Added sha204 library

Taken from the sha204_library folder in
https://github.com/jimblom/sha204-Breakout
Commit 8e1ac05ef987b1869605ad067db2bdbaec1c109f

ATSHA204 is a crypto cirquit from Atmel that enables
SHA256-based MAC and HMAC calculations as well as
secure key storage and random number generation.

This can be used to sign messages passed between
sensor nodes and prevent both man-in-the-middle and
replay attacking.

libraries/sha204/sha204_includes/sha204_lib_return_codes.h

@@ -0,0 +1,48 @@
+// ----------------------------------------------------------------------------
+//         ATMEL Microcontroller Software Support  -  Colorado Springs, CO -
+// ----------------------------------------------------------------------------
+// DISCLAIMER:  THIS SOFTWARE IS PROVIDED BY ATMEL "AS IS" AND ANY EXPRESS OR
+// IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES OF
+// MERCHANTABILITY, FITNESS FOR A PARTICULAR PURPOSE AND NON-INFRINGEMENT ARE
+// DISCLAIMED. IN NO EVENT SHALL ATMEL 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.
+// ----------------------------------------------------------------------------
+
+/** \file
+ *  \brief SHA204 Library Return Code Definitions
+ *  \author Atmel Crypto Products
+ *  \date  September 27, 2010
+ */
+
+#ifndef SHA204_LIB_RETURN_CODES_H
+#   define SHA204_LIB_RETURN_CODES_H
+
+#include <stddef.h>                 // data type definitions
+
+/** \todo Use same values for same meanings for SHA204 and AES132.
+ * */
+
+#define SHA204_SUCCESS              ((uint8_t)  0x00) //!< Function succeeded.
+#define SHA204_PARSE_ERROR          ((uint8_t)  0xD2) //!< response status byte indicates parsing error
+#define SHA204_CMD_FAIL             ((uint8_t)  0xD3) //!< response status byte indicates command execution error
+#define SHA204_STATUS_CRC           ((uint8_t)  0xD4) //!< response status byte indicates CRC error
+#define SHA204_STATUS_UNKNOWN       ((uint8_t)  0xD5) //!< response status byte is unknown
+#define SHA204_FUNC_FAIL            ((uint8_t)  0xE0) //!< Function could not execute due to incorrect condition / state.
+#define SHA204_GEN_FAIL             ((uint8_t)  0xE1) //!< unspecified error
+#define SHA204_BAD_PARAM            ((uint8_t)  0xE2) //!< bad argument (out of range, null pointer, etc.)
+#define SHA204_INVALID_ID           ((uint8_t)  0xE3) //!< invalid device id, id not set
+#define SHA204_INVALID_SIZE         ((uint8_t)  0xE4) //!< Count value is out of range or greater than buffer size.
+#define SHA204_BAD_CRC              ((uint8_t)  0xE5) //!< incorrect CRC received
+#define SHA204_RX_FAIL              ((uint8_t)  0xE6) //!< Timed out while waiting for response. Number of bytes received is > 0.
+#define SHA204_RX_NO_RESPONSE       ((uint8_t)  0xE7) //!< Not an error while the Command layer is polling for a command response.
+#define SHA204_RESYNC_WITH_WAKEUP   ((uint8_t)  0xE8) //!< re-synchronization succeeded, but only after generating a Wake-up
+
+#define SHA204_COMM_FAIL            ((uint8_t)  0xF0) //!< Communication with device failed. Same as in hardware dependent modules.
+#define SHA204_TIMEOUT              ((uint8_t)  0xF1) //!< Timed out while waiting for response. Number of bytes received is 0.
+
+#endif