wc_AesSetKey len parameter in aes-file-encrypt example about wolfssl-examples

[embhorn]

Hi @kenyiesnc

You are absolutely correct! The passed in key size should be used when setting the AES key. I've also updated the README to be more clear that the key size is in bits.

[kenyiesnc]

Ran into errors when I pass in key size in bits... it seems like wc_AesSetKey requires key size to be passed in bytes? https://github.com/wolfSSL/wolfssl/blob/aa8e5a29d45f9327029311bfb1b8994feaa62368/wolfcrypt/src/aes.c#L90

[embhorn]

The wc_AesSetKey API does take size in bytes. The example passes in size in bits. I modified the example to convert the size in the SizeCheck function:

int SizeCheck(int *size)
{
    int ret = 0;

    /* Use key size values (size/8) */
    if (*size == 128) {
        *size = AES_128_KEY_SIZE;
    }
    else if (*size == 192) {
        *size = AES_192_KEY_SIZE;
    }
    else if (*size == 256) {
        *size = AES_256_KEY_SIZE;
    }
    else {
        /* if the entered size does not match acceptable size */
        printf("Invalid AES key size\n");
        ret = -1080;
    }

    return ret;
}

[kenyiesnc]

Ok thanks for confirming. I was using the example code as basis for code in my program.