# utils/signature-utils

## Index

### Classes

* [Signature](https://josh-8.gitbook.io/celo-docs/developer-guide/summary/external-modules/broken-reference)

### Functions

* [bigNumberToBuffer](#const-bignumbertobuffer)
* [bufferToBigNumber](#const-buffertobignumber)
* [makeCanonical](#const-makecanonical)

## Functions

### `Const` bigNumberToBuffer

▸ **bigNumberToBuffer**(`input`: BigNumber, `lengthInBytes`: number): *Buffer*

*Defined in* [*packages/contractkit/src/utils/signature-utils.ts:27*](https://github.com/celo-org/celo-monorepo/blob/master/packages/contractkit/src/utils/signature-utils.ts#L27)

**Parameters:**

| Name            | Type      |
| --------------- | --------- |
| `input`         | BigNumber |
| `lengthInBytes` | number    |

**Returns:** *Buffer*

### `Const` bufferToBigNumber

▸ **bufferToBigNumber**(`input`: Buffer): *BigNumber*

*Defined in* [*packages/contractkit/src/utils/signature-utils.ts:23*](https://github.com/celo-org/celo-monorepo/blob/master/packages/contractkit/src/utils/signature-utils.ts#L23)

**Parameters:**

| Name    | Type   |
| ------- | ------ |
| `input` | Buffer |

**Returns:** *BigNumber*

### `Const` makeCanonical

▸ **makeCanonical**(`S`: BigNumber): *BigNumber*

*Defined in* [*packages/contractkit/src/utils/signature-utils.ts:14*](https://github.com/celo-org/celo-monorepo/blob/master/packages/contractkit/src/utils/signature-utils.ts#L14)

If the signature is in the "bottom" of the curve, it is non-canonical Non-canonical signatures are illegal in Ethereum and therefore the S value must be transposed to the lower intersection <https://github.com/bitcoin/bips/blob/master/bip-0062.mediawiki#Low_S_values_in_signatures>

**Parameters:**

| Name | Type      |
| ---- | --------- |
| `S`  | BigNumber |

**Returns:** *BigNumber*