Use counter mode encryption.

This commit is contained in:
Guus Sliepen 2011-10-06 09:34:34 +02:00
parent a0f795ff5b
commit 3b5898078a

View file

@ -45,7 +45,7 @@ char *logfilename;
Maybe do add some alert messages to give helpful error messages? Not more than TLS sends.
Use counter mode instead of OFB.
Use counter mode instead of OFB. (done)
Make sure ECC operations are fixed time (aka prevent side-channel attacks).
*/
@ -78,7 +78,7 @@ static bool send_record_priv(sptps_t *s, uint8_t type, const char *data, uint16_
if(!digest_create(&s->outdigest, plaintext, len + 7, plaintext + 7 + len))
return false;
if(!cipher_encrypt(&s->outcipher, plaintext + 4, sizeof ciphertext, ciphertext, NULL, false))
if(!cipher_counter_xor(&s->outcipher, plaintext + 4, sizeof ciphertext, ciphertext))
return false;
return s->send_data(s->handle, ciphertext, len + 19);
@ -149,8 +149,8 @@ static bool generate_key_material(sptps_t *s, const char *shared, size_t len) {
// Initialise cipher and digest structures if necessary
if(!s->outstate) {
bool result
= cipher_open_by_name(&s->incipher, "aes-256-ofb")
&& cipher_open_by_name(&s->outcipher, "aes-256-ofb")
= cipher_open_by_name(&s->incipher, "aes-256-ecb")
&& cipher_open_by_name(&s->outcipher, "aes-256-ecb")
&& digest_open_by_name(&s->indigest, "sha256", 16)
&& digest_open_by_name(&s->outdigest, "sha256", 16);
if(!result)
@ -251,17 +251,17 @@ static bool receive_sig(sptps_t *s, const char *data, uint16_t len) {
// TODO: only set new keys after ACK has been set/received
if(s->initiator) {
bool result
= cipher_set_key(&s->incipher, s->key, false)
= cipher_set_counter_key(&s->incipher, s->key)
&& digest_set_key(&s->indigest, s->key + cipher_keylength(&s->incipher), digest_keylength(&s->indigest))
&& cipher_set_key(&s->outcipher, s->key + cipher_keylength(&s->incipher) + digest_keylength(&s->indigest), true)
&& cipher_set_counter_key(&s->outcipher, s->key + cipher_keylength(&s->incipher) + digest_keylength(&s->indigest))
&& digest_set_key(&s->outdigest, s->key + cipher_keylength(&s->incipher) + digest_keylength(&s->indigest) + cipher_keylength(&s->outcipher), digest_keylength(&s->outdigest));
if(!result)
return false;
} else {
bool result
= cipher_set_key(&s->outcipher, s->key, true)
= cipher_set_counter_key(&s->outcipher, s->key)
&& digest_set_key(&s->outdigest, s->key + cipher_keylength(&s->outcipher), digest_keylength(&s->outdigest))
&& cipher_set_key(&s->incipher, s->key + cipher_keylength(&s->outcipher) + digest_keylength(&s->outdigest), false)
&& cipher_set_counter_key(&s->incipher, s->key + cipher_keylength(&s->outcipher) + digest_keylength(&s->outdigest))
&& digest_set_key(&s->indigest, s->key + cipher_keylength(&s->outcipher) + digest_keylength(&s->outdigest) + cipher_keylength(&s->incipher), digest_keylength(&s->indigest));
if(!result)
return false;
@ -326,7 +326,7 @@ bool receive_data(sptps_t *s, const char *data, size_t len) {
toread = len;
if(s->instate) {
if(!cipher_decrypt(&s->incipher, data, toread, s->inbuf + s->buflen, NULL, false))
if(!cipher_counter_xor(&s->incipher, data, toread, s->inbuf + s->buflen))
return false;
} else {
memcpy(s->inbuf + s->buflen, data, toread);
@ -366,7 +366,7 @@ bool receive_data(sptps_t *s, const char *data, size_t len) {
toread = len;
if(s->instate) {
if(!cipher_decrypt(&s->incipher, data, toread, s->inbuf + s->buflen, NULL, false))
if(!cipher_counter_xor(&s->incipher, data, toread, s->inbuf + s->buflen))
return false;
} else {
memcpy(s->inbuf + s->buflen, data, toread);