signalapp/libsignal-protocol-rust
signalapp/libsignal-protocol-rust
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Clean up error handling surrounding AES encryption

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This commit is contained in:
Jack Lloyd 2020-07-28 15:10:07 -04:00
parent 286cb46578
commit 0191ec0408
3 changed files with 29 additions and 32 deletions
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35
src/crypto.rs
View File

@ -6,31 +6,32 @@ use hmac::{Hmac, Mac};
use sha2::Sha256;
pub fn aes_256_cbc_encrypt(ptext: &[u8], key: &[u8], iv: &[u8]) -> Result<Vec<u8>> {
if key.len() != 32 {
return Err(SignalProtocolError::InvalidCipherKeyLength(key.len()));
match Cbc::<Aes256, Pkcs7>::new_var(key, iv) {
Ok(mode) => Ok(mode.encrypt_vec(&ptext)),
Err(block_modes::InvalidKeyIvLength) => {
return Err(SignalProtocolError::InvalidCipherCryptographicParameters(
key.len(),
iv.len(),
))
}
}
if iv.len() != 16 {
return Err(SignalProtocolError::InvalidCipherNonceLength(iv.len()));
}
let mode = Cbc::<Aes256, Pkcs7>::new_var(key, iv)
.map_err(|e| SignalProtocolError::InvalidArgument(format!("{}", e)))?;
Ok(mode.encrypt_vec(&ptext))
}
pub fn aes_256_cbc_decrypt(ctext: &[u8], key: &[u8], iv: &[u8]) -> Result<Vec<u8>> {
if key.len() != 32 {
return Err(SignalProtocolError::InvalidCipherKeyLength(key.len()));
}
if iv.len() != 16 {
return Err(SignalProtocolError::InvalidCipherNonceLength(iv.len()));
}
if ctext.len() == 0 || ctext.len() % 16 != 0 {
return Err(SignalProtocolError::InvalidCiphertext);
}
let mode = Cbc::<Aes256, Pkcs7>::new_var(key, iv)
.map_err(|e| SignalProtocolError::InvalidArgument(format!("{}", e)))?;
let mode = match Cbc::<Aes256, Pkcs7>::new_var(key, iv) {
Ok(mode) => mode,
Err(block_modes::InvalidKeyIvLength) => {
return Err(SignalProtocolError::InvalidCipherCryptographicParameters(
key.len(),
iv.len(),
))
}
};
Ok(mode
.decrypt_vec(ctext)
.map_err(|_| SignalProtocolError::InvalidCiphertext)?)

14
src/error.rs
View File

@ -42,9 +42,8 @@ pub enum SignalProtocolError {
InvalidRootKeyLength(usize),
InvalidChainKeyLength(usize),
InvalidCipherKeyLength(usize),
InvalidMacKeyLength(usize),
InvalidCipherNonceLength(usize),
InvalidCipherCryptographicParameters(usize, usize),
InvalidCiphertext,
NoSenderKeyState,
@ -137,15 +136,14 @@ impl fmt::Display for SignalProtocolError {
SignalProtocolError::InvalidRootKeyLength(l) => {
write!(f, "invalid root key length <{}>", l)
}
SignalProtocolError::InvalidCipherKeyLength(l) => {
write!(f, "invalid cipher key length <{}>", l)
}
SignalProtocolError::InvalidCipherCryptographicParameters(kl, nl) => write!(
f,
"invalid cipher key length <{}> or nonce length <{}>",
kl, nl
),
SignalProtocolError::InvalidMacKeyLength(l) => {
write!(f, "invalid MAC key length <{}>", l)
}
SignalProtocolError::InvalidCipherNonceLength(l) => {
write!(f, "invalid cipher nonce length <{}>", l)
}
SignalProtocolError::UntrustedIdentity(addr) => {
write!(f, "untrusted identity for address {}", addr)
}

12
src/ratchet/keys.rs
View File

@ -24,16 +24,14 @@ impl MessageKeys {
}
pub fn new(cipher_key: &[u8], mac_key: &[u8], iv: &[u8], counter: u32) -> Result<Self> {
if cipher_key.len() != 32 {
return Err(SignalProtocolError::InvalidCipherKeyLength(
cipher_key.len(),
));
}
if mac_key.len() != 32 {
return Err(SignalProtocolError::InvalidMacKeyLength(mac_key.len()));
}
if iv.len() != 16 {
return Err(SignalProtocolError::InvalidCipherNonceLength(iv.len()));
if cipher_key.len() != 32 || iv.len() != 16 {
return Err(SignalProtocolError::InvalidCipherCryptographicParameters(
cipher_key.len(),
iv.len(),
));
}
Ok(MessageKeys {