esp32sha256.txt

#include "mbedtls/md.h"

void setup()
{
Serial.begin(115200);

char *payload = "Hello SHA 256 from ESP32learning";
byte shaResult[32];

mbedtls_md_context_t ctx;
mbedtls_md_type_t md_type = MBEDTLS_MD_SHA256;

const size_t payloadLength = strlen(payload);

mbedtls_md_init(&ctx);
mbedtls_md_setup(&ctx, mbedtls_md_info_from_type(md_type), 0);
mbedtls_md_starts(&ctx);
mbedtls_md_update(&ctx, (const unsigned char *) payload, payloadLength);
mbedtls_md_finish(&ctx, shaResult);
mbedtls_md_free(&ctx);

Serial.print("Hash: ");

for(int i= 0; i< sizeof(shaResult); i++)
{
char str[3];
sprintf(str, "%02x", (int)shaResult[i]);
Serial.print(str);
}
}

void loop()
{
}