diff options
Diffstat (limited to 'packages/contracts/src')
| -rw-r--r-- | packages/contracts/src/contracts/current/protocol/AssetProxy/ERC20Proxy.sol | 133 | ||||
| -rw-r--r-- | packages/contracts/src/contracts/current/protocol/AssetProxy/MixinERC20Transfer.sol | 121 |
2 files changed, 132 insertions, 122 deletions
diff --git a/packages/contracts/src/contracts/current/protocol/AssetProxy/ERC20Proxy.sol b/packages/contracts/src/contracts/current/protocol/AssetProxy/ERC20Proxy.sol index b74d2c231..cb9c8c86c 100644 --- a/packages/contracts/src/contracts/current/protocol/AssetProxy/ERC20Proxy.sol +++ b/packages/contracts/src/contracts/current/protocol/AssetProxy/ERC20Proxy.sol @@ -31,7 +31,7 @@ contract ERC20Proxy is { // Id of this proxy. bytes4 constant PROXY_ID = bytes4(keccak256("ERC20Token(address)")); - + /// @dev Gets the proxy id associated with the proxy address. /// @return Proxy id. function getProxyId() @@ -41,4 +41,135 @@ contract ERC20Proxy is { return PROXY_ID; } + + /// @dev Internal version of `transferFrom`. + /// @param assetData Encoded byte array. + /// @param from Address to transfer asset from. + /// @param to Address to transfer asset to. + /// @param amount Amount of asset to transfer. + function transferFrom( + bytes assetData, + address from, + address to, + uint256 amount + ) + external + { + bool auth = authorized[msg.sender]; + + // `transferFrom`. + // The function is marked `external`, so no abi decodeding is done for + // us. Instead, we expect the `calldata` memory to contain the + // following: + // + // | Area | Offset | Length | Contents | + // |----------|--------|---------|-------------------------------------| + // | Header | 0 | 4 | function selector | + // | Params | | 4 * 32 | function parameters: | + // | | 4 | | 1. offset to assetData (*) | + // | | 36 | | 2. from | + // | | 68 | | 3. to | + // | | 100 | | 4. amount | + // | Data | | | assetData: | + // | | 132 | 32 | assetData Length | + // | | 164 | ** | assetData Contents | + // + // (*): offset is computed from start of function parameters, so offset + // by an additional 4 bytes in the calldata. + // + // WARNING: The ABIv2 specification allows additional padding between + // the Params and Data section. This will result in a larger + // offset to assetData. + + // Asset data itself is encoded as follows: + // + // | Area | Offset | Length | Contents | + // |----------|--------|---------|-------------------------------------| + // | Header | 0 | 4 | function selector | + // | Params | | 1 * 32 | function parameters: | + // | | 4 | 12 + 20 | 1. token address | + + // Transfer tokens. + // We do a raw call so we can check the success separate + // from the return data. + // We construct calldata for the `token.transferFrom` ABI. + // The layout of this calldata is in the table below. + // + // | Area | Offset | Length | Contents | + // |----------|--------|---------|-------------------------------------| + // | Header | 0 | 4 | function selector | + // | Params | | 3 * 32 | function parameters: | + // | | 4 | | 1. from | + // | | 36 | | 2. to | + // | | 68 | | 3. amount | + + assembly { + if iszero(auth) { + // Revert with `Error("SENDER_NOT_AUTHORIZED")` + mstore(0, 0x08c379a000000000000000000000000000000000000000000000000000000000) + mstore(32, 0x0000002000000000000000000000000000000000000000000000000000000000) + mstore(64, 0x0000001553454e4445525f4e4f545f415554484f52495a454400000000000000) + mstore(96, 0) + revert(0, 100) + } + + /////// Token contract address /////// + // The token address is found as follows: + // * It is stored at offset 4 in `assetData` contents. + // * This is stored at offset 32 from `assetData`. + // * The offset to `assetData` from Params is stored at offset + // 4 in calldata. + // * The offset of Params in calldata is 4. + // So we read location 4 and add 32 + 4 + 4 to it. + let token := calldataload(add(calldataload(4), 40)) + + /////// Setup Header Area /////// + // This area holds the 4-byte `transferFrom` selector. + // Any trailing data in transferFromSelector will be + // overwritten in the next `mstore` call. + mstore(0, 0x23b872dd00000000000000000000000000000000000000000000000000000000) + + /////// Setup Params Area /////// + // We copy the fields `from`, `to` and `amount` in bulk + // from our own calldata to the new calldata. + calldatacopy(4, 36, 96) + + /////// Call `token.transferFrom` using the calldata /////// + let success := call( + gas, // forward all gas + token, // call address of token contract + 0, // don't send any ETH + 0, // pointer to start of input + 100, // length of input + 0, // write output over input + 32 // output size should be 32 bytes + ) + + /////// Check return data. /////// + // If there is no return data, we assume the token incorrectly + // does not return a bool. In this case we expect it to revert + // on failure, which was handled above. + // If the token does return data, we require that it is a single + // nonzero 32 bytes value. + // So the transfer succeeded if the call succeeded and either + // returned nothing, or returned a non-zero 32 byte value. + success := and(success, or( + iszero(returndatasize), + and( + eq(returndatasize, 32), + gt(mload(0), 0) + ) + )) + if success { + return(0, 0) + } + + // Revert with `Error("TRANSFER_FAILED")` + mstore(0, 0x08c379a000000000000000000000000000000000000000000000000000000000) + mstore(32, 0x0000002000000000000000000000000000000000000000000000000000000000) + mstore(64, 0x0000000f5452414e534645525f4641494c454400000000000000000000000000) + mstore(96, 0) + revert(0, 100) + } + } } diff --git a/packages/contracts/src/contracts/current/protocol/AssetProxy/MixinERC20Transfer.sol b/packages/contracts/src/contracts/current/protocol/AssetProxy/MixinERC20Transfer.sol index 2cb12aa6b..5bd98a1f4 100644 --- a/packages/contracts/src/contracts/current/protocol/AssetProxy/MixinERC20Transfer.sol +++ b/packages/contracts/src/contracts/current/protocol/AssetProxy/MixinERC20Transfer.sol @@ -27,127 +27,6 @@ contract MixinERC20Transfer is MAuthorizable { using LibBytes for bytes; - - /// @dev Internal version of `transferFrom`. - /// @param assetData Encoded byte array. - /// @param from Address to transfer asset from. - /// @param to Address to transfer asset to. - /// @param amount Amount of asset to transfer. - function transferFrom( - bytes assetData, - address from, - address to, - uint256 amount - ) - external - onlyAuthorized() - { - // `transferFrom`. - // The function is marked `external`, so no abi decodeding is done for - // us. Instead, we expect the `calldata` memory to contain the - // following: - // - // | Area | Offset | Length | Contents | - // |----------|--------|---------|-------------------------------------| - // | Header | 0 | 4 | function selector | - // | Params | | 4 * 32 | function parameters: | - // | | 4 | | 1. offset to assetData (*) | - // | | 36 | | 2. from | - // | | 68 | | 3. to | - // | | 100 | | 4. amount | - // | Data | | | assetData: | - // | | 132 | 32 | assetData Length | - // | | 164 | ** | assetData Contents | - // - // (*): offset is computed from start of function parameters, so offset - // by an additional 4 bytes in the calldata. - // - // WARNING: The ABIv2 specification allows additional padding between - // the Params and Data section. This will result in a larger - // offset to assetData. - - // Asset data itself is encoded as follows: - // - // | Area | Offset | Length | Contents | - // |----------|--------|---------|-------------------------------------| - // | Header | 0 | 4 | function selector | - // | Params | | 1 * 32 | function parameters: | - // | | 4 | 12 + 20 | 1. token address | - - // Transfer tokens. - // We do a raw call so we can check the success separate - // from the return data. - // We construct calldata for the `token.transferFrom` ABI. - // The layout of this calldata is in the table below. - // - // | Area | Offset | Length | Contents | - // |----------|--------|---------|-------------------------------------| - // | Header | 0 | 4 | function selector | - // | Params | | 3 * 32 | function parameters: | - // | | 4 | | 1. from | - // | | 36 | | 2. to | - // | | 68 | | 3. amount | - - assembly { - /////// Token contract address /////// - // The token address is found as follows: - // * It is stored at offset 4 in `assetData` contents. - // * This is stored at offset 32 from `assetData`. - // * The offset to `assetData` from Params is stored at offset - // 4 in calldata. - // * The offset of Params in calldata is 4. - // So we read location 4 and add 32 + 4 + 4 to it. - let token := calldataload(add(calldataload(4), 40)) - - /////// Setup Header Area /////// - // This area holds the 4-byte `transferFrom` selector. - // Any trailing data in transferFromSelector will be - // overwritten in the next `mstore` call. - mstore(0, 0x23b872dd00000000000000000000000000000000000000000000000000000000) - - /////// Setup Params Area /////// - // We copy the fields `from`, `to` and `amount` in bulk - // from our own calldata to the new calldata. - calldatacopy(4, 36, 96) - - /////// Call `token.transferFrom` using the calldata /////// - let success := call( - gas, // forward all gas - token, // call address of token contract - 0, // don't send any ETH - 0, // pointer to start of input - 100, // length of input - 0, // write output over input - 32 // output size should be 32 bytes - ) - - /////// Check return data. /////// - // If there is no return data, we assume the token incorrectly - // does not return a bool. In this case we expect it to revert - // on failure, which was handled above. - // If the token does return data, we require that it is a single - // nonzero 32 bytes value. - // So the transfer succeeded if the call succeeded and either - // returned nothing, or returned a non-zero 32 byte value. - success := and(success, or( - iszero(returndatasize), - and( - eq(returndatasize, 32), - gt(mload(0), 0) - ) - )) - if success { - return(0, 0) - } - - // Revert with `Error("TRANSFER_FAILED")` - mstore(0, 0x08c379a000000000000000000000000000000000000000000000000000000000) - mstore(32, 0x0000002000000000000000000000000000000000000000000000000000000000) - mstore(64, 0x0000000f5452414e534645525f4641494c454400000000000000000000000000) - mstore(96, 0) - revert(0, 100) - } - } /// @dev Internal version of `transferFrom`. /// @param assetData Encoded byte array. |