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diff --git a/TPM2-Plugin/lib/include/tpm2_error.h b/TPM2-Plugin/lib/include/tpm2_error.h
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+//**********************************************************************;
+// Copyright (c) 2018, Intel Corporation
+// All rights reserved.
+//
+// Redistribution and use in source and binary forms, with or without
+// modification, are permitted provided that the following conditions are met:
+//
+// 1. Redistributions of source code must retain the above copyright notice,
+// this list of conditions and the following disclaimer.
+//
+// 2. 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.
+//
+// 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 HOLDER 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 LIB_TPM2_ERROR_H_
+#define LIB_TPM2_ERROR_H_
+
+#include <stdbool.h>
+
+#include <sapi/tpm20.h>
+
+/**
+ * Number of error layers
+ */
+#define TPM2_ERROR_TSS2_RC_LAYER_COUNT (TSS2_RC_LAYER_MASK >> TSS2_RC_LAYER_SHIFT)
+
+/**
+ * Mask for the error bits of tpm2 compliant return code.
+ */
+#define TPM2_ERROR_TSS2_RC_ERROR_MASK 0xFFFF
+
+/**
+ * Retrieves the error bits from a TSS2_RC. The error bits are
+ * contained in the first 2 octets.
+ * @param rc
+ *  The rc to query for the error bits.
+ * @return
+ *  The error bits.
+ */
+static inline UINT16 tpm2_error_get(TSS2_RC rc) {
+    return ((rc & TPM2_ERROR_TSS2_RC_ERROR_MASK));
+}
+
+/**
+ * A custom error handler prototype.
+ * @param rc
+ *  The rc to decode with only the error bits set, ie no need to mask the
+ *  layer bits out. Handlers will never be invoked with the error bits set
+ *  to 0, as zero always indicates success.
+ * @return
+ *  An error string describing the rc. If the handler cannot determine
+ *  a valid response, it can return NULL indicating that the framework
+ *  should just print the raw hexidecimal value of the error field of
+ *  a tpm2_err_layer_rc.
+ *  Note that this WILL NOT BE FREED by the caller,
+ *  i.e. static.
+ */
+typedef const char *(*tpm2_error_handler)(TSS2_RC rc);
+
+/**
+ * Register or unregister a custom layer error handler.
+ * @param layer
+ *  The layer in which to register a handler for. It is an error
+ *  to register for the following reserved layers:
+ *    - TSS2_TPM_RC_LAYER  - layer  0
+ *    - TSS2_SYS_RC_LAYER  - layer  8
+ *    - TSS2_MU_RC_LAYER   - layer  9
+ *    - TSS2_TCTI_RC_LAYER - layer 10
+ * @param name
+ *  A friendly layer name. It is an error for the name to be of
+ *  length 0 or greater than 4.
+ * @param handler
+ *  The handler function to register or NULL to unregister.
+ * @return
+ *  True on success or False on error.
+ */
+bool tpm2_error_set_handler(UINT8 layer, const char *name,
+        tpm2_error_handler handler);
+
+/**
+ * Given a TSS2_RC return code, provides a static error string in the format:
+ * <layer-name>:<layer-specific-msg>.
+ *
+ * The layer-name section will either be the friendly name, or if no layer
+ * handler is registered, the base10 layer number.
+ *
+ * The "layer-specific-msg" is layer specific and will contain details on the
+ * error that occurred or the error code if it couldn't look it up.
+ *
+ * Known layer specific substrings:
+ * TPM - The tpm layer produces 2 distinct format codes that allign with:
+ *   - Section 6.6 of: https://trustedcomputinggroup.org/wp-content/uploads/TPM-Rev-2.0-Part-2-Structures-01.38.pdf
+ *   - Section 39.4 of: https://trustedcomputinggroup.org/wp-content/uploads/TPM-Rev-2.0-Part-1-Architecture-01.38.pdf
+ *
+ *   The two formats are format 0 and format 1.
+ *   Format 0 string format:
+ *     - "<error|warn>(<version>): <description>
+ *     - Examples:
+ *       - error(1.2): bad tag
+ *       - warn(2.0): the 1st handle in the handle area references a transient object or session that is not loaded
+ *
+ *   Format 1 string format:
+ *      - <handle|session|parameter>(<index>):<description>
+ *      - Examples:
+ *        - handle(unk):value is out of range or is not correct for the context
+ *        - tpm:handle(5):value is out of range or is not correct for the context
+ *
+ *   Note that passing TPM2_RC_SUCCESS results in the layer specific message of "success".
+ *
+ *   The System, TCTI and Marshaling (MU) layers, all define simple string
+ *   returns analogous to strerror(3).
+ *
+ *   Unknown layers will have the layer number in decimal and then a layer specific string of
+ *   a hex value representing the error code. For example: 9:0x3
+ *
+ * @param rc
+ *  The error code to decode.
+ * @return
+ *  A human understandable error description string.
+ */
+const char *tpm2_error_str(TSS2_RC rc);
+
+#endif /* LIB_TPM2_ERROR_H_ */