[英]How can I change the return type of this function?
我正在通過使用rust的matasano加密挑戰 ,以及用於AES實現的rust-crypto。 我有這個功能來進行基本的ECB模式加密(基本上從rust-crypto存儲庫的例子中逐字逐句):
pub fn aes_enc_ecb_128(key: &[u8], data: &[u8])
-> Result<Vec<u8>, symmetriccipher::SymmetricCipherError> {
let mut encryptor = aes::ecb_encryptor(
aes::KeySize::KeySize128,
key,
blockmodes::NoPadding);
let mut final_result = Vec::<u8>::new();
let mut read_buffer = buffer::RefReadBuffer::new(data);
let mut buffer = [0; 4096];
let mut write_buffer = buffer::RefWriteBuffer::new(&mut buffer);
loop {
let result = encryptor.encrypt(&mut read_buffer,
&mut write_buffer,
true);
final_result.extend(write_buffer
.take_read_buffer()
.take_remaining().iter().map(|&i| i));
match result {
Ok(BufferResult::BufferUnderflow) => break,
Ok(_) => {},
Err(e) => return Err(e)
}
}
Ok(final_result)
}
上面的版本編譯沒有問題,並按預期工作。 但是,為了使其適合我的錯誤處理方案的其余部分,我想將返回類型更改為Result<Vec<u8>,&'static str>
。 這是應用該更改的功能:
pub fn aes_enc_ecb_128(key: &[u8], data: &[u8])
-> Result<Vec<u8>, &'static str> {
let mut encryptor = aes::ecb_encryptor(
aes::KeySize::KeySize128,
key,
blockmodes::NoPadding);
let mut final_result = Vec::<u8>::new();
let mut read_buffer = buffer::RefReadBuffer::new(data);
let mut buffer = [0; 4096];
let mut write_buffer = buffer::RefWriteBuffer::new(&mut buffer);
loop {
let result = encryptor.encrypt(&mut read_buffer,
&mut write_buffer,
true);
final_result.extend(write_buffer
.take_read_buffer()
.take_remaining().iter().map(|&i| i));
match result {
Ok(BufferResult::BufferUnderflow) => break,
Ok(_) => {},
Err(_) => return Err("Encryption failed")
}
}
Ok(final_result)
}
當我嘗試編譯此版本時,我收到以下錯誤(為清晰起見,刪除了路徑):
error: source trait is private
let result = encryptor.encrypt(&mut read_buffer,
&mut write_buffer,
true);
error: source trait is private
let r = decryptor.decrypt(&mut read_buffer, &mut write_buffer, true);
^~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
我能夠改變這種類型的唯一方法是將原始函數包裝在這樣的轉換函數中:
pub fn converted_enc(key: &[u8], data: &[u8])
-> Result<Vec<u8>, &'static str> {
match aes_enc_ecb_128(key,data) {
Ok(v) => Ok(v),
Err(_) => Err("Encryption failed")
}
}
為了使返回值適合我的其余API,我應該做什么而不是上面的內容,為什么更直接的方法失敗?
我使用以下版本的銹/貨:
rustc 1.2.0-nightly (0cc99f9cc 2015-05-17) (built 2015-05-18)
cargo 0.2.0-nightly (ac61996 2015-05-17) (built 2015-05-17)
我想你遇到過編譯器的錯誤。 你的代碼應該編譯
你可以use crypto::symmetriccipher::Encryptor;
作為一種解決方法:
pub fn aes_enc_ecb_128(key: &[u8], data: &[u8])
-> Result<Vec<u8>, &'static str> {
use crypto::symmetriccipher::Encryptor;
let mut encryptor = aes::ecb_encryptor(
aes::KeySize::KeySize128,
key,
blockmodes::NoPadding);
let mut final_result = Vec::<u8>::new();
let mut read_buffer = buffer::RefReadBuffer::new(data);
let mut buffer = [0; 4096];
let mut write_buffer = buffer::RefWriteBuffer::new(&mut buffer);
loop {
let result = encryptor.encrypt(&mut read_buffer,
&mut write_buffer,
true);
final_result.extend(write_buffer
.take_read_buffer()
.take_remaining().iter().map(|&i| i));
match result {
Ok(BufferResult::BufferUnderflow) => break,
Ok(_) => {},
Err(_) => return Err("Encryption failed")
}
}
Ok(final_result)
}
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