[][src]Struct sequoia_openpgp::serialize::stream::padding::Padder

pub struct Padder<'a> { /* fields omitted */ }

Pads a packet stream.

Writes a compressed data packet containing all packets written to this writer, and pads it according to the given policy.

The policy is a Fn(u64) -> u64, that given the number of bytes written to this writer N, computes the size the compression container should be padded up to. It is an error to return a number that is smaller than N.

Compatibility

This implementation uses the DEFLATE compression format. The packet structure contains a flag signaling the end of the stream (see Section 3.2.3 of RFC 1951), and any data appended after that is not part of the stream.

Section 9.3 of RFC 4880 recommends that this algorithm should be implemented, therefore support across various implementations should be good.

Examples

This example illustrates the use of Padder with the Padmé policy. Note that for brevity, the encryption and signature filters are omitted.

use std::io::Write;
use sequoia_openpgp as openpgp;
use openpgp::serialize::stream::{Message, LiteralWriter};
use openpgp::serialize::stream::padding::Padder;
use openpgp::types::CompressionAlgorithm;

let mut unpadded = vec![];
{
    let message = Message::new(&mut unpadded);
    // XXX: Insert Encryptor here.
    // XXX: Insert Signer here.
    let mut message = LiteralWriter::new(message).build()?;
    message.write_all(b"Hello world.")?;
    message.finalize()?;
}

let mut padded = vec![];
{
    let message = Message::new(&mut padded);
    // XXX: Insert Encryptor here.
    let message = Padder::new(message).build()?;
    // XXX: Insert Signer here.
    let mut message = LiteralWriter::new(message).build()?;
    message.write_all(b"Hello world.")?;
    message.finalize()?;
}
assert!(unpadded.len() < padded.len());

Implementations

impl<'a> Padder<'a>[src]

pub fn new(inner: Message<'a>) -> Self[src]

Creates a new padder with the given policy.

Examples

This example illustrates the use of Padder with the Padmé policy.

The most useful filter to push to the writer stack next is the Signer or the LiteralWriter. Finally, literal data must be wrapped using the LiteralWriter.

use sequoia_openpgp as openpgp;
use openpgp::serialize::stream::padding::Padder;

let message = Padder::new(message).build()?;
// Optionally add a `Signer` here.
// Add a `LiteralWriter` here.

pub fn with_policy(self, p: fn(_: u64) -> u64) -> Self[src]

Sets padding policy, returning the padder.

Examples

This example illustrates the use of Padder with an explicit policy.

use sequoia_openpgp as openpgp;
use openpgp::serialize::stream::padding::{Padder, padme};

let message = Padder::new(message).with_policy(padme).build()?;
// Optionally add a `Signer` here.
// Add a `LiteralWriter` here.

pub fn build(self) -> Result<Message<'a>>[src]

Builds the padder, returning the writer stack.

Examples

This example illustrates the use of Padder with the Padmé policy.

The most useful filter to push to the writer stack next is the Signer or the LiteralWriter. Finally, literal data must be wrapped using the LiteralWriter.

use sequoia_openpgp as openpgp;
use openpgp::serialize::stream::padding::Padder;

let message = Padder::new(message).build()?;
// Optionally add a `Signer` here.
// Add a `LiteralWriter` here.

Trait Implementations

impl<'a> Debug for Padder<'a>[src]

impl<'a> Write for Padder<'a>[src]

Auto Trait Implementations

impl<'a> !RefUnwindSafe for Padder<'a>

impl<'a> Send for Padder<'a>

impl<'a> Sync for Padder<'a>

impl<'a> Unpin for Padder<'a>

impl<'a> !UnwindSafe for Padder<'a>

Blanket Implementations

impl<T> Any for T where
    T: 'static + ?Sized
[src]

impl<T> Borrow<T> for T where
    T: ?Sized
[src]

impl<T> BorrowMut<T> for T where
    T: ?Sized
[src]

impl<T> From<T> for T[src]

impl<T, U> Into<U> for T where
    U: From<T>, 
[src]

impl<T> Same<T> for T

type Output = T

Should always be Self

impl<T, U> TryFrom<U> for T where
    U: Into<T>, 
[src]

type Error = Infallible

The type returned in the event of a conversion error.

impl<T, U> TryInto<U> for T where
    U: TryFrom<T>, 
[src]

type Error = <U as TryFrom<T>>::Error

The type returned in the event of a conversion error.