1 Commits

Author	SHA1	Message	Date
Matt Luongo	8db2de158d	EIP-152: Blake2b `F` precompile (#2129) ... * Brought issue #152 into the repo as a draft EIP. Thanks @tjade273! * Make the draft EIP consistent with the template Also added myself as an author * Break backwards compatibility into its own section * Added notes about the in-progress implementation Should have a working geth precompile and initial benchmarks shortly * Specify EIP-2046 as a requirement While 2046's cheaper precompile contract calls aren't a requirement for this EIP's implementation, shipping this precompile without EIP-2046 would make the F function expensive for some of the motivating usecases. * Don't use ABI encoding for precompile Replace the existing ABI encoding interface to the BLAKE2b `F` precompile with a loosely pack struct that's `staticcall`-friendly. H/t to @pdyraga for putting together the interface! * Add @pdyraga to the EIP authors. * Remove less relevant EIP rationale Let's not relitigate precompiles, WASM, etc in thie EIP :) * Use 0x09 as the precompile address If a conflicting EIP is moving forward the EIP editor can assign a new address * Choosing an EIP number Contributing docs suggest EIPs be named `eip-draft-with-a-title` until an editor has been assigned, but discussing this work off-platform without a number is a problem. Assigning 152 as the issue number where the `F` precompile was originally raised (https://github.com/ethereum/EIPs/issues/152) * Add a missing colon Thanks @axic 🙌 * Spelling updates * Add @MadeOfTin to the authors list * Prefer the original issue for discussion * Clarify the precompile's initial implementation * Make the precompile return value clear * Clean up references wording * More rationale around this BLAKE2b approach * Fix a couple misspellings * Updated the interface for F precompile - F precompile accepts now `abi.encodePacked` parameters taking exactly 213 bytes. This is safer and does not require left-padding data - `rounds` parameter is now the first one as the gas cost depends only on this parameter * Updated gas cost section proposing GFROUND=1 * Detailed benchmarks moved to appendix section * Benchmark stats are compared against ecRecover as a baseline * Clarification: f parameter is true if it is nonzero This rule is compatible with Solidity for boolean. * Avoid referring to abi.encodePacked The specification should not be Solidity-specific. Instead of referring to abi.encodePacked we now just say "tightly encoded". * Fixed incorrect link "specified in the RFC" linked to the geth PR for F precompile instead of linking to the BLAKE2b RFC. * Shortened the description about when parameter f is considered as true * Minor grammar improvement * Updated information about endianness of F precompile inputs BLAKE2b is consistently little-endian. abi.encodePacked encodes each of its arguments in big-endian order. We need to be clear which parameters should go as little-endian (h, m, t) and which parameters should go as big-endian (rounds, f). * Strict validation of f parameter * Initial test vectors for F precompile Test cases covered: - input length too short - input length too long - malformed f flag encoding - correct input, test vector from BLAKE2b RFC, Appendix A * Test vector for a non-final round * Test vector for the maximum number of rounds * Test vector for a single round * Added test vector for empty input * The final block indicator (8-bit word) does not have endianness * Clarify state vector encoding does not change in the output * Put too short input test vector next to empty input test vector * Added test vector for zero-rounds BLAKE2b case	2019-08-22 15:07:10 +02:00