Struct wolf_crypto::aes::ctr::AesCtr

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pub struct AesCtr { /* private fields */ }

Implementations§

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impl AesCtr

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pub fn new(key: &Key, iv: &Iv) -> Self

Create a new AES CTR instance.

§Arguments

key - The key material to use (which determines the number of rounds).
iv - The initialization vector (nonce).

§Returns

A new AES instance in CTR mode.

§Note

This copies the key and nonce in the underlying C code and is out of scope of this Rust API. At the end of the AesCtr’s lifetime these will be zeroed. It may be desirable to immediately zero the key and nonce passed to this function by reference post invocation.

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pub fn apply_keystream_sized<const S: usize>( &mut self, input: &[u8; S], output: &mut [u8; S], ) -> Res

Apply the underlying keystream to the output buffer, with the size of both the input and output buffers described at compile time to avoid most runtime checks.

§Arguments

input - The input to apply the keystream to.
output - The output buffer to store the result of applying the keystream.

§Errors

If the application of the keystream failed.
(Unlikely) If the size of the input and output buffer is greater than what can be represented by an unsigned int (u32).

§Example

use wolf_crypto::{buf::Iv, aes::{Key, ctr::AesCtr}};
// securely generate a random key and initialization vector ...

let mut input = [1u8; 32];
let mut output = [0u8; 32];

assert!(AesCtr::new(&key, &iv)
    .apply_keystream_sized(&input, &mut output)
    .is_ok());

assert_ne!(&input, &output);
assert_ne!(output, [0u8; 32]);

// and decrypt

let mut plain = [0u8; 32];
assert!(AesCtr::new(&key, &iv)
    .apply_keystream_sized(&output, &mut plain)
    .is_ok());

assert_eq!(&plain, &input);
key.zero();

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pub fn try_apply_keystream(&mut self, input: &[u8], output: &mut [u8]) -> Res

Try to apply the underlying keystream to the output buffer.

§Arguments

input - The input to apply the keystream to.
output - The output buffer to store the result of applying the keystream.

§Errors

If the application of the keystream failed.
If the input buffer is larger than the output buffer.
(Unlikely) If the size of the input or output buffer is greater than what can be represented by an unsigned int (u32).

§Example

use wolf_crypto::{buf::Iv, aes::{Key, ctr::AesCtr}};
// securely generate a random key and initialization vector ...

let mut input = [1u8; 32];
let mut output = [0u8; 32];

assert!(AesCtr::new(&key, &iv)
    .try_apply_keystream(input.as_slice(), output.as_mut_slice())
    .is_ok());

assert_ne!(&input, &output);
assert_ne!(output, [0u8; 32]);

// and decrypt

let mut plain = [0u8; 32];
assert!(AesCtr::new(&key, &iv)
    .try_apply_keystream(output.as_slice(), plain.as_mut_slice())
    .is_ok());

assert_eq!(&plain, &input);
key.zero();

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pub fn apply_keystream(&mut self, input: &[u8], output: &mut [u8])

Apply the underlying keystream to the output buffer using the encryption key.

§Arguments

input - The input to apply the keystream to.
output - The output buffer to store the result of applying the keystream.

§Panics

If the application of the keystream failed.
If the input buffer is larger than the output buffer.
(Unlikely) If the size of the input or output buffer is greater than what can be represented by an unsigned int (u32).

§Example

use wolf_crypto::{buf::Iv, aes::{Key, ctr::AesCtr}};
// securely generate a random key and initialization vector ...

let mut input = [1u8; 32];
let mut output = [0u8; 32];

AesCtr::new(&key, &iv)
    .apply_keystream(input.as_slice(), output.as_mut_slice());

assert_ne!(&input, &output);
assert_ne!(output, [0u8; 32]);

// and decrypt

let mut plain = [0u8; 32];
AesCtr::new(&key, &iv)
    .apply_keystream(output.as_slice(), plain.as_mut_slice());

assert_eq!(&plain, &input);
key.zero();

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pub unsafe fn apply_keystream_unchecked( &mut self, input: &[u8], output: &mut [u8], ) -> Res

Apply the underlying keystream to the output buffer.

This method performs no runtime safety checks.

§Safety

The output buffer must be at least the size of the input.
The size of both buffers must be representable by an unsigned int (u32).

§Arguments

input - The input to apply the keystream to.
output - The output buffer to store the result of applying the keystream.

§Errors

If the application of the keystream failed.

§Example

use wolf_crypto::{buf::Iv, aes::{Key, ctr::AesCtr}};

// securely generate a random key and initialization vector ...

let mut input = [1u8; 32];
let mut output = [0u8; 32];

assert!(AesCtr::new(&key, &iv)
    .apply_keystream_unchecked(input.as_slice(), output.as_mut_slice())
    .is_ok());

assert_ne!(&output, &input);

// and decrypt

let mut original = [0u8; 32];
assert!(AesCtr::new(&key, &iv)
    .apply_keystream_unchecked(output.as_slice(), original.as_mut_slice())
    .is_ok());

assert_eq!(&original, &input);

key.zero();