Added test vectors for StdRng, verified using rand_chacha.

Author: hpenne

src/rngs/std.rs

@@ -121,4 +121,93 @@ mod test {
 
         assert_eq!([x0, x1], target);
     }
+
+    #[test]
+    fn test_chacha_true_values_a() {
+        // Test vectors 1 and 2 from
+        // https://tools.ietf.org/html/draft-nir-cfrg-chacha20-poly1305-04
+        // but the expected values are replaced with the ones produced
+        // by Chacha12 (as generated by rand_chacha).
+        let seed = [0u8; 32];
+        let mut rng = StdRng::from_seed(seed);
+
+        let mut results = [0u32; 16];
+        for i in results.iter_mut() {
+            *i = rng.next_u32();
+        }
+        let expected = [
+            1788540059, 1408849159, 315498369, 3582142047, 3150129412, 343203913, 2777219198,
+            1595256366, 2046321669, 3236133586, 875096108, 2039282348, 748642874, 426368672,
+            803736417, 3190166337,
+        ];
+        assert_eq!(results, expected);
+
+        for i in results.iter_mut() {
+            *i = rng.next_u32();
+        }
+        let expected = [
+            1099486475, 4269030944, 863108230, 1024974988, 3085641926, 3435904281, 562369813,
+            3028926540, 3448579394, 301026465, 2545418950, 1137216539, 3393593065, 3226554768,
+            2963686439, 378791447,
+        ];
+        assert_eq!(results, expected);
+    }
+
+    #[test]
+    fn test_chacha_true_values_b() {
+        // Test vector 3 from
+        // https://tools.ietf.org/html/draft-nir-cfrg-chacha20-poly1305-04
+        // but the expected values are replaced with the ones produced
+        // by Chacha12 (as generated by rand_chacha).
+        let seed = [
+            0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0,
+            0, 0, 1,
+        ];
+        let mut rng = StdRng::from_seed(seed);
+
+        // Skip block 0
+        for _ in 0..16 {
+            rng.next_u32();
+        }
+
+        let mut results = [0u32; 16];
+        for i in results.iter_mut() {
+            *i = rng.next_u32();
+        }
+        let expected = [
+            1149489484, 1453872210, 205606722, 2561053166, 4209612569, 2282920975, 2059979989,
+            3051314295, 4135011526, 3904759261, 3697107527, 2431012387, 1801979597, 1269452364,
+            3197257745, 2154707421,
+        ];
+        assert_eq!(results, expected);
+    }
+
+    #[test]
+    fn test_chacha_true_values_c() {
+        // Test vector 4 from
+        // https://tools.ietf.org/html/draft-nir-cfrg-chacha20-poly1305-04
+        // but the expected values are replaced with the ones produced
+        // by Chacha12 (as generated by rand_chacha).
+        let seed = [
+            0, 0xff, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0,
+            0, 0, 0, 0,
+        ];
+        let expected = [
+            1614024310, 613097064, 193455541, 494774344, 2671734178, 1658534307, 1449802595,
+            1853279994, 129091709, 2135285029, 2884964524, 3629948889, 2335941772, 2471549797,
+            887756884, 3388159322,
+        ];
+        let expected_end = 3 * 16;
+        let mut results = [0u32; 16];
+
+        // Test block 2 by skipping block 0 and 1
+        let mut rng1 = StdRng::from_seed(seed);
+        for _ in 0..32 {
+            rng1.next_u32();
+        }
+        for i in results.iter_mut() {
+            *i = rng1.next_u32();
+        }
+        assert_eq!(results, expected);
+    }
 }