1use crate::{Array, BatchScheme, Signer, Specification, Verifier};
2use bytes::{Buf, BufMut};
3use commonware_codec::{Error as CodecError, FixedSize, Read, ReadExt, Write};
4use commonware_utils::{hex, union_unique};
5use ed25519_consensus::{self, VerificationKey};
6use rand::{CryptoRng, Rng, RngCore};
7use std::borrow::Cow;
8use std::fmt::{Debug, Display};
9use std::hash::{Hash, Hasher};
10use std::ops::Deref;
11use zeroize::{Zeroize, ZeroizeOnDrop};
12
13const CURVE_NAME: &str = "ed25519";
14const PRIVATE_KEY_LENGTH: usize = 32;
15const PUBLIC_KEY_LENGTH: usize = 32;
16const SIGNATURE_LENGTH: usize = 64;
17
18#[derive(Clone)]
20pub struct Ed25519 {
21 signer: ed25519_consensus::SigningKey,
22 verifier: ed25519_consensus::VerificationKey,
23}
24
25impl Specification for Ed25519 {
26 type PublicKey = PublicKey;
27 type Signature = Signature;
28}
29
30impl Verifier for Ed25519 {
31 fn verify(
32 namespace: Option<&[u8]>,
33 message: &[u8],
34 public_key: &Self::PublicKey,
35 signature: &Self::Signature,
36 ) -> bool {
37 match namespace {
38 Some(namespace) => {
39 let payload = union_unique(namespace, message);
40 public_key
41 .key
42 .verify(&signature.signature, &payload)
43 .is_ok()
44 }
45 None => public_key.key.verify(&signature.signature, message).is_ok(),
46 }
47 }
48}
49
50impl Signer for Ed25519 {
51 type PrivateKey = PrivateKey;
52
53 fn new<R: CryptoRng + Rng>(r: &mut R) -> Self {
54 let signer = ed25519_consensus::SigningKey::new(r);
55 let verifier = signer.verification_key();
56 Self { signer, verifier }
57 }
58
59 fn from(private_key: PrivateKey) -> Option<Self> {
60 let signer = private_key.key.clone();
61 let verifier = signer.verification_key();
62 Some(Self { signer, verifier })
63 }
64
65 fn private_key(&self) -> PrivateKey {
66 PrivateKey::from(self.signer.clone())
67 }
68
69 fn public_key(&self) -> PublicKey {
70 PublicKey::from(self.verifier)
71 }
72
73 fn sign(&mut self, namespace: Option<&[u8]>, message: &[u8]) -> Signature {
74 let sig = match namespace {
75 Some(namespace) => self.signer.sign(&union_unique(namespace, message)),
76 None => self.signer.sign(message),
77 };
78 Signature::from(sig)
79 }
80}
81
82pub struct Ed25519Batch {
84 verifier: ed25519_consensus::batch::Verifier,
85}
86
87impl Specification for Ed25519Batch {
88 type PublicKey = PublicKey;
89 type Signature = Signature;
90}
91
92impl BatchScheme for Ed25519Batch {
93 fn new() -> Self {
94 Ed25519Batch {
95 verifier: ed25519_consensus::batch::Verifier::new(),
96 }
97 }
98
99 fn add(
100 &mut self,
101 namespace: Option<&[u8]>,
102 message: &[u8],
103 public_key: &Self::PublicKey,
104 signature: &Self::Signature,
105 ) -> bool {
106 let payload = match namespace {
107 Some(namespace) => Cow::Owned(union_unique(namespace, message)),
108 None => Cow::Borrowed(message),
109 };
110 let item = ed25519_consensus::batch::Item::from((
111 public_key.key.into(),
112 signature.signature,
113 &payload,
114 ));
115 self.verifier.queue(item);
116 true
117 }
118
119 fn verify<R: RngCore + CryptoRng>(self, rng: &mut R) -> bool {
120 self.verifier.verify(rng).is_ok()
121 }
122}
123
124#[derive(Clone, Zeroize, ZeroizeOnDrop)]
126pub struct PrivateKey {
127 raw: [u8; PRIVATE_KEY_LENGTH],
128 key: ed25519_consensus::SigningKey,
129}
130
131impl Write for PrivateKey {
132 fn write(&self, buf: &mut impl BufMut) {
133 self.raw.write(buf);
134 }
135}
136
137impl Read for PrivateKey {
138 type Cfg = ();
139
140 fn read_cfg(buf: &mut impl Buf, _: &()) -> Result<Self, CodecError> {
141 let raw = <[u8; Self::SIZE]>::read(buf)?;
142 let key = ed25519_consensus::SigningKey::from(raw);
143 Ok(Self { raw, key })
144 }
145}
146
147impl FixedSize for PrivateKey {
148 const SIZE: usize = PRIVATE_KEY_LENGTH;
149}
150
151impl Array for PrivateKey {}
152
153impl Eq for PrivateKey {}
154
155impl Hash for PrivateKey {
156 fn hash<H: Hasher>(&self, state: &mut H) {
157 self.raw.hash(state);
158 }
159}
160
161impl PartialEq for PrivateKey {
162 fn eq(&self, other: &Self) -> bool {
163 self.raw == other.raw
164 }
165}
166
167impl Ord for PrivateKey {
168 fn cmp(&self, other: &Self) -> std::cmp::Ordering {
169 self.raw.cmp(&other.raw)
170 }
171}
172
173impl PartialOrd for PrivateKey {
174 fn partial_cmp(&self, other: &Self) -> Option<std::cmp::Ordering> {
175 Some(self.cmp(other))
176 }
177}
178
179impl AsRef<[u8]> for PrivateKey {
180 fn as_ref(&self) -> &[u8] {
181 &self.raw
182 }
183}
184
185impl Deref for PrivateKey {
186 type Target = [u8];
187 fn deref(&self) -> &[u8] {
188 &self.raw
189 }
190}
191
192impl From<ed25519_consensus::SigningKey> for PrivateKey {
193 fn from(key: ed25519_consensus::SigningKey) -> Self {
194 let raw = key.to_bytes();
195 Self { raw, key }
196 }
197}
198
199impl Debug for PrivateKey {
200 fn fmt(&self, f: &mut std::fmt::Formatter<'_>) -> std::fmt::Result {
201 write!(f, "{}", hex(&self.raw))
202 }
203}
204
205impl Display for PrivateKey {
206 fn fmt(&self, f: &mut std::fmt::Formatter<'_>) -> std::fmt::Result {
207 write!(f, "{}", hex(&self.raw))
208 }
209}
210
211#[derive(Clone, Eq, PartialEq, Ord, PartialOrd, Hash)]
213pub struct PublicKey {
214 raw: [u8; PUBLIC_KEY_LENGTH],
215 key: ed25519_consensus::VerificationKey,
216}
217
218impl Write for PublicKey {
219 fn write(&self, buf: &mut impl BufMut) {
220 self.raw.write(buf);
221 }
222}
223
224impl Read for PublicKey {
225 type Cfg = ();
226
227 fn read_cfg(buf: &mut impl Buf, _: &()) -> Result<Self, CodecError> {
228 let raw = <[u8; Self::SIZE]>::read(buf)?;
229 let key = VerificationKey::try_from(raw)
230 .map_err(|e| CodecError::Wrapped(CURVE_NAME, e.into()))?;
231 Ok(Self { raw, key })
232 }
233}
234
235impl FixedSize for PublicKey {
236 const SIZE: usize = PUBLIC_KEY_LENGTH;
237}
238
239impl Array for PublicKey {}
240
241impl AsRef<[u8]> for PublicKey {
242 fn as_ref(&self) -> &[u8] {
243 &self.raw
244 }
245}
246
247impl Deref for PublicKey {
248 type Target = [u8];
249 fn deref(&self) -> &[u8] {
250 &self.raw
251 }
252}
253
254impl From<VerificationKey> for PublicKey {
255 fn from(key: VerificationKey) -> Self {
256 let raw = key.to_bytes();
257 Self { raw, key }
258 }
259}
260
261impl Debug for PublicKey {
262 fn fmt(&self, f: &mut std::fmt::Formatter<'_>) -> std::fmt::Result {
263 write!(f, "{}", hex(&self.raw))
264 }
265}
266
267impl Display for PublicKey {
268 fn fmt(&self, f: &mut std::fmt::Formatter<'_>) -> std::fmt::Result {
269 write!(f, "{}", hex(&self.raw))
270 }
271}
272
273#[derive(Clone, Eq, PartialEq)]
275pub struct Signature {
276 raw: [u8; SIGNATURE_LENGTH],
277 signature: ed25519_consensus::Signature,
278}
279
280impl Write for Signature {
281 fn write(&self, buf: &mut impl BufMut) {
282 self.raw.write(buf);
283 }
284}
285
286impl Read for Signature {
287 type Cfg = ();
288
289 fn read_cfg(buf: &mut impl Buf, _: &()) -> Result<Self, CodecError> {
290 let raw = <[u8; Self::SIZE]>::read(buf)?;
291 let signature = ed25519_consensus::Signature::from(raw);
292 Ok(Self { raw, signature })
293 }
294}
295
296impl FixedSize for Signature {
297 const SIZE: usize = SIGNATURE_LENGTH;
298}
299
300impl Array for Signature {}
301
302impl Hash for Signature {
303 fn hash<H: Hasher>(&self, state: &mut H) {
304 self.raw.hash(state);
305 }
306}
307
308impl Ord for Signature {
309 fn cmp(&self, other: &Self) -> std::cmp::Ordering {
310 self.raw.cmp(&other.raw)
311 }
312}
313
314impl PartialOrd for Signature {
315 fn partial_cmp(&self, other: &Self) -> Option<std::cmp::Ordering> {
316 Some(self.cmp(other))
317 }
318}
319
320impl AsRef<[u8]> for Signature {
321 fn as_ref(&self) -> &[u8] {
322 &self.raw
323 }
324}
325
326impl Deref for Signature {
327 type Target = [u8];
328 fn deref(&self) -> &[u8] {
329 &self.raw
330 }
331}
332
333impl From<ed25519_consensus::Signature> for Signature {
334 fn from(value: ed25519_consensus::Signature) -> Self {
335 let raw = value.to_bytes();
336 Self {
337 raw,
338 signature: value,
339 }
340 }
341}
342
343impl Debug for Signature {
344 fn fmt(&self, f: &mut std::fmt::Formatter<'_>) -> std::fmt::Result {
345 write!(f, "{}", hex(&self.raw))
346 }
347}
348
349impl Display for Signature {
350 fn fmt(&self, f: &mut std::fmt::Formatter<'_>) -> std::fmt::Result {
351 write!(f, "{}", hex(&self.raw))
352 }
353}
354
355#[cfg(test)]
357mod tests {
358 use super::*;
359 use commonware_codec::{DecodeExt, Encode};
360 use rand::rngs::OsRng;
361
362 fn test_sign_and_verify(
363 private_key: PrivateKey,
364 public_key: PublicKey,
365 message: &[u8],
366 signature: Signature,
367 ) {
368 let mut signer = <Ed25519 as Signer>::from(private_key).unwrap();
369 let computed_signature = signer.sign(None, message);
370 assert_eq!(computed_signature, signature);
371 assert!(Ed25519::verify(
372 None,
373 message,
374 &public_key,
375 &computed_signature
376 ));
377 }
378
379 fn parse_private_key(private_key: &str) -> PrivateKey {
380 PrivateKey::decode(
381 commonware_utils::from_hex_formatted(private_key)
382 .unwrap()
383 .as_ref(),
384 )
385 .unwrap()
386 }
387
388 fn parse_public_key(public_key: &str) -> PublicKey {
389 PublicKey::decode(
390 commonware_utils::from_hex_formatted(public_key)
391 .unwrap()
392 .as_ref(),
393 )
394 .unwrap()
395 }
396
397 fn parse_signature(signature: &str) -> Signature {
398 Signature::decode(
399 commonware_utils::from_hex_formatted(signature)
400 .unwrap()
401 .as_ref(),
402 )
403 .unwrap()
404 }
405
406 fn vector_1() -> (PrivateKey, PublicKey, Vec<u8>, Signature) {
407 (
408 parse_private_key(
410 "
411 9d61b19deffd5a60ba844af492ec2cc4
412 4449c5697b326919703bac031cae7f60
413 ",
414 ),
415 parse_public_key(
417 "
418 d75a980182b10ab7d54bfed3c964073a
419 0ee172f3daa62325af021a68f707511a
420 ",
421 ),
422 b"".to_vec(),
424 parse_signature(
426 "
427 e5564300c360ac729086e2cc806e828a
428 84877f1eb8e5d974d873e06522490155
429 5fb8821590a33bacc61e39701cf9b46b
430 d25bf5f0595bbe24655141438e7a100b
431 ",
432 ),
433 )
434 }
435
436 fn vector_2() -> (PrivateKey, PublicKey, Vec<u8>, Signature) {
437 (
438 parse_private_key(
440 "
441 4ccd089b28ff96da9db6c346ec114e0f
442 5b8a319f35aba624da8cf6ed4fb8a6fb
443 ",
444 ),
445 parse_public_key(
447 "
448 3d4017c3e843895a92b70aa74d1b7ebc
449 9c982ccf2ec4968cc0cd55f12af4660c
450 ",
451 ),
452 [0x72].to_vec(),
454 parse_signature(
456 "
457 92a009a9f0d4cab8720e820b5f642540
458 a2b27b5416503f8fb3762223ebdb69da
459 085ac1e43e15996e458f3613d0f11d8c
460 387b2eaeb4302aeeb00d291612bb0c00
461 ",
462 ),
463 )
464 }
465
466 #[test]
467 fn test_codec_private_key() {
468 let private_key = parse_private_key(
469 "
470 9d61b19deffd5a60ba844af492ec2cc4
471 4449c5697b326919703bac031cae7f60
472 ",
473 );
474 let encoded = private_key.encode();
475 assert_eq!(encoded.len(), PRIVATE_KEY_LENGTH);
476 let decoded = PrivateKey::decode(encoded).unwrap();
477 assert_eq!(private_key, decoded);
478 }
479
480 #[test]
481 fn test_codec_public_key() {
482 let public_key = parse_public_key(
483 "
484 d75a980182b10ab7d54bfed3c964073a
485 0ee172f3daa62325af021a68f707511a
486 ",
487 );
488 let encoded = public_key.encode();
489 assert_eq!(encoded.len(), PUBLIC_KEY_LENGTH);
490 let decoded = PublicKey::decode(encoded).unwrap();
491 assert_eq!(public_key, decoded);
492 }
493
494 #[test]
495 fn test_codec_signature() {
496 let signature = parse_signature(
497 "
498 e5564300c360ac729086e2cc806e828a
499 84877f1eb8e5d974d873e06522490155
500 5fb8821590a33bacc61e39701cf9b46b
501 d25bf5f0595bbe24655141438e7a100b
502 ",
503 );
504 let encoded = signature.encode();
505 assert_eq!(encoded.len(), SIGNATURE_LENGTH);
506 let decoded = Signature::decode(encoded).unwrap();
507 assert_eq!(signature, decoded);
508 }
509
510 #[test]
511 fn rfc8032_test_vector_1() {
512 let (private_key, public_key, message, signature) = vector_1();
513 test_sign_and_verify(private_key, public_key, &message, signature)
514 }
515
516 #[test]
518 #[should_panic]
519 fn bad_signature() {
520 let (private_key, public_key, message, _) = vector_1();
521 let mut signer = <Ed25519 as Signer>::new(&mut OsRng);
522 let bad_signature = signer.sign(None, message.as_ref());
523 test_sign_and_verify(private_key, public_key, &message, bad_signature);
524 }
525
526 #[test]
528 #[should_panic]
529 fn different_message() {
530 let (private_key, public_key, _, signature) = vector_1();
531 let different_message = b"this is a different message".to_vec();
532 test_sign_and_verify(private_key, public_key, &different_message, signature);
533 }
534
535 #[test]
536 fn rfc8032_test_vector_2() {
537 let (private_key, public_key, message, signature) = vector_2();
538 test_sign_and_verify(private_key, public_key, &message, signature)
539 }
540
541 #[test]
542 fn rfc8032_test_vector_3() {
543 let private_key = parse_private_key(
544 "
545 c5aa8df43f9f837bedb7442f31dcb7b1
546 66d38535076f094b85ce3a2e0b4458f7
547 ",
548 );
549 let public_key = parse_public_key(
550 "
551 fc51cd8e6218a1a38da47ed00230f058
552 0816ed13ba3303ac5deb911548908025
553 ",
554 );
555 let message: [u8; 2] = [0xaf, 0x82];
556 let signature = parse_signature(
557 "
558 6291d657deec24024827e69c3abe01a3
559 0ce548a284743a445e3680d7db5ac3ac
560 18ff9b538d16f290ae67f760984dc659
561 4a7c15e9716ed28dc027beceea1ec40a
562 ",
563 );
564 test_sign_and_verify(private_key, public_key, &message, signature)
565 }
566
567 #[test]
568 fn rfc8032_test_vector_1024() {
569 let private_key = parse_private_key(
570 "
571 f5e5767cf153319517630f226876b86c
572 8160cc583bc013744c6bf255f5cc0ee5
573 ",
574 );
575 let public_key = parse_public_key(
576 "
577 278117fc144c72340f67d0f2316e8386
578 ceffbf2b2428c9c51fef7c597f1d426e
579 ",
580 );
581 let message = commonware_utils::from_hex_formatted(
582 "
583 08b8b2b733424243760fe426a4b54908
584 632110a66c2f6591eabd3345e3e4eb98
585 fa6e264bf09efe12ee50f8f54e9f77b1
586 e355f6c50544e23fb1433ddf73be84d8
587 79de7c0046dc4996d9e773f4bc9efe57
588 38829adb26c81b37c93a1b270b20329d
589 658675fc6ea534e0810a4432826bf58c
590 941efb65d57a338bbd2e26640f89ffbc
591 1a858efcb8550ee3a5e1998bd177e93a
592 7363c344fe6b199ee5d02e82d522c4fe
593 ba15452f80288a821a579116ec6dad2b
594 3b310da903401aa62100ab5d1a36553e
595 06203b33890cc9b832f79ef80560ccb9
596 a39ce767967ed628c6ad573cb116dbef
597 efd75499da96bd68a8a97b928a8bbc10
598 3b6621fcde2beca1231d206be6cd9ec7
599 aff6f6c94fcd7204ed3455c68c83f4a4
600 1da4af2b74ef5c53f1d8ac70bdcb7ed1
601 85ce81bd84359d44254d95629e9855a9
602 4a7c1958d1f8ada5d0532ed8a5aa3fb2
603 d17ba70eb6248e594e1a2297acbbb39d
604 502f1a8c6eb6f1ce22b3de1a1f40cc24
605 554119a831a9aad6079cad88425de6bd
606 e1a9187ebb6092cf67bf2b13fd65f270
607 88d78b7e883c8759d2c4f5c65adb7553
608 878ad575f9fad878e80a0c9ba63bcbcc
609 2732e69485bbc9c90bfbd62481d9089b
610 eccf80cfe2df16a2cf65bd92dd597b07
611 07e0917af48bbb75fed413d238f5555a
612 7a569d80c3414a8d0859dc65a46128ba
613 b27af87a71314f318c782b23ebfe808b
614 82b0ce26401d2e22f04d83d1255dc51a
615 ddd3b75a2b1ae0784504df543af8969b
616 e3ea7082ff7fc9888c144da2af58429e
617 c96031dbcad3dad9af0dcbaaaf268cb8
618 fcffead94f3c7ca495e056a9b47acdb7
619 51fb73e666c6c655ade8297297d07ad1
620 ba5e43f1bca32301651339e22904cc8c
621 42f58c30c04aafdb038dda0847dd988d
622 cda6f3bfd15c4b4c4525004aa06eeff8
623 ca61783aacec57fb3d1f92b0fe2fd1a8
624 5f6724517b65e614ad6808d6f6ee34df
625 f7310fdc82aebfd904b01e1dc54b2927
626 094b2db68d6f903b68401adebf5a7e08
627 d78ff4ef5d63653a65040cf9bfd4aca7
628 984a74d37145986780fc0b16ac451649
629 de6188a7dbdf191f64b5fc5e2ab47b57
630 f7f7276cd419c17a3ca8e1b939ae49e4
631 88acba6b965610b5480109c8b17b80e1
632 b7b750dfc7598d5d5011fd2dcc5600a3
633 2ef5b52a1ecc820e308aa342721aac09
634 43bf6686b64b2579376504ccc493d97e
635 6aed3fb0f9cd71a43dd497f01f17c0e2
636 cb3797aa2a2f256656168e6c496afc5f
637 b93246f6b1116398a346f1a641f3b041
638 e989f7914f90cc2c7fff357876e506b5
639 0d334ba77c225bc307ba537152f3f161
640 0e4eafe595f6d9d90d11faa933a15ef1
641 369546868a7f3a45a96768d40fd9d034
642 12c091c6315cf4fde7cb68606937380d
643 b2eaaa707b4c4185c32eddcdd306705e
644 4dc1ffc872eeee475a64dfac86aba41c
645 0618983f8741c5ef68d3a101e8a3b8ca
646 c60c905c15fc910840b94c00a0b9d0
647 ",
648 )
649 .unwrap();
650 let signature = parse_signature(
651 "
652 0aab4c900501b3e24d7cdf4663326a3a
653 87df5e4843b2cbdb67cbf6e460fec350
654 aa5371b1508f9f4528ecea23c436d94b
655 5e8fcd4f681e30a6ac00a9704a188a03
656 ",
657 );
658 test_sign_and_verify(private_key, public_key, &message, signature)
659 }
660
661 #[test]
662 fn rfc8032_test_vector_sha() {
663 let private_key = commonware_utils::from_hex_formatted(
664 "
665 833fe62409237b9d62ec77587520911e
666 9a759cec1d19755b7da901b96dca3d42
667 ",
668 )
669 .unwrap();
670 let public_key = commonware_utils::from_hex_formatted(
671 "
672 ec172b93ad5e563bf4932c70e1245034
673 c35467ef2efd4d64ebf819683467e2bf
674 ",
675 )
676 .unwrap();
677 let message = commonware_utils::from_hex_formatted(
678 "
679 ddaf35a193617abacc417349ae204131
680 12e6fa4e89a97ea20a9eeee64b55d39a
681 2192992a274fc1a836ba3c23a3feebbd
682 454d4423643ce80e2a9ac94fa54ca49f
683 ",
684 )
685 .unwrap();
686 let signature = commonware_utils::from_hex_formatted(
687 "
688 dc2a4459e7369633a52b1bf277839a00
689 201009a3efbf3ecb69bea2186c26b589
690 09351fc9ac90b3ecfdfbc7c66431e030
691 3dca179c138ac17ad9bef1177331a704
692 ",
693 )
694 .unwrap();
695 test_sign_and_verify(
696 PrivateKey::decode(private_key.as_ref()).unwrap(),
697 PublicKey::decode(public_key.as_ref()).unwrap(),
698 &message,
699 Signature::decode(signature.as_ref()).unwrap(),
700 )
701 }
702
703 #[test]
704 fn batch_verify_valid() {
705 let v1 = vector_1();
706 let v2 = vector_2();
707 let mut batch = Ed25519Batch::new();
708 assert!(batch.add(None, &v1.2, &v1.1, &v1.3));
709 assert!(batch.add(None, &v2.2, &v2.1, &v2.3));
710 assert!(batch.verify(&mut rand::thread_rng()));
711 }
712
713 #[test]
714 fn batch_verify_invalid() {
715 let v1 = vector_1();
716 let v2 = vector_2();
717 let mut bad_signature = v2.3.to_vec();
718 bad_signature[3] = 0xff;
719
720 let mut batch = Ed25519Batch::new();
721 assert!(batch.add(None, &v1.2, &v1.1, &v1.3));
722 assert!(batch.add(
723 None,
724 &v2.2,
725 &v2.1,
726 &Signature::decode(bad_signature.as_ref()).unwrap()
727 ));
728 assert!(!batch.verify(&mut rand::thread_rng()));
729 }
730
731 #[test]
732 fn test_zero_signature_fails() {
733 let (_, public_key, message, _) = vector_1();
734 let zero_sig = Signature::decode(vec![0u8; Signature::SIZE].as_ref()).unwrap();
735 assert!(!Ed25519::verify(None, &message, &public_key, &zero_sig));
736 }
737
738 #[test]
739 fn test_high_s_fails() {
740 let (_, public_key, message, signature) = vector_1();
741 let mut bad_signature = signature.to_vec();
742 bad_signature[63] |= 0x80; let bad_signature = Signature::decode(bad_signature.as_ref()).unwrap();
744 assert!(!Ed25519::verify(
745 None,
746 &message,
747 &public_key,
748 &bad_signature
749 ));
750 }
751
752 #[test]
753 fn test_invalid_r_fails() {
754 let (_, public_key, message, signature) = vector_1();
755 let mut bad_signature = signature.to_vec();
756 for b in bad_signature.iter_mut().take(32) {
757 *b = 0xff; }
759 let bad_signature = Signature::decode(bad_signature.as_ref()).unwrap();
760 assert!(!Ed25519::verify(
761 None,
762 &message,
763 &public_key,
764 &bad_signature
765 ));
766 }
767}