#include <stdio.h>
#include <string.h>

#include <mbedtls/md.h>

void show_sha256(char *buf, size_t len) {
    uint8_t output[32];
    memset(output, 0, sizeof(output));

    mbedtls_md_context_t ctx;
    mbedtls_md_init(&ctx);
    mbedtls_md_setup(&ctx, mbedtls_md_info_from_type(MBEDTLS_MD_SHA256), 0);
    mbedtls_md_starts(&ctx);
    mbedtls_md_update(&ctx, (const unsigned char *)buf, len);
    mbedtls_md_finish(&ctx, output);
    mbedtls_md_free(&ctx);

    for (int i = 0; i < sizeof(output); i++) {
        printf("%02x", output[i]);
    }
    printf("\n");

    return;
}