MySmartHome/MySensors
1
0
Fork 0
Code Issues Pull Requests Packages Projects Releases Wiki Activity

Enhance randomness (AVR, ESP8266, Linux, NRF5) (#845)

Browse Source 
This commit changes the way random numbers are available
with MySensors.

The AVR platform uses a 32 Bit random seed build from a floating
analog pin. The way of the generation of this seed is FIPS 140-2
compliant.

For support MCU with a fast way to generate random data, the
hwGetentropy() command is now available to allow rapid generation
of random data.

The ESP8266 platform uses the internal random source for randomness
for hwGetentropy() and Arduino's random() function.

The NRF5 platform initializes the pseudo random number generator
from internal hardware number generator. The internal AES-ECB unit
generates random data after filling with HWRNG data by AES-CBC.

On Linux getrandom() is implemented via syscall().

signerAtsha204SoftGetNonce speed:
AVR = ~14000us (sha204Soft)
NRF51 = ~152us (AES-CBC), 1739us (old sha204Soft)
NRF52 = ~31us (AES-CBC), 183us (old sha204Soft)
ESP8266 = ~20us (RANDOM_REG32), 380us (old sha204Soft)

All Nonce results tested for FIPS 140-2 compliance successfully.
This commit is contained in:
d00616
2017-05-21 14:12:09 +02:00
committed by Olivier
parent b479a0cf3f
commit 6c12dddf5a
11 changed files with 167 additions and 5 deletions
Download Patch File Download Diff File Expand all files Collapse all files
hal/architecture/MyHwAVR.cpp
+35
View File
@@ -202,6 +202,41 @@ int8_t hwSleep(uint8_t interrupt1, uint8_t mode1, uint8_t interrupt2, uint8_t mo
return ret;
}
inline void hwRandomNumberInit()
{
// This function initializes the random number generator with a seed
// of 32 bits. This method is good enough to earn FIPS 140-2 conform
// random data. This should reach to generate 32 Bit for randomSeed().
unsigned long seed = 0;
unsigned long start = millis();
unsigned long timeout = start + 20;
// Trigger floating effect of an unconnected pin
pinMode(MY_SIGNING_SOFT_RANDOMSEED_PIN, INPUT_PULLUP);
pinMode(MY_SIGNING_SOFT_RANDOMSEED_PIN, INPUT);
delay(10);
// Generate 32 bits of datas
for (uint8_t i=0; i<32; i++) {
int pinValue = analogRead(MY_SIGNING_SOFT_RANDOMSEED_PIN);
// Wait until the analog value has changed
while ((pinValue == analogRead(MY_SIGNING_SOFT_RANDOMSEED_PIN)) && (timeout>=millis())) {
seed ^= (millis() << i);
// Check of data generation is slow
if (timeout<=millis()) {
// Trigger pin again
pinMode(MY_SIGNING_SOFT_RANDOMSEED_PIN, INPUT_PULLUP);
pinMode(MY_SIGNING_SOFT_RANDOMSEED_PIN, INPUT);
// Pause a short while
delay(seed % 10);
timeout = millis()+20;
}
}
}
randomSeed(seed);
}
bool hwUniqueID(unique_id_t* uniqueID)
{
// not implemented yet