Gnosis compilation contracts.

2023-10-03 13:03:40 +00:00 · 2017-07-12 15:55:11 +02:00
parent 91f17a3662
commit b1c1fb6c83
33 changed files with 3303 additions and 0 deletions
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+pragma solidity ^0.4.11;
+import "../Oracles/Oracle.sol";
+
+
+/// @title Signed message oracle contract - Allows to set an outcome with a signed message
+/// @author Stefan George - <stefan@gnosis.pm>
+contract SignedMessageOracle is Oracle {
+
+    /*
+     *  Events
+     */
+    event SignerReplacement(address indexed newSigner);
+    event OutcomeAssignment(int outcome);
+
+    /*
+     *  Storage
+     */
+    address public signer;
+    bytes32 public descriptionHash;
+    uint nonce;
+    bool public isSet;
+    int public outcome;
+
+    /*
+     *  Modifiers
+     */
+    modifier isSigner () {
+        // Only signer is allowed to proceed
+        require(msg.sender == signer);
+        _;
+    }
+
+    /*
+     *  Public functions
+     */
+    /// @dev Constructor sets signer address based on signature
+    /// @param _descriptionHash Hash identifying off chain event description
+    /// @param v Signature parameter
+    /// @param r Signature parameter
+    /// @param s Signature parameter
+    function SignedMessageOracle(bytes32 _descriptionHash, uint8 v, bytes32 r, bytes32 s)
+        public
+    {
+        signer = ecrecover(_descriptionHash, v, r, s);
+        descriptionHash = _descriptionHash;
+    }
+
+    /// @dev Replaces signer
+    /// @param newSigner New signer
+    /// @param _nonce Unique nonce to prevent replay attacks
+    /// @param v Signature parameter
+    /// @param r Signature parameter
+    /// @param s Signature parameter
+    function replaceSigner(address newSigner, uint _nonce, uint8 v, bytes32 r, bytes32 s)
+        public
+        isSigner
+    {
+        // Result is not set yet and nonce and signer are valid
+        require(   !isSet
+                && _nonce > nonce
+                && signer == ecrecover(keccak256(descriptionHash, newSigner, _nonce), v, r, s));
+        nonce = _nonce;
+        signer = newSigner;
+        SignerReplacement(newSigner);
+    }
+
+    /// @dev Sets outcome based on signed message
+    /// @param _outcome Signed event outcome
+    /// @param v Signature parameter
+    /// @param r Signature parameter
+    /// @param s Signature parameter
+    function setOutcome(int _outcome, uint8 v, bytes32 r, bytes32 s)
+        public
+    {
+        // Result is not set yet and signer is valid
+        require(   !isSet
+                && signer == ecrecover(keccak256(descriptionHash, _outcome), v, r, s));
+        isSet = true;
+        outcome = _outcome;
+        OutcomeAssignment(_outcome);
+    }
+
+    /// @dev Returns if winning outcome
+    /// @return Is outcome set?
+    function isOutcomeSet()
+        public
+        constant
+        returns (bool)
+    {
+        return isSet;
+    }
+
+    /// @dev Returns winning outcome
+    /// @return Outcome
+    function getOutcome()
+        public
+        constant
+        returns (int)
+    {
+        return outcome;
+    }
+}