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

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

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@ -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);
}

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@ -69,46 +69,42 @@ namespace ZeroTier {
void Salsa20::init(const void *key,const void *iv)
{
#ifdef ZT_SALSA20_SSE
const uint32_t *k = (const uint32_t *)key;
const uint32_t *const k = (const uint32_t *)key;
_state.i[0] = 0x61707865;
_state.i[3] = 0x6b206574;
_state.i[13] = k[0];
_state.i[10] = k[1];
_state.i[7] = k[2];
_state.i[4] = k[3];
k += 4;
_state.i[1] = 0x3320646e;
_state.i[2] = 0x79622d32;
_state.i[15] = k[0];
_state.i[12] = k[1];
_state.i[9] = k[2];
_state.i[6] = k[3];
_state.i[14] = ((const uint32_t *)iv)[0];
_state.i[11] = ((const uint32_t *)iv)[1];
_state.i[3] = 0x6b206574;
_state.i[4] = k[3];
_state.i[5] = 0;
_state.i[6] = k[7];
_state.i[7] = k[2];
_state.i[8] = 0;
_state.i[9] = k[6];
_state.i[10] = k[1];
_state.i[11] = ((const uint32_t *)iv)[1];
_state.i[12] = k[5];
_state.i[13] = k[0];
_state.i[14] = ((const uint32_t *)iv)[0];
_state.i[15] = k[4];
#else
const char *const constants = "expand 32-byte k";
const uint8_t *k = (const uint8_t *)key;
const uint8_t *const k = (const uint8_t *)key;
_state.i[0] = U8TO32_LITTLE(constants + 0);
_state.i[1] = U8TO32_LITTLE(k + 0);
_state.i[2] = U8TO32_LITTLE(k + 4);
_state.i[3] = U8TO32_LITTLE(k + 8);
_state.i[4] = U8TO32_LITTLE(k + 12);
k += 16;
_state.i[5] = U8TO32_LITTLE(constants + 4);
_state.i[6] = U8TO32_LITTLE(((const uint8_t *)iv) + 0);
_state.i[7] = U8TO32_LITTLE(((const uint8_t *)iv) + 4);
_state.i[8] = 0;
_state.i[9] = 0;
_state.i[10] = U8TO32_LITTLE(constants + 8);
_state.i[11] = U8TO32_LITTLE(k + 0);
_state.i[12] = U8TO32_LITTLE(k + 4);
_state.i[13] = U8TO32_LITTLE(k + 8);
_state.i[14] = U8TO32_LITTLE(k + 12);
_state.i[11] = U8TO32_LITTLE(k + 16);
_state.i[12] = U8TO32_LITTLE(k + 20);
_state.i[13] = U8TO32_LITTLE(k + 24);
_state.i[14] = U8TO32_LITTLE(k + 28);
_state.i[15] = U8TO32_LITTLE(constants + 12);
_state.i[0] = U8TO32_LITTLE(constants + 0);
#endif
}

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@ -34,6 +34,43 @@ public:
Salsa20() {}
~Salsa20() { Utils::burn(&_state,sizeof(_state)); }
/**
* XOR d with s
*
* This is done efficiently using e.g. SSE if available. It's used when
* alternative Salsa20 implementations are used in Packet and is here
* since this is where all the SSE stuff is already included.
*
* @param d Destination to XOR
* @param s Source bytes to XOR with destination
* @param len Length of s and d
*/
static inline void memxor(uint8_t *d,const uint8_t *s,unsigned int len)
{
#ifdef ZT_SALSA20_SSE
while (len >= 16) {
_mm_storeu_si128(reinterpret_cast<__m128i *>(d),_mm_xor_si128(_mm_loadu_si128(reinterpret_cast<__m128i *>(d)),_mm_loadu_si128(reinterpret_cast<const __m128i *>(s))));
s += 16;
d += 16;
len -= 16;
}
#else
#ifndef ZT_NO_TYPE_PUNNING
while (len >= 16) {
(*reinterpret_cast<uint64_t *>(d)) ^= (*reinterpret_cast<const uint64_t *>(s));
s += 8;
d += 8;
(*reinterpret_cast<uint64_t *>(d)) ^= (*reinterpret_cast<const uint64_t *>(s));
s += 8;
d += 8;
len -= 16;
}
#endif
#endif
while (len--)
*(d++) ^= *(s++);
}
/**
* @param key 256-bit (32 byte) key
* @param iv 64-bit initialization vector

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@ -141,8 +141,6 @@ static const C25519TestVector C25519_TEST_VECTORS[ZT_NUM_C25519_TEST_VECTORS] =
//////////////////////////////////////////////////////////////////////////////
static unsigned char fuzzbuf[1048576];
static int testCrypto()
{
unsigned char buf1[16384];