printStackTrace();
+	    }
+	}
         return verify(hash(subject), hash(password), unhex(esub));
     }
 
@@ -51,6 +67,25 @@
     }
 
     public String encode(String subject, String password) {
+	// use hsub if the password is "#"
+	if (password.equals("#")) {
+	    try {
+		MessageDigest sha1 = MessageDigest.getInstance
+		    ("SHA-256", "BC");
+		byte[] iv = new byte[8];
+		new SecureRandom().nextBytes(iv);
+		sha1.update(iv);
+		sha1.update(subject.getBytes("ISO-8859-1"));
+		byte[] hash = sha1.digest();
+		byte[] res = new byte[24];
+		System.arraycopy(iv, 0, res, 0, 8);
+		System.arraycopy(hash, 0, res, 8, 16);
+		return hex(res);
+	    } catch (Exception ex) {
+		ex.printStackTrace();
+		return null;
+	    }
+	}
 	return hex(encode(hash(subject), hash(password)));
     }
     
@@ -124,5 +159,33 @@
 	System.out.println("Equal: "+esub1.equals(esub2));
 	System.out.println("Verify: "+e.verify(sub, pw, esub1));
 	System.out.println("Verify: "+e.verify(sub, pw, esub2));
+	
+	// hsub tests
+	String subject = "My first HSUB Test";
+	esub1 = e.encode(subject, "#");
+	esub2 = e.encode(subject, "#");
+	System.out.println(esub1);
+	System.out.println(esub2);
+	System.out.println("Equal: "+esub1.equals(esub2));
+	System.out.println("Verify: "+e.verify(subject, "#", esub1));
+	System.out.println("Verify: "+e.verify(subject, "#", esub2));
+	res = e.verify(subject, "#",
+		       "20ef87ce52c9cc32f892de02dcb6dcaa7739b3ca3929c732");
+        System.out.println("Correct: " +res);
+	res = e.verify(subject, "#",
+		       "72e376f05a680913951e469913ca24ded241cdb18dc82ea9");
+        System.out.println("Correct: " +res);
+	res = e.verify(subject, "#",
+		       "4344ddac2423951cd99353226a4ccdc3a567204b5af05f3e");
+        System.out.println("Correct: " +res);
+	res = e.verify("Xylophone City", "#",
+		       "36508980d496dfd9db884b5fd147df950f258bba0674ab0a");
+        System.out.println("Correct: " +res);
+	res = e.verify("A snowy day in October", "#",
+		       "f6e203ac99379e4fe557e3dacc5dfe3d117a88d6e7ca9c9d");
+        System.out.println("Correct: " +res);
+	res = e.verify(subject, "#",
+		       "20ef87ce52c9cc32f892de02dcb6dcaa7739b3ca3929c731");
+        System.out.println("Incorrect: " +res);	
     }
 }