ristretto255: add TestRistrettoFromUniformBytesTestVectors

ristretto255_test.go

@@ -2,6 +2,7 @@ package ristretto255
 
 import (
 	"bytes"
+	"crypto/sha512"
 	"encoding/hex"
 	"testing"
 
@@ -219,3 +220,33 @@ func TestRistrettoBadEncodingsTestVectors(t *testing.T) {
 		}
 	}
 }
+
+func TestRistrettoFromUniformBytesTestVectors(t *testing.T) {
+	inputs := []string{
+		"Ristretto is traditionally a short shot of espresso coffee",
+		"made with the normal amount of ground coffee but extracted with",
+		"about half the amount of water in the same amount of time",
+		"by using a finer grind.",
+		"This produces a concentrated shot of coffee per volume.",
+		"Just pulling a normal shot short will produce a weaker shot",
+		"and is not a Ristretto as some believe.",
+	}
+	elements := []string{
+		"3066f82a1a747d45120d1740f14358531a8f04bbffe6a819f86dfe50f44a0a46",
+		"f26e5b6f7d362d2d2a94c5d0e7602cb4773c95a2e5c31a64f133189fa76ed61b",
+		"006ccd2a9e6867e6a2c5cea83d3302cc9de128dd2a9a57dd8ee7b9d7ffe02826",
+		"f8f0c87cf237953c5890aec3998169005dae3eca1fbb04548c635953c817f92a",
+		"ae81e7dedf20a497e10c304a765c1767a42d6e06029758d2d7e8ef7cc4c41179",
+		"e2705652ff9f5e44d3e841bf1c251cf7dddb77d140870d1ab2ed64f1a9ce8628",
+		"80bd07262511cdde4863f8a7434cef696750681cb9510eea557088f76d9e5065",
+	}
+
+	var element Element
+	for i, input := range inputs {
+		hash := sha512.Sum512([]byte(input))
+		element.FromUniformBytes(hash[:])
+		if encoding := hex.EncodeToString(element.Encode(nil)); encoding != elements[i] {
+			t.Errorf("#%d: expected %q, got %q", i, elements[i], encoding)
+		}
+	}
+}