# _validate_ft4_signature · FT4 Rell API · Chromia Docs (concept)

> function _ validate_ ft4_ signature(flags: list<text>, account: account , auth_ descriptor: account_ auth_ descriptor ) Verifies that the signature found i

Source: https://docs.chromia.com/pages/ft4-rell/-f-t4-library/lib.ft4.core.auth/_validate_ft4_signature/

FUNCTION

# \_validate\_ft4\_signature

```signature
function _validate_ft4_signature(flags: list<text>, account: account, auth_descriptor: account_auth_descriptor)
```

[Source](https://gitlab.com/chromaway/ft4-lib/-/blob/development/rell/src/lib/ft4/core/auth/authentication.rell#lines-437)

Verifies that the signature found in the `ft_auth` operation is valid to authorize the
operation being called.

Can only be called from an operation.

Throws if the signature cannot be validated. Common reasons include:

* the signers of the auth descriptor did not sign this transaction
* too few signers signed the operation, in case of a multisig auth descriptor
* the auth descriptor does not give sufficient permissions for the operation that is being
  called

**Parameters**

* **flags** — the flags required by the operation
* **account** — the account the user authenticated as
* **auth\_descriptor** — the auth descriptor that is authorizing this operation

[View this page on docs.chromia.com](https://docs.chromia.com/pages/ft4-rell/-f-t4%20-library/lib.ft4.core.auth/_validate_ft4_signature.html)Generated API reference, mirrored from the live docs