Added generic CHAP layer, independent of iSCSI

src/crypto/chap.c

@@ -0,0 +1,108 @@
+/*
+ * Copyright (C) 2006 Michael Brown <mbrown@fensystems.co.uk>.
+ *
+ * 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 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., 675 Mass Ave, Cambridge, MA 02139, USA.
+ */
+
+#include <stddef.h>
+#include <stdlib.h>
+#include <errno.h>
+#include <assert.h>
+#include <malloc.h>
+#include <gpxe/crypto.h>
+#include <gpxe/chap.h>
+
+/** @file
+ *
+ * CHAP protocol
+ *
+ */
+
+/**
+ * Initialise CHAP challenge/response
+ *
+ * @v chap		CHAP challenge/response
+ * @v digest		Digest algorithm to use
+ * @ret rc		Return status code
+ *
+ * Initialises a CHAP challenge/response structure.  This routine
+ * allocates memory, and so may fail.  The allocated memory must
+ * eventually be freed by a call to chap_finish().
+ */
+int chap_init ( struct chap_challenge *chap,
+		struct digest_algorithm *digest ) {
+	assert ( chap->digest == NULL );
+	assert ( chap->digest_context == NULL );
+	assert ( chap->response == NULL );
+
+	chap->digest = digest;
+	chap->digest_context = malloc ( digest->context_len );
+	if ( ! chap->digest_context )
+		goto err;
+	chap->response = malloc ( digest->digest_len );
+	if ( ! chap->response )
+		goto err;
+	chap->response_len = digest->digest_len;
+	chap->digest->init ( chap->digest_context );
+	return 0;
+
+ err:
+	chap_finish ( chap );
+	return -ENOMEM;
+}
+
+/**
+ * Add data to the CHAP challenge
+ *
+ * @v chap		CHAP challenge/response
+ * @v data		Data to add
+ * @v len		Length of data to add
+ */
+void chap_update ( struct chap_challenge *chap, const void *data,
+		   size_t len ) {
+	assert ( chap->digest != NULL );
+	assert ( chap->digest_context != NULL );
+
+	chap->digest->update ( chap->digest_context, data, len );
+}
+
+/**
+ * Respond to the CHAP challenge
+ *
+ * @v chap		CHAP challenge/response
+ *
+ * Calculates the final CHAP response value, and places it in @c
+ * chap->response, with a length of @c chap->response_len.
+ */
+void chap_respond ( struct chap_challenge *chap ) {
+	assert ( chap->digest != NULL );
+	assert ( chap->digest_context != NULL );
+	assert ( chap->response != NULL );
+
+	chap->digest->finish ( chap->digest_context, chap->response );
+}
+
+/**
+ * Free resources used by a CHAP challenge/response
+ *
+ * @v chap		CHAP challenge/response
+ */
+void chap_finish ( struct chap_challenge *chap ) {
+	free ( chap->digest_context );
+	chap->digest_context = NULL;
+	free ( chap->response );
+	chap->response = NULL;
+	chap->digest = NULL;
+}