Crypto.cpp 5.0 KB

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  1. /*
  2. * Copyright (c) 2021, Idan Horowitz <idan.horowitz@serenityos.org>
  3. * Copyright (c) 2022, stelar7 <dudedbz@gmail.com>
  4. *
  5. * SPDX-License-Identifier: BSD-2-Clause
  6. */
  7. #include <AK/Random.h>
  8. #include <AK/StringBuilder.h>
  9. #include <LibJS/Runtime/TypedArray.h>
  10. #include <LibWeb/Bindings/ExceptionOrUtils.h>
  11. #include <LibWeb/Bindings/Intrinsics.h>
  12. #include <LibWeb/Crypto/Crypto.h>
  13. #include <LibWeb/Crypto/SubtleCrypto.h>
  14. #include <LibWeb/WebIDL/Buffers.h>
  15. namespace Web::Crypto {
  16. JS_DEFINE_ALLOCATOR(Crypto);
  17. JS::NonnullGCPtr<Crypto> Crypto::create(JS::Realm& realm)
  18. {
  19. return realm.heap().allocate<Crypto>(realm, realm);
  20. }
  21. Crypto::Crypto(JS::Realm& realm)
  22. : PlatformObject(realm)
  23. {
  24. }
  25. Crypto::~Crypto() = default;
  26. void Crypto::initialize(JS::Realm& realm)
  27. {
  28. Base::initialize(realm);
  29. WEB_SET_PROTOTYPE_FOR_INTERFACE(Crypto);
  30. m_subtle = SubtleCrypto::create(realm);
  31. }
  32. JS::NonnullGCPtr<SubtleCrypto> Crypto::subtle() const
  33. {
  34. return *m_subtle;
  35. }
  36. // https://w3c.github.io/webcrypto/#dfn-Crypto-method-getRandomValues
  37. WebIDL::ExceptionOr<JS::Handle<WebIDL::ArrayBufferView>> Crypto::get_random_values(JS::Handle<WebIDL::ArrayBufferView> array) const
  38. {
  39. // 1. If array is not an Int8Array, Uint8Array, Uint8ClampedArray, Int16Array, Uint16Array, Int32Array, Uint32Array, BigInt64Array, or BigUint64Array, then throw a TypeMismatchError and terminate the algorithm.
  40. if (!array->is_typed_array_base())
  41. return WebIDL::TypeMismatchError::create(realm(), "array must be one of Int8Array, Uint8Array, Uint8ClampedArray, Int16Array, Uint16Array, Int32Array, Uint32Array, BigInt64Array, or BigUint64Array"_fly_string);
  42. auto const& typed_array = *array->bufferable_object().get<JS::NonnullGCPtr<JS::TypedArrayBase>>();
  43. auto typed_array_record = JS::make_typed_array_with_buffer_witness_record(typed_array, JS::ArrayBuffer::Order::SeqCst);
  44. // IMPLEMENTATION DEFINED: If the viewed array buffer is out-of-bounds, throw a InvalidStateError and terminate the algorithm.
  45. if (JS::is_typed_array_out_of_bounds(typed_array_record))
  46. return WebIDL::InvalidStateError::create(realm(), MUST(String::formatted(JS::ErrorType::BufferOutOfBounds.message(), "TypedArray"sv)));
  47. // 2. If the byteLength of array is greater than 65536, throw a QuotaExceededError and terminate the algorithm.
  48. if (JS::typed_array_byte_length(typed_array_record) > 65536)
  49. return WebIDL::QuotaExceededError::create(realm(), "array's byteLength may not be greater than 65536"_fly_string);
  50. // FIXME: Handle SharedArrayBuffers
  51. // 3. Overwrite all elements of array with cryptographically strong random values of the appropriate type.
  52. fill_with_random(array->viewed_array_buffer()->buffer());
  53. // 4. Return array.
  54. return array;
  55. }
  56. // https://w3c.github.io/webcrypto/#dfn-Crypto-method-randomUUID
  57. WebIDL::ExceptionOr<String> Crypto::random_uuid() const
  58. {
  59. auto& vm = realm().vm();
  60. return TRY_OR_THROW_OOM(vm, generate_random_uuid());
  61. }
  62. void Crypto::visit_edges(Cell::Visitor& visitor)
  63. {
  64. Base::visit_edges(visitor);
  65. visitor.visit(m_subtle);
  66. }
  67. // https://w3c.github.io/webcrypto/#dfn-generate-a-random-uuid
  68. ErrorOr<String> generate_random_uuid()
  69. {
  70. // 1. Let bytes be a byte sequence of length 16.
  71. u8 bytes[16];
  72. // 2. Fill bytes with cryptographically secure random bytes.
  73. fill_with_random(bytes);
  74. // 3. Set the 4 most significant bits of bytes[6], which represent the UUID version, to 0100.
  75. bytes[6] &= ~(1 << 7);
  76. bytes[6] |= 1 << 6;
  77. bytes[6] &= ~(1 << 5);
  78. bytes[6] &= ~(1 << 4);
  79. // 4. Set the 2 most significant bits of bytes[8], which represent the UUID variant, to 10.
  80. bytes[8] |= 1 << 7;
  81. bytes[8] &= ~(1 << 6);
  82. /* 5. Return the string concatenation of
  83. «
  84. hexadecimal representation of bytes[0],
  85. hexadecimal representation of bytes[1],
  86. hexadecimal representation of bytes[2],
  87. hexadecimal representation of bytes[3],
  88. "-",
  89. hexadecimal representation of bytes[4],
  90. hexadecimal representation of bytes[5],
  91. "-",
  92. hexadecimal representation of bytes[6],
  93. hexadecimal representation of bytes[7],
  94. "-",
  95. hexadecimal representation of bytes[8],
  96. hexadecimal representation of bytes[9],
  97. "-",
  98. hexadecimal representation of bytes[10],
  99. hexadecimal representation of bytes[11],
  100. hexadecimal representation of bytes[12],
  101. hexadecimal representation of bytes[13],
  102. hexadecimal representation of bytes[14],
  103. hexadecimal representation of bytes[15]
  104. ».
  105. */
  106. StringBuilder builder;
  107. TRY(builder.try_appendff("{:02x}{:02x}{:02x}{:02x}-", bytes[0], bytes[1], bytes[2], bytes[3]));
  108. TRY(builder.try_appendff("{:02x}{:02x}-", bytes[4], bytes[5]));
  109. TRY(builder.try_appendff("{:02x}{:02x}-", bytes[6], bytes[7]));
  110. TRY(builder.try_appendff("{:02x}{:02x}-", bytes[8], bytes[9]));
  111. TRY(builder.try_appendff("{:02x}{:02x}{:02x}{:02x}{:02x}{:02x}", bytes[10], bytes[11], bytes[12], bytes[13], bytes[14], bytes[15]));
  112. return builder.to_string();
  113. }
  114. }