1292 lines
46 KiB
Rust
1292 lines
46 KiB
Rust
// Copyright (c) Facebook, Inc. and its affiliates.
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//
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// This source code is licensed under the MIT license found in the
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// LICENSE file in the root directory of this source tree.
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//! Provides the main OPAQUE API
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use crate::{
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ciphersuite::CipherSuite,
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envelope::{Envelope, EnvelopeCredentialsFormat, ExportKeySize},
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errors::{
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utils::{check_slice_size, check_slice_size_atleast},
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InternalPakeError, PakeError, ProtocolError,
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},
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group::Group,
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hash::Hash,
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key_exchange::traits::{KeyExchange, ToBytes},
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keypair::{KeyPair, SizedBytesExt},
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map_to_curve::GroupWithMapToCurve,
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oprf,
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serialization::{
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serialize, tokenize, u8_to_credential_type, CredentialType, ProtocolMessageType,
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},
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slow_hash::SlowHash,
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};
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use generic_array::{typenum::Unsigned, GenericArray};
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use generic_bytes::SizedBytes;
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use rand_core::{CryptoRng, RngCore};
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use std::collections::HashMap;
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use std::{convert::TryFrom, marker::PhantomData};
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use zeroize::Zeroize;
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static STR_OPAQUE_VERSION: &[u8] = b"OPAQUE00";
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// Messages
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// =========
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/// The message sent by the client to the server, to initiate registration
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pub struct RegisterFirstMessage<Grp> {
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/// blinded password information
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alpha: Grp,
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}
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impl<Grp: Group> TryFrom<&[u8]> for RegisterFirstMessage<Grp> {
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type Error = ProtocolError;
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fn try_from(first_message_bytes: &[u8]) -> Result<Self, Self::Error> {
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let elem_len = Grp::ElemLen::to_usize();
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let checked_slice = check_slice_size(first_message_bytes, elem_len, "first_message_bytes")?;
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// Check that the message is actually containing an element of the
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// correct subgroup
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let arr = GenericArray::from_slice(&checked_slice[checked_slice.len() - elem_len..]);
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let alpha = Grp::from_element_slice(arr)?;
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Ok(Self { alpha })
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}
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}
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impl<Grp: Group> RegisterFirstMessage<Grp> {
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/// Byte representation for the registration request
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pub fn to_bytes(&self) -> Vec<u8> {
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self.alpha.to_arr().to_vec()
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}
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/// Serialization into bytes
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pub fn serialize(&self) -> Vec<u8> {
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let mut registration_request: Vec<u8> = Vec::new();
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registration_request.extend_from_slice(&serialize(&self.alpha.to_arr(), 2));
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let mut output: Vec<u8> = Vec::new();
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output.push(ProtocolMessageType::from(self) as u8 + 1);
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output.extend_from_slice(&serialize(®istration_request, 3));
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output
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}
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/// Deserialization from bytes
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pub fn deserialize(input: &[u8]) -> Result<Self, ProtocolError> {
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if input.is_empty()
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|| input.is_empty()
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|| input[0] != ProtocolMessageType::RegistrationRequest as u8 + 1
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{
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return Err(PakeError::SerializationError.into());
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}
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let (data, remainder) = tokenize(input[1..].to_vec(), 3)?;
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if !remainder.is_empty() {
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return Err(PakeError::SerializationError.into());
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}
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let (alpha_bytes, remainder) = tokenize(data, 2)?;
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if !remainder.is_empty() {
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return Err(PakeError::SerializationError.into());
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}
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let checked_slice = check_slice_size(
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&alpha_bytes,
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Grp::ElemLen::to_usize(),
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"first_message_bytes",
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)?;
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// Check that the message is actually containing an element of the
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// correct subgroup
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let arr = GenericArray::from_slice(checked_slice);
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let alpha = Grp::from_element_slice(arr)?;
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Ok(Self { alpha })
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}
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}
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/// The answer sent by the server to the user, upon reception of the
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/// registration attempt
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pub struct RegisterSecondMessage<Grp> {
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/// The server's oprf output
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beta: Grp,
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/// Server's static public key
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server_s_pk: Vec<u8>,
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/// Envelope credentials format
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ecf: EnvelopeCredentialsFormat,
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}
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impl<Grp> TryFrom<&[u8]> for RegisterSecondMessage<Grp>
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where
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Grp: Group,
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{
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type Error = ProtocolError;
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fn try_from(bytes: &[u8]) -> Result<Self, Self::Error> {
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let elem_len = Grp::ElemLen::to_usize();
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let checked_slice = check_slice_size_atleast(bytes, elem_len, "second_message_bytes")?;
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// Check that the message is actually containing an element of the
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// correct subgroup
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let arr = GenericArray::from_slice(&checked_slice[..elem_len]);
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let beta = Grp::from_element_slice(arr)?;
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let server_s_pk = checked_slice[elem_len..].to_vec();
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// Note that we use a default envelope credentials format here, since it
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// is not included in the byte representation
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let ecf = EnvelopeCredentialsFormat::default()?;
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Ok(Self {
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beta,
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server_s_pk,
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ecf,
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})
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}
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}
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impl<Grp> RegisterSecondMessage<Grp>
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where
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Grp: Group,
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{
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/// Byte representation for the registration response message. This does not
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/// include the envelope credentials format
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pub fn to_bytes(&self) -> Vec<u8> {
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[&self.beta.to_arr().to_vec()[..], &self.server_s_pk[..]].concat()
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}
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/// Serialization into bytes
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pub fn serialize(&self) -> Vec<u8> {
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let mut registration_response: Vec<u8> = Vec::new();
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registration_response.extend_from_slice(&serialize(&self.beta.to_arr(), 2));
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registration_response.extend_from_slice(&serialize(&self.server_s_pk, 2));
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// Handle ecf serialization
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let secret_credentials: Vec<u8> = self
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.ecf
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.secret_credentials
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.iter()
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.map(|&x| x as u8 + 1)
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.collect();
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let cleartext_credentials: Vec<u8> = self
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.ecf
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.cleartext_credentials
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.iter()
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.map(|&x| x as u8 + 1)
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.collect();
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let ecf_serialized = [
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serialize(&secret_credentials, 1),
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serialize(&cleartext_credentials, 1),
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]
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.concat();
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registration_response.extend_from_slice(&ecf_serialized);
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let mut output: Vec<u8> = Vec::new();
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output.push(ProtocolMessageType::from(self) as u8 + 1);
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output.extend_from_slice(&serialize(®istration_response, 3));
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output
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}
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/// Deserialization from bytes
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pub fn deserialize(input: &[u8]) -> Result<Self, ProtocolError> {
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if input.is_empty() || input[0] != ProtocolMessageType::RegistrationResponse as u8 + 1 {
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return Err(PakeError::SerializationError.into());
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}
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let (data, remainder) = tokenize(input[1..].to_vec(), 3)?;
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if !remainder.is_empty() {
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return Err(PakeError::SerializationError.into());
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}
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let (beta_bytes, remainder) = tokenize(data, 2)?;
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let (server_s_pk, remainder) = tokenize(remainder, 2)?;
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// Handle ecf deserialization
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let (secret_credentials, remainder) = tokenize(remainder, 1)?;
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let (cleartext_credentials, remainder) = tokenize(remainder, 1)?;
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let sc = secret_credentials
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.iter()
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.map(|x| u8_to_credential_type(*x).ok_or(PakeError::SerializationError))
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.collect::<Result<Vec<CredentialType>, _>>()?;
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let cc = cleartext_credentials
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.iter()
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.map(|x| u8_to_credential_type(*x).ok_or(PakeError::SerializationError))
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.collect::<Result<Vec<CredentialType>, _>>()?;
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let ecf = EnvelopeCredentialsFormat::new(sc, cc)?;
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if !remainder.is_empty() {
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return Err(PakeError::SerializationError.into());
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}
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let checked_slice = check_slice_size(
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&beta_bytes,
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Grp::ElemLen::to_usize(),
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"second_message_bytes",
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)?;
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// Check that the message is actually containing an element of the
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// correct subgroup
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let arr = GenericArray::from_slice(&checked_slice);
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let beta = Grp::from_element_slice(arr)?;
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Ok(Self {
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ecf,
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server_s_pk,
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beta,
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})
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}
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}
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/// The final message from the client, containing sealed cryptographic
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/// identifiers
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pub struct RegisterThirdMessage<KeyFormat: KeyPair, D: Hash> {
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/// The "envelope" generated by the user, containing sealed
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/// cryptographic identifiers
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envelope: Envelope<D>,
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/// The user's public key
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client_s_pk: KeyFormat::Repr,
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}
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impl<KeyFormat, D> TryFrom<&[u8]> for RegisterThirdMessage<KeyFormat, D>
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where
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KeyFormat: KeyPair,
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D: Hash,
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{
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type Error = ProtocolError;
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fn try_from(third_message_bytes: &[u8]) -> Result<Self, Self::Error> {
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let key_len = <KeyFormat::Repr as SizedBytes>::Len::to_usize();
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let envelope_size = key_len + Envelope::<D>::additional_size();
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let checked_bytes = check_slice_size(
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third_message_bytes,
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envelope_size + key_len,
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"third_message",
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)?;
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let unchecked_client_s_pk = KeyFormat::Repr::from_bytes(&checked_bytes[envelope_size..])?;
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let client_s_pk = KeyFormat::check_public_key(unchecked_client_s_pk)?;
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Ok(Self {
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envelope: Envelope::<D>::from_bytes(&checked_bytes[..envelope_size])?,
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client_s_pk,
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})
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}
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}
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impl<KeyFormat, D> RegisterThirdMessage<KeyFormat, D>
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where
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KeyFormat: KeyPair,
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D: Hash,
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{
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/// Serialization into bytes
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pub fn serialize(&self) -> Vec<u8> {
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let mut registration_upload: Vec<u8> = Vec::new();
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registration_upload.extend_from_slice(&self.envelope.serialize());
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registration_upload.extend_from_slice(&serialize(&self.client_s_pk.to_arr(), 2));
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let mut output: Vec<u8> = Vec::new();
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output.push(ProtocolMessageType::from(self) as u8 + 1);
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output.extend_from_slice(&serialize(®istration_upload, 3));
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output
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}
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/// Deserialization from bytes
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pub fn deserialize(input: &[u8]) -> Result<Self, ProtocolError> {
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if input.is_empty() || input[0] != ProtocolMessageType::RegistrationUpload as u8 + 1 {
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return Err(PakeError::SerializationError.into());
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}
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let (data, remainder) = tokenize(input[1..].to_vec(), 3)?;
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if !remainder.is_empty() {
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return Err(PakeError::SerializationError.into());
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}
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let (envelope, remainder) = Envelope::<D>::deserialize(&data)?;
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let (client_s_pk, remainder) = tokenize(remainder, 2)?;
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if !remainder.is_empty() {
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return Err(PakeError::SerializationError.into());
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}
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Ok(Self {
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envelope,
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client_s_pk: KeyFormat::check_public_key(KeyFormat::Repr::from_bytes(&client_s_pk)?)?,
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})
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}
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}
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/// The message sent by the user to the server, to initiate registration
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pub struct LoginFirstMessage<CS: CipherSuite> {
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/// blinded password information
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alpha: CS::Group,
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ke1_message: <CS::KeyExchange as KeyExchange<CS::Hash, CS::KeyFormat>>::KE1Message,
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}
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impl<CS: CipherSuite> TryFrom<&[u8]> for LoginFirstMessage<CS> {
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type Error = ProtocolError;
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fn try_from(first_message_bytes: &[u8]) -> Result<Self, Self::Error> {
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Self::deserialize(first_message_bytes)
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}
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}
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impl<CS: CipherSuite> LoginFirstMessage<CS> {
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/// byte representation for the login request
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fn to_bytes(&self) -> Vec<u8> {
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[&self.alpha.to_arr()[..], &self.ke1_message.to_bytes()].concat()
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}
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/// Serialization into bytes
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pub fn serialize(&self) -> Vec<u8> {
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let mut credential_request: Vec<u8> = Vec::new();
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credential_request.extend_from_slice(&serialize(&self.alpha.to_arr(), 2));
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let mut output: Vec<u8> = Vec::new();
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output.push(ProtocolMessageType::from(self) as u8 + 1);
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output.extend_from_slice(&serialize(&credential_request, 3));
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output.extend_from_slice(&self.ke1_message.to_bytes());
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output
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}
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/// Deserialization from bytes
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pub fn deserialize(input: &[u8]) -> Result<Self, ProtocolError> {
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if input.is_empty() || input[0] != ProtocolMessageType::CredentialRequest as u8 + 1 {
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return Err(PakeError::SerializationError.into());
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}
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let (data, ke1m) = tokenize(input[1..].to_vec(), 3)?;
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let (alpha_bytes, remainder) = tokenize(data, 2)?;
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if !remainder.is_empty() {
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return Err(PakeError::SerializationError.into());
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}
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let elem_len = <CS::Group as Group>::ElemLen::to_usize();
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let checked_slice = check_slice_size(&alpha_bytes, elem_len, "login_first_message_bytes")?;
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let arr = GenericArray::from_slice(&checked_slice[..elem_len]);
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let alpha = <CS::Group as Group>::from_element_slice(arr)?;
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let ke1_message =
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<CS::KeyExchange as KeyExchange<CS::Hash, CS::KeyFormat>>::KE1Message::try_from(
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&ke1m[..],
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)?;
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Ok(Self { alpha, ke1_message })
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}
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}
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/// The answer sent by the server to the user, upon reception of the
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/// login attempt.
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pub struct LoginSecondMessage<CS: CipherSuite> {
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/// the server's oprf output
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beta: CS::Group,
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/// the user's sealed information,
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envelope: Envelope<CS::Hash>,
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ke2_message: <CS::KeyExchange as KeyExchange<CS::Hash, CS::KeyFormat>>::KE2Message,
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}
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impl<CS: CipherSuite> LoginSecondMessage<CS> {
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/// Serialization into bytes
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pub fn serialize(&self) -> Vec<u8> {
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let mut credential_response: Vec<u8> = Vec::new();
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credential_response.extend_from_slice(&serialize(&self.beta.to_arr(), 2));
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credential_response.extend_from_slice(&self.envelope.to_bytes());
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let mut output: Vec<u8> = Vec::new();
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output.push(ProtocolMessageType::from(self) as u8 + 1);
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output.extend_from_slice(&serialize(&credential_response, 3));
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output.extend_from_slice(&self.ke2_message.to_bytes());
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output
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}
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/// Deserialization from bytes
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pub fn deserialize(input: &[u8]) -> Result<Self, ProtocolError> {
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if input.is_empty() || input[0] != ProtocolMessageType::CredentialResponse as u8 + 1 {
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return Err(PakeError::SerializationError.into());
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}
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let (data, ke2m) = tokenize(input[1..].to_vec(), 3)?;
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let (beta_bytes, envelope_bytes) = tokenize(data, 2)?;
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let concatenated = [&beta_bytes[..], &envelope_bytes[..], &ke2m[..]].concat();
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Self::try_from(&concatenated[..])
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}
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}
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impl<CS: CipherSuite> TryFrom<&[u8]> for LoginSecondMessage<CS> {
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type Error = ProtocolError;
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fn try_from(second_message_bytes: &[u8]) -> Result<Self, Self::Error> {
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let elem_len = <CS::Group as Group>::ElemLen::to_usize();
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let checked_slice =
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check_slice_size_atleast(second_message_bytes, elem_len, "login_second_message_bytes")?;
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// Check that the message is actually containing an element of the
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// correct subgroup
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let beta_bytes = &checked_slice[..elem_len];
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let arr = GenericArray::from_slice(beta_bytes);
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let beta = CS::Group::from_element_slice(arr)?;
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let (envelope, remainder) = Envelope::<CS::Hash>::deserialize(&checked_slice[elem_len..])?;
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let ke2_message_size = CS::KeyExchange::ke2_message_size();
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let checked_remainder =
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check_slice_size_atleast(&remainder, ke2_message_size, "login_second_message_bytes")?;
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let ke2_message =
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<CS::KeyExchange as KeyExchange<CS::Hash, CS::KeyFormat>>::KE2Message::try_from(
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&checked_remainder,
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)?;
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Ok(Self {
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beta,
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envelope,
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ke2_message,
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})
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}
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}
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/// The answer sent by the client to the server, upon reception of the
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/// sealed envelope
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pub struct LoginThirdMessage<CS: CipherSuite> {
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ke3_message: <CS::KeyExchange as KeyExchange<CS::Hash, CS::KeyFormat>>::KE3Message,
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}
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impl<CS: CipherSuite> TryFrom<&[u8]> for LoginThirdMessage<CS> {
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type Error = ProtocolError;
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fn try_from(bytes: &[u8]) -> Result<Self, Self::Error> {
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let ke3_message =
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<CS::KeyExchange as KeyExchange<CS::Hash, CS::KeyFormat>>::KE3Message::try_from(bytes)?;
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Ok(Self { ke3_message })
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}
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}
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impl<CS: CipherSuite> LoginThirdMessage<CS> {
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/// Serialization into bytes
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pub fn serialize(&self) -> Vec<u8> {
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let mut output: Vec<u8> = Vec::new();
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output.push(ProtocolMessageType::from(self) as u8 + 1);
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output.extend_from_slice(&self.ke3_message.to_bytes());
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output
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}
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/// byte representation for the login finalization
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pub fn to_bytes(&self) -> Vec<u8> {
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self.ke3_message.to_bytes()
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}
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}
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// Registration
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// ============
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|
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/// The state elements the client holds to register itself
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pub struct ClientRegistration<CS: CipherSuite> {
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/// User identity
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id_u: Vec<u8>,
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/// Server identity
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id_s: Vec<u8>,
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/// token containing the client's password and the blinding factor
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pub(crate) token: oprf::Token<CS::Group>,
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}
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|
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impl<CS: CipherSuite> TryFrom<&[u8]> for ClientRegistration<CS> {
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|
type Error = ProtocolError;
|
|
fn try_from(input: &[u8]) -> Result<Self, Self::Error> {
|
|
let (id_u, bytes) = tokenize(input.to_vec(), 2)?;
|
|
let (id_s, bytes) = tokenize(bytes.to_vec(), 2)?;
|
|
|
|
let min_expected_len = <CS::Group as Group>::ScalarLen::to_usize();
|
|
let checked_slice = (if bytes.len() <= min_expected_len {
|
|
Err(InternalPakeError::SizeError {
|
|
name: "client_registration_bytes",
|
|
len: min_expected_len,
|
|
actual_len: bytes.len(),
|
|
})
|
|
} else {
|
|
Ok(bytes)
|
|
})?;
|
|
|
|
// Check that the message is actually containing an element of the
|
|
// correct subgroup
|
|
let scalar_len = min_expected_len;
|
|
let blinding_factor_bytes = GenericArray::from_slice(&checked_slice[..scalar_len]);
|
|
let blinding_factor = CS::Group::from_scalar_slice(blinding_factor_bytes)?;
|
|
let password = checked_slice[scalar_len..].to_vec();
|
|
Ok(Self {
|
|
id_u,
|
|
id_s,
|
|
token: oprf::Token {
|
|
data: password,
|
|
blind: blinding_factor,
|
|
},
|
|
})
|
|
}
|
|
}
|
|
|
|
impl<CS: CipherSuite> ClientRegistration<CS> {
|
|
/// byte representation for the client's registration state
|
|
pub fn to_bytes(&self) -> Vec<u8> {
|
|
let output: Vec<u8> = [
|
|
&serialize(&self.id_u, 2),
|
|
&serialize(&self.id_s, 2),
|
|
&CS::Group::scalar_as_bytes(&self.token.blind)[..],
|
|
&self.token.data,
|
|
]
|
|
.concat();
|
|
output
|
|
}
|
|
}
|
|
|
|
impl<CS: CipherSuite> ClientRegistration<CS> {
|
|
/// Returns an initial "blinded" request to send to the server, as well as a ClientRegistration
|
|
///
|
|
/// # Arguments
|
|
/// * `password` - A user password
|
|
///
|
|
/// # Example
|
|
///
|
|
/// ```
|
|
/// use opaque_ke::opaque::ClientRegistration;
|
|
/// # use opaque_ke::errors::ProtocolError;
|
|
/// use rand_core::{OsRng, RngCore};
|
|
/// use opaque_ke::ciphersuite::CipherSuite;
|
|
/// struct Default;
|
|
/// impl CipherSuite for Default {
|
|
/// type Group = curve25519_dalek::ristretto::RistrettoPoint;
|
|
/// type KeyFormat = opaque_ke::keypair::X25519KeyPair;
|
|
/// type KeyExchange = opaque_ke::key_exchange::tripledh::TripleDH;
|
|
/// type Hash = sha2::Sha256;
|
|
/// type SlowHash = opaque_ke::slow_hash::NoOpHash;
|
|
/// }
|
|
/// let mut rng = OsRng;
|
|
/// let (register_m1, registration_state) = ClientRegistration::<Default>::start(b"hunter2", &mut rng)?;
|
|
/// # Ok::<(), ProtocolError>(())
|
|
/// ```
|
|
pub fn start<R: RngCore + CryptoRng>(
|
|
password: &[u8],
|
|
blinding_factor_rng: &mut R,
|
|
) -> Result<(RegisterFirstMessage<CS::Group>, Self), ProtocolError> {
|
|
Self::start_with_user_and_server_name(
|
|
&Vec::new(),
|
|
&Vec::new(),
|
|
password,
|
|
blinding_factor_rng,
|
|
#[cfg(test)]
|
|
std::convert::identity,
|
|
)
|
|
}
|
|
|
|
/// Same as ClientRegistration::start, but also accepts a username and
|
|
/// server name as input
|
|
/// as well as an optional postprocessing function for the blinding factor(used in tests)
|
|
pub fn start_with_user_and_server_name<R: RngCore + CryptoRng>(
|
|
user_name: &[u8],
|
|
server_name: &[u8],
|
|
password: &[u8],
|
|
blinding_factor_rng: &mut R,
|
|
#[cfg(test)] postprocess: fn(<CS::Group as Group>::Scalar) -> <CS::Group as Group>::Scalar,
|
|
) -> Result<(RegisterFirstMessage<CS::Group>, Self), ProtocolError> {
|
|
let (token, alpha) = oprf::blind::<R, CS::Group>(
|
|
&password,
|
|
blinding_factor_rng,
|
|
#[cfg(test)]
|
|
postprocess,
|
|
)?;
|
|
|
|
Ok((
|
|
RegisterFirstMessage::<CS::Group> { alpha },
|
|
Self {
|
|
id_u: user_name.to_vec(),
|
|
id_s: server_name.to_vec(),
|
|
token,
|
|
},
|
|
))
|
|
}
|
|
}
|
|
|
|
type ClientRegistrationFinishResult<KeyFormat, D> = (
|
|
RegisterThirdMessage<KeyFormat, D>,
|
|
GenericArray<u8, ExportKeySize>,
|
|
);
|
|
|
|
impl<CS: CipherSuite> ClientRegistration<CS> {
|
|
/// "Unblinds" the server's answer and returns a final message containing
|
|
/// cryptographic identifiers, to be sent to the server on setup finalization
|
|
///
|
|
/// # Arguments
|
|
/// * `message` - the server's answer to the initial registration attempt
|
|
///
|
|
/// # Example
|
|
///
|
|
/// ```
|
|
/// use opaque_ke::{opaque::{ClientRegistration, ServerRegistration}, keypair::X25519KeyPair};
|
|
/// # use opaque_ke::errors::ProtocolError;
|
|
/// # use opaque_ke::keypair::KeyPair;
|
|
/// use rand_core::{OsRng, RngCore};
|
|
/// use opaque_ke::ciphersuite::CipherSuite;
|
|
/// struct Default;
|
|
/// impl CipherSuite for Default {
|
|
/// type Group = curve25519_dalek::ristretto::RistrettoPoint;
|
|
/// type KeyFormat = opaque_ke::keypair::X25519KeyPair;
|
|
/// type KeyExchange = opaque_ke::key_exchange::tripledh::TripleDH;
|
|
/// type Hash = sha2::Sha256;
|
|
/// type SlowHash = opaque_ke::slow_hash::NoOpHash;
|
|
/// }
|
|
/// let mut client_rng = OsRng;
|
|
/// let mut server_rng = OsRng;
|
|
/// let server_kp = X25519KeyPair::generate_random(&mut server_rng)?;
|
|
/// let (register_m1, client_state) = ClientRegistration::<Default>::start(b"hunter2", &mut client_rng)?;
|
|
/// let (register_m2, server_state) =
|
|
/// ServerRegistration::<Default>::start(register_m1, &mut server_rng)?;
|
|
/// let mut client_rng = OsRng;
|
|
/// let register_m3 = client_state.finish(register_m2, server_kp.public(), &mut client_rng)?;
|
|
/// # Ok::<(), ProtocolError>(())
|
|
/// ```
|
|
pub fn finish<R: CryptoRng + RngCore>(
|
|
self,
|
|
r2: RegisterSecondMessage<CS::Group>,
|
|
server_s_pk: &<CS::KeyFormat as KeyPair>::Repr,
|
|
rng: &mut R,
|
|
) -> Result<ClientRegistrationFinishResult<CS::KeyFormat, CS::Hash>, ProtocolError> {
|
|
let mut r2_cloned = r2;
|
|
r2_cloned.server_s_pk = server_s_pk.to_arr().to_vec();
|
|
self.finish_using_transmitted_server_public_key(r2_cloned, rng)
|
|
}
|
|
|
|
/// Same as finish, but without the server public key check
|
|
pub fn finish_using_transmitted_server_public_key<R: CryptoRng + RngCore>(
|
|
self,
|
|
r2: RegisterSecondMessage<CS::Group>,
|
|
rng: &mut R,
|
|
) -> Result<ClientRegistrationFinishResult<CS::KeyFormat, CS::Hash>, ProtocolError> {
|
|
let client_static_keypair = CS::KeyFormat::generate_random(rng)?;
|
|
|
|
let password_derived_key =
|
|
get_password_derived_key::<CS::Group, CS::SlowHash, CS::Hash>(&self.token, r2.beta)?;
|
|
|
|
let mut credentials_map: HashMap<CredentialType, Vec<u8>> = HashMap::new();
|
|
credentials_map.insert(
|
|
CredentialType::SkU,
|
|
client_static_keypair.private().to_arr().to_vec(),
|
|
);
|
|
credentials_map.insert(
|
|
CredentialType::PkU,
|
|
client_static_keypair.public().to_arr().to_vec(),
|
|
);
|
|
credentials_map.insert(CredentialType::PkS, r2.server_s_pk);
|
|
credentials_map.insert(CredentialType::IdU, self.id_u.clone());
|
|
credentials_map.insert(CredentialType::IdS, self.id_s.clone());
|
|
|
|
let (envelope, export_key) =
|
|
Envelope::<CS::Hash>::seal(&password_derived_key, r2.ecf, credentials_map, rng)?;
|
|
|
|
Ok((
|
|
RegisterThirdMessage {
|
|
envelope,
|
|
client_s_pk: client_static_keypair.public().clone(),
|
|
},
|
|
export_key,
|
|
))
|
|
}
|
|
}
|
|
|
|
// This can't be derived because of the use of a phantom parameter
|
|
impl<CS: CipherSuite> Zeroize for ClientRegistration<CS> {
|
|
fn zeroize(&mut self) {
|
|
self.token.data.zeroize();
|
|
self.token.blind.zeroize();
|
|
}
|
|
}
|
|
|
|
impl<CS: CipherSuite> Drop for ClientRegistration<CS> {
|
|
fn drop(&mut self) {
|
|
self.zeroize();
|
|
}
|
|
}
|
|
|
|
// This can't be derived because of the use of a phantom parameter
|
|
impl<CS: CipherSuite> Zeroize for ClientLogin<CS> {
|
|
fn zeroize(&mut self) {
|
|
self.token.data.zeroize();
|
|
self.token.blind.zeroize();
|
|
}
|
|
}
|
|
|
|
impl<CS: CipherSuite> Drop for ClientLogin<CS> {
|
|
fn drop(&mut self) {
|
|
self.zeroize();
|
|
}
|
|
}
|
|
|
|
/// The state elements the server holds to record a registration
|
|
pub struct ServerRegistration<CS: CipherSuite> {
|
|
envelope: Option<Envelope<CS::Hash>>,
|
|
client_s_pk: Option<<CS::KeyFormat as KeyPair>::Repr>,
|
|
pub(crate) oprf_key: <CS::Group as Group>::Scalar,
|
|
}
|
|
|
|
impl<CS: CipherSuite> TryFrom<&[u8]> for ServerRegistration<CS>
|
|
where
|
|
<<CS::KeyFormat as KeyPair>::Repr as SizedBytes>::Len:
|
|
std::ops::Add<<<CS::KeyFormat as KeyPair>::Repr as SizedBytes>::Len>,
|
|
generic_array::typenum::Sum<
|
|
<<CS::KeyFormat as KeyPair>::Repr as SizedBytes>::Len,
|
|
<<CS::KeyFormat as KeyPair>::Repr as SizedBytes>::Len,
|
|
>: generic_array::ArrayLength<u8>,
|
|
{
|
|
type Error = ProtocolError;
|
|
|
|
/// The format of a serialized ServerRegistration object:
|
|
/// oprf_key | client_s_pk | envelope
|
|
fn try_from(input: &[u8]) -> Result<Self, Self::Error> {
|
|
let scalar_len = <CS::Group as Group>::ScalarLen::to_usize();
|
|
if input.len() == scalar_len {
|
|
return Ok(Self {
|
|
oprf_key: CS::Group::from_scalar_slice(GenericArray::from_slice(input))?,
|
|
client_s_pk: None,
|
|
envelope: None,
|
|
});
|
|
}
|
|
|
|
// Need to do this check manually because envelope is variable-size
|
|
let key_len = <<CS::KeyFormat as KeyPair>::Repr as SizedBytes>::Len::to_usize();
|
|
|
|
let checked_bytes =
|
|
check_slice_size_atleast(&input, scalar_len + key_len, "server_registration_bytes")?;
|
|
|
|
let oprf_key_bytes = GenericArray::from_slice(&checked_bytes[..scalar_len]);
|
|
let oprf_key = CS::Group::from_scalar_slice(oprf_key_bytes)?;
|
|
let unchecked_client_s_pk = <CS::KeyFormat as KeyPair>::Repr::from_bytes(
|
|
&checked_bytes[scalar_len..scalar_len + key_len],
|
|
)?;
|
|
let client_s_pk = CS::KeyFormat::check_public_key(unchecked_client_s_pk)?;
|
|
|
|
let envelope = Envelope::<CS::Hash>::from_bytes(&checked_bytes[scalar_len + key_len..])?;
|
|
|
|
Ok(Self {
|
|
envelope: Some(envelope),
|
|
client_s_pk: Some(client_s_pk),
|
|
oprf_key,
|
|
})
|
|
}
|
|
}
|
|
|
|
impl<CS: CipherSuite> ServerRegistration<CS>
|
|
where
|
|
<<CS::KeyFormat as KeyPair>::Repr as SizedBytes>::Len:
|
|
std::ops::Add<<<CS::KeyFormat as KeyPair>::Repr as SizedBytes>::Len>,
|
|
generic_array::typenum::Sum<
|
|
<<CS::KeyFormat as KeyPair>::Repr as SizedBytes>::Len,
|
|
<<CS::KeyFormat as KeyPair>::Repr as SizedBytes>::Len,
|
|
>: generic_array::ArrayLength<u8>,
|
|
{
|
|
/// byte representation for the server's registration state
|
|
pub fn to_bytes(&self) -> Vec<u8> {
|
|
let mut output: Vec<u8> = CS::Group::scalar_as_bytes(&self.oprf_key).to_vec();
|
|
self.client_s_pk
|
|
.iter()
|
|
.for_each(|v| output.extend_from_slice(&v.to_arr()));
|
|
self.envelope
|
|
.iter()
|
|
.for_each(|v| output.extend_from_slice(&v.to_bytes()));
|
|
output
|
|
}
|
|
|
|
/// From the client's "blinded" password, returns a response to be
|
|
/// sent back to the client, as well as a ServerRegistration
|
|
///
|
|
/// # Arguments
|
|
/// * `message` - the initial registration message
|
|
///
|
|
/// # Example
|
|
///
|
|
/// ```
|
|
/// use opaque_ke::{opaque::*, keypair::X25519KeyPair};
|
|
/// # use opaque_ke::errors::ProtocolError;
|
|
/// use rand_core::{OsRng, RngCore};
|
|
/// use opaque_ke::ciphersuite::CipherSuite;
|
|
/// struct Default;
|
|
/// impl CipherSuite for Default {
|
|
/// type Group = curve25519_dalek::ristretto::RistrettoPoint;
|
|
/// type KeyFormat = opaque_ke::keypair::X25519KeyPair;
|
|
/// type KeyExchange = opaque_ke::key_exchange::tripledh::TripleDH;
|
|
/// type Hash = sha2::Sha256;
|
|
/// type SlowHash = opaque_ke::slow_hash::NoOpHash;
|
|
/// }
|
|
/// let mut client_rng = OsRng;
|
|
/// let mut server_rng = OsRng;
|
|
/// let (register_m1, client_state) = ClientRegistration::<Default>::start(b"hunter2", &mut client_rng)?;
|
|
/// let (register_m2, server_state) =
|
|
/// ServerRegistration::<Default>::start(register_m1, &mut server_rng)?;
|
|
/// # Ok::<(), ProtocolError>(())
|
|
/// ```
|
|
pub fn start<R: RngCore + CryptoRng>(
|
|
message: RegisterFirstMessage<CS::Group>,
|
|
rng: &mut R,
|
|
) -> Result<(RegisterSecondMessage<CS::Group>, Self), ProtocolError> {
|
|
Self::start_with_server_pk(message, &Vec::new(), rng)
|
|
}
|
|
|
|
/// Same as start, but with the ability to supply a server_s_pk as input
|
|
pub fn start_with_server_pk<R: RngCore + CryptoRng>(
|
|
message: RegisterFirstMessage<CS::Group>,
|
|
server_s_pk: &[u8],
|
|
rng: &mut R,
|
|
) -> Result<(RegisterSecondMessage<CS::Group>, Self), ProtocolError> {
|
|
Self::start_with_server_pk_and_ecf(
|
|
message,
|
|
server_s_pk,
|
|
EnvelopeCredentialsFormat::default()?,
|
|
rng,
|
|
)
|
|
}
|
|
|
|
/// Same as start, but with the ability to supply a server_s_pk as input and envelope credentials format
|
|
pub fn start_with_server_pk_and_ecf<R: RngCore + CryptoRng>(
|
|
message: RegisterFirstMessage<CS::Group>,
|
|
server_s_pk: &[u8],
|
|
ecf: EnvelopeCredentialsFormat,
|
|
rng: &mut R,
|
|
) -> Result<(RegisterSecondMessage<CS::Group>, Self), ProtocolError> {
|
|
// RFC: generate oprf_key (salt) and v_u = g^oprf_key
|
|
let oprf_key = CS::Group::random_scalar(rng);
|
|
|
|
// Compute beta = alpha^oprf_key
|
|
let beta = oprf::evaluate::<CS::Group>(message.alpha, &oprf_key)?;
|
|
|
|
Ok((
|
|
RegisterSecondMessage {
|
|
beta,
|
|
server_s_pk: server_s_pk.to_vec(),
|
|
ecf,
|
|
},
|
|
Self {
|
|
envelope: None,
|
|
client_s_pk: None,
|
|
oprf_key,
|
|
},
|
|
))
|
|
}
|
|
|
|
/// From the client's cryptographic identifiers, fully populates and
|
|
/// returns a ServerRegistration
|
|
///
|
|
/// # Arguments
|
|
/// * `message` - the final client message
|
|
///
|
|
/// # Example
|
|
///
|
|
/// ```
|
|
/// use opaque_ke::{opaque::*, keypair::{KeyPair, X25519KeyPair}};
|
|
/// # use opaque_ke::errors::ProtocolError;
|
|
/// use rand_core::{OsRng, RngCore};
|
|
/// use opaque_ke::ciphersuite::CipherSuite;
|
|
/// struct Default;
|
|
/// impl CipherSuite for Default {
|
|
/// type Group = curve25519_dalek::ristretto::RistrettoPoint;
|
|
/// type KeyFormat = opaque_ke::keypair::X25519KeyPair;
|
|
/// type KeyExchange = opaque_ke::key_exchange::tripledh::TripleDH;
|
|
/// type Hash = sha2::Sha256;
|
|
/// type SlowHash = opaque_ke::slow_hash::NoOpHash;
|
|
/// }
|
|
/// let mut client_rng = OsRng;
|
|
/// let mut server_rng = OsRng;
|
|
/// let server_kp = X25519KeyPair::generate_random(&mut server_rng)?;
|
|
/// let (register_m1, client_state) = ClientRegistration::<Default>::start(b"hunter2", &mut client_rng)?;
|
|
/// let (register_m2, server_state) =
|
|
/// ServerRegistration::<Default>::start(register_m1, &mut server_rng)?;
|
|
/// let mut client_rng = OsRng;
|
|
/// let (register_m3, _export_key) = client_state.finish(register_m2, server_kp.public(), &mut client_rng)?;
|
|
/// let client_record = server_state.finish(register_m3)?;
|
|
/// # Ok::<(), ProtocolError>(())
|
|
/// ```
|
|
pub fn finish(
|
|
self,
|
|
message: RegisterThirdMessage<CS::KeyFormat, CS::Hash>,
|
|
) -> Result<Self, ProtocolError> {
|
|
Ok(Self {
|
|
envelope: Some(message.envelope),
|
|
client_s_pk: Some(message.client_s_pk),
|
|
oprf_key: self.oprf_key,
|
|
})
|
|
}
|
|
}
|
|
|
|
// Login
|
|
// =====
|
|
|
|
/// The state elements the client holds to perform a login
|
|
pub struct ClientLogin<CS: CipherSuite> {
|
|
/// User identity
|
|
id_u: Vec<u8>,
|
|
/// Server identity
|
|
id_s: Vec<u8>,
|
|
/// token containing the client's password and the blinding factor
|
|
token: oprf::Token<CS::Group>,
|
|
ke1_state: <CS::KeyExchange as KeyExchange<CS::Hash, CS::KeyFormat>>::KE1State,
|
|
}
|
|
|
|
impl<CS: CipherSuite> TryFrom<&[u8]> for ClientLogin<CS> {
|
|
type Error = ProtocolError;
|
|
fn try_from(input: &[u8]) -> Result<Self, Self::Error> {
|
|
let (id_u, bytes) = tokenize(input.to_vec(), 2)?;
|
|
let (id_s, bytes) = tokenize(bytes.to_vec(), 2)?;
|
|
|
|
let scalar_len = <CS::Group as Group>::ScalarLen::to_usize();
|
|
let ke1_state_size =
|
|
<CS::KeyExchange as KeyExchange<CS::Hash, CS::KeyFormat>>::ke1_state_size();
|
|
|
|
let min_expected_len = scalar_len + ke1_state_size;
|
|
let checked_slice = (if bytes.len() <= min_expected_len {
|
|
Err(InternalPakeError::SizeError {
|
|
name: "client_login_bytes",
|
|
len: min_expected_len,
|
|
actual_len: bytes.len(),
|
|
})
|
|
} else {
|
|
Ok(bytes.clone())
|
|
})?;
|
|
|
|
let blinding_factor_bytes = GenericArray::from_slice(&checked_slice[..scalar_len]);
|
|
let blinding_factor = CS::Group::from_scalar_slice(blinding_factor_bytes)?;
|
|
let ke1_state =
|
|
<CS::KeyExchange as KeyExchange<CS::Hash, CS::KeyFormat>>::KE1State::try_from(
|
|
&checked_slice[scalar_len..scalar_len + ke1_state_size],
|
|
)?;
|
|
let password = bytes[scalar_len + ke1_state_size..].to_vec();
|
|
Ok(Self {
|
|
id_u,
|
|
id_s,
|
|
token: oprf::Token {
|
|
data: password,
|
|
blind: blinding_factor,
|
|
},
|
|
ke1_state,
|
|
})
|
|
}
|
|
}
|
|
|
|
impl<CS: CipherSuite> ClientLogin<CS> {
|
|
/// byte representation for the client's login state
|
|
pub fn to_bytes(&self) -> Vec<u8> {
|
|
let output: Vec<u8> = [
|
|
&serialize(&self.id_u, 2),
|
|
&serialize(&self.id_s, 2),
|
|
&CS::Group::scalar_as_bytes(&self.token.blind)[..],
|
|
&self.ke1_state.to_bytes(),
|
|
&self.token.data,
|
|
]
|
|
.concat();
|
|
output
|
|
}
|
|
}
|
|
|
|
type ClientLoginFinishResult<CS> = (
|
|
LoginThirdMessage<CS>,
|
|
Vec<u8>,
|
|
GenericArray<u8, ExportKeySize>,
|
|
);
|
|
|
|
impl<CS: CipherSuite> ClientLogin<CS> {
|
|
/// Returns an initial "blinded" password request to send to the server, as well as a ClientLogin
|
|
///
|
|
/// # Arguments
|
|
/// * `password` - A user password
|
|
///
|
|
/// # Example
|
|
///
|
|
/// ```
|
|
/// use opaque_ke::opaque::ClientLogin;
|
|
/// # use opaque_ke::errors::ProtocolError;
|
|
/// use rand_core::{OsRng, RngCore};
|
|
/// use opaque_ke::ciphersuite::CipherSuite;
|
|
/// struct Default;
|
|
/// impl CipherSuite for Default {
|
|
/// type Group = curve25519_dalek::ristretto::RistrettoPoint;
|
|
/// type KeyFormat = opaque_ke::keypair::X25519KeyPair;
|
|
/// type KeyExchange = opaque_ke::key_exchange::tripledh::TripleDH;
|
|
/// type Hash = sha2::Sha256;
|
|
/// type SlowHash = opaque_ke::slow_hash::NoOpHash;
|
|
/// }
|
|
/// let mut client_rng = OsRng;
|
|
/// let (login_m1, client_login_state) = ClientLogin::<Default>::start(b"hunter2", &mut client_rng)?;
|
|
/// # Ok::<(), ProtocolError>(())
|
|
/// ```
|
|
pub fn start<R: RngCore + CryptoRng>(
|
|
password: &[u8],
|
|
rng: &mut R,
|
|
) -> Result<(LoginFirstMessage<CS>, Self), ProtocolError> {
|
|
Self::start_with_user_and_server_name(
|
|
&Vec::new(),
|
|
&Vec::new(),
|
|
password,
|
|
rng,
|
|
#[cfg(test)]
|
|
std::convert::identity,
|
|
)
|
|
}
|
|
|
|
/// Same as start, but allows the user to supply a username and server name
|
|
/// and, in tests, a postprocessing function
|
|
pub fn start_with_user_and_server_name<R: RngCore + CryptoRng>(
|
|
user_name: &[u8],
|
|
server_name: &[u8],
|
|
password: &[u8],
|
|
rng: &mut R,
|
|
#[cfg(test)] postprocess: fn(<CS::Group as Group>::Scalar) -> <CS::Group as Group>::Scalar,
|
|
) -> Result<(LoginFirstMessage<CS>, Self), ProtocolError> {
|
|
let (token, alpha) = oprf::blind::<R, CS::Group>(
|
|
&password,
|
|
rng,
|
|
#[cfg(test)]
|
|
postprocess,
|
|
)?;
|
|
|
|
let (ke1_state, ke1_message) = CS::KeyExchange::generate_ke1(alpha.to_arr().to_vec(), rng)?;
|
|
|
|
let l1 = LoginFirstMessage { alpha, ke1_message };
|
|
|
|
Ok((
|
|
l1,
|
|
Self {
|
|
id_u: user_name.to_vec(),
|
|
id_s: server_name.to_vec(),
|
|
token,
|
|
ke1_state,
|
|
},
|
|
))
|
|
}
|
|
|
|
/// "Unblinds" the server's answer and returns the opened assets from
|
|
/// the server
|
|
///
|
|
/// # Arguments
|
|
/// * `message` - the server's answer to the initial login attempt
|
|
///
|
|
/// # Example
|
|
///
|
|
/// ```
|
|
/// use opaque_ke::opaque::{ClientLogin, ServerLogin};
|
|
/// # use opaque_ke::opaque::{ClientRegistration, ServerRegistration};
|
|
/// # use opaque_ke::errors::ProtocolError;
|
|
/// # use opaque_ke::keypair::{X25519KeyPair, KeyPair};
|
|
/// use rand_core::{OsRng, RngCore};
|
|
/// use opaque_ke::ciphersuite::CipherSuite;
|
|
/// struct Default;
|
|
/// impl CipherSuite for Default {
|
|
/// type Group = curve25519_dalek::ristretto::RistrettoPoint;
|
|
/// type KeyFormat = opaque_ke::keypair::X25519KeyPair;
|
|
/// type KeyExchange = opaque_ke::key_exchange::tripledh::TripleDH;
|
|
/// type Hash = sha2::Sha256;
|
|
/// type SlowHash = opaque_ke::slow_hash::NoOpHash;
|
|
/// }
|
|
/// let mut client_rng = OsRng;
|
|
/// # let mut server_rng = OsRng;
|
|
/// # let (register_m1, client_state) = ClientRegistration::<Default>::start(b"hunter2", &mut client_rng)?;
|
|
/// # let server_kp = X25519KeyPair::generate_random(&mut server_rng)?;
|
|
/// # let (register_m2, server_state) = ServerRegistration::<Default>::start(register_m1, &mut server_rng)?;
|
|
/// # let (register_m3, _export_key) = client_state.finish(register_m2, server_kp.public(), &mut client_rng)?;
|
|
/// # let p_file = server_state.finish(register_m3)?;
|
|
/// let (login_m1, client_login_state) = ClientLogin::<Default>::start(b"hunter2", &mut client_rng)?;
|
|
/// let (login_m2, server_login_state) = ServerLogin::start(p_file, &server_kp.private(), login_m1, &mut server_rng)?;
|
|
/// let (login_m3, client_transport, _export_key) = client_login_state.finish(login_m2, &server_kp.public(), &mut client_rng)?;
|
|
/// # Ok::<(), ProtocolError>(())
|
|
/// ```
|
|
pub fn finish<R: RngCore + CryptoRng>(
|
|
self,
|
|
l2: LoginSecondMessage<CS>,
|
|
_server_s_pk: &<<CS as CipherSuite>::KeyFormat as KeyPair>::Repr,
|
|
_client_e_sk_rng: &mut R,
|
|
) -> Result<ClientLoginFinishResult<CS>, ProtocolError> {
|
|
let l2_bytes: Vec<u8> = [&l2.beta.to_arr()[..], &l2.envelope.to_bytes()].concat();
|
|
|
|
let password_derived_key =
|
|
get_password_derived_key::<CS::Group, CS::SlowHash, CS::Hash>(&self.token, l2.beta)?;
|
|
|
|
let opened_envelope = &l2
|
|
.envelope
|
|
.open(&password_derived_key)
|
|
.map_err(|e| match e {
|
|
InternalPakeError::SealOpenHmacError => PakeError::InvalidLoginError,
|
|
err => PakeError::from(err),
|
|
})?;
|
|
|
|
let (shared_secret, ke3_message) = CS::KeyExchange::generate_ke3(
|
|
l2_bytes,
|
|
l2.ke2_message,
|
|
&self.ke1_state,
|
|
<CS::KeyFormat as KeyPair>::Repr::from_bytes(
|
|
&opened_envelope.credentials_map[&CredentialType::PkS],
|
|
)?,
|
|
<CS::KeyFormat as KeyPair>::Repr::from_bytes(
|
|
&opened_envelope.credentials_map[&CredentialType::SkU],
|
|
)?,
|
|
)?;
|
|
|
|
Ok((
|
|
LoginThirdMessage { ke3_message },
|
|
shared_secret,
|
|
opened_envelope.export_key,
|
|
))
|
|
}
|
|
}
|
|
|
|
/// The state elements the server holds to record a login
|
|
pub struct ServerLogin<CS: CipherSuite> {
|
|
ke2_state: <CS::KeyExchange as KeyExchange<CS::Hash, CS::KeyFormat>>::KE2State,
|
|
_cs: PhantomData<CS>,
|
|
}
|
|
|
|
impl<CS: CipherSuite> TryFrom<&[u8]> for ServerLogin<CS> {
|
|
type Error = ProtocolError;
|
|
fn try_from(bytes: &[u8]) -> Result<Self, Self::Error> {
|
|
Ok(Self {
|
|
_cs: PhantomData,
|
|
ke2_state:
|
|
<CS::KeyExchange as KeyExchange<CS::Hash, CS::KeyFormat>>::KE2State::try_from(
|
|
bytes,
|
|
)?,
|
|
})
|
|
}
|
|
}
|
|
|
|
type ServerLoginStartResult<CS> = (LoginSecondMessage<CS>, ServerLogin<CS>);
|
|
|
|
impl<CS: CipherSuite> ServerLogin<CS> {
|
|
/// byte representation for the server's login state
|
|
pub fn to_bytes(&self) -> Vec<u8> {
|
|
self.ke2_state.to_bytes()
|
|
}
|
|
|
|
/// From the client's "blinded"" password, returns a challenge to be
|
|
/// sent back to the client, as well as a ServerLogin
|
|
///
|
|
/// # Arguments
|
|
/// * `message` - the initial registration message
|
|
///
|
|
/// # Example
|
|
///
|
|
/// ```
|
|
/// use opaque_ke::opaque::{ClientLogin, ServerLogin};
|
|
/// # use opaque_ke::opaque::{ClientRegistration, ServerRegistration};
|
|
/// # use opaque_ke::errors::ProtocolError;
|
|
/// # use opaque_ke::keypair::{KeyPair, X25519KeyPair};
|
|
/// use rand_core::{OsRng, RngCore};
|
|
/// use opaque_ke::ciphersuite::CipherSuite;
|
|
/// struct Default;
|
|
/// impl CipherSuite for Default {
|
|
/// type Group = curve25519_dalek::ristretto::RistrettoPoint;
|
|
/// type KeyFormat = opaque_ke::keypair::X25519KeyPair;
|
|
/// type KeyExchange = opaque_ke::key_exchange::tripledh::TripleDH;
|
|
/// type Hash = sha2::Sha256;
|
|
/// type SlowHash = opaque_ke::slow_hash::NoOpHash;
|
|
/// }
|
|
/// let mut client_rng = OsRng;
|
|
/// let mut server_rng = OsRng;
|
|
/// let server_kp = X25519KeyPair::generate_random(&mut server_rng)?;
|
|
/// # let (register_m1, client_state) = ClientRegistration::<Default>::start(b"hunter2", &mut client_rng)?;
|
|
/// # let (register_m2, server_state) =
|
|
/// ServerRegistration::<Default>::start(register_m1, &mut server_rng)?;
|
|
/// # let (register_m3, _export_key) = client_state.finish(register_m2, server_kp.public(), &mut client_rng)?;
|
|
/// # let p_file = server_state.finish(register_m3)?;
|
|
/// let (login_m1, client_login_state) = ClientLogin::<Default>::start(b"hunter2", &mut client_rng)?;
|
|
/// let (login_m2, server_login_state) = ServerLogin::start(p_file, &server_kp.private(), login_m1, &mut server_rng)?;
|
|
/// # Ok::<(), ProtocolError>(())
|
|
/// ```
|
|
pub fn start<R: RngCore + CryptoRng>(
|
|
password_file: ServerRegistration<CS>,
|
|
server_s_sk: &<CS::KeyFormat as KeyPair>::Repr,
|
|
l1: LoginFirstMessage<CS>,
|
|
rng: &mut R,
|
|
) -> Result<ServerLoginStartResult<CS>, ProtocolError> {
|
|
let l1_bytes = &l1.to_bytes();
|
|
let beta = oprf::evaluate(l1.alpha, &password_file.oprf_key)?;
|
|
|
|
let client_s_pk = password_file
|
|
.client_s_pk
|
|
.ok_or(InternalPakeError::SealError)?;
|
|
let envelope = password_file.envelope.ok_or(InternalPakeError::SealError)?;
|
|
|
|
let l2_component: Vec<u8> = [&beta.to_arr()[..], &envelope.to_bytes()].concat();
|
|
|
|
let (ke2_state, ke2_message) = CS::KeyExchange::generate_ke2(
|
|
rng,
|
|
l1_bytes.to_vec(),
|
|
l2_component,
|
|
l1.ke1_message,
|
|
client_s_pk,
|
|
server_s_sk.clone(),
|
|
)?;
|
|
|
|
let l2 = LoginSecondMessage {
|
|
beta,
|
|
envelope,
|
|
ke2_message,
|
|
};
|
|
|
|
Ok((
|
|
l2,
|
|
Self {
|
|
_cs: PhantomData,
|
|
ke2_state,
|
|
},
|
|
))
|
|
}
|
|
|
|
/// From the client's second & final message, check the client's
|
|
/// authentication & produce a message transport
|
|
///
|
|
/// # Arguments
|
|
/// * `message` - the client's second login message
|
|
///
|
|
/// # Example
|
|
///
|
|
/// ```
|
|
/// use opaque_ke::opaque::{ClientLogin, ServerLogin};
|
|
/// # use opaque_ke::opaque::{ClientRegistration, ServerRegistration};
|
|
/// # use opaque_ke::errors::ProtocolError;
|
|
/// # use opaque_ke::keypair::{KeyPair, X25519KeyPair};
|
|
/// use rand_core::{OsRng, RngCore};
|
|
/// use opaque_ke::ciphersuite::CipherSuite;
|
|
/// struct Default;
|
|
/// impl CipherSuite for Default {
|
|
/// type Group = curve25519_dalek::ristretto::RistrettoPoint;
|
|
/// type KeyFormat = opaque_ke::keypair::X25519KeyPair;
|
|
/// type KeyExchange = opaque_ke::key_exchange::tripledh::TripleDH;
|
|
/// type Hash = sha2::Sha256;
|
|
/// type SlowHash = opaque_ke::slow_hash::NoOpHash;
|
|
/// }
|
|
/// let mut client_rng = OsRng;
|
|
/// let mut server_rng = OsRng;
|
|
/// let server_kp = X25519KeyPair::generate_random(&mut server_rng)?;
|
|
/// # let (register_m1, client_state) = ClientRegistration::<Default>::start(b"hunter2", &mut client_rng)?;
|
|
/// # let (register_m2, server_state) =
|
|
/// ServerRegistration::<Default>::start(register_m1, &mut server_rng)?;
|
|
/// # let (register_m3, _export_key) = client_state.finish(register_m2, server_kp.public(), &mut client_rng)?;
|
|
/// # let p_file = server_state.finish(register_m3)?;
|
|
/// let (login_m1, client_login_state) = ClientLogin::<Default>::start(b"hunter2", &mut client_rng)?;
|
|
/// let (login_m2, server_login_state) = ServerLogin::start(p_file, &server_kp.private(), login_m1, &mut server_rng)?;
|
|
/// let (login_m3, client_transport, _export_key) = client_login_state.finish(login_m2, &server_kp.public(), &mut client_rng)?;
|
|
/// let mut server_transport = server_login_state.finish(login_m3)?;
|
|
/// # Ok::<(), ProtocolError>(())
|
|
/// ```
|
|
pub fn finish(&self, message: LoginThirdMessage<CS>) -> Result<Vec<u8>, ProtocolError> {
|
|
<CS::KeyExchange as KeyExchange<CS::Hash, CS::KeyFormat>>::finish_ke(
|
|
message.ke3_message,
|
|
&self.ke2_state,
|
|
)
|
|
.map_err(|e| match e {
|
|
ProtocolError::VerificationError(PakeError::KeyExchangeMacValidationError) => {
|
|
ProtocolError::VerificationError(PakeError::InvalidLoginError)
|
|
}
|
|
err => err,
|
|
})
|
|
}
|
|
}
|
|
|
|
// Helper functions
|
|
fn get_password_derived_key<G: GroupWithMapToCurve, SH: SlowHash<D>, D: Hash>(
|
|
token: &oprf::Token<G>,
|
|
beta: G,
|
|
) -> Result<Vec<u8>, InternalPakeError> {
|
|
let oprf_output = oprf::finalize::<G, D>(
|
|
&token.data,
|
|
&oprf::unblind::<G>(token, beta),
|
|
STR_OPAQUE_VERSION,
|
|
);
|
|
SH::hash(oprf_output)
|
|
}
|