Added generic CHAP layer, independent of iSCSI

src/include/gpxe/chap.h

@@ -0,0 +1,51 @@
+#ifndef _GPXE_CHAP_H
+#define _GPXE_CHAP_H
+
+/** @file
+ *
+ * CHAP protocol
+ *
+ */
+
+#include <stdint.h>
+#include <gpxe/md5.h>
+
+struct digest_algorithm;
+
+/** A CHAP challenge/response */
+struct chap_challenge {
+	/** Digest algorithm used for the response */
+	struct digest_algorithm *digest;
+	/** Context used by the digest algorithm */
+	uint8_t *digest_context;
+	/** CHAP response */
+	uint8_t *response;
+	/** Length of CHAP response */
+	size_t response_len;
+};
+
+extern int chap_init ( struct chap_challenge *chap,
+		       struct digest_algorithm *digest );
+extern void chap_update ( struct chap_challenge *chap, const void *data,
+			  size_t len );
+extern void chap_respond ( struct chap_challenge *chap );
+extern void chap_finish ( struct chap_challenge *chap );
+
+/**
+ * Add identifier data to the CHAP challenge
+ *
+ * @v chap		CHAP challenge/response
+ * @v identifier	CHAP identifier
+ *
+ * The CHAP identifier is the first byte of the CHAP challenge.  This
+ * function is a notational convenience for calling chap_update() for
+ * the identifier byte.
+ */
+static inline void chap_set_identifier ( struct chap_challenge *chap,
+					 unsigned int identifier ) {
+	uint8_t ident_byte = identifier;
+
+	chap_update ( chap, &ident_byte, sizeof ( ident_byte ) );
+}
+
+#endif /* _GPXE_CHAP_H */