[crypto] Add our own general-purpose cipher-block chaining routines

src/include/gpxe/cbc.h

@@ -0,0 +1,50 @@
+#ifndef _GPXE_CBC_H
+#define _GPXE_CBC_H
+
+/** @file
+ *
+ * Cipher-block chaining
+ *
+ */
+
+#include <gpxe/crypto.h>
+
+/**
+ * Set key
+ *
+ * @v ctx		Context
+ * @v key		Key
+ * @v keylen		Key length
+ * @v cipher		Underlying cipher algorithm
+ * @v cbc_ctx		CBC context
+ * @ret rc		Return status code
+ */
+static inline int cbc_setkey ( void *ctx, const void *key, size_t keylen,
+			       struct cipher_algorithm *cipher,
+			       void *cbc_ctx __unused ) {
+
+	return cipher_setkey ( cipher, ctx, key, keylen );
+}
+
+/**
+ * Set initialisation vector
+ *
+ * @v ctx		Context
+ * @v iv		Initialisation vector
+ * @v cipher		Underlying cipher algorithm
+ * @v cbc_ctx		CBC context
+ */
+static inline void cbc_setiv ( void *ctx __unused, const void *iv,
+			       struct cipher_algorithm *cipher,
+			       void *cbc_ctx ) {
+	memcpy ( cbc_ctx, iv, cipher->blocksize );
+}
+
+extern void cbc_encrypt ( void *ctx, const void *src, void *dst,
+			  size_t len, struct cipher_algorithm *cipher,
+			  void *cbc_ctx );
+extern void cbc_decrypt ( void *ctx, const void *src, void *dst,
+			  size_t len, struct cipher_algorithm *cipher,
+			  void *cbc_ctx );
+
+#endif /* _GPXE_CBC_H */