1 files changed, 72 insertions, 0 deletions
diff --git a/kbiff/kbiffcrypt.cpp b/kbiff/kbiffcrypt.cpp
new file mode 100644
index 0000000..66ce0b0
--- /dev/null
+++ b/kbiff/kbiffcrypt.cpp
@@ -0,0 +1,72 @@
+/*
+ * kbiffcrypt.cpp
+ * Copyright (C) 2005 Michael Hendricks <michael@palmcluster.org>
+ *
+ * This file contains the implementation of the functions in
+ * the KBiffCrypt namespace.
+ *
+ * $Id$
+ */
+#include "kbiffcrypt.h"
+
+#include <kmdcodec.h>
+#include <qcstring.h>
+
+QString KBiffCrypt::hmac_md5(const QString& text, const QString& k)
+{
+    // If the original key is too long, the new key will be a hash of
+    // the original key.  Then the new key might have NULL bytes in it,
+    // so we can't use QCString
+    QByteArray   key = (QByteArray)k.utf8();
+
+    KMD5         context; // for calculating MD5 sums
+    KMD5::Digest digest;  // intermediate storage for MD5 sums
+
+    // inner and outer padding (key XORd with ipad and opad, respectively)
+    QByteArray k_ipad(64);
+    QByteArray k_opad(64);
+
+
+    // if key is longer than 64 bytes reset it to key=MD5(key)
+    if (key.size() > 64) {
+        // cast to a QCString because we don't want to hash the
+        // trailing NULL byte
+        KMD5 tctx((QCString)key);
+
+        key.duplicate((char*)tctx.rawDigest(), 16);
+    }
+
+    /* the HMAC-MD5 transform looks like this:
+     *
+     * MD5(K XOR opad, MD5(K XOR ipad, text))
+     *
+     * where K is an n byte key
+     * ipad is the byte 0x36 repeated 64 times
+     * opad is the byte 0x5c repeated 64 times
+     * text is the data being protected
+     */
+
+    // XOR key with ipad and opad values, copying
+    // the pad values after the key's end
+    for (unsigned int i=0; i<64; i++) {
+        if( i < key.size() ) {
+            k_ipad[i] = key[i] ^ 0x36;
+            k_opad[i] = key[i] ^ 0x5c;
+        } else {
+            k_ipad[i] = 0x36;
+            k_opad[i] = 0x5c;
+        }
+    }
+
+    // perform inner MD5
+    context.reset();                      // init context for 1st pass
+    context.update(k_ipad);               // start with inner pad
+    context.update(text.utf8());          // then text of datagram
+    context.rawDigest(digest);            // finish up 1st pass
+
+    // perform outer MD5
+    context.reset();                     // init context for 2nd pass
+    context.update(k_opad);              // start with outer pad
+    context.update(digest, 16);          // then results of 1st hash
+    return context.hexDigest();          // finish up 2nd pass and return
+}