add power impl and expose Fq::from_montgomery_limbs

CHANGELOG.md

@@ -31,3 +31,30 @@
 # 0.7.0
 
 * Fix: Add `no_std` compatibility.
+
+# 0.8.0
+
+* Add fiat-generated finite field implementations by @hdevalence in #64
+* refactor(arkworks): feature-gated Arkworks compatibility by @TalDerei in #67
+* Implement Bls12377 using our own backend by @cronokirby in #71
+* ci: add job to test u32_backend by @redshiftzero in #72
+* Arkworks feature gating by @cronokirby in #73
+* Implement traits in a no_std context when possible by @cronokirby in #74
+* Implement the start of a minimal curve implementation by @cronokirby in #75
+* ci: add job building with no alloc feature by @redshiftzero in #76
+* arkworks independent projective arithmetic ops by @redshiftzero in #77
+* Make modular reduction work for large byte sizes by @cronokirby in #78
+* Implement FromStr for all the fields by @cronokirby in #79
+* Implement a checked conversion from bytes method in Fq by @cronokirby in #81
+* arkworks-independent sqrts, point encoding/decoding by @cronokirby in #80
+* ci: use larger runners by @conorsch in #83
+* ci: dedicated profile for release + debug_assert by @conorsch in #84
+* rearranging arkworks / non-arkworks ECC code by @redshiftzero in #82
+
+# 0.9.0
+
+* Make raw constructors of field elements private by @cronokirby in #90
+* Add missing methods as need for integrating the latest version of this crate by @cronokirby in #91
+* fix: field modulus by @TalDerei in #92
+* adjust anyhow scope and remove unused dependencies by @neithanmo in #96
+* add power impl and expose `Fq::from_montgomery_limbs` by @redshiftzero in #98

Cargo.toml

@@ -1,6 +1,6 @@
 [package]
 name = "decaf377"
-version = "0.8.0"
+version = "0.9.0"
 authors = [
     "Henry de Valence <[email protected]>",
     "redshiftzero <[email protected]>",

src/fields/fq.rs

@@ -125,6 +125,18 @@ impl Fq {
         };
         Self::from_le_bytes_mod_order(&bytes)
     }
+
+    /// Raise this element to a given power.
+    ///
+    /// Note: Arkworks provides another method for this, called `pow`.
+    pub fn power<S: AsRef<[u64]>>(&self, exp: S) -> Self {
+        let mut res = Fq::from(1u64);
+        let exp_u64 = exp.as_ref();
+        for _ in 0..exp_u64[0] {
+            res *= self;
+        }
+        res
+    }
 }
 
 #[cfg(test)]

src/fields/fq/u32/wrapper.rs

@@ -87,6 +87,9 @@ impl Fq {
         Self(fiat::FqMontgomeryDomainFieldElement(limbs))
     }
 
+    /// Instantiate a constant field element from its montgomery limbs.
+    ///
+    /// This should only be used if you are familiar with the internals of the library.
     pub const fn from_montgomery_limbs(limbs: [u64; N_64]) -> Fq {
         Self(fiat::FqMontgomeryDomainFieldElement([
             limbs[0] as u32,

src/fields/fq/u64/wrapper.rs

@@ -70,7 +70,10 @@ impl Fq {
         bytes
     }
 
-    pub(crate) const fn from_montgomery_limbs(limbs: [u64; N]) -> Fq {
+    /// Instantiate a constant field element from its montgomery limbs.
+    ///
+    /// This should only be used if you are familiar with the internals of the library.
+    pub const fn from_montgomery_limbs(limbs: [u64; N]) -> Fq {
         Self(fiat::FqMontgomeryDomainFieldElement(limbs))
     }