> For the complete documentation index, see [llms.txt](https://docs.startrail.io/llms.txt). Markdown versions of documentation pages are available by appending `.md` to page URLs; this page is available as [Markdown](https://docs.startrail.io/ethereum-signature-validator-api/ethereum-signature-validator-api.md).

# Ethereum Signature Validator API

Authenticates SDK users from their EOAs

### **Features**

* Provide HTTP API endpoint
* Return the result of validation with error message

### **How to use API**

* Call HTTP API endpoint with arguments set in request body

## Authenticates SDK users from their EOAs

<mark style="color:orange;">`PUT`</mark> `https://asia-northeast1-startrail-api-prod.cloudfunctions.net/ethereum-signature-validator`

This module recovers Ethereum address (EOA) from message and signature, and validates that the recovered address is equal to the signer's address.

#### Request Body

| Name                                        | Type   | Description                                                                                                                                                                                                                                  |
| ------------------------------------------- | ------ | -------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------- |
| message<mark style="color:red;">\*</mark>   | String | raw message that signature is generated from (it does not have to be hashing)                                                                                                                                                                |
| signature<mark style="color:red;">\*</mark> | String | 0x prefixed signature that is generated by secp256k1 algorithm such as eth\_sign function                                                                                                                                                    |
| address<mark style="color:red;">\*</mark>   | String | Ethreum Address(EOA) of the signer(Both lowercase and mixed case which is compatible with EIP55 are accepted)                                                                                                                                |
| signMethod                                  | String | <p><code>eth\_sign</code>or <code>personal\_sign</code><br></p><p>A specific sign method with which signature is generated. If not specified, both <code>eth\_sign</code> and <code>personal\_sign</code> method is used to validate EOA</p> |

{% tabs %}
{% tab title="200: OK Validation has succeeded with valid input. Check `isValid` field in the response." %}

```javascript
// Validation Success
{ isValid: true, invalidReason: null, triedSignMethods: ['eth_sign'] }

// Validation Failure
{ isValid: false, invalidReason: 'Signature is invalid', triedSignMethods: ['eth_sign', 'personal_sign'] }
```

{% endtab %}

{% tab title="400: Bad Request Validation has failed with invalid input" %}

```javascript
// Validation Failure
{ isValid: false, invalidReason: 'Request parameters are not properly set' }

{ isValid: false, invalidReason: 'Signature format is invalid' }

{ isValid: false, invalidReason: 'Ethereum address is invalid' }
```

{% endtab %}
{% endtabs %}

## **Sample Request command**

```javascript
curl -X PUT \
  -H "Content-type: application/json" \
  --data '{"message": "test-message", "signature": "0x633bc7c201cf45fff0c1724b77c90c825a04c1b818f043915e2fedd55b4cfe681b425fe844ea3684a3860dc250527e318d3225b2d21ad0f75e419db4f0939a1b1c", "address": "0xBFC1331F8111102A51588b3b4A3E2F317B3a0363"}' \
 https://asia-northeast1-startrail-api-prod.cloudfunctions.net/ethereum-signature-validator
```

```javascript
curl -X PUT \
  -H "Content-type: application/json" \
  --data '{"message": "test-message", "signature": "0x7cdf2aa9dfb2da8c6f8fe63269b4dbfb923451f0e36087479e7f2897718a6d0b6438bd44e367907e30c65a4b950c9e11f94049d38a0ca1dd4d419e107a3dade31c", "address": "0xBFC1331F8111102A51588b3b4A3E2F317B3a0363", "signMethod": "personal_sign"}' \
  https://asia-northeast1-startrail-api-prod.cloudfunctions.net/ethereum-signature-validator
```


---

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