Introduce the s96at library

Add s96at.h, which defines and documents the library API
as well as s96at.c which contains the implementation.

Add auxiliary sha.c which contain the implementation
of the SHA-256 padding according to FIPS 180-2.

Update CMakeLists.txt to build libs96at.so.

Remove obsolete files.

Signed-off-by: Michalis Pappas <mpappas@fastmail.fm>

s96at/CMakeLists.txt

@@ -1,5 +1,5 @@
 #set(CMAKE_TOOLCHAIN_FILE CMakeToolchain.txt)
-project(s96-204 C)
+project(s96at C)
 
 # Required cmake version
 cmake_minimum_required(VERSION 3.0.2)
@@ -11,19 +11,22 @@ MESSAGE(STATUS "CMAKE_C_COMPILER: " ${CMAKE_C_COMPILER})
 add_compile_options(-Wall -Werror)
 include_directories(include)
 
-set(SRC ${CMAKE_SOURCE_DIR}/src/cmd.c
+set(SRC ${CMAKE_SOURCE_DIR}/src/s96at.c
+	${CMAKE_SOURCE_DIR}/src/cmd.c
 	${CMAKE_SOURCE_DIR}/src/crc.c
 	${CMAKE_SOURCE_DIR}/src/debug.c
 	${CMAKE_SOURCE_DIR}/src/io.c
 	${CMAKE_SOURCE_DIR}/src/i2c_linux.c
-	${CMAKE_SOURCE_DIR}/src/packet.c)
+	${CMAKE_SOURCE_DIR}/src/packet.c
+	${CMAKE_SOURCE_DIR}/src/sha.c)
 
 set(I2C_DEVICE "/dev/i2c-0")
 
 #add_definitions(-DEXT_DEBUG_INFO)
 add_definitions(-DCMAKE_BUILD_TYPE=Debug)
 
-add_executable(${PROJECT_NAME} ${SRC} ${CMAKE_SOURCE_DIR}/src/main.c)
+add_library(${PROJECT_NAME} SHARED ${SRC})
+set_target_properties(${PROJECT_NAME} PROPERTIES PUBLIC_HEADER include/s96at.h)
 
 target_compile_definitions(${PROJECT_NAME}
 	PRIVATE -DI2C_DEVICE="${I2C_DEVICE}"

s96at/include/cmd.h

@@ -21,35 +21,41 @@ enum {
 #define ZONE_OTP_SIZE 		64
 #define ZONE_DATA_SIZE		512
 
+#define ZONE_CONFIG_NUM_WORDS  22
+#define ZONE_DATA_NUM_SLOTS    16
+#define ZONE_OTP_NUM_WORDS     16
+
 #define LOCK_CONFIG_LOCKED	0x0
 #define LOCK_CONFIG_UNLOCKED	0x55
 #define LOCK_DATA_LOCKED	0x0
 #define LOCK_DATA_UNLOCKED	0x55
 
-/* Sizes for out parameter (RandOut) */
-#define NONCE_SHORT_LEN		1
-#define NONCE_LONG_LEN		32
-
-/* Sizes for in parameter (NumIn) */
-#define NONCE_SHORT_NUMIN	20
-#define NONCE_LONG_NUMIN	32
-
-#define NONCE_MODE_UPDATE_SEED  0
-#define NONCE_MODE_NO_SEED      1
-#define NONCE_MODE_PASSTHROUGH  3
+#define TEMPKEY_SOURCE_RANDOM	0
+#define TEMPKEY_SOURCE_INPUT	1
 
 #define HMAC_LEN		32
 #define RANDOM_LEN		32
 #define DEVREV_LEN		4
 #define SERIALNUM_LEN		9
 #define MAC_LEN			32
 #define SHA_LEN			32
-#define SHA_BLOCK_LEN		64
 
 #define WORD_SIZE		4
 #define MAX_READ_SIZE		32 /* bytes */
 #define MAX_WRITE_SIZE		32
 
+#define MAC_MODE_TEMPKEY_SOURCE_SHIFT  2
+#define MAC_MODE_USE_OTP_88_BITS_SHIFT 4
+#define MAC_MODE_USE_OTP_64_BITS_SHIFT 5
+#define MAC_MODE_USE_SN_SHIFT          6
+
+#define NONCE_MODE_RANDOM		0
+#define NONCE_MODE_RANDOM_NO_SEED	1
+#define NONCE_MODE_PASSTHROUGH		3
+
+#define SHA_MODE_INIT          0x00
+#define SHA_MODE_COMPUTE       0x01
+
 /* Word address values */
 #define PKT_FUNC_RESET		0x0
 #define PKT_FUNC_SLEEP		0x1