Dear all,
After extracting openssl-1.1.1.tar.gz, openssl can be configured
without asm by passing no-asm flag during config command.
The expanded key can be obtained like follows:
//Getting expanded key from inside openssl
//Copied from crypto/evp/e_aes.c
typedef struct {
union {
double align;
AES_KEY ks;
} ks;
block128_f block;
union {
cbc128_f cbc;
ctr128_f ctr;
} stream;
} EVP_AES_KEY;
EVP_CIPHER_CTX *cipher_ctx = ssl->enc_write_ctx;
EVP_AES_KEY * cipher_data = EVP_CIPHER_CTX_get_cipher_data(cipher_ctx);
printf("Encrypted Expanded Key is : ");
for(i=0;i<((cipher_ctx->cipher->key_len)/sizeof(cipher_data->ks.ks.rd_key[0])*11);i++)
{
printf("%08x", cipher_data->ks.ks.rd_key[i]);
}
printf("\n");
To get the 128 bit encrypted key :
unsigned char* key = unsigned char* malloc(16);
int i;
for (i=0; i<4; i++) {
key[4*i] = cipher_data->ks.ks.rd_key[i] >> 24;
key[4*i+1] = cipher_data->ks.ks.rd_key[i] >> 16;
key[4*i+2] = cipher_data->ks.ks.rd_key[i] >> 8;
key[4*i+3] = cipher_data->ks.ks.rd_key[i];
}
I am using this 128 bit key and using it in *Rijndael* Key Schedule
function to get the expanded key. The expanded key will be 128*11 bit long.
This expanded key is equal to the expanded key obtained from accessing
structures inside openssl(shown in section "Getting expanded key from
inside openssl" ) which is expected.
Now if I configure openssl without no-asm flag and get the expanded key
from inside openssl and compare it with the expanded key calculated using
the function I wrote. They are not equal. As far as I know there is only
one way to calculate expanded key. I have even checked whether the expanded
key inside openssl is inverse cipher expanded key but yet it is different.
Can someone point me in the right direction.
Thanks!
--
Best Regards,
Hemant Ranvir
*"To live a creative life, we must lose our fear of being wrong.**" -
J.C.Pearce*
--
openssl-users mailing list
To unsubscribe: https://mta.openssl.org/mailman/listinfo/openssl-users
