dark/zerotiertspu
1
0
Fork 0
Code Issues Pull requests Projects Releases Packages Wiki Activity Actions

Some code cleanup and make sure any type punning is guarded with ZT_NO_TYPE_PUNNING.

Browse source
This commit is contained in:
Adam Ierymenko 2017-04-20 09:33:35 -07:00
parent e7a2c6ecef
commit a8ced184dc
4 changed files with 76 additions and 63 deletions
Download patch file Download diff file Expand all files Collapse all files

60
node/Packet.cpp
View file

@ -1109,38 +1109,26 @@ void Packet::armor(const void *key,bool encryptPayload,unsigned int counter)
setCipher(encryptPayload ? ZT_PROTO_CIPHER_SUITE__C25519_POLY1305_SALSA2012 : ZT_PROTO_CIPHER_SUITE__C25519_POLY1305_NONE);
_salsa20MangleKey((const unsigned char *)key,mangledKey);
if (ZT_HAS_FAST_CRYPTO()) {
const unsigned int payloadLen = (encryptPayload) ? (size() - ZT_PACKET_IDX_VERB) : 0;
const unsigned int encryptLen = (encryptPayload) ? (size() - ZT_PACKET_IDX_VERB) : 0;
uint64_t keyStream[(ZT_PROTO_MAX_PACKET_LENGTH + 64 + 8) / 8];
ZT_FAST_SINGLE_PASS_SALSA2012(keyStream,payloadLen + 64,(data + ZT_PACKET_IDX_IV),mangledKey);
uint64_t *ksptr = keyStream + 8; // encryption starts after first Salsa20 block
uint8_t *dptr = data + ZT_PACKET_IDX_VERB;
unsigned int ksrem = payloadLen;
while (ksrem >= 8) {
ksrem -= 8;
*(reinterpret_cast<uint64_t *>(dptr)) ^= *(ksptr++);
dptr += 8;
}
for(unsigned int i=0;i<ksrem;++i) {
dptr[i] ^= reinterpret_cast<const uint8_t *>(ksptr)[i];
}
ZT_FAST_SINGLE_PASS_SALSA2012(keyStream,encryptLen + 64,(data + ZT_PACKET_IDX_IV),mangledKey);
Salsa20::memxor(data + ZT_PACKET_IDX_VERB,reinterpret_cast<const uint8_t *>(keyStream + 8),encryptLen);
uint64_t mac[2];
Poly1305::compute(mac,data + ZT_PACKET_IDX_VERB,size() - ZT_PACKET_IDX_VERB,keyStream);
#ifdef ZT_NO_TYPE_PUNNING
memcpy(data + ZT_PACKET_IDX_MAC,mac,8);
#else
(*reinterpret_cast<uint64_t *>(data + ZT_PACKET_IDX_MAC)) = mac[0];
#endif
} else {
Salsa20 s20(mangledKey,data + ZT_PACKET_IDX_IV);
uint64_t macKey[4];
s20.crypt12(ZERO_KEY,macKey,sizeof(macKey));
uint8_t *const payload = data + ZT_PACKET_IDX_VERB;
const unsigned int payloadLen = size() - ZT_PACKET_IDX_VERB;
if (encryptPayload)
s20.crypt12(payload,payload,payloadLen);
uint64_t mac[2];
Poly1305::compute(mac,payload,payloadLen,macKey);
memcpy(data + ZT_PACKET_IDX_MAC,mac,8);
@ -1157,39 +1145,33 @@ bool Packet::dearmor(const void *key)
if ((cs == ZT_PROTO_CIPHER_SUITE__C25519_POLY1305_NONE)||(cs == ZT_PROTO_CIPHER_SUITE__C25519_POLY1305_SALSA2012)) {
_salsa20MangleKey((const unsigned char *)key,mangledKey);
if (ZT_HAS_FAST_CRYPTO()) {
uint64_t keyStream[(ZT_PROTO_MAX_PACKET_LENGTH + 64 + 8) / 8];
ZT_FAST_SINGLE_PASS_SALSA2012(keyStream,((cs == ZT_PROTO_CIPHER_SUITE__C25519_POLY1305_SALSA2012) ? (payloadLen + 64) : 64),(data + ZT_PACKET_IDX_IV),mangledKey);
uint64_t mac[2];
Poly1305::compute(mac,payload,payloadLen,keyStream);
#ifdef ZT_NO_TYPE_PUNNING
if (!Utils::secureEq(mac,data + ZT_PACKET_IDX_MAC,8))
return false; // MAC failed, packet is corrupt, modified, or is not from the sender
if (cs == ZT_PROTO_CIPHER_SUITE__C25519_POLY1305_SALSA2012) {
uint64_t *ksptr = keyStream + 8; // encryption starts after first Salsa20 block
uint8_t *dptr = data + ZT_PACKET_IDX_VERB;
unsigned int ksrem = payloadLen;
while (ksrem >= 8) {
ksrem -= 8;
*(reinterpret_cast<uint64_t *>(dptr)) ^= *(ksptr++);
dptr += 8;
}
for(unsigned int i=0;i<ksrem;++i) {
dptr[i] ^= reinterpret_cast<const uint8_t *>(ksptr)[i];
}
}
return false;
#else
if ((*reinterpret_cast<const uint64_t *>(data + ZT_PACKET_IDX_MAC)) != mac[0]) // also secure, constant time
return false;
#endif
if (cs == ZT_PROTO_CIPHER_SUITE__C25519_POLY1305_SALSA2012)
Salsa20::memxor(data + ZT_PACKET_IDX_VERB,reinterpret_cast<const uint8_t *>(keyStream + 8),payloadLen);
} else {
Salsa20 s20(mangledKey,data + ZT_PACKET_IDX_IV);
uint64_t macKey[4];
s20.crypt12(ZERO_KEY,macKey,sizeof(macKey));
uint64_t mac[2];
Poly1305::compute(mac,payload,payloadLen,macKey);
#ifdef ZT_NO_TYPE_PUNNING
if (!Utils::secureEq(mac,data + ZT_PACKET_IDX_MAC,8))
return false; // MAC failed, packet is corrupt, modified, or is not from the sender
return false;
#else
if ((*reinterpret_cast<const uint64_t *>(data + ZT_PACKET_IDX_MAC)) != mac[0]) // also secure, constant time
return false;
#endif
if (cs == ZT_PROTO_CIPHER_SUITE__C25519_POLY1305_SALSA2012)
s20.crypt12(payload,payload,payloadLen);
}