libss 0.1.0

libss is a Rust library for secret sharing.
Documentation 
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use crate::Field;
use rand::{thread_rng, Rng};

/// Represents a polynomial with coefficients in Fq
#[derive(PartialEq, Debug)]
pub struct Polynomial<Fq: Field> {
    coefficients: Vec<Fq>,
}

impl<Fq: Field> Polynomial<Fq> {
    /// Generates a polynomial with random coefficients and a given intercept
    pub fn from_intercept(intercept: Fq, degree: usize) -> Polynomial<Fq> {
        let mut result = Vec::with_capacity(degree);
        for _ in 1..degree {
            result.push(thread_rng().gen::<Fq>());
        }
        result.push(intercept);

        Polynomial {
            coefficients: result,
        }
    }

    /// Evaluates a Polynomial with coefficients in field Fq at a given x value
    pub fn evaluate_at(&self, x: Fq) -> Fq {
        // https://www.geeksforgeeks.org/horners-method-polynomial-evaluation/
        self.coefficients
            .iter()
            .skip(1)
            .fold(*self.coefficients.first().unwrap(), |result, &a_i| {
                a_i + (result * x)
            })
    }
}

#[cfg(test)]
mod test {
    use crate::gf256::GF256;
    use crate::polynomial::Polynomial;
    use crate::Field;

    quickcheck! {
        fn test_eval_at_zero(intercept: GF256) -> bool {
            let poly = Polynomial::from_intercept(intercept, 4);

            poly.evaluate_at(GF256::zero()) == intercept
        }

        fn test_eval_at_one(intercept: GF256) -> bool {
            let poly = Polynomial::from_intercept(intercept, 4);
            let sum_coeff = poly.coefficients.iter().fold(GF256::zero(), |sum, &x| sum + x);

            poly.evaluate_at(GF256::one()) == sum_coeff
        }
    }
}