| ... | @@ -7,6 +7,7 @@ const assert = std.debug.assert; | ... | @@ -7,6 +7,7 @@ const assert = std.debug.assert; |
| 7 | const testing = std.testing; | 7 | const testing = std.testing; |
| 8 | const builtin = @import("builtin"); | 8 | const builtin = @import("builtin"); |
| 9 | const maxInt = std.math.maxInt; | 9 | const maxInt = std.math.maxInt; |
| | 10 | const Poly1305 = std.crypto.Poly1305; |
| 10 | | 11 | |
| 11 | const QuarterRound = struct { | 12 | const QuarterRound = struct { |
| 12 | a: usize, | 13 | a: usize, |
| ... | @@ -434,3 +435,205 @@ test "crypto.chacha20 test vector 5" { | ... | @@ -434,3 +435,205 @@ test "crypto.chacha20 test vector 5" { |
| 434 | chaCha20With64BitNonce(result[0..], input[0..], 0, key, nonce); | 435 | chaCha20With64BitNonce(result[0..], input[0..], 0, key, nonce); |
| 435 | testing.expectEqualSlices(u8, &expected_result, &result); | 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