Hello Dear Friends!
I use STM32F439 MCU and it has AES encryption peripheral. I tried to encrypt data in the format of uint32_t and it encrypted data and I tested it successfully on online tools. However, I wanted to encrypt data in the format of char which will be transferred by tcp/ip protocol. Then, when I recived this encrypted data in the format of hex it did not recive in true format. On the other hand, when I decrypt the encrypted data I got data that I sent at first. Therefore, it decrypts data correctly. But there is something wrong in the step of encryption of data. I searched for endianless topic for this problem on google but I could not solve it. Is there anyone who will help me?
From now on, thanks for helps!
The related part of codes are avaiable as shown below;
char spi_mydata[16];
uint32_t spi_encrypted_data[16];
static err_t tcp_rmii_recv(void *arg, struct tcp_pcb *pcb, struct pbuf *p, err_t err){
int i;
int len;
char *pc;
if (err == ERR_OK && p != NULL) {
/* Inform TCP that we have taken the data. */
tcp_recved(pcb, p->tot_len);
//pointer to the pay load
pc=(char *)p->payload;
//size of the pay load
len =p->tot_len;
//copy to our own buffer
for (i=0; i<len; i++){
spi_mydata[i]= pc[i];
}
//Close TCP when receiving "X"
if (spi_mydata[0]=='X'){
close_conn(pcb);
}
//Free the packet buffer
pbuf_free(p);
//check output buffer capacity
if (len >tcp_sndbuf(tcp_spi_conn_pcb)){
len= tcp_sndbuf(tcp_spi_conn_pcb);
}
//Send out the data
HAL_CRYP_Encrypt(&hcryp, (uint32_t*)spi_mydata, 16, spi_encrypted_data, 1000);
err = tcp_write(tcp_spi_conn_pcb,spi_encrypted_data , len, 0);
tcp_sent(tcp_spi_conn_pcb, NULL); /* No need to call back */
}
else {
pbuf_free(p);
}
if (err == ERR_OK && p == NULL) {
close_conn(pcb);
}
return ERR_OK;
}
