From ab0d36e7848c0dd95b9f693d57986d0c0921dd25 Mon Sep 17 00:00:00 2001 From: Aumetra Weisman Date: Tue, 23 Jul 2024 22:16:48 +0200 Subject: [PATCH] align all the precisions (its ugly) --- dsa/src/components.rs | 9 ++++++--- dsa/src/generate/secret_number.rs | 4 ++-- dsa/src/signing_key.rs | 14 ++++++++++++-- dsa/tests/deterministic.rs | 29 ++++++++++++++++++----------- 4 files changed, 38 insertions(+), 18 deletions(-) diff --git a/dsa/src/components.rs b/dsa/src/components.rs index c03cccea..6458a777 100644 --- a/dsa/src/components.rs +++ b/dsa/src/components.rs @@ -73,9 +73,12 @@ impl<'a> DecodeValue<'a> for Components { let q = reader.decode::>()?; let g = reader.decode::>()?; - let p = BoxedUint::from_be_slice(p.as_bytes(), (p.as_bytes().len() * 8) as u32).unwrap(); - let q = BoxedUint::from_be_slice(q.as_bytes(), (q.as_bytes().len() * 8) as u32).unwrap(); - let g = BoxedUint::from_be_slice(g.as_bytes(), (g.as_bytes().len() * 8) as u32).unwrap(); + // Just use the precision of `p` since `p` will be the largest value and all values need to have the same precision + let precision = (p.as_bytes().len() * 8) as u32; + + let p = BoxedUint::from_be_slice(p.as_bytes(), precision).unwrap(); + let q = BoxedUint::from_be_slice(q.as_bytes(), precision).unwrap(); + let g = BoxedUint::from_be_slice(g.as_bytes(), precision).unwrap(); let p = NonZero::new(p).unwrap(); let q = NonZero::new(q).unwrap(); diff --git a/dsa/src/generate/secret_number.rs b/dsa/src/generate/secret_number.rs index 218bb574..83e3379c 100644 --- a/dsa/src/generate/secret_number.rs +++ b/dsa/src/generate/secret_number.rs @@ -27,7 +27,7 @@ where let size = (q.bits() / 8) as usize; // Reduce hash mod q - let hash = BoxedUint::from_be_slice(hash, (hash.len() * 8) as u32).unwrap(); + let hash = BoxedUint::from_be_slice(hash, q.bits_precision()).unwrap(); let hash = (hash % q).to_be_bytes(); let hash = strip_leading_zeros(&hash, size); @@ -41,7 +41,7 @@ where loop { rfc6979::generate_k_mut::(x_bytes, q_bytes, hash, &[], &mut buffer); - let k = BoxedUint::from_be_slice(&buffer, (buffer.len() * 8) as u32).unwrap(); + let k = BoxedUint::from_be_slice(&buffer, q.bits_precision()).unwrap(); if let Some(inv_k) = k.inv_mod(q).into() { if (bool::from(k.is_nonzero())) & (k < **q) { debug_assert!(bool::from(k.is_odd())); diff --git a/dsa/src/signing_key.rs b/dsa/src/signing_key.rs index f0222430..35b4d6a1 100644 --- a/dsa/src/signing_key.rs +++ b/dsa/src/signing_key.rs @@ -94,6 +94,12 @@ impl SigningKey { let (p, q, g) = (components.p(), components.q(), components.g()); let x = self.x(); + // Verify all the precisions check out. Otherwise the math operations will fail + debug_assert_eq!(p.bits_precision(), q.bits_precision()); + debug_assert_eq!(q.bits_precision(), g.bits_precision()); + debug_assert_eq!(g.bits_precision(), x.bits_precision()); + debug_assert_eq!(x.bits_precision(), k.bits_precision()); + let params = BoxedMontyParams::new(Odd::new(k).unwrap()); let form = BoxedMontyForm::new((**g).clone(), params); let r = NonZero::new(form.pow(p).retrieve() % q).unwrap(); @@ -209,14 +215,18 @@ impl<'a> TryFrom> for SigningKey { let parameters = value.algorithm.parameters_any()?; let components = parameters.decode_as::()?; + // Use the precision of `p`. `p` will always have the largest precision. + // Every operation is mod `p` anyway, so it will always fit. + let precision = components.p().bits_precision(); + let x = UintRef::from_der(value.private_key)?; - let x = BoxedUint::from_be_slice(x.as_bytes(), x.as_bytes().len() as u32 * 8).unwrap(); + let x = BoxedUint::from_be_slice(x.as_bytes(), precision).unwrap(); let x = NonZero::new(x).unwrap(); let y = if let Some(y_bytes) = value.public_key { let y = UintRef::from_der(y_bytes)?; NonZero::new( - BoxedUint::from_be_slice(y.as_bytes(), y.as_bytes().len() as u32 * 8).unwrap(), + BoxedUint::from_be_slice(y.as_bytes(), precision).unwrap(), ) .unwrap() } else { diff --git a/dsa/tests/deterministic.rs b/dsa/tests/deterministic.rs index cac7f95d..8236af68 100644 --- a/dsa/tests/deterministic.rs +++ b/dsa/tests/deterministic.rs @@ -8,9 +8,9 @@ use signature::DigestSigner; const MESSAGE: &[u8] = b"sample"; const MESSAGE_2: &[u8] = b"test"; -fn decode_hex_number(txt: &str) -> BoxedUint { +fn decode_hex_number(txt: &str, precision: u32) -> BoxedUint { let val = hex::decode(txt).unwrap(); - BoxedUint::from_be_slice(&val, val.len() as u32 * 8).unwrap() + BoxedUint::from_be_slice(&val, precision).unwrap() } fn dsa_1024_signing_key() -> SigningKey { @@ -18,25 +18,25 @@ fn dsa_1024_signing_key() -> SigningKey { E6533B86B18BED6E8A48B784A14C252C5BE0DBF60B86D6385BD2F12FB763ED88\ 73ABFD3F5BA2E0A8C0A59082EAC056935E529DAF7C610467899C77ADEDFC846C\ 881870B7B19B2B58F9BE0521A17002E3BDD6B86685EE90B3D9A1B02B782B1779"; - let p = decode_hex_number(p_str); + let p = decode_hex_number(p_str, 1024); let q_str = "996F967F6C8E388D9E28D01E205FBA957A5698B1"; - let q = decode_hex_number(q_str); + let q = decode_hex_number(q_str, 1024); let g_str = "07B0F92546150B62514BB771E2A0C0CE387F03BDA6C56B505209FF25FD3C133D\ 89BBCD97E904E09114D9A7DEFDEADFC9078EA544D2E401AEECC40BB9FBBF78FD\ 87995A10A1C27CB7789B594BA7EFB5C4326A9FE59A070E136DB77175464ADCA4\ 17BE5DCE2F40D10A46A3A3943F26AB7FD9C0398FF8C76EE0A56826A8A88F1DBD"; - let g = decode_hex_number(g_str); + let g = decode_hex_number(g_str, 1024); let x_str = "411602CB19A6CCC34494D79D98EF1E7ED5AF25F7"; - let x = decode_hex_number(x_str); + let x = decode_hex_number(x_str, 1024); let y_str = "5DF5E01DED31D0297E274E1691C192FE5868FEF9E19A84776454B100CF16F653\ 92195A38B90523E2542EE61871C0440CB87C322FC4B4D2EC5E1E7EC766E1BE8D\ 4CE935437DC11C3C8FD426338933EBFE739CB3465F4D3668C5E473508253B1E6\ 82F65CBDC4FAE93C2EA212390E54905A86E2223170B44EAA7DA5DD9FFCFB7F3B"; - let y = decode_hex_number(y_str); + let y = decode_hex_number(y_str, 1024); let (p, q, g, y, x) = ( NonZero::new(p).unwrap(), @@ -63,8 +63,9 @@ fn dsa_2048_signing_key() -> SigningKey { F1BF14D4BB4563CA28371621CAD3324B6A2D392145BEBFAC748805236F5CA2FE\ 92B871CD8F9C36D3292B5509CA8CAA77A2ADFC7BFD77DDA6F71125A7456FEA15\ 3E433256A2261C6A06ED3693797E7995FAD5AABBCFBE3EDA2741E375404AE25B", + 2048, ); - let q = decode_hex_number("F2C3119374CE76C9356990B465374A17F23F9ED35089BD969F61C6DDE9998C1F"); + let q = decode_hex_number("F2C3119374CE76C9356990B465374A17F23F9ED35089BD969F61C6DDE9998C1F", 2048); let g = decode_hex_number( "5C7FF6B06F8F143FE8288433493E4769C4D988ACE5BE25A0E24809670716C613\ D7B0CEE6932F8FAA7C44D2CB24523DA53FBE4F6EC3595892D1AA58C4328A06C4\ @@ -74,9 +75,10 @@ fn dsa_2048_signing_key() -> SigningKey { 3A10B1C4D203CC76A470A33AFDCBDD92959859ABD8B56E1725252D78EAC66E71\ BA9AE3F1DD2487199874393CD4D832186800654760E1E34C09E4D155179F9EC0\ DC4473F996BDCE6EED1CABED8B6F116F7AD9CF505DF0F998E34AB27514B0FFE7", + 2048, ); - let x = decode_hex_number("69C7548C21D0DFEA6B9A51C9EAD4E27C33D3B3F180316E5BCAB92C933F0E4DBC"); + let x = decode_hex_number("69C7548C21D0DFEA6B9A51C9EAD4E27C33D3B3F180316E5BCAB92C933F0E4DBC", 2048); let y = decode_hex_number( "667098C654426C78D7F8201EAC6C203EF030D43605032C2F1FA937E5237DBD94\ 9F34A0A2564FE126DC8B715C5141802CE0979C8246463C40E6B6BDAA2513FA61\ @@ -86,6 +88,7 @@ fn dsa_2048_signing_key() -> SigningKey { 687972A2D382599C9BAC4E0ED7998193078913032558134976410B89D2C171D1\ 23AC35FD977219597AA7D15C1A9A428E59194F75C721EBCBCFAE44696A499AFA\ 74E04299F132026601638CB87AB79190D4A0986315DA8EEC6561C938996BEADF", + 2048, ); let (p, q, g, y, x) = ( @@ -129,9 +132,13 @@ where /// Create a signature container from the two components in their textual hexadecimal form fn from_str_signature(r: &str, s: &str) -> Signature { + assert_eq!(r.len(), s.len()); + + let precision = (r.len() * 8) as u32; + Signature::from_components( - NonZero::new(decode_hex_number(r)).unwrap(), - NonZero::new(decode_hex_number(s)).unwrap(), + NonZero::new(decode_hex_number(r, precision)).unwrap(), + NonZero::new(decode_hex_number(s, precision)).unwrap(), ) }