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Revert "ssh-cipher: allows to decrypt a payload without altering state" #416

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Merged
tarcieri merged 1 commit into from
Nov 8, 2025
Merged

Revert "ssh-cipher: allows to decrypt a payload without altering state" #416

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54 changes: 19 additions & 35 deletions ssh-cipher/src/decryptor.rs
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Original file line number Diff line number Diff line change
Expand Up @@ -28,7 +28,6 @@ pub struct Decryptor {
}

/// Inner decryptor enum which is deliberately kept out of the public API.
#[derive(Clone)]
enum Inner {
#[cfg(feature = "aes-cbc")]
Aes128Cbc(cbc::Decryptor<Aes128>),
Expand All @@ -46,31 +45,6 @@ enum Inner {
TDesCbc(cbc::Decryptor<TdesEde3>),
}

impl Inner {
fn decrypt(&mut self, buffer: &mut [u8]) -> Result<()> {
#[cfg(any(feature = "aes-cbc", feature = "aes-ctr", feature = "tdes"))]
match self {
#[cfg(feature = "aes-cbc")]
Self::Aes128Cbc(cipher) => cbc_decrypt(cipher, buffer),
#[cfg(feature = "aes-cbc")]
Self::Aes192Cbc(cipher) => cbc_decrypt(cipher, buffer),
#[cfg(feature = "aes-cbc")]
Self::Aes256Cbc(cipher) => cbc_decrypt(cipher, buffer),
#[cfg(feature = "aes-ctr")]
Self::Aes128Ctr(cipher) => ctr_decrypt(cipher, buffer),
#[cfg(feature = "aes-ctr")]
Self::Aes192Ctr(cipher) => ctr_decrypt(cipher, buffer),
#[cfg(feature = "aes-ctr")]
Self::Aes256Ctr(cipher) => ctr_decrypt(cipher, buffer),
#[cfg(feature = "tdes")]
Self::TDesCbc(cipher) => cbc_decrypt(cipher, buffer),
}
.map_err(|_| Error::Length)?;

Ok(())
}
}

impl Decryptor {
/// Create a new decryptor object with the given [`Cipher`], key, and IV.
pub fn new(cipher: Cipher, key: &[u8], iv: &[u8]) -> Result<Self> {
Expand Down Expand Up @@ -123,16 +97,26 @@ impl Decryptor {
/// Returns [`Error::Length`] in the event that `buffer` is not a multiple of the cipher's
/// block size.
pub fn decrypt(&mut self, buffer: &mut [u8]) -> Result<()> {
self.inner.decrypt(buffer)
}
#[cfg(any(feature = "aes-cbc", feature = "aes-ctr", feature = "tdes"))]
match &mut self.inner {
#[cfg(feature = "aes-cbc")]
Inner::Aes128Cbc(cipher) => cbc_decrypt(cipher, buffer),
#[cfg(feature = "aes-cbc")]
Inner::Aes192Cbc(cipher) => cbc_decrypt(cipher, buffer),
#[cfg(feature = "aes-cbc")]
Inner::Aes256Cbc(cipher) => cbc_decrypt(cipher, buffer),
#[cfg(feature = "aes-ctr")]
Inner::Aes128Ctr(cipher) => ctr_decrypt(cipher, buffer),
#[cfg(feature = "aes-ctr")]
Inner::Aes192Ctr(cipher) => ctr_decrypt(cipher, buffer),
#[cfg(feature = "aes-ctr")]
Inner::Aes256Ctr(cipher) => ctr_decrypt(cipher, buffer),
#[cfg(feature = "tdes")]
Inner::TDesCbc(cipher) => cbc_decrypt(cipher, buffer),
}
.map_err(|_| Error::Length)?;

/// Decrypt the given buffer in place without altering the internal state
///
/// Returns [`Error::Length`] in the event that `buffer` is not a multiple of the cipher's
/// block size.
pub fn peek_decrypt(&self, buffer: &mut [u8]) -> Result<()> {
let mut inner = self.inner.clone();
inner.decrypt(buffer)
Ok(())
}
}

Expand Down