diff --git a/lib/Makefile.am b/lib/Makefile.am
index fc1e93f3..be323ee4 100644
--- a/lib/Makefile.am
+++ b/lib/Makefile.am
@@ -5,8 +5,8 @@ libfko_source_files = \
     fko_client_timeout.c fko_common.h fko_digest.c fko_encode.c \
     fko_decode.c fko_encryption.c fko_error.c fko_funcs.c fko_message.c \
     fko_message.h fko_nat_access.c fko_rand_value.c fko_server_auth.c \
-    fko.h fko_limits.h fko_timestamp.c fko_user.c fko_util.h md5.c md5.h \
-    rijndael.c rijndael.h sha1.c sha1.h sha2.c sha2.h strlcat.c \
+    fko.h fko_limits.h fko_timestamp.c fko_user.c fko_user.h fko_util.h \
+    md5.c md5.h rijndael.c rijndael.h sha1.c sha1.h sha2.c sha2.h strlcat.c \
     strlcpy.c fko_context.h fko_state.h fko_context.h gpgme_funcs.c \
     gpgme_funcs.h
 
diff --git a/lib/fko_common.h b/lib/fko_common.h
index b86e6e8c..bf1bad25 100644
--- a/lib/fko_common.h
+++ b/lib/fko_common.h
@@ -121,6 +121,7 @@
 #include "fko_state.h"
 #include "fko_context.h"
 #include "fko_message.h"
+#include "fko_user.h"
 
 /* Try to cover for those that do not have bzero.
 */
diff --git a/lib/fko_decode.c b/lib/fko_decode.c
index 574c80f0..22ac92b4 100644
--- a/lib/fko_decode.c
+++ b/lib/fko_decode.c
@@ -196,6 +196,11 @@ fko_decode_spa_data(fko_ctx_t ctx)
     }
 
     b64_decode(tbuf, (unsigned char*)ctx->username);
+    if(validate_username(ctx->username) != FKO_SUCCESS)
+    {
+        free(tbuf);
+        return(FKO_ERROR_INVALID_DATA);
+    }
 
     /* Extract the timestamp value.
     */
diff --git a/lib/fko_user.c b/lib/fko_user.c
index 0c909dd2..04b271a1 100644
--- a/lib/fko_user.c
+++ b/lib/fko_user.c
@@ -41,7 +41,7 @@ int
 fko_set_username(fko_ctx_t ctx, const char *spoof_user)
 {
     char   *username = NULL;
-    int     i;
+    int     res = FKO_SUCCESS;
 
     /* Must be initialized
     */
@@ -88,14 +88,8 @@ fko_set_username(fko_ctx_t ctx, const char *spoof_user)
     if(strnlen(username, MAX_SPA_USERNAME_SIZE) == MAX_SPA_USERNAME_SIZE)
         *(username + MAX_SPA_USERNAME_SIZE - 1) = '\0';
 
-    /* Make sure it is just alpha-numeric chars and dashes
-    */
-    if(isalnum(username[0]) == 0)
-        return(FKO_ERROR_INVALID_DATA);
-
-    for (i=1; i < strnlen(username, MAX_SPA_USERNAME_SIZE); i++)
-        if((isalnum(username[i]) == 0) && username[i] != '-')
-            return(FKO_ERROR_INVALID_DATA);
+    if((res = validate_username(username)) != FKO_SUCCESS)
+        return res;
 
     /* Just in case this is a subsquent call to this function.  We
      * do not want to be leaking memory.
@@ -128,4 +122,24 @@ fko_get_username(fko_ctx_t ctx, char **username)
     return(FKO_SUCCESS);
 }
 
+int
+validate_username(const char *username)
+{
+    int i;
+
+    if(username == NULL || strnlen(username, MAX_SPA_USERNAME_SIZE) == 0)
+        return(FKO_ERROR_INVALID_DATA);
+
+    /* Make sure it is just alpha-numeric chars and dashes
+    */
+    if(isalnum(username[0]) == 0)
+        return(FKO_ERROR_INVALID_DATA);
+
+    for (i=1; i < strnlen(username, MAX_SPA_USERNAME_SIZE); i++)
+        if((isalnum(username[i]) == 0) && username[i] != '-')
+            return(FKO_ERROR_INVALID_DATA);
+
+    return FKO_SUCCESS;
+}
+
 /***EOF***/
diff --git a/lib/fko_user.h b/lib/fko_user.h
new file mode 100644
index 00000000..b521dca0
--- /dev/null
+++ b/lib/fko_user.h
@@ -0,0 +1,41 @@
+/*
+ *****************************************************************************
+ *
+ * File:    fko_message.h
+ *
+ * Author:  Michael Rash
+ *
+ * Purpose: Provide validation functions for SPA messages
+ *
+ * Copyright 2012 Michael Rash (mbr@cipherdyne.org)
+ *
+ *  License (GNU Public License):
+ *
+ *  This program is free software; you can redistribute it and/or
+ *  modify it under the terms of the GNU General Public License
+ *  as published by the Free Software Foundation; either version 2
+ *  of the License, or (at your option) any later version.
+ *
+ *  This program is distributed in the hope that it will be useful,
+ *  but WITHOUT ANY WARRANTY; without even the implied warranty of
+ *  MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+ *  GNU General Public License for more details.
+ *
+ *  You should have received a copy of the GNU General Public License
+ *  along with this program; if not, write to the Free Software
+ *  Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA  02111-1307
+ *  USA
+ *
+ *****************************************************************************
+*/
+
+#ifndef FKO_USER_H
+#define FKO_USER_H 1
+
+/* SPA message format validation functions.
+*/
+int validate_username(const char *username);
+
+#endif /* FKO_USER_H */
+
+/***EOF***/
diff --git a/test/bogus_spa_packets b/test/bogus_spa_packets
index 25049c7b..ce31e7df 100644
--- a/test/bogus_spa_packets
+++ b/test/bogus_spa_packets
@@ -1,8 +1,6 @@
 [+] TEST: [perl FKO module] [FUZZING] generate invalid SPA pkts
 [+] Bogus user: AAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAA, SPA packet: 8CDE3EbCA2lPCfaREyVuOb0O7Y4f4X19NhmRLaNbYKM2C9phb61rHl//A/IiKLjvzQwLfFg+Vcw5MRJJNUVFU6fc/KVn8Ga+L1dVs2hmBeqNu6I+owJp2RGMYwBBiaKHa9HfG3bFd+qvxxf8aq9YYLeBE5jS1MztyggXJYl0bjPMB+ldKw2gwJz2YUyQJI/CvJOml4b8/lE16b3KjyMi0VSpQgVTpIV4wp/4pFmAu5BFVzPhNF7aqJdEYJWHgLIlKVbbLBXf9QYw
-[+] Bogus user: -1, SPA packet: 8chLxRMt6BlbbHcSN/JIJRQe3GtlqWA/h2jvNMTIgA1FDn042sIBC9Zi2ooqPXyp52/iGjIiVeIynemhrJ9xm8VSX0ymrqDcy0zeOqk/EtviZF0WRpGSUwNEZL5XIdRQhVPan9iG5NREkWJmkojQXwP4Bv1Fwq1Ak
 [+] Bogus user: -1, SPA packet: +E10NRuOugEt1bcWSv7y7R1o3V4SFAaZk2RRJIEbGKiNv8eXRm8pXgA5eqLg7DYmNYB81kR6j7K/HkxARxkQM1WJ1Bo/cyQqFIgRYkS7sfW4Y8xdTCkpV7AdD/gX+3dgi4X3BH5CBXvRHQOu3TJand0vjOkH0Aqmc
-[+] Bogus user: (NULL), SPA packet: /OhXqxE0/q58cTUa+cFm9yWOxJ87OPOTpS3V1CFuxDxknF+ExOYgF2fRCs0F5UXnNzx5KXKy8mTrgspYdSmhpnV7HoP74MrLVbPSeCc1dIpzaTGj74r9RD5mEeW2e/OHf2AWiutw0mt8P86V7w8nobgAMDkyyIIi8
 [+] Bogus user: 123%123, SPA packet: +OdiES5bJzsJ2Vgx3g4fTiQAD/D4NraR0yk6tvdPyfhQ5WEvTzeUgon8RRHXp646RDK/jYSQVdgU7sDf9/WSmiqrMiUGXI2Cz4Vl6HwzkK8jvyrR3VyjK8qLCkG/xq+pOsbwWzYmxirJBcJ+j6+dSakgRgtpICF64
 [+] Bogus user: 123.123, SPA packet: +nossY0gFa063W/T3MJg7U6WiOBJ9TdPlbPUbSKtlrgSgNBwWyO3IcD3RZLWf5RKnWFInNZ+ltA6mwu1GCrhRIuzUdlDVBi9v2q6LeCR92eRrCsJmnKCbQjHkKfGiitYHbkvZNqcMZjXGfMuC8wbnc85xhOra1z5M
 [+] Bogus user: 123$123, SPA packet: 9/dll4vYi5iIf2P6mdlAVw12HtnlnbrkGs9RkrRa8TD+RtnLlFbKH+jhanLGahHYUI8aU9pbWKTc7sjBARNiu8Hh1tc+c36AYCjiIYijxoVCDiTE7WQ9P+USYQdn5dahFqJLDW3R5y9uVxsGniZ2RbRMltMpuCEdM