# Struct ring::hmac::SigningContext [−] [src]

    pub struct SigningContext { /* fields omitted */ }

A context for multi-step (Init-Update-Finish) HMAC signing.

Use `sign` for single-step HMAC signing.

C analog: `HMAC_CTX`.

## Methods

### `impl SigningContext`
[src]

#### `fn with_key(signing_key: &SigningKey) -> SigningContext`

Constructs a new HMAC signing context using the given digest algorithm and key.

C analog: `HMAC_CTX_init`

#### `fn update(&mut self, data: &[u8])`

Updates the HMAC with all the data in `data`. `update` may be called zero or more times until `finish` is called.

C analog: `HMAC_Update`

#### `fn sign(self) -> Signature`

Finalizes the HMAC calculation and returns the HMAC value. `sign` consumes the context so it cannot be (mis-)used after `sign` has been called.

It is generally not safe to implement HMAC verification by comparing

C analog: `HMAC_Final`

## Trait Implementations

### `impl Clone for SigningContext`
[src]

#### `fn clone(&self) -> SigningContext`

Returns a copy of the value. Read more

#### `fn clone_from(&mut self, source: &Self)`
1.0.0

Performs copy-assignment from `source`. Read more

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