- initial import

src/libs/srtp/crypto/include/gf2_8.h

@@ -0,0 +1,79 @@
+/*
+ * gf2_8.h
+ *
+ * GF(256) implementation
+ *
+ * David A. McGrew
+ * Cisco Systems, Inc.
+ */
+
+/*
+ *	
+ * Copyright (c) 2001-2006, Cisco Systems, Inc.
+ * All rights reserved.
+ * 
+ * Redistribution and use in source and binary forms, with or without
+ * modification, are permitted provided that the following conditions
+ * are met:
+ * 
+ *   Redistributions of source code must retain the above copyright
+ *   notice, this list of conditions and the following disclaimer.
+ * 
+ *   Redistributions in binary form must reproduce the above
+ *   copyright notice, this list of conditions and the following
+ *   disclaimer in the documentation and/or other materials provided
+ *   with the distribution.
+ * 
+ *   Neither the name of the Cisco Systems, Inc. nor the names of its
+ *   contributors may be used to endorse or promote products derived
+ *   from this software without specific prior written permission.
+ * 
+ * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
+ * "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT
+ * LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS
+ * FOR A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE
+ * COPYRIGHT HOLDERS OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT,
+ * INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES
+ * (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR
+ * SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
+ * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT,
+ * STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE)
+ * ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED
+ * OF THE POSSIBILITY OF SUCH DAMAGE.
+ *
+ */
+
+
+#ifndef GF2_8_H
+#define GF2_8_H
+
+#include "datatypes.h"  /* for uint8_t definition */
+
+typedef uint8_t gf2_8;
+
+#define gf2_8_field_polynomial 0x1B
+
+/*
+ * gf2_8_shift(x) returns 
+ */
+
+/*
+ * gf2_8_shift(z) returns the result of the GF(2^8) 'multiply by x' 
+ * operation, using the field representation from AES; that is, the 
+ * next gf2_8 value in the cyclic representation of that field.  The 
+ * value z should be an uint8_t.
+ */
+
+#define gf2_8_shift(z) (((z) & 128) ? \
+       (((z) << 1) ^ gf2_8_field_polynomial) : ((z) << 1))
+
+gf2_8
+gf2_8_compute_inverse(gf2_8 x);
+
+void
+test_gf2_8(void);
+
+gf2_8
+gf2_8_multiply(gf2_8 x, gf2_8 y);
+
+#endif /* GF2_8_H */