libnettle aes 256 ctr example encrypt/decrypt

libnettle-aes-256-ctr.c

#include <stdlib.h>
#include <stdio.h>
#include <stdint.h>
#include <string.h>
#include <nettle/aes.h>
#include <nettle/ctr.h>

int main() {

    struct aes256_ctx *ctx = malloc(sizeof(struct aes256_ctx));

    uint8_t key[32] = {148,86,234,177,203,100,167,131,80,160,6,244,74,153,
                         168,217,127,183,61,14,9,191,195,249,145,5,251,218,
                         232,170,152,31};

    // Encrypt
    uint8_t ctr[16] = {188,14,95,229,78,112,182,107,34,206,248,225,52,22,16,183};

    aes256_set_encrypt_key(ctx, key);

    uint8_t *clear_text = "hello";
    uint8_t *data = malloc(strlen(clear_text));

    ctr_crypt(ctx, (nettle_cipher_func *)aes256_encrypt,
              AES_BLOCK_SIZE, ctr,
              strlen(clear_text), data, clear_text);

    // Decrypt
    uint8_t ctr2[16] = {188,14,95,229,78,112,182,107,34,206,248,225,52,22,16,183};

    ctr_crypt(ctx, (nettle_cipher_func *)aes256_encrypt,
              AES_BLOCK_SIZE, ctr2,
              strlen(clear_text), data, data);

    printf("data: %s\n", data);    
    
    return 0;
}

i have one question, what is the strength of nettle against openssl? we can get the same aes encryption with openssl but i don't see the strength of nettle except in encrypting the key transmission