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/*
Copyright Michael Lodder. All Rights Reserved.
SPDX-License-Identifier: Apache-2.0
*/
//! Oberon allows endpoints to issue multi-factor capable tokens to consumers
//! who can prove their validity with disclosing the tokens themselves without requiring
//! email, SMS, or authenticator apps. Endpoints
//! only need to store a single public key and not any tokens. An attacker that breaks
//! into the server doesn't have any password/token files to steal and only would see
//! a public key. The proof of token validity is only 96 bytes while the token itself
//! is only 48 bytes. The issuing party and verifying servers can be separate entities.
//!
//! Tokens are created by signing an identitifier with a secret key.
//!
//! Tokens are presented to a verifier as a zero-knowledge proof such that
//! the verifier never learns the value of the token. Additional blindings
//! can be applied to the token so additional security factors are required
//! before using it. One example is a pin or password.
//!
//! ```
//! use oberon::*;
//! use rand::thread_rng;
//!
//! let sk = SecretKey::hash(b"my super secret key seed");
//! let pk = PublicKey::from(&sk);
//! let id = b"test identity";
//! let token = sk.sign(id).unwrap();
//! let blinding = Blinding::new(b"<your passcode>");
//! let blinded_token = token - &blinding;
//!
//! let timestamp = [0x00, 0x05, 0xc0, 0xba, 0xea, 0x9c, 0x82, 0xb0];
//!
//! match Proof::new(&blinded_token, &[blinding], id, ×tamp, thread_rng()) {
//! None => panic!(""),
//! Some(proof) => {
//! assert_eq!(proof.open(pk, id, ×tamp).unwrap_u8(), 1u8);
//! }
//! }
//! ```
//!
//! This crate supports no-std by default. As such this means only 2 additional factors
//! can be used. This is usually not a problem since 3FA is good enough. If you need
//! more than 3FA (what security context are in???) this can be done with some work
//! as is described below.
//!
//! Blinding factors are applied to tokens as follows
//!
//! ```
//! use oberon::{SecretKey, Token, Blinding};
//!
//! let sk = SecretKey::hash(b"my super secret key seed");
//! let token = sk.sign(b"test identity").unwrap();
//!
//! let blinded_token = token - Blinding::new(b"<your pin number>");
//! let blinded_token = blinded_token - Blinding::new(b"<another factor like HSM key>");
//! let blinded_token = blinded_token - Blinding::new(b"<another factor like ENV>");
//! ```
//!
//! It is important that the blindings are subtracted and not added since addition is used
//! by `Proof::new`
//!
//! This scenario uses 3 extra blindings. In no-std mode, only two can be passed
//! to `Proof::new`. In order to apply the third and still have this work, you simply
//! reverse all but two of the blindings by adding them back in.
//! This restriction doesn't apply when `alloc` or `std` features are used.
//!
//! This crate also supports compiling to wasm. Make sure to use --features=wasm
//! to get the necessary functions
#![no_std]
#![deny(
warnings,
missing_docs,
unused_import_braces,
unused_qualifications,
trivial_casts,
trivial_numeric_casts
)]
#![cfg_attr(docsrs, feature(doc_cfg))]
#[cfg(feature = "alloc")]
extern crate alloc;
#[cfg(feature = "std")]
extern crate std;
#[cfg(feature = "wasm")]
macro_rules! wasm_slice_impl {
($name:ident) => {
impl wasm_bindgen::describe::WasmDescribe for $name {
fn describe() {
wasm_bindgen::describe::inform(wasm_bindgen::describe::SLICE)
}
}
impl wasm_bindgen::convert::IntoWasmAbi for $name {
type Abi = wasm_bindgen::convert::WasmSlice;
fn into_abi(self) -> Self::Abi {
let a = self.to_bytes();
Self::Abi {
ptr: a.as_ptr().into_abi(),
len: a.len() as u32,
}
}
}
impl wasm_bindgen::convert::FromWasmAbi for $name {
type Abi = wasm_bindgen::convert::WasmSlice;
#[inline]
unsafe fn from_abi(js: Self::Abi) -> Self {
use core::{convert::TryFrom, slice};
let ptr = <*mut u8>::from_abi(js.ptr);
let len = js.len as usize;
let r = slice::from_raw_parts(ptr, len);
match <[u8; $name::BYTES]>::try_from(r) {
Ok(d) => $name::from_bytes(&d).unwrap(),
Err(_) => Self::default(),
}
}
}
impl wasm_bindgen::convert::OptionIntoWasmAbi for $name {
fn none() -> wasm_bindgen::convert::WasmSlice {
wasm_bindgen::convert::WasmSlice { ptr: 0, len: 0 }
}
}
impl wasm_bindgen::convert::OptionFromWasmAbi for $name {
fn is_none(slice: &wasm_bindgen::convert::WasmSlice) -> bool {
slice.ptr == 0
}
}
impl TryFrom<wasm_bindgen::JsValue> for $name {
type Error = &'static str;
fn try_from(value: wasm_bindgen::JsValue) -> Result<Self, Self::Error> {
serde_json::from_str::<$name>(&value.as_string().unwrap())
.map_err(|_| "unable to deserialize value")
}
}
};
}
mod blinding;
#[cfg(feature = "ffi")]
mod ffi;
#[cfg(feature = "php")]
mod php;
mod proof;
mod public_key;
#[cfg(feature = "python")]
mod python;
mod secret_key;
mod token;
mod util;
#[cfg(feature = "wasm")]
mod web;
#[cfg(not(any(feature = "rust", feature = "alloc", feature = "blstrs_plus")))]
compile_error!("Please select bls12_381_plus or blstrs_plus as your elliptic curve");
/// The inner representation types
pub mod inner_types {
#[cfg(not(feature = "std"))]
pub use bls12_381_plus::{
elliptic_curve,
ff::{Field, PrimeField},
group::{self, Curve, Group, GroupEncoding, prime::PrimeCurveAffine},
*
};
#[cfg(feature = "std")]
pub use blstrs_plus::{
elliptic_curve,
ff::{Field, PrimeField},
group::{self, Curve, Group, GroupEncoding, prime::PrimeCurveAffine},
pairing_lib::{self, MillerLoopResult, MultiMillerLoop},
*
};
}
pub use blinding::*;
#[cfg_attr(docsrs, doc(cfg(feature = "ffi")))]
#[cfg(feature = "ffi")]
pub use ffi::*;
#[cfg_attr(docsrs, doc(cfg(feature = "php")))]
#[cfg(feature = "php")]
pub use php::*;
pub use proof::*;
pub use public_key::*;
#[cfg_attr(docsrs, doc(cfg(feature = "python")))]
#[cfg(feature = "python")]
pub use python::*;
pub use secret_key::*;
pub use token::*;
#[cfg_attr(docsrs, doc(cfg(feature = "wasm")))]
#[cfg(feature = "wasm")]
pub use web::*;