dev: Drop dead code in ChaCha20Poly1305RFC module

Author: Abeeujah

lightning/src/crypto/chacha20poly1305rfc.rs

@@ -51,24 +51,6 @@ impl ChaCha20Poly1305RFC {
 		ChaCha20Poly1305RFC { cipher, mac, finished: false, data_len: 0, aad_len: aad.len() as u64 }
 	}
 
-	pub fn encrypt(&mut self, input: &[u8], output: &mut [u8], out_tag: &mut [u8]) {
-		assert!(input.len() == output.len());
-		assert!(!self.finished);
-		self.cipher.process(input, output);
-		self.data_len += input.len();
-		self.mac.input(output);
-		ChaCha20Poly1305RFC::pad_mac_16(&mut self.mac, self.data_len);
-		self.finished = true;
-		self.mac.input(&self.aad_len.to_le_bytes());
-		self.mac.input(&(self.data_len as u64).to_le_bytes());
-		out_tag.copy_from_slice(&self.mac.result());
-	}
-
-	pub fn encrypt_full_message_in_place(&mut self, input_output: &mut [u8], out_tag: &mut [u8]) {
-		self.encrypt_in_place(input_output);
-		self.finish_and_get_tag(out_tag);
-	}
-
 	// Encrypt `input_output` in-place. To finish and calculate the tag, use `finish_and_get_tag`
 	// below.
 	pub(in super::super) fn encrypt_in_place(&mut self, input_output: &mut [u8]) {
@@ -89,44 +71,6 @@ impl ChaCha20Poly1305RFC {
 		out_tag.copy_from_slice(&self.mac.result());
 	}
 
-	/// Decrypt the `input`, checking the given `tag` prior to writing the decrypted contents
-	/// into `output`. Note that, because `output` is not touched until the `tag` is checked,
-	/// this decryption is *variable time*.
-	pub fn variable_time_decrypt(
-		&mut self, input: &[u8], output: &mut [u8], tag: &[u8],
-	) -> Result<(), ()> {
-		assert!(input.len() == output.len());
-		assert!(!self.finished);
-
-		self.finished = true;
-
-		self.mac.input(input);
-
-		self.data_len += input.len();
-		ChaCha20Poly1305RFC::pad_mac_16(&mut self.mac, self.data_len);
-		self.mac.input(&self.aad_len.to_le_bytes());
-		self.mac.input(&(self.data_len as u64).to_le_bytes());
-
-		let calc_tag = self.mac.result();
-		if fixed_time_eq(&calc_tag, tag) {
-			self.cipher.process(input, output);
-			Ok(())
-		} else {
-			Err(())
-		}
-	}
-
-	pub fn check_decrypt_in_place(
-		&mut self, input_output: &mut [u8], tag: &[u8],
-	) -> Result<(), ()> {
-		self.decrypt_in_place(input_output);
-		if self.finish_and_check_tag(tag) {
-			Ok(())
-		} else {
-			Err(())
-		}
-	}
-
 	/// Decrypt in place, without checking the tag. Use `finish_and_check_tag` to check it
 	/// later when decryption finishes.
 	///