Validate discriminants by default and add fixed discriminant (#786)

* Validate discriminants by default and add from_trusted_* functions * Use explicit from_trusted_* function * cleanup * Get rid of from_trusted methods * Use fixed discriminant * doc
MystenLabs · May 17, 2024 · ba175be · ba175be
1 parent 33f4df4
commit ba175be
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Showing 8 changed files with 71 additions and 109 deletions.
diff --git a/Cargo.lock b/Cargo.lock
diff --git a/fastcrypto-cli/src/vdf.rs b/fastcrypto-cli/src/vdf.rs
diff --git a/fastcrypto-vdf/Cargo.toml b/fastcrypto-vdf/Cargo.toml
@@ -20,6 +20,7 @@ rand_chacha = "0.3.1"
 serde.workspace = true
 bcs.workspace = true
 serde_with = "2.1.0"
+lazy_static = "1.4.0"
 
 [features]
 experimental = []

diff --git a/fastcrypto-vdf/src/class_group/discriminant.rs b/fastcrypto-vdf/src/class_group/discriminant.rs
@@ -1,29 +1,51 @@
 // Copyright (c) 2022, Mysten Labs, Inc.
 // SPDX-License-Identifier: Apache-2.0
 
+use crate::class_group::bigint_serde;
 use crate::math::hash_prime;
 use crate::math::hash_prime::is_probable_prime;
 use crate::math::parameterized_group::Parameter;
 use fastcrypto::error::FastCryptoError::InvalidInput;
 use fastcrypto::error::{FastCryptoError, FastCryptoResult};
+use lazy_static::lazy_static;
 use num_bigint::{BigInt, ToBigInt};
 use num_integer::Integer;
-use num_traits::Signed;
+use num_traits::{One, Signed};
 use serde::{Deserialize, Serialize};
 use std::ops::Neg;
+use std::str::FromStr;
 
 /// A discriminant for an imaginary class group. The discriminant is a negative integer congruent to
 /// 1 mod 8.
-#[derive(PartialEq, Eq, Debug, Clone, Serialize, Deserialize)]
+#[derive(PartialEq, Eq, Debug, Clone, Serialize)]
 pub struct Discriminant(#[serde(with = "crate::class_group::bigint_serde")] BigInt);
 
+lazy_static! {
+    /// Fixed 3072 bit discriminant. Generated from the seed [1,2,3] using [Discriminant::from_seed].
+    // TODO: Generate this using a seed that we provably cannot influence.
+    pub static ref DISCRIMINANT_3072: Discriminant = Discriminant(BigInt::from_str("-4080390101490206102067801750685552291425412528983716161454985565795560716833845004659207152503580931176637478422335625954692628868126419714053340412299850300602673802493259771830686596468801304317015718872352674945215883546019961626928140286675493693757393881479657605888983279619347902770789061953207866325747708864327315769009839190765716943013935708854055658243676903245686125751909996824976354309908771869043784640567352757672203749399825983258156684652782580603170228640173640869773628592618889352385821753919281706169861276929330689892675986265846043432389737049521845230769417696140636288030698887830215613149485135897148487896368642774768920061430225392365148291796645740474628778185683682893521776342856643134668770656709308404166182149870849376649591338267281149794078240401323227967073641261327798339424740171219484355109588337730742391198073121589465833677609362668436116144203312494461735357918360857667357985711").unwrap());
+}
+
+impl<'de> Deserialize<'de> for Discriminant {
+    fn deserialize<D>(deserializer: D) -> Result<Discriminant, D::Error>
+    where
+        D: serde::Deserializer<'de>,
+    {
+        Discriminant::try_from(bigint_serde::deserialize(deserializer)?)
+            .map_err(serde::de::Error::custom)
+    }
+}
+
 impl TryFrom<BigInt> for Discriminant {
     type Error = FastCryptoError;
 
-    /// A valid discriminant should be a negative prime congruent to 1 mod 8. The sign and
-    /// congruency are checked here but the primality is _not_. See also [Discriminant::check_primality].
+    /// A valid discriminant should be a negative prime congruent to 1 mod 8. For large discriminants,
+    /// this is very slow to check.
     fn try_from(value: BigInt) -> FastCryptoResult<Self> {
-        if !value.is_negative() || value.mod_floor(&BigInt::from(8)) != BigInt::from(1) {
+        if !value.is_negative()
+            || value.mod_floor(&BigInt::from(8)) != BigInt::one()
+            || !is_probable_prime(value.abs().magnitude())
+        {
             return Err(InvalidInput);
         }
         Ok(Self(value))
@@ -41,18 +63,12 @@ impl Discriminant {
         &self.0
     }
 
-    /// Check the primality of this discriminant and return an error if it is not prime.
-    pub fn check_primality(&self) -> FastCryptoResult<()> {
-        match is_probable_prime(
-            &self
-                .0
-                .abs()
-                .to_biguint()
-                .expect("Absolute value is non-negative"),
-        ) {
-            true => Ok(()),
-            false => Err(InvalidInput),
-        }
+    /// Create a discriminant from the given value. It is assumed that the discriminant is a negative
+    /// prime which is 1 mod 8. If this is not the case, some functions may panic, so this should only
+    /// be used in tests.
+    #[cfg(test)]
+    pub(crate) fn from_trusted_bigint(value: BigInt) -> Self {
+        Self(value)
     }
 }
 
@@ -64,12 +80,12 @@ impl Parameter for Discriminant {
             return Err(InvalidInput);
         }
         // Set the lower three bits to ensure that the prime is 7 mod 8 which makes the discriminant 1 mod 8.
-        Self::try_from(
+        Ok(Self(
             hash_prime::hash_prime(seed, size_in_bits / 8, &[0, 1, 2, size_in_bits - 1])
                 .to_bigint()
                 .expect("Never fails")
                 .neg(),
-        )
+        ))
     }
 }
 
@@ -79,7 +95,7 @@ mod tests {
 
     #[test]
     fn test_discriminant() {
-        let discriminant = Discriminant::try_from(-BigInt::from(223)).unwrap();
+        let discriminant = Discriminant(-BigInt::from(223));
         assert_eq!(discriminant.bits(), 8);
         assert_eq!(discriminant.as_bigint(), &-BigInt::from(223));
 
@@ -95,8 +111,7 @@ mod tests {
 
         // Not prime
         let candidate = BigInt::from(-231);
-        let discriminant = Discriminant::try_from(candidate).unwrap();
-        assert!(discriminant.check_primality().is_err());
+        assert!(Discriminant::try_from(candidate).is_err());
     }
 
     #[test]
@@ -105,24 +120,30 @@ mod tests {
         let target_size = 1024;
         let discriminant = Discriminant::from_seed(&seed, target_size).unwrap();
         assert_eq!(discriminant.bits() as usize, target_size);
-        assert!(discriminant.check_primality().is_ok());
 
         // Test vector from chiavdf computed using https://github.com/Chia-Network/chiavdf/blob/2844974ff81274060778a56dfefd2515bc567b90/tests/test_verifier.py.
         assert_eq!(discriminant.as_bigint().to_str_radix(16), "-95a0b0523b6c516e813d745e7e58b3c7223d511f6008a0ff2757c9a0f15cba8841293cc903af3a40654670c9dee17ec14da1457360aafe40a93831d90c3dd59738d8a24e415b6e33780224fa24171de1d4a1ca5fe4c877bf44361e7ba869126ac12367714eb4246a5e310515508ad35e170aee19cae371069d6d92e94c21d63f");
     }
 
     #[test]
     fn test_discriminant_to_from_bytes() {
-        let discriminant = Discriminant::try_from(BigInt::from(-223)).unwrap();
+        let discriminant = Discriminant(BigInt::from(-223));
         let bytes = bcs::to_bytes(&discriminant).unwrap();
         let discriminant2 = bcs::from_bytes(&bytes).unwrap();
         assert_eq!(discriminant, discriminant2);
-        assert!(discriminant.check_primality().is_ok());
 
         let discriminant = Discriminant::from_seed(&[0x01, 0x02, 0x03], 512).unwrap();
         let bytes = bcs::to_bytes(&discriminant).unwrap();
         let discriminant2 = bcs::from_bytes(&bytes).unwrap();
         assert_eq!(discriminant, discriminant2);
-        assert!(discriminant.check_primality().is_ok());
+
+        // Test serde on invalid discriminants
+        let invalid_discriminant_bytes =
+            bcs::to_bytes(&BigInt::from(-221).to_signed_bytes_be()).unwrap();
+        assert!(bcs::from_bytes::<Discriminant>(&invalid_discriminant_bytes).is_err());
+
+        let invalid_discriminant_bytes =
+            bcs::to_bytes(&BigInt::from(17).to_signed_bytes_be()).unwrap();
+        assert!(bcs::from_bytes::<Discriminant>(&invalid_discriminant_bytes).is_err());
     }
 }
diff --git a/fastcrypto-vdf/src/class_group/hash.rs b/fastcrypto-vdf/src/class_group/hash.rs
@@ -231,7 +231,7 @@ mod tests {
 
     #[test]
     fn qf_from_seed_regression_tests() {
-        let discriminant = Discriminant::try_from(-BigInt::from_str_radix("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", 16).unwrap()).unwrap();
+        let discriminant = Discriminant::from_trusted_bigint(-BigInt::from_str_radix("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", 16).unwrap());
 
         let qf = QuadraticForm::hash_to_group(b"seed", &discriminant, 64).unwrap();
         assert_eq!(bcs::to_bytes(&qf).unwrap(), hex::decode("8b0104397d87d59220ec1bbbf79f471689ad0a48f67625abed478749b2f110d79990684b782160a7e00288c240160d10da0198298fd68f7e3fa0964975f1816d5bb38c978ea1bc9fb5aaefa62971435de9565801c80e545b497d00783c0d518722311c6fa7e924bff4f4765f6f3c6b3de8dcf1c314e7ea8df998de524af394e5cec7dfc867cf07f7eb501dfc279102ff304620732b3d44d3ceeadbd054e20eb953eed85ac684044b1192c1ccaeb9ba79695b28204e7148e8560e4b782c6b20ea20123bda9061eed1920d7ff1fd9741220ee1fac09f596524a12aa993734f2fa4ccf792d46c3bf8320073def0c938e6fb608b8866f70fc380f1a37f3fd9c52935837f5ff06ef6ab882599460e7b950ab17a75602a0b29523ab99c4d030923244a5a9e0431759c59a33a471641c013dadaebdc711baf3a05320330959f13b88c6619c64201bc10517c0bbc69524e6d3345eaeade453ea1ebe8b4ce41068e321399c41e8a90831f9713aa2df564423dfa2fe36e65ccf8157c9ebd24f4ac545482b1a609b7bce94316af8e53cbe191ba073b312a60831ea1f657a92ded17350710ed960309f9853536dd6c8dc45ed0069b1feb7e4acbc7adcf15252e96d5c35e37afbd5b6c413c8511e8225b0f938ae03225b5f2a856aed3551f424795b08807fdc0e38566acdebd699e4db85cf216e3467e9ca3d6c82cfaf77d8446e612de64b1fd3a5df8c5a982df1470daf56f3a15787b35439769c6003693c9b88bf14962b40995931baad12c0e00ac9456556deee599db40209dffe5ebf04f193776ba1dbf3c6fa1a81daafb80ec83e9ce0f8365b8f8fffedf13fe1c2d34d12c2bc5c3c223dd1ea6158645d229e65ccf774c04e4aa4715a67d20f2a20752553c30410651990bbb27d1be95c8b690c7a4edd6450ecbeef312e862944c3eeac7ad25541c14aa6c3da7c14bb4ab6119be67dda0ff244b18711c3da20570ecc1536c3c5cfe297bce254df07fe52d05f54d59272d1fe8c6b30c0eb60a6154b86c71e48379a109986a3632dea79fa0e77fe49931abae8a9188163dc388e772342c0f66d90791a3dd8e337211884aea2b7c2f7920862ade85b6e93d4b1e6afe44a0bf62ed509917cde6ef93a8f6dcd763831652e5c193b7b7ed7d9bb937d1ca1870").unwrap());
@@ -251,7 +251,7 @@ mod tests {
 
     #[test]
     fn qf_default_hash_test() {
-        let discriminant = Discriminant::try_from(-BigInt::from_str_radix("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", 16).unwrap()).unwrap();
+        let discriminant = Discriminant::from_trusted_bigint(-BigInt::from_str_radix("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", 16).unwrap());
 
         let qf =
             QuadraticForm::hash_to_group_with_default_parameters(b"seed", &discriminant).unwrap();

diff --git a/fastcrypto-vdf/src/class_group/reduction.rs b/fastcrypto-vdf/src/class_group/reduction.rs
@@ -63,7 +63,7 @@ mod tests {
 
     #[test]
     fn test_normalization_and_reduction() {
-        let discriminant = Discriminant::try_from(BigInt::from(-223)).unwrap();
+        let discriminant = Discriminant::from_trusted_bigint(BigInt::from(-223));
         let mut quadratic_form = QuadraticForm::from_a_b_and_discriminant(
             BigInt::from(41),
             BigInt::from(49),

diff --git a/fastcrypto-vdf/src/class_group/tests.rs b/fastcrypto-vdf/src/class_group/tests.rs
@@ -1,18 +1,16 @@
 // Copyright (c) 2022, Mysten Labs, Inc.
 // SPDX-License-Identifier: Apache-2.0
 
-use std::str::FromStr;
-
 use num_bigint::BigInt;
 
-use crate::class_group::discriminant::Discriminant;
+use crate::class_group::discriminant::{Discriminant, DISCRIMINANT_3072};
 use crate::class_group::QuadraticForm;
 use crate::math::parameterized_group::ParameterizedGroupElement;
 
 #[test]
 fn test_composition() {
     // The order of the class group (the class number) for -223 is 7 (see https://mathworld.wolfram.com/ClassNumber.html).
-    let discriminant = Discriminant::try_from(BigInt::from(-223)).unwrap();
+    let discriminant = Discriminant::from_trusted_bigint(BigInt::from(-223));
     let mut g = QuadraticForm::generator(&discriminant);
 
     for _ in 1..=6 {
@@ -24,7 +22,7 @@ fn test_composition() {
 
 #[test]
 fn test_qf_to_from_bytes() {
-    let discriminant = Discriminant::try_from(BigInt::from(-223)).unwrap();
+    let discriminant = Discriminant::from_trusted_bigint(BigInt::from(-223));
     let expected = QuadraticForm::generator(&discriminant);
     let bytes = bcs::to_bytes(&expected).unwrap();
     let actual = bcs::from_bytes(&bytes).unwrap();
@@ -33,11 +31,11 @@ fn test_qf_to_from_bytes() {
 
 #[test]
 fn test_large_qf_to_from_bytes() {
-    let discriminant = Discriminant::try_from(BigInt::from_str("-4080390101490206102067801750685552291425412528983716161454985565795560716833845004659207152503580931176637478422335625954692628868126419714053340412299850300602673802493259771830686596468801304317015718872352674945215883546019961626928140286675493693757393881479657605888983279619347902770789061953207866325747708864327315769009839190765716943013935708854055658243676903245686125751909996824976354309908771869043784640567352757672203749399825983258156684652782580603170228640173640869773628592618889352385821753919281706169861276929330689892675986265846043432389737049521845230769417696140636288030698887830215613149485135897148487896368642774768920061430225392365148291796645740474628778185683682893521776342856643134668770656709308404166182149870849376649591338267281149794078240401323227967073641261327798339424740171219484355109588337730742391198073121589465833677609362668436116144203312494461735357918360857667357985711").unwrap()).unwrap();
-    assert_eq!(discriminant.bits(), 3072);
+    assert_eq!(DISCRIMINANT_3072.bits(), 3072);
 
     let expected =
-        QuadraticForm::hash_to_group_with_default_parameters(&[1, 2, 3], &discriminant).unwrap();
+        QuadraticForm::hash_to_group_with_default_parameters(&[1, 2, 3], &DISCRIMINANT_3072)
+            .unwrap();
     let bytes = bcs::to_bytes(&expected).unwrap();
     let actual = bcs::from_bytes(&bytes).unwrap();
     assert_eq!(expected, actual);

diff --git a/fastcrypto-vdf/src/vdf/mod.rs b/fastcrypto-vdf/src/vdf/mod.rs
@@ -36,26 +36,19 @@ pub trait VDF {
 
 #[cfg(test)]
 mod tests {
-    use crate::class_group::discriminant::Discriminant;
+    use fastcrypto::hash::{HashFunction, Sha256};
+
+    use crate::class_group::discriminant::DISCRIMINANT_3072;
     use crate::class_group::QuadraticForm;
     use crate::vdf::wesolowski::DefaultVDF;
     use crate::vdf::VDF;
-    use fastcrypto::hash::{HashFunction, Sha256};
-    use num_bigint::BigInt;
-    use std::str::FromStr;
 
     #[test]
     fn vdf_e2e_test() {
         // This test runs an e2e test of the VDF-based randomness protocol with a 3072 bit discriminant.
-
-        // Fixed 3072 bit discriminant. Generated from the seed [1,2,3] using [Discriminant::from_seed].
-        let discriminant =
-            Discriminant::try_from(BigInt::from_str("-4080390101490206102067801750685552291425412528983716161454985565795560716833845004659207152503580931176637478422335625954692628868126419714053340412299850300602673802493259771830686596468801304317015718872352674945215883546019961626928140286675493693757393881479657605888983279619347902770789061953207866325747708864327315769009839190765716943013935708854055658243676903245686125751909996824976354309908771869043784640567352757672203749399825983258156684652782580603170228640173640869773628592618889352385821753919281706169861276929330689892675986265846043432389737049521845230769417696140636288030698887830215613149485135897148487896368642774768920061430225392365148291796645740474628778185683682893521776342856643134668770656709308404166182149870849376649591338267281149794078240401323227967073641261327798339424740171219484355109588337730742391198073121589465833677609362668436116144203312494461735357918360857667357985711").unwrap())
-                .unwrap();
-
         // Number of iterations for the VDF
         let iterations = 100;
-        let vdf = DefaultVDF::new(discriminant.clone(), iterations);
+        let vdf = DefaultVDF::new(DISCRIMINANT_3072.clone(), iterations);
 
         // Add some randomness
         let mut combined_randomness = Vec::new();
@@ -74,7 +67,7 @@ mod tests {
         // Compute the VDF input from the combined randomness
         let input = QuadraticForm::hash_to_group_with_default_parameters(
             &combined_randomness,
-            &discriminant,
+            &DISCRIMINANT_3072,
         )
         .unwrap();
         assert_eq!(bcs::to_bytes(&input).unwrap(), hex::decode("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").unwrap());