port: freertos: implement sha256 API

Signed-off-by: Mike Szczys <[email protected]>

port/freertos/golioth_sys_freertos.c

@@ -4,11 +4,14 @@
  * SPDX-License-Identifier: Apache-2.0
  */
 #include <golioth/golioth_sys.h>
+#include <golioth/golioth_status.h>
 #include <FreeRTOS.h>
 #include <task.h>
 #include <semphr.h>
 #include <timers.h>
 #include <string.h>  // memset
+#include "../utils/hex.h"
+#include "mbedtls/sha256.h"
 
 /*--------------------------------------------------
  * Time
@@ -192,6 +195,76 @@ void golioth_sys_thread_destroy(golioth_sys_thread_t thread)
     vTaskDelete((TaskHandle_t) thread);
 }
 
+/*-------------------------------------------------
+ * Hash
+ *------------------------------------------------*/
+
+golioth_sys_sha256_t golioth_sys_sha256_create(void)
+{
+    mbedtls_sha256_context *hash = golioth_sys_malloc(sizeof(mbedtls_sha256_context));
+    if (!hash)
+    {
+        return NULL;
+    }
+
+    mbedtls_sha256_init(hash);
+    mbedtls_sha256_starts(hash, 0);
+
+    return (golioth_sys_sha256_t) hash;
+}
+
+void golioth_sys_sha256_destroy(golioth_sys_sha256_t sha_ctx)
+{
+    if (!sha_ctx)
+    {
+        return;
+    }
+
+    mbedtls_sha256_context *hash = sha_ctx;
+    mbedtls_sha256_free(hash);
+}
+
+enum golioth_status golioth_sys_sha256_update(golioth_sys_sha256_t sha_ctx,
+                                              const uint8_t *input,
+                                              size_t len)
+{
+    if (!sha_ctx || !input)
+    {
+        return GOLIOTH_ERR_NULL;
+    }
+
+    mbedtls_sha256_context *hash = sha_ctx;
+    int err = mbedtls_sha256_update(hash, input, len);
+    if (err)
+    {
+        return GOLIOTH_ERR_FAIL;
+    }
+
+    return GOLIOTH_OK;
+}
+
+enum golioth_status golioth_sys_sha256_finish(golioth_sys_sha256_t sha_ctx, uint8_t *output)
+{
+    if (!sha_ctx || !output)
+    {
+        return GOLIOTH_ERR_NULL;
+    }
+
+    mbedtls_sha256_context *hash = sha_ctx;
+    int err = mbedtls_sha256_finish(hash, output);
+    if (err)
+    {
+        return GOLIOTH_ERR_FAIL;
+    }
+
+    return GOLIOTH_OK;
+}
+
+size_t golioth_sys_hex2bin(const char *hex, size_t hexlen, uint8_t *buf, size_t buflen)
+{
+    return hex2bin(hex, hexlen, buf, buflen);
+}
+
 /*--------------------------------------------------
  * Misc
  *------------------------------------------------*/