diff --git a/lib/EAPBase/include/EAP.h b/lib/EAPBase/include/EAP.h
index 70d5358..f1bac15 100644
--- a/lib/EAPBase/include/EAP.h
+++ b/lib/EAPBase/include/EAP.h
@@ -91,6 +91,40 @@ namespace eap
     ///
     struct diameter_avp_header_ven;
 
+    ///
+    /// Appends Diameter AVP to response packet
+    ///
+    /// \param[in   ] code    AVP code
+    /// \param[in   ] flags   AVP flags
+    /// \param[in   ] data    AVP data (<16777212B)
+    /// \param[in   ] size    Size of \p data in bytes
+    /// \param[inout] packet  Response packet to append data to
+    ///
+    void diameter_avp_append(
+        _In_                       unsigned int    code,
+        _In_                       unsigned char   flags,
+        _In_bytecount_(size) const void            *data,
+        _In_                       unsigned int    size,
+        _Inout_                    sanitizing_blob &packet);
+
+    ///
+    /// Appends Diameter AVP to response packet
+    ///
+    /// \param[in   ] code       AVP code
+    /// \param[in   ] vendor_id  Vendor-ID
+    /// \param[in   ] flags      AVP flags
+    /// \param[in   ] data       AVP data (<16777212B)
+    /// \param[in   ] size       Size of \p data in bytes
+    /// \param[inout] packet     Response packet to append data to
+    ///
+    void diameter_avp_append(
+        _In_                       unsigned int    code,
+        _In_                       unsigned int    vendor_id,
+        _In_                       unsigned char   flags,
+        _In_bytecount_(size) const void            *data,
+        _In_                       unsigned int    size,
+        _Inout_                    sanitizing_blob &packet);
+
     ///
     /// EAP packet
     ///
diff --git a/lib/EAPBase/src/EAP.cpp b/lib/EAPBase/src/EAP.cpp
index 64e9072..e3f84e1 100644
--- a/lib/EAPBase/src/EAP.cpp
+++ b/lib/EAPBase/src/EAP.cpp
@@ -24,6 +24,78 @@ using namespace std;
 using namespace winstd;
 
 
+//////////////////////////////////////////////////////////////////////
+// eap::diameter_avp_append
+//////////////////////////////////////////////////////////////////////
+
+void eap::diameter_avp_append(
+    _In_                       unsigned int    code,
+    _In_                       unsigned char   flags,
+    _In_bytecount_(size) const void            *data,
+    _In_                       unsigned int    size,
+    _Inout_                    sanitizing_blob &packet)
+{
+    unsigned int
+        padding = (unsigned int)((4 - size) % 4),
+        size_outer;
+
+    packet.reserve(
+        packet.size() + 
+        (size_outer = 
+        sizeof(diameter_avp_header) + // Diameter header
+        size)                       + // Data
+        padding);                     // Data padding
+
+    // Diameter AVP header
+    diameter_avp_header hdr;
+    *reinterpret_cast<unsigned int*>(hdr.code) = htonl(code);
+    hdr.flags = flags;
+    hton24(size_outer, hdr.length);
+    packet.insert(packet.end(), reinterpret_cast<const unsigned char*>(&hdr), reinterpret_cast<const unsigned char*>(&hdr + 1));
+
+    // Data
+    packet.insert(packet.end(), reinterpret_cast<const unsigned char*>(data), reinterpret_cast<const unsigned char*>(data) + size);
+    packet.insert(packet.end(), padding, 0);
+}
+
+
+//////////////////////////////////////////////////////////////////////
+// eap::diameter_avp_append
+//////////////////////////////////////////////////////////////////////
+
+void eap::diameter_avp_append(
+    _In_                       unsigned int    code,
+    _In_                       unsigned int    vendor_id,
+    _In_                       unsigned char   flags,
+    _In_bytecount_(size) const void            *data,
+    _In_                       unsigned int    size,
+    _Inout_                    sanitizing_blob &packet)
+{
+    unsigned int
+        padding = (unsigned int)((4 - size) % 4),
+        size_outer;
+
+    packet.reserve(
+        packet.size() + 
+        (size_outer = 
+        sizeof(diameter_avp_header_ven) + // Diameter header
+        size)                           + // Data
+        padding);                         // Data padding
+
+    // Diameter AVP header
+    diameter_avp_header_ven hdr;
+    *reinterpret_cast<unsigned int*>(hdr.code) = htonl(code);
+    hdr.flags = flags | diameter_avp_flag_vendor;
+    hton24(size_outer, hdr.length);
+    *reinterpret_cast<unsigned int*>(hdr.vendor) = htonl(vendor_id);
+    packet.insert(packet.end(), reinterpret_cast<const unsigned char*>(&hdr), reinterpret_cast<const unsigned char*>(&hdr + 1));
+
+    // Data
+    packet.insert(packet.end(), reinterpret_cast<const unsigned char*>(data), reinterpret_cast<const unsigned char*>(data) + size);
+    packet.insert(packet.end(), padding, 0);
+}
+
+
 //////////////////////////////////////////////////////////////////////
 // eap::packet
 //////////////////////////////////////////////////////////////////////