| ... | ... | @@ -7,6 +7,7 @@ const assert = std.debug.assert; |
| 7 | 7 | const testing = std.testing; |
| 8 | 8 | const builtin = @import("builtin"); |
| 9 | 9 | const maxInt = std.math.maxInt; |
| 10 | const Poly1305 = std.crypto.Poly1305; |
| 10 | 11 | |
| 11 | 12 | const QuarterRound = struct { |
| 12 | 13 | a: usize, |
| ... | ... | @@ -434,3 +435,205 @@ test "crypto.chacha20 test vector 5" { |
| 434 | 435 | chaCha20With64BitNonce(result[0..], input[0..], 0, key, nonce); |
| 435 | 436 | testing.expectEqualSlices(u8, &expected_result, &result); |
| 436 | 437 | } |
| 438 | |
| 439 | pub const chacha20poly1305_tag_size = 16; |
| 440 | |
| 441 | pub fn chacha20poly1305Seal(dst: []u8, plaintext: []const u8, data: []const u8, key: [32]u8, nonce: [12]u8) void { |
| 442 | assert(dst.len >= plaintext.len + chacha20poly1305_tag_size); |
| 443 | |
| 444 | // derive poly1305 key |
| 445 | var polyKey = [_]u8{0} ** 32; |
| 446 | chaCha20IETF(polyKey[0..], polyKey[0..], 0, key, nonce); |
| 447 | |
| 448 | // encrypt plaintext |
| 449 | chaCha20IETF(dst[0..plaintext.len], plaintext, 1, key, nonce); |
| 450 | |
| 451 | // construct mac |
| 452 | var mac = Poly1305.init(polyKey[0..]); |
| 453 | mac.update(data); |
| 454 | if (data.len % 16 != 0) { |
| 455 | const zeros = [_]u8{0} ** 16; |
| 456 | const padding = 16 - (data.len % 16); |
| 457 | mac.update(zeros[0..padding]); |
| 458 | } |
| 459 | mac.update(dst[0..plaintext.len]); |
| 460 | if (plaintext.len % 16 != 0) { |
| 461 | const zeros = [_]u8{0} ** 16; |
| 462 | const padding = 16 - (plaintext.len % 16); |
| 463 | mac.update(zeros[0..padding]); |
| 464 | } |
| 465 | var lens: [16]u8 = undefined; |
| 466 | mem.writeIntSliceLittle(u64, lens[0..8], data.len); |
| 467 | mem.writeIntSliceLittle(u64, lens[8..16], plaintext.len); |
| 468 | mac.update(lens[0..]); |
| 469 | mac.final(dst[plaintext.len..]); |
| 470 | } |
| 471 | |
| 472 | /// Verifies and decrypts an authenticated message produced by chacha20poly1305Seal. |
| 473 | pub fn chacha20poly1305Open(dst: []u8, msgAndTag: []const u8, data: []const u8, key: [32]u8, nonce: [12]u8) !void { |
| 474 | if (msgAndTag.len < chacha20poly1305_tag_size) { |
| 475 | return error.InvalidMessage; |
| 476 | } |
| 477 | |
| 478 | // split ciphertext and tag |
| 479 | assert(dst.len >= msgAndTag.len - chacha20poly1305_tag_size); |
| 480 | var ciphertext = msgAndTag[0 .. msgAndTag.len - chacha20poly1305_tag_size]; |
| 481 | var polyTag = msgAndTag[ciphertext.len..]; |
| 482 | |
| 483 | // derive poly1305 key |
| 484 | var polyKey = [_]u8{0} ** 32; |
| 485 | chaCha20IETF(polyKey[0..], polyKey[0..], 0, key, nonce); |
| 486 | |
| 487 | // construct mac |
| 488 | var mac = Poly1305.init(polyKey[0..]); |
| 489 | |
| 490 | mac.update(data); |
| 491 | if (data.len % 16 != 0) { |
| 492 | const zeros = [_]u8{0} ** 16; |
| 493 | const padding = 16 - (data.len % 16); |
| 494 | mac.update(zeros[0..padding]); |
| 495 | } |
| 496 | mac.update(ciphertext); |
| 497 | if (ciphertext.len % 16 != 0) { |
| 498 | const zeros = [_]u8{0} ** 16; |
| 499 | const padding = 16 - (ciphertext.len % 16); |
| 500 | mac.update(zeros[0..padding]); |
| 501 | } |
| 502 | var lens: [16]u8 = undefined; |
| 503 | mem.writeIntSliceLittle(u64, lens[0..8], data.len); |
| 504 | mem.writeIntSliceLittle(u64, lens[8..16], ciphertext.len); |
| 505 | mac.update(lens[0..]); |
| 506 | var computedTag: [16]u8 = undefined; |
| 507 | mac.final(computedTag[0..]); |
| 508 | |
| 509 | // verify mac in constant time |
| 510 | // TODO: we can't currently guarantee that this will run in constant time. |
| 511 | // See https://github.com/ziglang/zig/issues/1776 |
| 512 | var acc: u8 = 0; |
| 513 | for (computedTag) |_, i| { |
| 514 | acc |= (computedTag[i] ^ polyTag[i]); |
| 515 | } |
| 516 | if (acc != 0) { |
| 517 | return error.AuthenticationFailed; |
| 518 | } |
| 519 | |
| 520 | // decrypt ciphertext |
| 521 | chaCha20IETF(dst[0..ciphertext.len], ciphertext, 1, key, nonce); |
| 522 | } |
| 523 | |
| 524 | test "seal" { |
| 525 | { |
| 526 | const plaintext = ""; |
| 527 | const data = ""; |
| 528 | const key = [_]u8{ |
| 529 | 0x80, 0x81, 0x82, 0x83, 0x84, 0x85, 0x86, 0x87, 0x88, 0x89, 0x8a, 0x8b, 0x8c, 0x8d, 0x8e, 0x8f, |
| 530 | 0x90, 0x91, 0x92, 0x93, 0x94, 0x95, 0x96, 0x97, 0x98, 0x99, 0x9a, 0x9b, 0x9c, 0x9d, 0x9e, 0x9f, |
| 531 | }; |
| 532 | const nonce = [_]u8{ 0x7, 0x0, 0x0, 0x0, 0x40, 0x41, 0x42, 0x43, 0x44, 0x45, 0x46, 0x47 }; |
| 533 | const exp_out = [_]u8{ 0xa0, 0x78, 0x4d, 0x7a, 0x47, 0x16, 0xf3, 0xfe, 0xb4, 0xf6, 0x4e, 0x7f, 0x4b, 0x39, 0xbf, 0x4 }; |
| 534 | |
| 535 | var out: [exp_out.len]u8 = undefined; |
| 536 | chacha20poly1305Seal(out[0..], plaintext, data, key, nonce); |
| 537 | testing.expectEqualSlices(u8, exp_out[0..], out[0..]); |
| 538 | } |
| 539 | { |
| 540 | const plaintext = [_]u8{ |
| 541 | 0x4c, 0x61, 0x64, 0x69, 0x65, 0x73, 0x20, 0x61, 0x6e, 0x64, 0x20, 0x47, 0x65, 0x6e, 0x74, 0x6c, |
| 542 | 0x65, 0x6d, 0x65, 0x6e, 0x20, 0x6f, 0x66, 0x20, 0x74, 0x68, 0x65, 0x20, 0x63, 0x6c, 0x61, 0x73, |
| 543 | 0x73, 0x20, 0x6f, 0x66, 0x20, 0x27, 0x39, 0x39, 0x3a, 0x20, 0x49, 0x66, 0x20, 0x49, 0x20, 0x63, |
| 544 | 0x6f, 0x75, 0x6c, 0x64, 0x20, 0x6f, 0x66, 0x66, 0x65, 0x72, 0x20, 0x79, 0x6f, 0x75, 0x20, 0x6f, |
| 545 | 0x6e, 0x6c, 0x79, 0x20, 0x6f, 0x6e, 0x65, 0x20, 0x74, 0x69, 0x70, 0x20, 0x66, 0x6f, 0x72, 0x20, |
| 546 | 0x74, 0x68, 0x65, 0x20, 0x66, 0x75, 0x74, 0x75, 0x72, 0x65, 0x2c, 0x20, 0x73, 0x75, 0x6e, 0x73, |
| 547 | 0x63, 0x72, 0x65, 0x65, 0x6e, 0x20, 0x77, 0x6f, 0x75, 0x6c, 0x64, 0x20, 0x62, 0x65, 0x20, 0x69, |
| 548 | 0x74, 0x2e, |
| 549 | }; |
| 550 | const data = [_]u8{ 0x50, 0x51, 0x52, 0x53, 0xc0, 0xc1, 0xc2, 0xc3, 0xc4, 0xc5, 0xc6, 0xc7 }; |
| 551 | const key = [_]u8{ |
| 552 | 0x80, 0x81, 0x82, 0x83, 0x84, 0x85, 0x86, 0x87, 0x88, 0x89, 0x8a, 0x8b, 0x8c, 0x8d, 0x8e, 0x8f, |
| 553 | 0x90, 0x91, 0x92, 0x93, 0x94, 0x95, 0x96, 0x97, 0x98, 0x99, 0x9a, 0x9b, 0x9c, 0x9d, 0x9e, 0x9f, |
| 554 | }; |
| 555 | const nonce = [_]u8{ 0x7, 0x0, 0x0, 0x0, 0x40, 0x41, 0x42, 0x43, 0x44, 0x45, 0x46, 0x47 }; |
| 556 | const exp_out = [_]u8{ |
| 557 | 0xd3, 0x1a, 0x8d, 0x34, 0x64, 0x8e, 0x60, 0xdb, 0x7b, 0x86, 0xaf, 0xbc, 0x53, 0xef, 0x7e, 0xc2, |
| 558 | 0xa4, 0xad, 0xed, 0x51, 0x29, 0x6e, 0x8, 0xfe, 0xa9, 0xe2, 0xb5, 0xa7, 0x36, 0xee, 0x62, 0xd6, |
| 559 | 0x3d, 0xbe, 0xa4, 0x5e, 0x8c, 0xa9, 0x67, 0x12, 0x82, 0xfa, 0xfb, 0x69, 0xda, 0x92, 0x72, 0x8b, |
| 560 | 0x1a, 0x71, 0xde, 0xa, 0x9e, 0x6, 0xb, 0x29, 0x5, 0xd6, 0xa5, 0xb6, 0x7e, 0xcd, 0x3b, 0x36, |
| 561 | 0x92, 0xdd, 0xbd, 0x7f, 0x2d, 0x77, 0x8b, 0x8c, 0x98, 0x3, 0xae, 0xe3, 0x28, 0x9, 0x1b, 0x58, |
| 562 | 0xfa, 0xb3, 0x24, 0xe4, 0xfa, 0xd6, 0x75, 0x94, 0x55, 0x85, 0x80, 0x8b, 0x48, 0x31, 0xd7, 0xbc, |
| 563 | 0x3f, 0xf4, 0xde, 0xf0, 0x8e, 0x4b, 0x7a, 0x9d, 0xe5, 0x76, 0xd2, 0x65, 0x86, 0xce, 0xc6, 0x4b, |
| 564 | 0x61, 0x16, 0x1a, 0xe1, 0xb, 0x59, 0x4f, 0x9, 0xe2, 0x6a, 0x7e, 0x90, 0x2e, 0xcb, 0xd0, 0x60, |
| 565 | 0x6, 0x91, |
| 566 | }; |
| 567 | |
| 568 | var out: [exp_out.len]u8 = undefined; |
| 569 | chacha20poly1305Seal(out[0..], plaintext[0..], data[0..], key, nonce); |
| 570 | testing.expectEqualSlices(u8, exp_out[0..], out[0..]); |
| 571 | } |
| 572 | } |
| 573 | |
| 574 | test "open" { |
| 575 | { |
| 576 | const ciphertext = [_]u8{ 0xa0, 0x78, 0x4d, 0x7a, 0x47, 0x16, 0xf3, 0xfe, 0xb4, 0xf6, 0x4e, 0x7f, 0x4b, 0x39, 0xbf, 0x4 }; |
| 577 | const data = ""; |
| 578 | const key = [_]u8{ |
| 579 | 0x80, 0x81, 0x82, 0x83, 0x84, 0x85, 0x86, 0x87, 0x88, 0x89, 0x8a, 0x8b, 0x8c, 0x8d, 0x8e, 0x8f, |
| 580 | 0x90, 0x91, 0x92, 0x93, 0x94, 0x95, 0x96, 0x97, 0x98, 0x99, 0x9a, 0x9b, 0x9c, 0x9d, 0x9e, 0x9f, |
| 581 | }; |
| 582 | const nonce = [_]u8{ 0x7, 0x0, 0x0, 0x0, 0x40, 0x41, 0x42, 0x43, 0x44, 0x45, 0x46, 0x47 }; |
| 583 | const exp_out = ""; |
| 584 | |
| 585 | var out: [exp_out.len]u8 = undefined; |
| 586 | try chacha20poly1305Open(out[0..], ciphertext[0..], data, key, nonce); |
| 587 | testing.expectEqualSlices(u8, exp_out[0..], out[0..]); |
| 588 | } |
| 589 | { |
| 590 | const ciphertext = [_]u8{ |
| 591 | 0xd3, 0x1a, 0x8d, 0x34, 0x64, 0x8e, 0x60, 0xdb, 0x7b, 0x86, 0xaf, 0xbc, 0x53, 0xef, 0x7e, 0xc2, |
| 592 | 0xa4, 0xad, 0xed, 0x51, 0x29, 0x6e, 0x8, 0xfe, 0xa9, 0xe2, 0xb5, 0xa7, 0x36, 0xee, 0x62, 0xd6, |
| 593 | 0x3d, 0xbe, 0xa4, 0x5e, 0x8c, 0xa9, 0x67, 0x12, 0x82, 0xfa, 0xfb, 0x69, 0xda, 0x92, 0x72, 0x8b, |
| 594 | 0x1a, 0x71, 0xde, 0xa, 0x9e, 0x6, 0xb, 0x29, 0x5, 0xd6, 0xa5, 0xb6, 0x7e, 0xcd, 0x3b, 0x36, |
| 595 | 0x92, 0xdd, 0xbd, 0x7f, 0x2d, 0x77, 0x8b, 0x8c, 0x98, 0x3, 0xae, 0xe3, 0x28, 0x9, 0x1b, 0x58, |
| 596 | 0xfa, 0xb3, 0x24, 0xe4, 0xfa, 0xd6, 0x75, 0x94, 0x55, 0x85, 0x80, 0x8b, 0x48, 0x31, 0xd7, 0xbc, |
| 597 | 0x3f, 0xf4, 0xde, 0xf0, 0x8e, 0x4b, 0x7a, 0x9d, 0xe5, 0x76, 0xd2, 0x65, 0x86, 0xce, 0xc6, 0x4b, |
| 598 | 0x61, 0x16, 0x1a, 0xe1, 0xb, 0x59, 0x4f, 0x9, 0xe2, 0x6a, 0x7e, 0x90, 0x2e, 0xcb, 0xd0, 0x60, |
| 599 | 0x6, 0x91, |
| 600 | }; |
| 601 | const data = [_]u8{ 0x50, 0x51, 0x52, 0x53, 0xc0, 0xc1, 0xc2, 0xc3, 0xc4, 0xc5, 0xc6, 0xc7 }; |
| 602 | const key = [_]u8{ |
| 603 | 0x80, 0x81, 0x82, 0x83, 0x84, 0x85, 0x86, 0x87, 0x88, 0x89, 0x8a, 0x8b, 0x8c, 0x8d, 0x8e, 0x8f, |
| 604 | 0x90, 0x91, 0x92, 0x93, 0x94, 0x95, 0x96, 0x97, 0x98, 0x99, 0x9a, 0x9b, 0x9c, 0x9d, 0x9e, 0x9f, |
| 605 | }; |
| 606 | const nonce = [_]u8{ 0x7, 0x0, 0x0, 0x0, 0x40, 0x41, 0x42, 0x43, 0x44, 0x45, 0x46, 0x47 }; |
| 607 | const exp_out = [_]u8{ |
| 608 | 0x4c, 0x61, 0x64, 0x69, 0x65, 0x73, 0x20, 0x61, 0x6e, 0x64, 0x20, 0x47, 0x65, 0x6e, 0x74, 0x6c, |
| 609 | 0x65, 0x6d, 0x65, 0x6e, 0x20, 0x6f, 0x66, 0x20, 0x74, 0x68, 0x65, 0x20, 0x63, 0x6c, 0x61, 0x73, |
| 610 | 0x73, 0x20, 0x6f, 0x66, 0x20, 0x27, 0x39, 0x39, 0x3a, 0x20, 0x49, 0x66, 0x20, 0x49, 0x20, 0x63, |
| 611 | 0x6f, 0x75, 0x6c, 0x64, 0x20, 0x6f, 0x66, 0x66, 0x65, 0x72, 0x20, 0x79, 0x6f, 0x75, 0x20, 0x6f, |
| 612 | 0x6e, 0x6c, 0x79, 0x20, 0x6f, 0x6e, 0x65, 0x20, 0x74, 0x69, 0x70, 0x20, 0x66, 0x6f, 0x72, 0x20, |
| 613 | 0x74, 0x68, 0x65, 0x20, 0x66, 0x75, 0x74, 0x75, 0x72, 0x65, 0x2c, 0x20, 0x73, 0x75, 0x6e, 0x73, |
| 614 | 0x63, 0x72, 0x65, 0x65, 0x6e, 0x20, 0x77, 0x6f, 0x75, 0x6c, 0x64, 0x20, 0x62, 0x65, 0x20, 0x69, |
| 615 | 0x74, 0x2e, |
| 616 | }; |
| 617 | |
| 618 | var out: [exp_out.len]u8 = undefined; |
| 619 | try chacha20poly1305Open(out[0..], ciphertext[0..], data[0..], key, nonce); |
| 620 | testing.expectEqualSlices(u8, exp_out[0..], out[0..]); |
| 621 | |
| 622 | // corrupting the ciphertext, data, key, or nonce should cause a failure |
| 623 | var bad_ciphertext = ciphertext; |
| 624 | bad_ciphertext[0] ^= 1; |
| 625 | testing.expectError(error.AuthenticationFailed, chacha20poly1305Open(out[0..], bad_ciphertext[0..], data[0..], key, nonce)); |
| 626 | var bad_data = data; |
| 627 | bad_data[0] ^= 1; |
| 628 | testing.expectError(error.AuthenticationFailed, chacha20poly1305Open(out[0..], ciphertext[0..], bad_data[0..], key, nonce)); |
| 629 | var bad_key = key; |
| 630 | bad_key[0] ^= 1; |
| 631 | testing.expectError(error.AuthenticationFailed, chacha20poly1305Open(out[0..], ciphertext[0..], data[0..], bad_key, nonce)); |
| 632 | var bad_nonce = nonce; |
| 633 | bad_nonce[0] ^= 1; |
| 634 | testing.expectError(error.AuthenticationFailed, chacha20poly1305Open(out[0..], ciphertext[0..], data[0..], key, bad_nonce)); |
| 635 | |
| 636 | // a short ciphertext should result in a different error |
| 637 | testing.expectError(error.InvalidMessage, chacha20poly1305Open(out[0..], "", data[0..], key, bad_nonce)); |
| 638 | } |
| 639 | } |
Andrew Kelley <andrew@ziglang.org> 2019-12-30 17:39:46-05:00
GitHub <noreply@github.com> 2019-12-30 17:39:46-05:00