# Ethereum & EVM compatible

## Sign Transaction

The D'CENT Web SDK provides functions for signing transaction of coins.

### **getEthereumSignedTransaction()**

#### Supported Coin Type

* ETHEREUM
* RSK
* XDC

#### Parameters

* coinType
* nonce
* gasPrice
* gasLimit
* to (address)
* value
* data
* key path for signing
* chain ID

#### Returned response object:

```json
{
    "header": {
        "version": "1.0",
        "response_from": "ethereum",
        "status": "success"
    },
    "body": {
        "command": "transaction",
        "parameter": {
            "sign_v": "0x78",
            "sign_r": "0xf9e4c3ed......9557ad37",
            "sign_s": "0x697a2abf......b76c4cb2",
            "signed": "f86c0884......b76c4cb2"
        }
    }
}
```

### getTokenSignedTransaction()

#### Supported Coin Type

* ERC20
* RRC20
* XRC20

#### Parameters

* coinType
* nonce
* gasPrice
* gasLimit
* value
* key path for signing
* chain ID
* contract information example :

  ```javascript
  {
    name: 'OmiseGO',
    address: '0xd26114cd6EE289AccF82350c8d8487fedB8A0C07',
    to: '0x354609C4c9a15d4265cF6D94010568D5Cf4d0c1B',
    decimals: 18,
    value: '100000000000000000',
    symbol: 'OMG'
  }  
  ```

#### Returned response object

```json
{
    "header": {
        "version": "1.0",
        "response_from": "erc20",
        "status": "success"
    },
    "body": {
        "command": "transaction",
        "parameter": {
            "signed": "0xf8a91584......cc79c29a",
            "sign": {
                "sign_v": "0x26",
                "sign_r": "0x33930787......d4456f53",
                "sign_s": "0x708126c7......cc79c29a"
            }
        }
    }
}
```

## Ethereum Signed Message

You can get a signature value to sign a user message with that private key With a given key path (BIP32). The input message is prefixed with 'Ethereum sign message' and then hashed and signed.

```javascript
var message = 'This is a message!'
var result
try {
    result = await DcentWebConnector.getEthereumSignedMessage(message, "m/44'/60'/0'/0/0");
} catch (e) {
    console.log(e)
    result = e
}
```

Returned response object has:

```json
{
    "header": {
        "version": "1.0",
        "response_from": "ethereum",
        "status": "success"
    },
    "body": {
        "command": "msg_sign",
        "parameter": {
            "address": "0x54b9c508aC61Eaf2CD8F9cA510ec3897CfB09382",
            "sign": "0x0d935339......06a6291b"
        }
    }
}
```

## Signed Data

You can get a signature value to sign message with that private key With a given key path (BIP32). The input data is hex string format. The input data is hashed and signed.

```javascript
var message = "0x1901f2cee375fa42b42143804025fc449deafd50cc031ca257e0b194a650a912090feb4221181ff3f1a83ea7313993ca9218496e424604ba9492bb4052c03d5c3df8"
var key =  "m/44'/60'/0'/0/0"
var result
try {
    result = await DcentWebConnector.getSignedData(key, message);
} catch (e) {
    console.log(e)
    result = e
}
```

Returned response object has:

```json
{
    "header": {
        "version": "1.0",
        "response_from": "ethereum",
        "status": "success"
    },
    "body": {
        "command": "sign_data",
        "parameter": {
            "address": "0x54b9c508aC61Eaf2CD8F9cA510ec3897CfB09382",
            "sign": "0x0d935339......06a6291b"
        }
    }
}
```

## Signed Message

You can get a signature value to sign a user message with that private key With a given key path (BIP32). The input message is prefixed depending on the coin type and then hashed and signed.

```javascript
var message = 'This is a message!'
var key =  "m/44'/60'/0'/0/0"
var result
try {
    result = await DcentWebConnector.getSignedMessage( DcentWebConnector.coinType.ETHEREUM, key, message);
} catch (e) {
    console.log(e)
    result = e
}
```

Returned response object has:

```json
{
    "header": {
        "version": "1.0",
        "response_from": "ethereum",
        "status": "success"
    },
    "body": {
        "command": "msg_sign",
        "parameter": {
            "address": "0x54b9c508aC61Eaf2CD8F9cA510ec3897CfB09382",
            "sign": "0x0d935339......06a6291b"
        }
    }
}
```


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