Basic support for EAC documents (e.g. German Identification Card)

-new files armsrc/epa.[ch] for ePA (electronic "Personalausweis") related functions
    -Offers elementary functions (EPA_PACE_MSE_Set_AT etc.)
    -Also offers one new USB command: EPA_PACE_Collect_Nonce
-created new command subtree in client: client/hfepa.[ch] ("hf epa")
    -offers "hf epa cnonces" (collect encrypted PACE nonces)
-more to come

armsrc/epa.h

@@ -0,0 +1,36 @@
+//-----------------------------------------------------------------------------
+// Frederik Möllers - August 2012
+//
+// This code is licensed to you under the terms of the GNU GPL, version 2 or,
+// at your option, any later version. See the LICENSE.txt file for the text of
+// the license.
+//-----------------------------------------------------------------------------
+// Routines to support the German eletronic "Personalausweis" (ID card)
+//-----------------------------------------------------------------------------
+
+#ifndef __EPA_H
+#define __EPA_H
+
+// this struct is used by EPA_Parse_CardAccess and contains info about the
+// PACE protocol supported by the chip
+typedef struct {
+	uint8_t oid[10];
+	uint8_t version;
+	uint8_t parameter_id;
+} pace_version_info_t;
+
+// note: EPA_PACE_GetNonce is declared in apps.h
+
+// general functions
+void EPA_Finish();
+size_t EPA_Parse_CardAccess(uint8_t *data,
+                            size_t length,
+                            pace_version_info_t *pace_info);
+int EPA_Read_CardAccess(uint8_t *buffer, size_t max_length);
+int EPA_Setup();
+
+// PACE related functions
+int EPA_PACE_MSE_Set_AT(pace_version_info_t pace_version_info, uint8_t password);
+int EPA_PACE_Get_Nonce(uint8_t requested_length, uint8_t *nonce);
+
+#endif /* __EPA_H */