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diff --git a/inc/platform/sha256.h b/inc/platform/sha256.h
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+/*********************************************************************
+* Filename:   sha256.h
+* Author:     Brad Conte (brad AT bradconte.com)
+* Copyright:
+* Disclaimer: This code is presented "as is" without any guarantees.
+* Details:    Defines the API for the corresponding SHA1 implementation.
+*********************************************************************/
+
+/*
+ This code is released into the public domain free of any restrictions.
+ The author requests acknowledgement if the code is used, but does not require it.
+ This code is provided free of any liability and without any quality claims by the author.
+ https://github.com/B-Con/crypto-algorithms
+ */
+
+#ifndef SHA256_H
+#define SHA256_H
+
+/*************************** HEADER FILES ***************************/
+#include <stdint.h>
+#include <stdbool.h>
+#include <string.h>
+
+/** @defgroup  SHA256_API Sha256
+    * @brief APIs for using SHA256
+    * @{
+    */
+
+/*============================================================================*
+ *                              Macros
+ *============================================================================*/
+/** @defgroup SHA256_API_Exported_Macros SHA256 APIs Exported Macros
+    * @{
+    */
+
+#define SHA256_BLOCK_SIZE 32            // SHA256 outputs a 32 byte digest
+
+#define SHA256_USE_DYNAMIC_ALLOC 0
+
+/** End of SHA256_API_Exported_Macros
+    * @}
+    */
+
+/*============================================================================*
+ *                              Types
+ *============================================================================*/
+/** @defgroup SHA256_API_Exported_Types SHA256 APIs Exported Types
+    * @{
+    */
+
+typedef unsigned char BYTE;             // 8-bit byte
+typedef unsigned int  WORD;             // 32-bit word, change to "long" for 16-bit machines
+
+/**  @brief Context structure to store SHA256 algorithm intermediate information */
+typedef struct
+{
+    BYTE data[64];
+    WORD datalen;
+    unsigned long long bitlen;
+    WORD state[8];
+} SHA256_CTX;
+
+/** End of SHA256_API_Exported_Types
+    * @}
+    */
+
+/*============================================================================*
+ *                              Functions
+ *============================================================================*/
+/** @defgroup SHA256_API_Exported_Functions SHA256 APIs Exported Functions
+    * @brief
+    * @{
+    */
+
+void SHA256_Init(SHA256_CTX *ctx);
+void SHA256_Update(SHA256_CTX *ctx, const BYTE data[], size_t len);
+void SHA256_Final(SHA256_CTX *ctx, BYTE hash[]);
+void SHA256(const void *in, size_t len, uint8_t *result);
+bool SHA256_Alloc(SHA256_CTX **ctx);
+void SHA256_Free(SHA256_CTX *ctx);
+
+/** End of SHA256_API_Exported_Functions
+    * @}
+    */
+
+
+/** End of SHA256_API
+    * @}
+    */
+
+#endif   // SHA256_H
+