> For the complete documentation index, see [llms.txt](https://docs.zkid.app/llms.txt). Markdown versions of documentation pages are available by appending `.md` to page URLs; this page is available as [Markdown](https://docs.zkid.app/introduction/method.md).

# Method

## verifyDidLogin

```typescript
export async function verifyDidLogin<T extends 'did_login' | 'did_login$Kilt' = 'did_login'>(
  message: HexString | Uint8Array | string,
  data: RequestRpcs<T>[T][1],
  resolver?: DidResolver
): Promise<boolean> {
......
}
```

**Description**

This SDK function aims for helping developers to authenticate User. This should be invoked after using the `didLogin(params)` function in the Provider, `verifyDidLogin(params)` function helps verify whether the User is actually the Owner of the DID.

**Params**

* `message`: the message which the User signed on (this should be the same with the `massage` in `didLogin(params)`)
* `signature`: the signature on that message, started with '0x'
* `publicKey`: the publicKey of User's `AuthenticationKey`, which is contains in the DID info (can be obtained by `getCurrentDid()` function in the Provider.

**Return** `Boolean` -- Whether the signature is actually signed by the User (in other word -- Whether developers should allow the User to login)

**Usage**

Check more details about [this SDK Function on our Github](https://github.com/zCloak-Network/zkid-login/tree/master/packages/verify).

```typescript
import { verifyDidLogin } from '@zcloak/login-verify';

// to sign message
const message = '';

const did = await provider.getCurrentDid();

const signature = await provider.didLogin(message);

// to verify the signature in order to authenticate the user
const result = verifyDidLogin(message, signature, did.authenticationKey);

console.log(result)
```

## verifyCredentialDigest

```typescript
export async function verifyCredentialDigest<
  T extends
    | 'did_requestCredentialDigest'
    | 'did_requestCredentialDigest$Kilt' = 'did_requestCredentialDigest'
>(
  credentialDigest: RequestRpcs<T>[T][1],
  challenge: string,
  owner: T extends 'did_requestCredentialDigest' ? DidUrl : DidUri,
  resolver?: DidResolver
): Promise<boolean> {
......
}
```

**Description**

This [`verifyCredentialDigest`](https://github.com/zCloak-Network/zkid-login/blob/master/packages/verify/src/verifyCredentialDigest.ts#L27) method provided in our SDK can be used to check whether the Digest Disclosure is valid, whether the User is the Credential’s Owner.

**Params**

* `credentialDigest`: the `RequestCredentialDigestReponse` of login-rpc, can be obtained use `did_requestCredentialDigest` method
* `challenge`: a random string, the same with the `challenge` in the `did_requestCredentialDigest` method
* `owner`: the credential owner

**Return**

`boolean` -- The Verification result of the Digest Disclosure

**Usage**

Check more details about [this SDK Function on our Github](https://github.com/zCloak-Network/zkid-login/tree/master/packages/verify).

```typescript
import { verifyCredentialDigest } from '@zcloak/login-verify';

const challenge = '';

const did = await provider.getCurrentDid();

// verify credential digest
const credentialDigest = await provider.requestCredentialDigest(challenge);

const result = await verifyCredentialDigest(credentialDigest, challenge, did.didUri);
```

## verifyCredentialContent

```typescript
export async function verifyCredentialContent<
  T extends
    | 'did_requestCredentialContent'
    | 'did_requestCredentialContent$Kilt' = 'did_requestCredentialContent'
>(
  credential: RequestRpcs<T>[T][1],
  challenge: string,
  owner: T extends 'did_requestCredentialContent' ? DidUrl : DidUri,
  resolver?: DidResolver
): Promise<boolean> {
......
}
```

**Description**

This [`verifyCredentialContent`](https://github.com/zCloak-Network/zkid-login/blob/master/packages/verify/src/verifyCredentialContent.ts#L27) method provided in our SDK can be used to check whether the Selective Disclosure or All Credential Content Disclosure is valid, whether the User is the Credential's Owner.

**Params**

* `credentialDigest`: the `RequestCredentialContentReponse` of login-rpc, can be obtained use `did_requestCredentialContent` method
* `challenge`: a random string, the same with the `challenge` in the `did_requestCredentialDigest` method
* `owner`: the credential owner

**Return**

`boolean` -- The Verification result of the **Selective Disclosure** or **All Credential Content Disclosure**.

**Usage**

Check more details about [this SDK Function on our Github](https://github.com/zCloak-Network/zkid-login/tree/master/packages/verify).

```typescript
import { verifyCredentialContent } from '@zcloak/login-verify';

const challenge = '';

const did = await provider.getCurrentDid();

const credential = await provider.requestCredentialContent(challenge);

// verify credential content
const result = await verifyCredentialContent(credential, challenge, did.didUri);

console.log(result);
```