implemented PGP fingerprinting

src/libstrongswan/plugins/pgp/Makefile.am

@@ -6,6 +6,7 @@ AM_CFLAGS = -rdynamic
 plugin_LTLIBRARIES = libstrongswan-pgp.la
 
 libstrongswan_pgp_la_SOURCES = pgp_plugin.h pgp_plugin.c \
+  pgp_encoder.h pgp_encoder.c \
   pgp_builder.h pgp_builder.c
 
 libstrongswan_pgp_la_LDFLAGS = -module -avoid-version

src/libstrongswan/plugins/pgp/pgp_encoder.c

@@ -0,0 +1,68 @@
+/*
+ * Copyright (C) 2009 Martin Willi
+ * Hochschule fuer Technik Rapperswil
+ *
+ * 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.  See <http://www.fsf.org/copyleft/gpl.txt>.
+ *
+ * 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.
+ */
+
+#include "pgp_encoder.h"
+
+#include <debug.h>
+
+/**
+ * Build a PGPv3 fingerprint
+ */
+static bool build_v3_fingerprint(chunk_t *encoding, va_list args)
+{
+	hasher_t *hasher;
+	chunk_t n, e;
+	
+	if (key_encoding_args(args, KEY_PART_RSA_MODULUS, &n,
+						  KEY_PART_RSA_PUB_EXP, &e, KEY_PART_END))
+	{
+		hasher = lib->crypto->create_hasher(lib->crypto, HASH_MD5);
+		if (!hasher)
+		{
+			DBG1("MD5 hash algorithm not supported, PGP fingerprinting failed");
+			return FALSE;
+		}
+		/* remove leading zero bytes before hashing modulus and exponent */
+		while (n.len > 0 && n.ptr[0] == 0x00)
+		{
+			n = chunk_skip(n, 1);
+		}
+		while (e.len > 0 && e.ptr[0] == 0x00)
+		{
+			e = chunk_skip(e, 1);
+		}
+		hasher->allocate_hash(hasher, n, NULL);
+		hasher->allocate_hash(hasher, e, encoding);
+		hasher->destroy(hasher);
+		return TRUE;
+	}
+	return FALSE;
+}
+
+/**
+ * See header.
+ */
+bool pgp_encoder_encode(key_encoding_type_t type, chunk_t *encoding,
+						  va_list args)
+{
+	switch (type)
+	{
+		case KEY_ID_PGPV3:
+			return build_v3_fingerprint(encoding, args);
+		default:
+			return FALSE;
+	}
+}
+

src/libstrongswan/plugins/pgp/pgp_encoder.h

@@ -0,0 +1,32 @@
+/*
+ * Copyright (C) 2009 Martin Willi
+ * Hochschule fuer Technik Rapperswil
+ *
+ * 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.  See <http://www.fsf.org/copyleft/gpl.txt>.
+ *
+ * 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.
+ */
+
+/**
+ * @defgroup pgp_encoder pgp_encoder
+ * @{ @ingroup pgp
+ */
+
+#ifndef PGP_ENCODER_H_
+#define PGP_ENCODER_H_
+
+#include <credentials/keys/key_encoding.h>
+
+/**
+ * Encoding function for PGP fingerprints.
+ */
+bool pgp_encoder_encode(key_encoding_type_t type, chunk_t *encoding,
+						va_list args);
+
+#endif /* PGP_ENCODER_ @}*/

src/libstrongswan/plugins/pgp/pgp_plugin.c

@@ -17,6 +17,7 @@
 
 #include <library.h>
 #include "pgp_builder.h"
+#include "pgp_encoder.h"
 
 typedef struct private_pgp_plugin_t private_pgp_plugin_t;
 
@@ -40,6 +41,9 @@ static void destroy(private_pgp_plugin_t *this)
 							(builder_constructor_t)pgp_public_key_builder);
 	lib->creds->remove_builder(lib->creds,
 							(builder_constructor_t)pgp_private_key_builder);
+	
+	lib->encoding->remove_encoder(lib->encoding, pgp_encoder_encode);
+	
 	free(this);
 }
 
@@ -59,6 +63,8 @@ plugin_t *plugin_create()
 	lib->creds->add_builder(lib->creds, CRED_PRIVATE_KEY, KEY_RSA,
 							(builder_constructor_t)pgp_private_key_builder);
 	
+	lib->encoding->add_encoder(lib->encoding, pgp_encoder_encode);
+	
 	return &this->public.plugin;
 }