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// Licensed to the .NET Foundation under one or more agreements.
// The .NET Foundation licenses this file to you under the MIT license.
using System.Diagnostics;
using System.Runtime.InteropServices;
namespace System.Formats.Asn1
{
public static partial class AsnDecoder
{
/// <summary>
/// Reads an Enumerated value from <paramref name="source"/> with a specified tag under
/// the specified encoding rules, returning the contents as a slice of the buffer.
/// </summary>
/// <param name="source">The buffer containing encoded data.</param>
/// <param name="ruleSet">The encoding constraints to use when interpreting the data.</param>
/// <param name="bytesConsumed">
/// When this method returns, the total number of bytes for the encoded value.
/// This parameter is treated as uninitialized.
/// </param>
/// <param name="expectedTag">
/// The tag to check for before reading, or <see langword="null"/> for the default tag (Universal 10).
/// </param>
/// <returns>
/// The slice of the buffer containing the bytes of the Enumerated value,
/// in signed big-endian form.
/// </returns>
/// <exception cref="ArgumentOutOfRangeException">
/// <paramref name="ruleSet"/> is not defined.
/// </exception>
/// <exception cref="AsnContentException">
/// the next value does not have the correct tag.
///
/// -or-
///
/// the length encoding is not valid under the current encoding rules.
///
/// -or-
///
/// the contents are not valid under the current encoding rules.
/// </exception>
/// <exception cref="ArgumentException">
/// <paramref name="expectedTag"/>.<see cref="Asn1Tag.TagClass"/> is
/// <see cref="TagClass.Universal"/>, but
/// <paramref name="expectedTag"/>.<see cref="Asn1Tag.TagValue"/> is not correct for
/// the method.
/// </exception>
public static ReadOnlySpan<byte> ReadEnumeratedBytes(
ReadOnlySpan<byte> source,
AsnEncodingRules ruleSet,
out int bytesConsumed,
Asn1Tag? expectedTag = null)
{
return GetIntegerContents(
source,
ruleSet,
expectedTag ?? Asn1Tag.Enumerated,
UniversalTagNumber.Enumerated,
out bytesConsumed);
}
/// <summary>
/// Reads an Enumerated from <paramref name="source"/> with a specified tag under
/// the specified encoding rules, converting it to the
/// non-[<see cref="FlagsAttribute"/>] enum specified by <typeparamref name="TEnum"/>.
/// </summary>
/// <param name="source">The buffer containing encoded data.</param>
/// <param name="ruleSet">The encoding constraints to use when interpreting the data.</param>
/// <param name="bytesConsumed">
/// When this method returns, the total number of bytes for the encoded value.
/// This parameter is treated as uninitialized.
/// </param>
/// <param name="expectedTag">
/// The tag to check for before reading, or <see langword="null"/> for the default tag (Universal 10).
/// </param>
/// <typeparam name="TEnum">Destination enum type</typeparam>
/// <returns>
/// The Enumerated value converted to a <typeparamref name="TEnum"/>.
/// </returns>
/// <remarks>
/// This method does not validate that the return value is defined within
/// <typeparamref name="TEnum"/>.
/// </remarks>
/// <exception cref="ArgumentOutOfRangeException">
/// <paramref name="ruleSet"/> is not defined.
/// </exception>
/// <exception cref="AsnContentException">
/// the next value does not have the correct tag.
///
/// -or-
///
/// the length encoding is not valid under the current encoding rules.
///
/// -or-
///
/// the contents are not valid under the current encoding rules.
///
/// -or-
///
/// the encoded value is too big to fit in a <typeparamref name="TEnum"/> value.
/// </exception>
/// <exception cref="ArgumentException">
/// <typeparamref name="TEnum"/> is not an enum type.
///
/// -or-
///
/// <typeparamref name="TEnum"/> was declared with <see cref="FlagsAttribute"/>.
///
/// -or-
///
/// <paramref name="expectedTag"/>.<see cref="Asn1Tag.TagClass"/> is
/// <see cref="TagClass.Universal"/>, but
/// <paramref name="expectedTag"/>.<see cref="Asn1Tag.TagValue"/> is not correct for
/// the method.
/// </exception>
public static TEnum ReadEnumeratedValue<TEnum>(
ReadOnlySpan<byte> source,
AsnEncodingRules ruleSet,
out int bytesConsumed,
Asn1Tag? expectedTag = null)
where TEnum : Enum
{
Type tEnum = typeof(TEnum);
return (TEnum)Enum.ToObject(
tEnum,
ReadEnumeratedValue(
source,
ruleSet,
tEnum,
out bytesConsumed,
expectedTag));
}
/// <summary>
/// Reads an Enumerated from <paramref name="source"/> with a specified tag under
/// the specified encoding rules, converting it to the
/// non-[<see cref="FlagsAttribute"/>] enum specified by <paramref name="enumType"/>.
/// </summary>
/// <param name="source">The buffer containing encoded data.</param>
/// <param name="ruleSet">The encoding constraints to use when interpreting the data.</param>
/// <param name="enumType">Type object representing the destination type.</param>
/// <param name="bytesConsumed">
/// When this method returns, the total number of bytes for the encoded value.
/// This parameter is treated as uninitialized.
/// </param>
/// <param name="expectedTag">
/// The tag to check for before reading, or <see langword="null"/> for the default tag (Universal 10).
/// </param>
/// <returns>
/// The Enumerated value converted to a <paramref name="enumType"/>.
/// </returns>
/// <remarks>
/// This method does not validate that the return value is defined within
/// <paramref name="enumType"/>.
/// </remarks>
/// <exception cref="AsnContentException">
/// the next value does not have the correct tag.
///
/// -or-
///
/// the length encoding is not valid under the current encoding rules.
///
/// -or-
///
/// the contents are not valid under the current encoding rules.
///
/// -or-
///
/// the encoded value is too big to fit in a <paramref name="enumType"/> value.
/// </exception>
/// <exception cref="ArgumentException">
/// <paramref name="enumType"/> is not an enum type.
///
/// -or-
///
/// <paramref name="enumType"/> was declared with <see cref="FlagsAttribute"/>.
///
/// -or-
///
/// <paramref name="enumType"/>.<see cref="Asn1Tag.TagClass"/> is
/// <see cref="TagClass.Universal"/>, but
/// <paramref name="enumType"/>.<see cref="Asn1Tag.TagValue"/> is not correct for
/// the method.
/// </exception>
/// <exception cref="ArgumentNullException">
/// <paramref name="enumType"/> is <see langword="null" />.
/// </exception>
public static Enum ReadEnumeratedValue(
ReadOnlySpan<byte> source,
AsnEncodingRules ruleSet,
Type enumType,
out int bytesConsumed,
Asn1Tag? expectedTag = null)
{
if (enumType == null)
throw new ArgumentNullException(nameof(enumType));
const UniversalTagNumber TagNumber = UniversalTagNumber.Enumerated;
Asn1Tag localTag = expectedTag ?? Asn1Tag.Enumerated;
// This will throw an ArgumentException if TEnum isn't an enum type,
// so we don't need to validate it.
Type backingType = enumType.GetEnumUnderlyingType();
if (enumType.IsDefined(typeof(FlagsAttribute), false))
{
throw new ArgumentException(
SR.Argument_EnumeratedValueRequiresNonFlagsEnum,
nameof(enumType));
}
// T-REC-X.690-201508 sec 8.4 says the contents are the same as for integers.
int sizeLimit = GetPrimitiveIntegerSize(backingType);
if (backingType == typeof(int) ||
backingType == typeof(long) ||
backingType == typeof(short) ||
backingType == typeof(sbyte))
{
if (!TryReadSignedInteger(
source,
ruleSet,
sizeLimit,
localTag,
TagNumber,
out long value,
out int consumed))
{
throw new AsnContentException(SR.ContentException_EnumeratedValueTooBig);
}
bytesConsumed = consumed;
return (Enum)Enum.ToObject(enumType, value);
}
if (backingType == typeof(uint) ||
backingType == typeof(ulong) ||
backingType == typeof(ushort) ||
backingType == typeof(byte))
{
if (!TryReadUnsignedInteger(
source,
ruleSet,
sizeLimit,
localTag,
TagNumber,
out ulong value,
out int consumed))
{
throw new AsnContentException(SR.ContentException_EnumeratedValueTooBig);
}
bytesConsumed = consumed;
return (Enum)Enum.ToObject(enumType, value);
}
throw new AsnContentException(
SR.Format(
SR.Argument_EnumeratedValueBackingTypeNotSupported,
backingType.FullName));
}
}
public partial class AsnReader
{
/// <summary>
/// Reads the next value as a Enumerated with a specified tag, returning the contents
/// as a <see cref="ReadOnlyMemory{T}"/> over the original data.
/// </summary>
/// <param name="expectedTag">
/// The tag to check for before reading, or <see langword="null"/> for the default tag (Universal 10).
/// </param>
/// <returns>
/// The bytes of the Enumerated value, in signed big-endian form.
/// </returns>
/// <exception cref="AsnContentException">
/// the next value does not have the correct tag.
///
/// -or-
///
/// the length encoding is not valid under the current encoding rules.
///
/// -or-
///
/// the contents are not valid under the current encoding rules.
/// </exception>
/// <exception cref="ArgumentException">
/// <paramref name="expectedTag"/>.<see cref="Asn1Tag.TagClass"/> is
/// <see cref="TagClass.Universal"/>, but
/// <paramref name="expectedTag"/>.<see cref="Asn1Tag.TagValue"/> is not correct for
/// the method.
/// </exception>
/// <seealso cref="ReadEnumeratedValue{TEnum}"/>
public ReadOnlyMemory<byte> ReadEnumeratedBytes(Asn1Tag? expectedTag = null)
{
ReadOnlySpan<byte> bytes =
AsnDecoder.ReadEnumeratedBytes(_data.Span, RuleSet, out int consumed, expectedTag);
ReadOnlyMemory<byte> memory = AsnDecoder.Slice(_data, bytes);
_data = _data.Slice(consumed);
return memory;
}
/// <summary>
/// Reads the next value as an Enumerated with a specified tag, converting it to the
/// non-[<see cref="FlagsAttribute"/>] enum specified by <typeparamref name="TEnum"/>.
/// </summary>
/// <param name="expectedTag">
/// The tag to check for before reading, or <see langword="null"/> for the default tag (Universal 10).
/// </param>
/// <typeparam name="TEnum">Destination enum type</typeparam>
/// <returns>
/// The Enumerated value converted to a <typeparamref name="TEnum"/>.
/// </returns>
/// <remarks>
/// This method does not validate that the return value is defined within
/// <typeparamref name="TEnum"/>.
/// </remarks>
/// <exception cref="AsnContentException">
/// the next value does not have the correct tag.
///
/// -or-
///
/// the length encoding is not valid under the current encoding rules.
///
/// -or-
///
/// the contents are not valid under the current encoding rules.
///
/// -or-
///
/// the encoded value is too big to fit in a <typeparamref name="TEnum"/> value.
/// </exception>
/// <exception cref="ArgumentException">
/// <typeparamref name="TEnum"/> is not an enum type.
///
/// -or-
///
/// <typeparamref name="TEnum"/> was declared with <see cref="FlagsAttribute"/>.
///
/// -or-
///
/// <paramref name="expectedTag"/>.<see cref="Asn1Tag.TagClass"/> is
/// <see cref="TagClass.Universal"/>, but
/// <paramref name="expectedTag"/>.<see cref="Asn1Tag.TagValue"/> is not correct for
/// the method.
/// </exception>
public TEnum ReadEnumeratedValue<TEnum>(Asn1Tag? expectedTag = null) where TEnum : Enum
{
TEnum ret = AsnDecoder.ReadEnumeratedValue<TEnum>(_data.Span, RuleSet, out int consumed, expectedTag);
_data = _data.Slice(consumed);
return ret;
}
/// <summary>
/// Reads the next value as an Enumerated with a specified tag, converting it to the
/// non-[<see cref="FlagsAttribute"/>] enum specified by <paramref name="enumType"/>.
/// </summary>
/// <param name="enumType">Type object representing the destination type.</param>
/// <param name="expectedTag">
/// The tag to check for before reading, or <see langword="null"/> for the default tag (Universal 10).
/// </param>
/// <returns>
/// The Enumerated value converted to a <paramref name="enumType"/>.
/// </returns>
/// <remarks>
/// This method does not validate that the return value is defined within
/// <paramref name="enumType"/>.
/// </remarks>
/// <exception cref="AsnContentException">
/// the next value does not have the correct tag.
///
/// -or-
///
/// the length encoding is not valid under the current encoding rules.
///
/// -or-
///
/// the contents are not valid under the current encoding rules.
///
/// -or-
///
/// the encoded value is too big to fit in a <paramref name="enumType"/> value.
/// </exception>
/// <exception cref="ArgumentException">
/// <paramref name="enumType"/> is not an enum type.
///
/// -or-
///
/// <paramref name="enumType"/> was declared with <see cref="FlagsAttribute"/>.
///
/// -or-
///
/// <paramref name="enumType"/>.<see cref="Asn1Tag.TagClass"/> is
/// <see cref="TagClass.Universal"/>, but
/// <paramref name="enumType"/>.<see cref="Asn1Tag.TagValue"/> is not correct for
/// the method.
/// </exception>
/// <exception cref="ArgumentNullException">
/// <paramref name="enumType"/> is <see langword="null" />.
/// </exception>
public Enum ReadEnumeratedValue(Type enumType, Asn1Tag? expectedTag = null)
{
Enum ret = AsnDecoder.ReadEnumeratedValue(_data.Span, RuleSet, enumType, out int consumed, expectedTag);
_data = _data.Slice(consumed);
return ret;
}
}
}
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