1 files changed, 145 insertions, 0 deletions
diff --git a/src/main/java/de/thedevstack/conversationsplus/xmpp/jid/JidUtil.java b/src/main/java/de/thedevstack/conversationsplus/xmpp/jid/JidUtil.java
new file mode 100644
index 00000000..433f1f4f
--- /dev/null
+++ b/src/main/java/de/thedevstack/conversationsplus/xmpp/jid/JidUtil.java
@@ -0,0 +1,145 @@
+package de.thedevstack.conversationsplus.xmpp.jid;
+
+import android.util.LruCache;
+
+import net.java.otr4j.session.SessionID;
+
+import java.net.IDN;
+
+import gnu.inet.encoding.Stringprep;
+import gnu.inet.encoding.StringprepException;
+
+/**
+ */
+public class JidUtil {
+    private static LruCache<String,Jid> cache = new LruCache<>(1024);
+
+    public static Jid fromSessionID(final SessionID id) throws InvalidJidException {
+        if (id.getUserID().isEmpty()) {
+            return fromString(id.getAccountID());
+        } else {
+            return fromString(id.getAccountID()+"/"+id.getUserID());
+        }
+    }
+
+    public static Jid fromString(final String jid) throws InvalidJidException {
+        return fromString(jid, false);
+    }
+
+    public static Jid fromString(final String jid, final boolean safe) throws InvalidJidException {
+        if (jid == null) throw new InvalidJidException(InvalidJidException.IS_NULL);
+
+        Jid fromCache = JidUtil.cache.get(jid);
+        if (fromCache != null) {
+            return fromCache;
+        }
+
+        // Hackish Android way to count the number of chars in a string... should work everywhere.
+        final int atCount = jid.length() - jid.replace("@", "").length();
+        final int slashCount = jid.length() - jid.replace("/", "").length();
+
+        // Throw an error if there's anything obvious wrong with the JID...
+        if (jid.isEmpty() || jid.length() > 3071) {
+            throw new InvalidJidException(InvalidJidException.INVALID_LENGTH);
+        }
+
+        // Go ahead and check if the localpart or resourcepart is empty.
+        if (jid.startsWith("@") || (jid.endsWith("@") && slashCount == 0) || jid.startsWith("/") || (jid.endsWith("/") && slashCount < 2)) {
+            throw new InvalidJidException(InvalidJidException.INVALID_CHARACTER);
+        }
+
+        String finaljid;
+        String localpart;
+        String domainpart;
+        String resourcepart;
+
+        final int domainpartStart;
+        final int atLoc = jid.indexOf("@");
+        final int slashLoc = jid.indexOf("/");
+        // If there is no "@" in the JID (eg. "example.net" or "example.net/resource")
+        // or there are one or more "@" signs but they're all in the resourcepart (eg. "example.net/@/rp@"):
+        if (atCount == 0 || (atCount > 0 && slashLoc != -1 && atLoc > slashLoc)) {
+            localpart = "";
+            finaljid = "";
+            domainpartStart = 0;
+        } else {
+            final String lp = jid.substring(0, atLoc);
+            try {
+                localpart = safe ? lp : Stringprep.nodeprep(lp);
+            } catch (final StringprepException e) {
+                throw new InvalidJidException(InvalidJidException.STRINGPREP_FAIL, e);
+            }
+            if (localpart.isEmpty() || localpart.length() > 1023) {
+                throw new InvalidJidException(InvalidJidException.INVALID_PART_LENGTH);
+            }
+            domainpartStart = atLoc + 1;
+            finaljid = lp + "@";
+        }
+
+        final String dp;
+        if (slashCount > 0) {
+            final String rp = jid.substring(slashLoc + 1, jid.length());
+            try {
+                resourcepart = safe ? rp : Stringprep.resourceprep(rp);
+            } catch (final StringprepException e) {
+                throw new InvalidJidException(InvalidJidException.STRINGPREP_FAIL, e);
+            }
+            if (resourcepart.isEmpty() || resourcepart.length() > 1023) {
+                throw new InvalidJidException(InvalidJidException.INVALID_PART_LENGTH);
+            }
+            try {
+                dp = IDN.toUnicode(Stringprep.nameprep(jid.substring(domainpartStart, slashLoc)), IDN.USE_STD3_ASCII_RULES);
+            } catch (final StringprepException e) {
+                throw new InvalidJidException(InvalidJidException.STRINGPREP_FAIL, e);
+            }
+            finaljid = finaljid + dp + "/" + rp;
+        } else {
+            resourcepart = "";
+            try{
+                dp = IDN.toUnicode(Stringprep.nameprep(jid.substring(domainpartStart, jid.length())), IDN.USE_STD3_ASCII_RULES);
+            } catch (final StringprepException e) {
+                throw new InvalidJidException(InvalidJidException.STRINGPREP_FAIL, e);
+            }
+            finaljid = finaljid + dp;
+        }
+
+        // Remove trailing "." before storing the domain part.
+        if (dp.endsWith(".")) {
+            try {
+                domainpart = IDN.toASCII(dp.substring(0, dp.length() - 1), IDN.USE_STD3_ASCII_RULES);
+            } catch (final IllegalArgumentException e) {
+                throw new InvalidJidException(e);
+            }
+        } else {
+            try {
+                domainpart = IDN.toASCII(dp, IDN.USE_STD3_ASCII_RULES);
+            } catch (final IllegalArgumentException e) {
+                throw new InvalidJidException(e);
+            }
+        }
+
+        // TODO: Find a proper domain validation library; validate individual parts, separators, etc.
+        if (domainpart.isEmpty() || domainpart.length() > 1023) {
+            throw new InvalidJidException(InvalidJidException.INVALID_PART_LENGTH);
+        }
+
+        Jid createdJid = new Jid(finaljid, localpart, domainpart, resourcepart);
+
+        JidUtil.cache.put(jid, createdJid);
+
+        return createdJid;
+    }
+
+    public static Jid fromParts(final String localpart, final String domainpart, final String resourcepart) throws InvalidJidException {
+        String out;
+        if (localpart == null || localpart.isEmpty()) {
+            out = domainpart;
+        } else {
+            out = localpart + "@" + domainpart;
+        }
+        if (resourcepart != null && !resourcepart.isEmpty()) {
+            out = out + "/" + resourcepart;
+        }
+        return JidUtil.fromString(out, false);
+    }
+}