From 6a442d5df98a3af7f539fb214516444bdd115f21 Mon Sep 17 00:00:00 2001
From: Love Hornquist Astrand <lha@h5l.org>
Date: Mon, 10 Dec 2012 12:38:35 -0800
Subject: [PATCH] guess that this is how arcfour prf works

---
 lib/krb5/crypto-arcfour.c | 26 +++++++++++++++++++++++++-
 1 file changed, 25 insertions(+), 1 deletion(-)

diff --git a/lib/krb5/crypto-arcfour.c b/lib/krb5/crypto-arcfour.c
index 9954d02f8..ca2d7862c 100644
--- a/lib/krb5/crypto-arcfour.c
+++ b/lib/krb5/crypto-arcfour.c
@@ -309,6 +309,30 @@ ARCFOUR_encrypt(krb5_context context,
 	return ARCFOUR_subdecrypt (context, key, data, len, keyusage, ivec);
 }
 
+static krb5_error_code
+ARCFOUR_prf(krb5_context context,
+	    krb5_crypto crypto,
+	    const krb5_data *in,
+	    krb5_data *out)
+{
+    struct _krb5_checksum_type *c = _krb5_find_checksum(CKSUMTYPE_SHA1);
+    krb5_error_code ret;
+    Checksum res;
+
+    ret = krb5_data_alloc(out, c->checksumsize);
+    if (ret)
+	return ret;
+
+    res.checksum.data = out->data;
+    res.checksum.length = out->length;
+
+    ret = _krb5_internal_hmac(context, c, in->data, in->length, 0, &crypto->key, &res);
+    if (ret)
+	krb5_data_free(out);
+    return 0;
+}
+
+
 struct _krb5_encryption_type _krb5_enctype_arcfour_hmac_md5 = {
     ETYPE_ARCFOUR_HMAC_MD5,
     "arcfour-hmac-md5",
@@ -322,5 +346,5 @@ struct _krb5_encryption_type _krb5_enctype_arcfour_hmac_md5 = {
     F_SPECIAL,
     ARCFOUR_encrypt,
     0,
-    NULL
+    ARCFOUR_prf
 };