--- /dev/null
+//! "Edwards25519" elliptic curve group.
+
+use crate::{c2_Element, c2_Scalar, Group};
+use alloc::vec::Vec;
+use curve25519_dalek::{constants::ED25519_BASEPOINT_POINT, edwards::CompressedEdwardsY};
+use hkdf::Hkdf;
+use rand_core::{CryptoRng, RngCore};
+use sha2::{Digest, Sha256};
+
+/// Ed25519 elliptic curve group.
+#[derive(Debug, PartialEq, Eq)]
+pub struct Ed25519Group;
+
+impl Group for Ed25519Group {
+ type Scalar = c2_Scalar;
+ type Element = c2_Element;
+ type TranscriptHash = Sha256;
+
+ fn name() -> &'static str {
+ "Ed25519"
+ }
+
+ fn const_m() -> c2_Element {
+ // python -c "import binascii, spake2; b=binascii.hexlify(spake2.ParamsEd25519.M.to_bytes()); print(', '.join(['0x'+b[i:i+2] for i in range(0,len(b),2)]))"
+ // 15cfd18e385952982b6a8f8c7854963b58e34388c8e6dae891db756481a02312
+ CompressedEdwardsY([
+ 0x15, 0xcf, 0xd1, 0x8e, 0x38, 0x59, 0x52, 0x98, 0x2b, 0x6a, 0x8f, 0x8c, 0x78, 0x54,
+ 0x96, 0x3b, 0x58, 0xe3, 0x43, 0x88, 0xc8, 0xe6, 0xda, 0xe8, 0x91, 0xdb, 0x75, 0x64,
+ 0x81, 0xa0, 0x23, 0x12,
+ ])
+ .decompress()
+ .unwrap()
+ }
+
+ fn const_n() -> c2_Element {
+ // python -c "import binascii, spake2; b=binascii.hexlify(spake2.ParamsEd25519.N.to_bytes()); print(', '.join(['0x'+b[i:i+2] for i in range(0,len(b),2)]))"
+ // f04f2e7eb734b2a8f8b472eaf9c3c632576ac64aea650b496a8a20ff00e583c3
+ CompressedEdwardsY([
+ 0xf0, 0x4f, 0x2e, 0x7e, 0xb7, 0x34, 0xb2, 0xa8, 0xf8, 0xb4, 0x72, 0xea, 0xf9, 0xc3,
+ 0xc6, 0x32, 0x57, 0x6a, 0xc6, 0x4a, 0xea, 0x65, 0x0b, 0x49, 0x6a, 0x8a, 0x20, 0xff,
+ 0x00, 0xe5, 0x83, 0xc3,
+ ])
+ .decompress()
+ .unwrap()
+ }
+
+ fn const_s() -> c2_Element {
+ // python -c "import binascii, spake2; b=binascii.hexlify(spake2.ParamsEd25519.S.to_bytes()); print(', '.join(['0x'+b[i:i+2] for i in range(0,len(b),2)]))"
+ // 6f00dae87c1be1a73b5922ef431cd8f57879569c222d22b1cd71e8546ab8e6f1
+ CompressedEdwardsY([
+ 0x6f, 0x00, 0xda, 0xe8, 0x7c, 0x1b, 0xe1, 0xa7, 0x3b, 0x59, 0x22, 0xef, 0x43, 0x1c,
+ 0xd8, 0xf5, 0x78, 0x79, 0x56, 0x9c, 0x22, 0x2d, 0x22, 0xb1, 0xcd, 0x71, 0xe8, 0x54,
+ 0x6a, 0xb8, 0xe6, 0xf1,
+ ])
+ .decompress()
+ .unwrap()
+ }
+
+ fn hash_to_scalar(s: &[u8]) -> c2_Scalar {
+ ed25519_hash_to_scalar(s)
+ }
+
+ fn random_scalar<T>(cspring: &mut T) -> c2_Scalar
+ where
+ T: RngCore + CryptoRng,
+ {
+ c2_Scalar::random(cspring)
+ }
+
+ fn scalar_neg(s: &c2_Scalar) -> c2_Scalar {
+ -s
+ }
+
+ fn element_to_bytes(s: &c2_Element) -> Vec<u8> {
+ s.compress().as_bytes().to_vec()
+ }
+
+ fn element_length() -> usize {
+ 32
+ }
+
+ fn bytes_to_element(b: &[u8]) -> Option<c2_Element> {
+ if b.len() != 32 {
+ return None;
+ }
+
+ let mut bytes = [0u8; 32];
+ bytes.copy_from_slice(b);
+
+ let cey = CompressedEdwardsY(bytes);
+ cey.decompress()
+ }
+
+ fn basepoint_mult(s: &c2_Scalar) -> c2_Element {
+ ED25519_BASEPOINT_POINT * s
+ }
+ fn scalarmult(e: &c2_Element, s: &c2_Scalar) -> c2_Element {
+ e * s
+ }
+
+ fn add(a: &c2_Element, b: &c2_Element) -> c2_Element {
+ a + b
+ }
+}
+
+fn ed25519_hash_to_scalar(s: &[u8]) -> c2_Scalar {
+ //c2_Scalar::hash_from_bytes::<Sha512>(&s)
+ // spake2.py does:
+ // h = HKDF(salt=b"", ikm=s, hash=SHA256, info=b"SPAKE2 pw", len=32+16)
+ // i = int(h, 16)
+ // i % q
+
+ let mut okm = [0u8; 32 + 16];
+ Hkdf::<Sha256>::new(Some(b""), s)
+ .expand(b"SPAKE2 pw", &mut okm)
+ .unwrap();
+ //println!("expanded: {}{}", "................................", okm.iter().to_hex()); // ok
+
+ let mut reducible = [0u8; 64]; // little-endian
+ for (i, x) in okm.iter().enumerate().take(32 + 16) {
+ reducible[32 + 16 - 1 - i] = *x;
+ }
+ //println!("reducible: {}", reducible.iter().to_hex());
+ c2_Scalar::from_bytes_mod_order_wide(&reducible)
+ //let reduced = c2_Scalar::reduce(&reducible);
+ //println!("reduced: {}", reduced.as_bytes().to_hex());
+ //println!("done");
+ //reduced
+}
+
+/// Hash `idA` and `idB` identities.
+pub(crate) fn hash_ab(
+ password_vec: &[u8],
+ id_a: &[u8],
+ id_b: &[u8],
+ first_msg: &[u8],
+ second_msg: &[u8],
+ key_bytes: &[u8],
+) -> Vec<u8> {
+ assert_eq!(first_msg.len(), 32);
+ assert_eq!(second_msg.len(), 32);
+ // the transcript is fixed-length, made up of 6 32-byte values:
+ // byte 0-31 : sha256(pw)
+ // byte 32-63 : sha256(idA)
+ // byte 64-95 : sha256(idB)
+ // byte 96-127 : X_msg
+ // byte 128-159: Y_msg
+ // byte 160-191: K_bytes
+ let mut transcript = [0u8; 6 * 32];
+
+ let mut pw_hash = Sha256::new();
+ pw_hash.update(password_vec);
+ transcript[0..32].copy_from_slice(&pw_hash.finalize());
+
+ let mut ida_hash = Sha256::new();
+ ida_hash.update(id_a);
+ transcript[32..64].copy_from_slice(&ida_hash.finalize());
+
+ let mut idb_hash = Sha256::new();
+ idb_hash.update(id_b);
+ transcript[64..96].copy_from_slice(&idb_hash.finalize());
+
+ transcript[96..128].copy_from_slice(first_msg);
+ transcript[128..160].copy_from_slice(second_msg);
+ transcript[160..192].copy_from_slice(key_bytes);
+
+ //println!("transcript: {:?}", transcript.iter().to_hex());
+
+ //let mut hash = G::TranscriptHash::default();
+ let mut hash = Sha256::new();
+ hash.update(transcript.to_vec());
+ hash.finalize().to_vec()
+}
+
+/// Hash symmetric identities.
+pub(crate) fn hash_symmetric(
+ password_vec: &[u8],
+ id_s: &[u8],
+ msg_u: &[u8],
+ msg_v: &[u8],
+ key_bytes: &[u8],
+) -> Vec<u8> {
+ assert_eq!(msg_u.len(), 32);
+ assert_eq!(msg_v.len(), 32);
+ // # since we don't know which side is which, we must sort the messages
+ // first_msg, second_msg = sorted([msg1, msg2])
+ // transcript = b"".join([sha256(pw).digest(),
+ // sha256(idSymmetric).digest(),
+ // first_msg, second_msg, K_bytes])
+
+ // the transcript is fixed-length, made up of 5 32-byte values:
+ // byte 0-31 : sha256(pw)
+ // byte 32-63 : sha256(idSymmetric)
+ // byte 64-95 : X_msg
+ // byte 96-127 : Y_msg
+ // byte 128-159: K_bytes
+ let mut transcript = [0u8; 5 * 32];
+
+ let mut pw_hash = Sha256::new();
+ pw_hash.update(password_vec);
+ transcript[0..32].copy_from_slice(&pw_hash.finalize());
+
+ let mut ids_hash = Sha256::new();
+ ids_hash.update(id_s);
+ transcript[32..64].copy_from_slice(&ids_hash.finalize());
+
+ if msg_u < msg_v {
+ transcript[64..96].copy_from_slice(msg_u);
+ transcript[96..128].copy_from_slice(msg_v);
+ } else {
+ transcript[64..96].copy_from_slice(msg_v);
+ transcript[96..128].copy_from_slice(msg_u);
+ }
+ transcript[128..160].copy_from_slice(key_bytes);
+
+ let mut hash = Sha256::new();
+ hash.update(transcript.to_vec());
+ hash.finalize().to_vec()
+}
#[cfg_attr(test, macro_use)]
extern crate std;
+mod ed25519;
+mod error;
+mod group;
+
+pub use self::{
+ ed25519::Ed25519Group,
+ error::{Error, Result},
+ group::Group,
+};
+
use alloc::vec::Vec;
use core::{fmt, ops::Deref, str};
-use curve25519_dalek::{
- constants::ED25519_BASEPOINT_POINT,
- edwards::{CompressedEdwardsY, EdwardsPoint as c2_Element},
- scalar::Scalar as c2_Scalar,
-};
-use hkdf::Hkdf;
+use curve25519_dalek::{edwards::EdwardsPoint as c2_Element, scalar::Scalar as c2_Scalar};
use rand_core::{CryptoRng, RngCore};
-use sha2::{Digest, Sha256};
#[cfg(feature = "getrandom")]
use rand_core::OsRng;
-/// SPAKE2 errors.
-#[derive(Copy, Clone, Debug, Eq, PartialEq)]
-pub enum Error {
- /// Bad side
- BadSide,
-
- /// Corrupt message
- CorruptMessage,
-
- /// Wrong length
- WrongLength,
-}
-
-impl fmt::Display for Error {
- fn fmt(&self, fmt: &mut fmt::Formatter<'_>) -> fmt::Result {
- match self {
- Error::BadSide => fmt.write_str("bad side"),
- Error::CorruptMessage => fmt.write_str("corrupt message"),
- Error::WrongLength => fmt.write_str("invalid length"),
- }
- }
-}
-
-#[cfg(feature = "std")]
-impl std::error::Error for Error {}
-
-/// Password.
+/// Password
// TODO(tarcieri): avoid allocation?
#[derive(PartialEq, Eq, Clone)]
pub struct Password(Vec<u8>);
impl Password {
- /// Create a new password
- pub fn new(p: &[u8]) -> Password {
- Password(p.to_vec())
+ /// Create a new password.
+ pub fn new(p: impl AsRef<[u8]>) -> Password {
+ Password(p.as_ref().to_vec())
}
}
}
impl Identity {
- /// Create a new identity
+ /// Create a new identity.
pub fn new(p: &[u8]) -> Identity {
Identity(p.to_vec())
}
}
-/// Group trait
-// TODO(tarcieri): replace with `group` crate?
-pub trait Group {
- /// Scalar element
- type Scalar;
-
- /// Base field element
- type Element;
-
- /// Transcript hash
- type TranscriptHash;
-
- /// Name
- fn name() -> &'static str;
-
- /// `m` constant
- fn const_m() -> Self::Element;
-
- /// `n` constant
- fn const_n() -> Self::Element;
-
- /// `s` constant
- fn const_s() -> Self::Element;
-
- /// Hash to scalar
- fn hash_to_scalar(s: &[u8]) -> Self::Scalar;
-
- /// Generate a random scalar
- fn random_scalar<T>(cspring: &mut T) -> Self::Scalar
- where
- T: RngCore + CryptoRng;
-
- /// Scalar negation
- fn scalar_neg(s: &Self::Scalar) -> Self::Scalar;
-
- /// Convert base field element to bytes
- fn element_to_bytes(e: &Self::Element) -> Vec<u8>;
-
- /// Convert bytes to base field element
- fn bytes_to_element(b: &[u8]) -> Option<Self::Element>;
-
- /// Length of a base field element
- fn element_length() -> usize;
-
- /// Fixed-base scalar multiplication
- fn basepoint_mult(s: &Self::Scalar) -> Self::Element;
-
- /// Variable-base scalar multiplication
- fn scalarmult(e: &Self::Element, s: &Self::Scalar) -> Self::Element;
-
- /// Group operation
- fn add(a: &Self::Element, b: &Self::Element) -> Self::Element;
-}
-
-/// Ed25519 elliptic curve group.
-#[derive(Debug, PartialEq, Eq)]
-pub struct Ed25519Group;
-
-impl Group for Ed25519Group {
- type Scalar = c2_Scalar;
- type Element = c2_Element;
- type TranscriptHash = Sha256;
-
- fn name() -> &'static str {
- "Ed25519"
- }
-
- fn const_m() -> c2_Element {
- // python -c "import binascii, spake2; b=binascii.hexlify(spake2.ParamsEd25519.M.to_bytes()); print(', '.join(['0x'+b[i:i+2] for i in range(0,len(b),2)]))"
- // 15cfd18e385952982b6a8f8c7854963b58e34388c8e6dae891db756481a02312
- CompressedEdwardsY([
- 0x15, 0xcf, 0xd1, 0x8e, 0x38, 0x59, 0x52, 0x98, 0x2b, 0x6a, 0x8f, 0x8c, 0x78, 0x54,
- 0x96, 0x3b, 0x58, 0xe3, 0x43, 0x88, 0xc8, 0xe6, 0xda, 0xe8, 0x91, 0xdb, 0x75, 0x64,
- 0x81, 0xa0, 0x23, 0x12,
- ])
- .decompress()
- .unwrap()
- }
-
- fn const_n() -> c2_Element {
- // python -c "import binascii, spake2; b=binascii.hexlify(spake2.ParamsEd25519.N.to_bytes()); print(', '.join(['0x'+b[i:i+2] for i in range(0,len(b),2)]))"
- // f04f2e7eb734b2a8f8b472eaf9c3c632576ac64aea650b496a8a20ff00e583c3
- CompressedEdwardsY([
- 0xf0, 0x4f, 0x2e, 0x7e, 0xb7, 0x34, 0xb2, 0xa8, 0xf8, 0xb4, 0x72, 0xea, 0xf9, 0xc3,
- 0xc6, 0x32, 0x57, 0x6a, 0xc6, 0x4a, 0xea, 0x65, 0x0b, 0x49, 0x6a, 0x8a, 0x20, 0xff,
- 0x00, 0xe5, 0x83, 0xc3,
- ])
- .decompress()
- .unwrap()
- }
-
- fn const_s() -> c2_Element {
- // python -c "import binascii, spake2; b=binascii.hexlify(spake2.ParamsEd25519.S.to_bytes()); print(', '.join(['0x'+b[i:i+2] for i in range(0,len(b),2)]))"
- // 6f00dae87c1be1a73b5922ef431cd8f57879569c222d22b1cd71e8546ab8e6f1
- CompressedEdwardsY([
- 0x6f, 0x00, 0xda, 0xe8, 0x7c, 0x1b, 0xe1, 0xa7, 0x3b, 0x59, 0x22, 0xef, 0x43, 0x1c,
- 0xd8, 0xf5, 0x78, 0x79, 0x56, 0x9c, 0x22, 0x2d, 0x22, 0xb1, 0xcd, 0x71, 0xe8, 0x54,
- 0x6a, 0xb8, 0xe6, 0xf1,
- ])
- .decompress()
- .unwrap()
- }
-
- fn hash_to_scalar(s: &[u8]) -> c2_Scalar {
- ed25519_hash_to_scalar(s)
- }
-
- fn random_scalar<T>(cspring: &mut T) -> c2_Scalar
- where
- T: RngCore + CryptoRng,
- {
- c2_Scalar::random(cspring)
- }
-
- fn scalar_neg(s: &c2_Scalar) -> c2_Scalar {
- -s
- }
-
- fn element_to_bytes(s: &c2_Element) -> Vec<u8> {
- s.compress().as_bytes().to_vec()
- }
-
- fn element_length() -> usize {
- 32
- }
-
- fn bytes_to_element(b: &[u8]) -> Option<c2_Element> {
- if b.len() != 32 {
- return None;
- }
-
- let mut bytes = [0u8; 32];
- bytes.copy_from_slice(b);
-
- let cey = CompressedEdwardsY(bytes);
- cey.decompress()
- }
-
- fn basepoint_mult(s: &c2_Scalar) -> c2_Element {
- ED25519_BASEPOINT_POINT * s
- }
- fn scalarmult(e: &c2_Element, s: &c2_Scalar) -> c2_Element {
- e * s
- }
-
- fn add(a: &c2_Element, b: &c2_Element) -> c2_Element {
- a + b
- }
-}
-
-fn ed25519_hash_to_scalar(s: &[u8]) -> c2_Scalar {
- //c2_Scalar::hash_from_bytes::<Sha512>(&s)
- // spake2.py does:
- // h = HKDF(salt=b"", ikm=s, hash=SHA256, info=b"SPAKE2 pw", len=32+16)
- // i = int(h, 16)
- // i % q
-
- let mut okm = [0u8; 32 + 16];
- Hkdf::<Sha256>::new(Some(b""), s)
- .expand(b"SPAKE2 pw", &mut okm)
- .unwrap();
- //println!("expanded: {}{}", "................................", okm.iter().to_hex()); // ok
-
- let mut reducible = [0u8; 64]; // little-endian
- for (i, x) in okm.iter().enumerate().take(32 + 16) {
- reducible[32 + 16 - 1 - i] = *x;
- }
- //println!("reducible: {}", reducible.iter().to_hex());
- c2_Scalar::from_bytes_mod_order_wide(&reducible)
- //let reduced = c2_Scalar::reduce(&reducible);
- //println!("reduced: {}", reduced.as_bytes().to_hex());
- //println!("done");
- //reduced
-}
-
-fn ed25519_hash_ab(
- password_vec: &[u8],
- id_a: &[u8],
- id_b: &[u8],
- first_msg: &[u8],
- second_msg: &[u8],
- key_bytes: &[u8],
-) -> Vec<u8> {
- assert_eq!(first_msg.len(), 32);
- assert_eq!(second_msg.len(), 32);
- // the transcript is fixed-length, made up of 6 32-byte values:
- // byte 0-31 : sha256(pw)
- // byte 32-63 : sha256(idA)
- // byte 64-95 : sha256(idB)
- // byte 96-127 : X_msg
- // byte 128-159: Y_msg
- // byte 160-191: K_bytes
- let mut transcript = [0u8; 6 * 32];
-
- let mut pw_hash = Sha256::new();
- pw_hash.update(password_vec);
- transcript[0..32].copy_from_slice(&pw_hash.finalize());
-
- let mut ida_hash = Sha256::new();
- ida_hash.update(id_a);
- transcript[32..64].copy_from_slice(&ida_hash.finalize());
-
- let mut idb_hash = Sha256::new();
- idb_hash.update(id_b);
- transcript[64..96].copy_from_slice(&idb_hash.finalize());
-
- transcript[96..128].copy_from_slice(first_msg);
- transcript[128..160].copy_from_slice(second_msg);
- transcript[160..192].copy_from_slice(key_bytes);
-
- //println!("transcript: {:?}", transcript.iter().to_hex());
-
- //let mut hash = G::TranscriptHash::default();
- let mut hash = Sha256::new();
- hash.update(transcript.to_vec());
- hash.finalize().to_vec()
-}
-
-fn ed25519_hash_symmetric(
- password_vec: &[u8],
- id_s: &[u8],
- msg_u: &[u8],
- msg_v: &[u8],
- key_bytes: &[u8],
-) -> Vec<u8> {
- assert_eq!(msg_u.len(), 32);
- assert_eq!(msg_v.len(), 32);
- // # since we don't know which side is which, we must sort the messages
- // first_msg, second_msg = sorted([msg1, msg2])
- // transcript = b"".join([sha256(pw).digest(),
- // sha256(idSymmetric).digest(),
- // first_msg, second_msg, K_bytes])
-
- // the transcript is fixed-length, made up of 5 32-byte values:
- // byte 0-31 : sha256(pw)
- // byte 32-63 : sha256(idSymmetric)
- // byte 64-95 : X_msg
- // byte 96-127 : Y_msg
- // byte 128-159: K_bytes
- let mut transcript = [0u8; 5 * 32];
-
- let mut pw_hash = Sha256::new();
- pw_hash.update(password_vec);
- transcript[0..32].copy_from_slice(&pw_hash.finalize());
-
- let mut ids_hash = Sha256::new();
- ids_hash.update(id_s);
- transcript[32..64].copy_from_slice(&ids_hash.finalize());
-
- if msg_u < msg_v {
- transcript[64..96].copy_from_slice(msg_u);
- transcript[96..128].copy_from_slice(msg_v);
- } else {
- transcript[64..96].copy_from_slice(msg_v);
- transcript[96..128].copy_from_slice(msg_u);
- }
- transcript[128..160].copy_from_slice(key_bytes);
-
- let mut hash = Sha256::new();
- hash.update(transcript.to_vec());
- hash.finalize().to_vec()
-}
-
-/* "session type pattern" */
-
+/// Session type identifying the "side" in a SPAKE2 exchange.
#[derive(Debug, PartialEq, Eq)]
enum Side {
A,
}
impl<G: Group> Spake2<G> {
- fn start_internal(
- side: Side,
- password: &Password,
- id_a: &Identity,
- id_b: &Identity,
- id_s: &Identity,
- xy_scalar: G::Scalar,
- ) -> (Spake2<G>, Vec<u8>) {
- //let password_scalar: G::Scalar = hash_to_scalar::<G::Scalar>(password);
- let password_scalar: G::Scalar = G::hash_to_scalar(password);
-
- // a: X = B*x + M*pw
- // b: Y = B*y + N*pw
- // sym: X = B*x * S*pw
- let blinding = match side {
- Side::A => G::const_m(),
- Side::B => G::const_n(),
- Side::Symmetric => G::const_s(),
- };
- let m1: G::Element = G::add(
- &G::basepoint_mult(&xy_scalar),
- &G::scalarmult(&blinding, &password_scalar),
- );
- //let m1: G::Element = &G::basepoint_mult(&x) + &(blinding * &password_scalar);
- let msg1: Vec<u8> = G::element_to_bytes(&m1);
- let mut password_vec = Vec::new();
- password_vec.extend_from_slice(password);
- let mut id_a_copy = Vec::new();
- id_a_copy.extend_from_slice(id_a);
- let mut id_b_copy = Vec::new();
- id_b_copy.extend_from_slice(id_b);
- let mut id_s_copy = Vec::new();
- id_s_copy.extend_from_slice(id_s);
-
- let mut msg_and_side = vec![match side {
- Side::A => 0x41, // 'A'
- Side::B => 0x42, // 'B'
- Side::Symmetric => 0x53, // 'S'
- }];
- msg_and_side.extend_from_slice(&msg1);
-
- (
- Spake2 {
- side,
- xy_scalar,
- password_vec, // string
- id_a: id_a_copy,
- id_b: id_b_copy,
- id_s: id_s_copy,
- msg1,
- password_scalar, // scalar
- },
- msg_and_side,
- )
- }
-
- fn start_a_internal(
- password: &Password,
- id_a: &Identity,
- id_b: &Identity,
- xy_scalar: G::Scalar,
- ) -> (Spake2<G>, Vec<u8>) {
- Self::start_internal(
- Side::A,
- password,
- id_a,
- id_b,
- &Identity::new(b""),
- xy_scalar,
- )
- }
-
- fn start_b_internal(
- password: &Password,
- id_a: &Identity,
- id_b: &Identity,
- xy_scalar: G::Scalar,
- ) -> (Spake2<G>, Vec<u8>) {
- Self::start_internal(
- Side::B,
- password,
- id_a,
- id_b,
- &Identity::new(b""),
- xy_scalar,
- )
- }
-
- fn start_symmetric_internal(
- password: &Password,
- id_s: &Identity,
- xy_scalar: G::Scalar,
- ) -> (Spake2<G>, Vec<u8>) {
- Self::start_internal(
- Side::Symmetric,
- password,
- &Identity::new(b""),
- &Identity::new(b""),
- id_s,
- xy_scalar,
- )
- }
-
- /// Start with identity `a`.
+ /// Start with identity `idA`.
///
/// Uses the system RNG.
#[cfg(feature = "getrandom")]
Self::start_a_with_rng(password, id_a, id_b, OsRng)
}
- /// Start with identity `b`.
+ /// Start with identity `idB`.
///
/// Uses the system RNG.
#[cfg(feature = "getrandom")]
Self::start_symmetric_with_rng(password, id_s, OsRng)
}
- /// Start with identity `a` and the provided cryptographically secure RNG.
+ /// Start with identity `idA` and the provided cryptographically secure RNG.
pub fn start_a_with_rng(
password: &Password,
id_a: &Identity,
Self::start_a_internal(password, id_a, id_b, xy_scalar)
}
- /// Start with identity `b` and the provided cryptographically secure RNG.
+ /// Start with identity `idB` and the provided cryptographically secure RNG.
pub fn start_b_with_rng(
password: &Password,
id_a: &Identity,
}
/// Finish SPAKE2.
- pub fn finish(self, msg2: &[u8]) -> Result<Vec<u8>, Error> {
+ pub fn finish(self, msg2: &[u8]) -> Result<Vec<u8>> {
if msg2.len() != 1 + G::element_length() {
return Err(Error::WrongLength);
}
// note that both sides must use the same order
Ok(match self.side {
- Side::A => ed25519_hash_ab(
+ Side::A => ed25519::hash_ab(
&self.password_vec,
&self.id_a,
&self.id_b,
&msg2[1..],
&key_bytes,
),
- Side::B => ed25519_hash_ab(
+ Side::B => ed25519::hash_ab(
&self.password_vec,
&self.id_a,
&self.id_b,
self.msg1.as_slice(),
&key_bytes,
),
- Side::Symmetric => ed25519_hash_symmetric(
+ Side::Symmetric => ed25519::hash_symmetric(
&self.password_vec,
&self.id_s,
&self.msg1,
),
})
}
+
+ fn start_internal(
+ side: Side,
+ password: &Password,
+ id_a: &Identity,
+ id_b: &Identity,
+ id_s: &Identity,
+ xy_scalar: G::Scalar,
+ ) -> (Spake2<G>, Vec<u8>) {
+ //let password_scalar: G::Scalar = hash_to_scalar::<G::Scalar>(password);
+ let password_scalar: G::Scalar = G::hash_to_scalar(password);
+
+ // a: X = B*x + M*pw
+ // b: Y = B*y + N*pw
+ // sym: X = B*x * S*pw
+ let blinding = match side {
+ Side::A => G::const_m(),
+ Side::B => G::const_n(),
+ Side::Symmetric => G::const_s(),
+ };
+ let m1: G::Element = G::add(
+ &G::basepoint_mult(&xy_scalar),
+ &G::scalarmult(&blinding, &password_scalar),
+ );
+ //let m1: G::Element = &G::basepoint_mult(&x) + &(blinding * &password_scalar);
+ let msg1: Vec<u8> = G::element_to_bytes(&m1);
+ let mut password_vec = Vec::new();
+ password_vec.extend_from_slice(password);
+ let mut id_a_copy = Vec::new();
+ id_a_copy.extend_from_slice(id_a);
+ let mut id_b_copy = Vec::new();
+ id_b_copy.extend_from_slice(id_b);
+ let mut id_s_copy = Vec::new();
+ id_s_copy.extend_from_slice(id_s);
+
+ let mut msg_and_side = vec![match side {
+ Side::A => 0x41, // 'A'
+ Side::B => 0x42, // 'B'
+ Side::Symmetric => 0x53, // 'S'
+ }];
+ msg_and_side.extend_from_slice(&msg1);
+
+ (
+ Spake2 {
+ side,
+ xy_scalar,
+ password_vec, // string
+ id_a: id_a_copy,
+ id_b: id_b_copy,
+ id_s: id_s_copy,
+ msg1,
+ password_scalar, // scalar
+ },
+ msg_and_side,
+ )
+ }
+
+ fn start_a_internal(
+ password: &Password,
+ id_a: &Identity,
+ id_b: &Identity,
+ xy_scalar: G::Scalar,
+ ) -> (Spake2<G>, Vec<u8>) {
+ Self::start_internal(
+ Side::A,
+ password,
+ id_a,
+ id_b,
+ &Identity::new(b""),
+ xy_scalar,
+ )
+ }
+
+ fn start_b_internal(
+ password: &Password,
+ id_a: &Identity,
+ id_b: &Identity,
+ xy_scalar: G::Scalar,
+ ) -> (Spake2<G>, Vec<u8>) {
+ Self::start_internal(
+ Side::B,
+ password,
+ id_a,
+ id_b,
+ &Identity::new(b""),
+ xy_scalar,
+ )
+ }
+
+ fn start_symmetric_internal(
+ password: &Password,
+ id_s: &Identity,
+ xy_scalar: G::Scalar,
+ ) -> (Spake2<G>, Vec<u8>) {
+ Self::start_internal(
+ Side::Symmetric,
+ password,
+ &Identity::new(b""),
+ &Identity::new(b""),
+ id_s,
+ xy_scalar,
+ )
+ }
}
impl<G: Group> fmt::Debug for Spake2<G> {
}
}
-#[cfg(test)]
-mod tests;
+/// This compares results against the python compatibility tests:
+/// spake2.test.test_compat.SPAKE2.test_asymmetric . The python test passes a
+/// deterministic RNG (used only for tests, of course) into the per-Group
+/// "random_scalar()" function, which results in some particular scalar.
+#[cfg(all(test, feature = "std"))]
+mod tests {
+ use crate::*;
+ use curve25519_dalek::constants::ED25519_BASEPOINT_POINT;
+ use num_bigint::BigUint;
+
+ // the python tests show the long-integer form of scalars. the rust code
+ // wants an array of bytes (little-endian). Make sure the way we convert
+ // things works correctly.
+ fn decimal_to_scalar(d: &[u8]) -> c2_Scalar {
+ let bytes = BigUint::parse_bytes(d, 10).unwrap().to_bytes_le();
+ assert_eq!(bytes.len(), 32);
+ let mut b2 = [0u8; 32];
+ b2.copy_from_slice(&bytes);
+ c2_Scalar::from_bytes_mod_order(b2)
+ }
+
+ #[test]
+ fn test_convert() {
+ let t1_decimal =
+ b"2238329342913194256032495932344128051776374960164957527413114840482143558222";
+ let t1_scalar = decimal_to_scalar(t1_decimal);
+ let t1_bytes = t1_scalar.to_bytes();
+ let expected = [
+ 0x4e, 0x5a, 0xb4, 0x34, 0x5d, 0x47, 0x08, 0x84, 0x59, 0x13, 0xb4, 0x64, 0x1b, 0xc2,
+ 0x7d, 0x52, 0x52, 0xa5, 0x85, 0x10, 0x1b, 0xcc, 0x42, 0x44, 0xd4, 0x49, 0xf4, 0xa8,
+ 0x79, 0xd9, 0xf2, 0x04,
+ ];
+ assert_eq!(t1_bytes, expected);
+ //println!("t1_scalar is {:?}", t1_scalar);
+ }
+
+ #[test]
+ fn test_serialize_basepoint() {
+ // make sure elements are serialized same as the python library
+ let exp = "5866666666666666666666666666666666666666666666666666666666666666";
+ let base_vec = ED25519_BASEPOINT_POINT.compress().as_bytes().to_vec();
+ let base_hex = hex::encode(base_vec);
+ println!("exp: {:?}", exp);
+ println!("got: {:?}", base_hex);
+ assert_eq!(exp, base_hex);
+ }
+
+ #[test]
+ fn test_password_to_scalar() {
+ let password = Password::new(b"password");
+ let expected_pw_scalar = decimal_to_scalar(
+ b"3515301705789368674385125653994241092664323519848410154015274772661223168839",
+ );
+ let pw_scalar = Ed25519Group::hash_to_scalar(&password);
+ println!("exp: {:?}", hex::encode(expected_pw_scalar.as_bytes()));
+ println!("got: {:?}", hex::encode(pw_scalar.as_bytes()));
+ assert_eq!(&pw_scalar, &expected_pw_scalar);
+ }
+
+ #[test]
+ fn test_sizes() {
+ let (s1, msg1) = Spake2::<Ed25519Group>::start_a(
+ &Password::new(b"password"),
+ &Identity::new(b"idA"),
+ &Identity::new(b"idB"),
+ );
+ assert_eq!(msg1.len(), 1 + 32);
+ let (s2, msg2) = Spake2::<Ed25519Group>::start_b(
+ &Password::new(b"password"),
+ &Identity::new(b"idA"),
+ &Identity::new(b"idB"),
+ );
+ assert_eq!(msg2.len(), 1 + 32);
+ let key1 = s1.finish(&msg2).unwrap();
+ let key2 = s2.finish(&msg1).unwrap();
+ assert_eq!(key1.len(), 32);
+ assert_eq!(key2.len(), 32);
+
+ let (s1, msg1) = Spake2::<Ed25519Group>::start_symmetric(
+ &Password::new(b"password"),
+ &Identity::new(b"idS"),
+ );
+ assert_eq!(msg1.len(), 1 + 32);
+ let (s2, msg2) = Spake2::<Ed25519Group>::start_symmetric(
+ &Password::new(b"password"),
+ &Identity::new(b"idS"),
+ );
+ assert_eq!(msg2.len(), 1 + 32);
+ let key1 = s1.finish(&msg2).unwrap();
+ let key2 = s2.finish(&msg1).unwrap();
+ assert_eq!(key1.len(), 32);
+ assert_eq!(key2.len(), 32);
+ }
+
+ #[test]
+ fn test_hash_ab() {
+ let key = ed25519::hash_ab(
+ b"pw",
+ b"idA",
+ b"idB",
+ b"XXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXX", // len=32
+ b"YYYYYYYYYYYYYYYYYYYYYYYYYYYYYYYY",
+ b"KKKKKKKKKKKKKKKKKKKKKKKKKKKKKKKK",
+ );
+ let expected_key = "d59d9ba920f7092565cec747b08d5b2e981d553ac32fde0f25e5b4a4cfca3efd";
+ assert_eq!(hex::encode(key), expected_key);
+ }
+
+ #[test]
+ fn test_hash_symmetric() {
+ let key = ed25519::hash_symmetric(
+ b"pw",
+ b"idSymmetric",
+ b"XXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXX",
+ b"YYYYYYYYYYYYYYYYYYYYYYYYYYYYYYYY",
+ b"KKKKKKKKKKKKKKKKKKKKKKKKKKKKKKKK",
+ );
+ let expected_key = "b0b31e4401aae37d91a9a8bf6fbb1298cafc005ff9142e3ffc5b9799fb11128b";
+ assert_eq!(hex::encode(key), expected_key);
+ }
+
+ #[test]
+ fn test_asymmetric() {
+ let scalar_a = decimal_to_scalar(
+ b"2611694063369306139794446498317402240796898290761098242657700742213257926693",
+ );
+ let scalar_b = decimal_to_scalar(
+ b"7002393159576182977806091886122272758628412261510164356026361256515836884383",
+ );
+ let expected_pw_scalar = decimal_to_scalar(
+ b"3515301705789368674385125653994241092664323519848410154015274772661223168839",
+ );
+
+ println!("scalar_a is {}", hex::encode(scalar_a.as_bytes()));
+
+ let (s1, msg1) = Spake2::<Ed25519Group>::start_a_internal(
+ &Password::new(b"password"),
+ &Identity::new(b"idA"),
+ &Identity::new(b"idB"),
+ scalar_a,
+ );
+ let expected_msg1 = "416fc960df73c9cf8ed7198b0c9534e2e96a5984bfc5edc023fd24dacf371f2af9";
+
+ println!();
+ println!("xys1: {:?}", hex::encode(s1.xy_scalar.as_bytes()));
+ println!();
+ println!("pws1: {:?}", hex::encode(s1.password_scalar.as_bytes()));
+ println!("exp : {:?}", hex::encode(expected_pw_scalar.as_bytes()));
+ println!();
+ println!("msg1: {:?}", hex::encode(&msg1));
+ println!("exp : {:?}", expected_msg1);
+ println!();
+
+ assert_eq!(
+ hex::encode(expected_pw_scalar.as_bytes()),
+ hex::encode(s1.password_scalar.as_bytes())
+ );
+ assert_eq!(hex::encode(&msg1), expected_msg1);
+
+ let (s2, msg2) = Spake2::<Ed25519Group>::start_b_internal(
+ &Password::new(b"password"),
+ &Identity::new(b"idA"),
+ &Identity::new(b"idB"),
+ scalar_b,
+ );
+ assert_eq!(expected_pw_scalar, s2.password_scalar);
+ assert_eq!(
+ hex::encode(&msg2),
+ "42354e97b88406922b1df4bea1d7870f17aed3dba7c720b313edae315b00959309"
+ );
+
+ let key1 = s1.finish(&msg2).unwrap();
+ let key2 = s2.finish(&msg1).unwrap();
+ assert_eq!(key1, key2);
+ assert_eq!(
+ hex::encode(key1),
+ "712295de7219c675ddd31942184aa26e0a957cf216bc230d165b215047b520c1"
+ );
+ }
+
+ #[test]
+ fn test_debug() {
+ let (s1, _msg1) = Spake2::<Ed25519Group>::start_a(
+ &Password::new(b"password"),
+ &Identity::new(b"idA"),
+ &Identity::new(b"idB"),
+ );
+ println!("s1: {:?}", s1);
+ assert_eq!(
+ format!("{:?}", s1),
+ "SPAKE2 { group: \"Ed25519\", side: A, idA: (s=idA), idB: (s=idB), idS: (s=) }"
+ );
+
+ let (s2, _msg1) = Spake2::<Ed25519Group>::start_symmetric(
+ &Password::new(b"password"),
+ &Identity::new(b"idS"),
+ );
+ println!("s2: {:?}", s2);
+ assert_eq!(
+ format!("{:?}", s2),
+ "SPAKE2 { group: \"Ed25519\", side: Symmetric, idA: (s=), idB: (s=), idS: (s=idS) }"
+ );
+ }
+}
+++ /dev/null
-//! This compares results against the python compatibility tests:
-//! spake2.test.test_compat.SPAKE2.test_asymmetric . The python test passes a
-//! deterministic RNG (used only for tests, of course) into the per-Group
-//! "random_scalar()" function, which results in some particular scalar.
-
-#![cfg(feature = "std")]
-
-use super::*;
-use curve25519_dalek::constants::ED25519_BASEPOINT_POINT;
-
-use num_bigint::BigUint;
-
-// the python tests show the long-integer form of scalars. the rust code
-// wants an array of bytes (little-endian). Make sure the way we convert
-// things works correctly.
-fn decimal_to_scalar(d: &[u8]) -> c2_Scalar {
- let bytes = BigUint::parse_bytes(d, 10).unwrap().to_bytes_le();
- assert_eq!(bytes.len(), 32);
- let mut b2 = [0u8; 32];
- b2.copy_from_slice(&bytes);
- c2_Scalar::from_bytes_mod_order(b2)
-}
-
-#[test]
-fn test_convert() {
- let t1_decimal =
- b"2238329342913194256032495932344128051776374960164957527413114840482143558222";
- let t1_scalar = decimal_to_scalar(t1_decimal);
- let t1_bytes = t1_scalar.to_bytes();
- let expected = [
- 0x4e, 0x5a, 0xb4, 0x34, 0x5d, 0x47, 0x08, 0x84, 0x59, 0x13, 0xb4, 0x64, 0x1b, 0xc2, 0x7d,
- 0x52, 0x52, 0xa5, 0x85, 0x10, 0x1b, 0xcc, 0x42, 0x44, 0xd4, 0x49, 0xf4, 0xa8, 0x79, 0xd9,
- 0xf2, 0x04,
- ];
- assert_eq!(t1_bytes, expected);
- //println!("t1_scalar is {:?}", t1_scalar);
-}
-
-#[test]
-fn test_serialize_basepoint() {
- // make sure elements are serialized same as the python library
- let exp = "5866666666666666666666666666666666666666666666666666666666666666";
- let base_vec = ED25519_BASEPOINT_POINT.compress().as_bytes().to_vec();
- let base_hex = hex::encode(base_vec);
- println!("exp: {:?}", exp);
- println!("got: {:?}", base_hex);
- assert_eq!(exp, base_hex);
-}
-
-#[test]
-fn test_password_to_scalar() {
- let password = Password::new(b"password");
- let expected_pw_scalar = decimal_to_scalar(
- b"3515301705789368674385125653994241092664323519848410154015274772661223168839",
- );
- let pw_scalar = Ed25519Group::hash_to_scalar(&password);
- println!("exp: {:?}", hex::encode(expected_pw_scalar.as_bytes()));
- println!("got: {:?}", hex::encode(pw_scalar.as_bytes()));
- assert_eq!(&pw_scalar, &expected_pw_scalar);
-}
-
-#[test]
-fn test_sizes() {
- let (s1, msg1) = Spake2::<Ed25519Group>::start_a(
- &Password::new(b"password"),
- &Identity::new(b"idA"),
- &Identity::new(b"idB"),
- );
- assert_eq!(msg1.len(), 1 + 32);
- let (s2, msg2) = Spake2::<Ed25519Group>::start_b(
- &Password::new(b"password"),
- &Identity::new(b"idA"),
- &Identity::new(b"idB"),
- );
- assert_eq!(msg2.len(), 1 + 32);
- let key1 = s1.finish(&msg2).unwrap();
- let key2 = s2.finish(&msg1).unwrap();
- assert_eq!(key1.len(), 32);
- assert_eq!(key2.len(), 32);
-
- let (s1, msg1) = Spake2::<Ed25519Group>::start_symmetric(
- &Password::new(b"password"),
- &Identity::new(b"idS"),
- );
- assert_eq!(msg1.len(), 1 + 32);
- let (s2, msg2) = Spake2::<Ed25519Group>::start_symmetric(
- &Password::new(b"password"),
- &Identity::new(b"idS"),
- );
- assert_eq!(msg2.len(), 1 + 32);
- let key1 = s1.finish(&msg2).unwrap();
- let key2 = s2.finish(&msg1).unwrap();
- assert_eq!(key1.len(), 32);
- assert_eq!(key2.len(), 32);
-}
-
-#[test]
-fn test_hash_ab() {
- let key = ed25519_hash_ab(
- b"pw",
- b"idA",
- b"idB",
- b"XXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXX", // len=32
- b"YYYYYYYYYYYYYYYYYYYYYYYYYYYYYYYY",
- b"KKKKKKKKKKKKKKKKKKKKKKKKKKKKKKKK",
- );
- let expected_key = "d59d9ba920f7092565cec747b08d5b2e981d553ac32fde0f25e5b4a4cfca3efd";
- assert_eq!(hex::encode(key), expected_key);
-}
-
-#[test]
-fn test_hash_symmetric() {
- let key = ed25519_hash_symmetric(
- b"pw",
- b"idSymmetric",
- b"XXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXX",
- b"YYYYYYYYYYYYYYYYYYYYYYYYYYYYYYYY",
- b"KKKKKKKKKKKKKKKKKKKKKKKKKKKKKKKK",
- );
- let expected_key = "b0b31e4401aae37d91a9a8bf6fbb1298cafc005ff9142e3ffc5b9799fb11128b";
- assert_eq!(hex::encode(key), expected_key);
-}
-
-#[test]
-fn test_asymmetric() {
- let scalar_a = decimal_to_scalar(
- b"2611694063369306139794446498317402240796898290761098242657700742213257926693",
- );
- let scalar_b = decimal_to_scalar(
- b"7002393159576182977806091886122272758628412261510164356026361256515836884383",
- );
- let expected_pw_scalar = decimal_to_scalar(
- b"3515301705789368674385125653994241092664323519848410154015274772661223168839",
- );
-
- println!("scalar_a is {}", hex::encode(scalar_a.as_bytes()));
-
- let (s1, msg1) = Spake2::<Ed25519Group>::start_a_internal(
- &Password::new(b"password"),
- &Identity::new(b"idA"),
- &Identity::new(b"idB"),
- scalar_a,
- );
- let expected_msg1 = "416fc960df73c9cf8ed7198b0c9534e2e96a5984bfc5edc023fd24dacf371f2af9";
-
- println!();
- println!("xys1: {:?}", hex::encode(s1.xy_scalar.as_bytes()));
- println!();
- println!("pws1: {:?}", hex::encode(s1.password_scalar.as_bytes()));
- println!("exp : {:?}", hex::encode(expected_pw_scalar.as_bytes()));
- println!();
- println!("msg1: {:?}", hex::encode(&msg1));
- println!("exp : {:?}", expected_msg1);
- println!();
-
- assert_eq!(
- hex::encode(expected_pw_scalar.as_bytes()),
- hex::encode(s1.password_scalar.as_bytes())
- );
- assert_eq!(hex::encode(&msg1), expected_msg1);
-
- let (s2, msg2) = Spake2::<Ed25519Group>::start_b_internal(
- &Password::new(b"password"),
- &Identity::new(b"idA"),
- &Identity::new(b"idB"),
- scalar_b,
- );
- assert_eq!(expected_pw_scalar, s2.password_scalar);
- assert_eq!(
- hex::encode(&msg2),
- "42354e97b88406922b1df4bea1d7870f17aed3dba7c720b313edae315b00959309"
- );
-
- let key1 = s1.finish(&msg2).unwrap();
- let key2 = s2.finish(&msg1).unwrap();
- assert_eq!(key1, key2);
- assert_eq!(
- hex::encode(key1),
- "712295de7219c675ddd31942184aa26e0a957cf216bc230d165b215047b520c1"
- );
-}
-
-#[test]
-fn test_debug() {
- let (s1, _msg1) = Spake2::<Ed25519Group>::start_a(
- &Password::new(b"password"),
- &Identity::new(b"idA"),
- &Identity::new(b"idB"),
- );
- println!("s1: {:?}", s1);
- assert_eq!(
- format!("{:?}", s1),
- "SPAKE2 { group: \"Ed25519\", side: A, idA: (s=idA), idB: (s=idB), idS: (s=) }"
- );
-
- let (s2, _msg1) = Spake2::<Ed25519Group>::start_symmetric(
- &Password::new(b"password"),
- &Identity::new(b"idS"),
- );
- println!("s2: {:?}", s2);
- assert_eq!(
- format!("{:?}", s2),
- "SPAKE2 { group: \"Ed25519\", side: Symmetric, idA: (s=), idB: (s=), idS: (s=idS) }"
- );
-}
projects / PAKEs.git / commitdiff