- These functions are declared twice in slow-hash.c. Remove one of the copies.
- The declarations have the wrong return type, should be void, not int.
Function definitions here: 1e74586ee9/src/crypto/aesb.c (L151-L180)
Test plan: make release-test
Contains two modifications to improve ASIC resistance: shuffle and integer math.
Shuffle makes use of the whole 64-byte cache line instead of 16 bytes only, making Cryptonight 4 times more demanding for memory bandwidth.
Integer math adds 64:32 bit integer division followed by 64 bit integer square root, adding large and unavoidable computational latency to the main loop.
More details and performance numbers: https://github.com/SChernykh/xmr-stak-cpu/blob/master/README.md
hash: add prehashed version cn_slow_hash_prehashed
slow-hash: let cn_slow_hash take 4th parameter for deciding prehashed or not
slow-hash: add support for prehashed version for the other 3 platforms
The basic approach it to delegate all sensitive data (master key, secret
ephemeral key, key derivation, ....) and related operations to the device.
As device has low memory, it does not keep itself the values
(except for view/spend keys) but once computed there are encrypted (with AES
are equivalent) and return back to monero-wallet-cli. When they need to be
manipulated by the device, they are decrypted on receive.
Moreover, using the client for storing the value in encrypted form limits
the modification in the client code. Those values are transfered from one
C-structure to another one as previously.
The code modification has been done with the wishes to be open to any
other hardware wallet. To achieve that a C++ class hw::Device has been
introduced. Two initial implementations are provided: the "default", which
remaps all calls to initial Monero code, and the "Ledger", which delegates
all calls to Ledger device.
CryptoNight does exactly 524,288 iterations over the scratchpad as defined in CNS008, saying 500,000 could be confusing. I know its meant to give a rough idea (around 500k) to the reader but if you are reading the code, might as well know the exact number.
This was disabled earlier as part of diagnosing failing tests
on ARM, which turned out to be due to aliasing, fixed by
adding -fno-strict-aliasing. So, re-enabling it back.
