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Add local context for rvsol
1 parent 89e4f94 commit 6116ed8

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+56
-10
lines changed

2 files changed

+56
-10
lines changed

‎rvsol/src/PreimageOracle.sol

Lines changed: 27 additions & 0 deletions
Original file line numberDiff line numberDiff line change
@@ -32,6 +32,33 @@ contract PreimageOracle {
3232
preimageLengths[key] = size;
3333
}
3434

35+
// temporary method for localization. Will be removed to PreimageKeyLib.sol
36+
function localize(bytes32 _key, bytes32 _localContext) internal view returns (bytes32 localizedKey_) {
37+
assembly {
38+
// Grab the current free memory pointer to restore later.
39+
let ptr := mload(0x40)
40+
// Store the local data key and caller next to each other in memory for hashing.
41+
mstore(0, _key)
42+
mstore(0x20, caller())
43+
mstore(0x40, _localContext)
44+
// Localize the key with the above `localize` operation.
45+
localizedKey_ := or(and(keccak256(0, 0x60), not(shl(248, 0xFF))), shl(248, 1))
46+
// Restore the free memory pointer.
47+
mstore(0x40, ptr)
48+
}
49+
}
50+
51+
// temporary method for localization. Will be removed to PreimageKeyLib.sol
52+
function cheatLocalKey(uint256 partOffset, bytes32 key, bytes32 part, uint256 size, bytes32 localContext) external {
53+
// sanity check key is local key using prefix
54+
require(uint8(key[0]) == 1, "must be used for local key");
55+
56+
bytes32 localizedKey = localize(key, localContext);
57+
preimagePartOk[localizedKey][partOffset] = true;
58+
preimageParts[localizedKey][partOffset] = part;
59+
preimageLengths[localizedKey] = size;
60+
}
61+
3562
// loadKeccak256PreimagePart prepares the pre-image to be read by keccak256 key,
3663
// starting at the given offset, up to 32 bytes (clipped at preimage length, if out of data).
3764
function loadKeccak256PreimagePart(uint256 _partOffset, bytes calldata _preimage) external {

‎rvsol/src/Step.sol

Lines changed: 29 additions & 10 deletions
Original file line numberDiff line numberDiff line change
@@ -11,7 +11,7 @@ contract Step {
1111
}
1212

1313
// Executes a single RISC-V instruction, starting from
14-
function step(bytes calldata stateData, bytes calldata proof) public returns (bytes32) {
14+
function step(bytes calldata stateData, bytes calldata proof, bytes32 localContext) public returns (bytes32) {
1515
assembly {
1616
function revertWithCode(code) {
1717
mstore(0, code)
@@ -270,8 +270,8 @@ contract Step {
270270
// expected memory check: no allocated memory (start after scratch + free-mem-ptr + zero slot = 0x80)
271271
revert(0, 0)
272272
}
273-
if iszero(eq(stateData.offset, 100)) {
274-
// 32*3+4 = 100 expected state data offset
273+
if iszero(eq(stateData.offset, 132)) {
274+
// 32*4+4 = 132 expected state data offset
275275
revert(0, 0)
276276
}
277277
if iszero(eq(calldataload(sub(stateData.offset, 32)), stateSize())) {
@@ -283,11 +283,12 @@ contract Step {
283283
out := add(v, padding)
284284
}
285285
if iszero(eq(proof.offset, add(add(stateData.offset, paddedLen(stateSize())), 32))) {
286-
// 100+stateSize+padding+32 = expected proof offset
286+
// 132+stateSize+padding+32 = expected proof offset
287287
revert(0, 0)
288288
}
289289
function proofContentOffset() -> out { // since we can't reference proof.offset in functions, blame Yul
290-
out := 516
290+
// 132+362+(32-362%32)+32=548
291+
out := 548
291292
}
292293
if iszero(eq(proof.offset, proofContentOffset())) {
293294
revert(0, 0)
@@ -772,10 +773,28 @@ contract Step {
772773
revertWithCode(0xbadf00d0)
773774
}
774775

775-
function readPreimageValue(addr, count) -> out {
776+
function localize(preImageKey, localContext_) -> localizedKey {
777+
// TODO: deduplicate definition of localize using lib
778+
// Grab the current free memory pointer to restore later.
779+
let ptr := mload(0x40)
780+
// Store the local data key and caller next to each other in memory for hashing.
781+
mstore(0, preImageKey)
782+
mstore(0x20, caller())
783+
mstore(0x40, localContext_)
784+
// Localize the key with the above `localize` operation.
785+
localizedKey := or(and(keccak256(0, 0x60), not(shl(248, 0xFF))), shl(248, 1))
786+
// Restore the free memory pointer.
787+
mstore(0x40, ptr)
788+
}
789+
790+
function readPreimageValue(addr, count, localContext_) -> out {
776791
let preImageKey := getPreimageKey()
777792
let offset := getPreimageOffset()
778-
793+
// If the preimage key is a local key, localize it in the context of the caller.
794+
let preImageKeyPrefix := shr(248, preImageKey) // 256-8=248
795+
if eq(preImageKeyPrefix, 1) {
796+
preImageKey := localize(preImageKey, localContext_)
797+
}
779798
// make call to pre-image oracle contract
780799
let pdatB32, pdatlen := readPreimagePart(preImageKey, offset)
781800
if iszero64(pdatlen) { // EOF
@@ -811,7 +830,7 @@ contract Step {
811830
//
812831
// Syscall handling
813832
//
814-
function sysCall() {
833+
function sysCall(localContext_) {
815834
let a7 := getRegister(toU64(17))
816835
switch a7
817836
case 93 { // exit the calling thread. No multi-thread support yet, so just exit.
@@ -872,7 +891,7 @@ contract Step {
872891
n := count
873892
errCode := toU64(0)
874893
} case 5 { // preimage read
875-
n := readPreimageValue(addr, count)
894+
n := readPreimageValue(addr, count, localContext_)
876895
errCode := toU64(0)
877896
} default {
878897
n := u64Mask() // -1 (reading error)
@@ -1275,7 +1294,7 @@ contract Step {
12751294
case 0 { // 000 = ECALL/EBREAK
12761295
switch shr64(toU64(20), instr) // I-type, top 12 bits
12771296
case 0 { // imm12 = 000000000000 ECALL
1278-
sysCall()
1297+
sysCall(localContext)
12791298
setPC(add64(_pc, toU64(4)))
12801299
} default { // imm12 = 000000000001 EBREAK
12811300
setPC(add64(_pc, toU64(4))) // ignore breakpoint

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