AsnDecoder.ReadNamedBitListValue Method

Definition

Namespace:

System.Formats.Asn1

Assembly:

System.Formats.Asn1.dll

Overloads

ReadNamedBitListValue(ReadOnlySpan<Byte>, AsnEncodingRules, Type, Int32, Nullable<Asn1Tag>)	Reads a NamedBitList from source with a specified tag under the specified encoding rules, converting it to the [FlagsAttribute] enum specified by flagsEnumType.
ReadNamedBitListValue<TFlagsEnum>(ReadOnlySpan<Byte>, AsnEncodingRules, Int32, Nullable<Asn1Tag>)	Reads a NamedBitList from source with a specified tag under the specified encoding rules, converting it to the [FlagsAttribute] enum specified by TFlagsEnum.

ReadNamedBitListValue(ReadOnlySpan<Byte>, AsnEncodingRules, Type, Int32, Nullable<Asn1Tag>)

Source:

AsnDecoder.NamedBitList.cs

Reads a NamedBitList from source with a specified tag under the specified encoding rules, converting it to the [FlagsAttribute] enum specified by flagsEnumType.

public static Enum ReadNamedBitListValue (ReadOnlySpan<byte> source, System.Formats.Asn1.AsnEncodingRules ruleSet, Type flagsEnumType, out int bytesConsumed, System.Formats.Asn1.Asn1Tag? expectedTag = default);

static member ReadNamedBitListValue : ReadOnlySpan<byte> * System.Formats.Asn1.AsnEncodingRules * Type * int * Nullable<System.Formats.Asn1.Asn1Tag> -> Enum

Public Shared Function ReadNamedBitListValue (source As ReadOnlySpan(Of Byte), ruleSet As AsnEncodingRules, flagsEnumType As Type, ByRef bytesConsumed As Integer, Optional expectedTag As Nullable(Of Asn1Tag) = Nothing) As Enum

Parameters

source

ReadOnlySpan<Byte>

The buffer containing encoded data.

ruleSet

AsnEncodingRules

The encoding constraints to use when interpreting the data.

flagsEnumType

Type

Type object representing the destination type.

bytesConsumed

Int32

When this method returns, the total number of bytes for the encoded value. This parameter is treated as uninitialized.

expectedTag

Nullable<Asn1Tag>

The tag to check for before reading, or null for the default tag (Universal 3).

Returns

Enum

The NamedBitList value converted to a flagsEnumType.

Exceptions

ArgumentOutOfRangeException

ruleSet is not defined.

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 flagsEnumType value.

ArgumentException

flagsEnumType is not an enum type.

-or-

flagsEnumType was not declared with FlagsAttribute

-or-

expectedTag.TagClass is Universal, but expectedTag.TagValue is not correct for the method.

ArgumentNullException

flagsEnumType is null

ReadNamedBitListValue<TFlagsEnum>(ReadOnlySpan<Byte>, AsnEncodingRules, Int32, Nullable<Asn1Tag>)

Source:

AsnDecoder.NamedBitList.cs

Reads a NamedBitList from source with a specified tag under the specified encoding rules, converting it to the [FlagsAttribute] enum specified by TFlagsEnum.

public static TFlagsEnum ReadNamedBitListValue<TFlagsEnum> (ReadOnlySpan<byte> source, System.Formats.Asn1.AsnEncodingRules ruleSet, out int bytesConsumed, System.Formats.Asn1.Asn1Tag? expectedTag = default) where TFlagsEnum : Enum;

static member ReadNamedBitListValue : ReadOnlySpan<byte> * System.Formats.Asn1.AsnEncodingRules * int * Nullable<System.Formats.Asn1.Asn1Tag> -> 'FlagsEnum (requires 'FlagsEnum :> Enum)

Public Shared Function ReadNamedBitListValue(Of TFlagsEnum As Enum) (source As ReadOnlySpan(Of Byte), ruleSet As AsnEncodingRules, ByRef bytesConsumed As Integer, Optional expectedTag As Nullable(Of Asn1Tag) = Nothing) As TFlagsEnum

Type Parameters

TFlagsEnum

Destination enum type.

Parameters

source

ReadOnlySpan<Byte>

The buffer containing encoded data.

ruleSet

AsnEncodingRules

The encoding constraints to use when interpreting the data.

bytesConsumed

Int32

When this method returns, the total number of bytes for the encoded value. This parameter is treated as uninitialized.

expectedTag

Nullable<Asn1Tag>

The tag to check for before reading, or null for the default tag (Universal 3).

Returns

TFlagsEnum

The NamedBitList value converted to a TFlagsEnum.

Exceptions

ArgumentOutOfRangeException

ruleSet is not defined.

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 TFlagsEnum value.

ArgumentException

TFlagsEnum is not an enum type.

-or-

TFlagsEnum was not declared with FlagsAttribute

-or-

expectedTag.TagClass is Universal, but expectedTag.TagValue is not correct for the method.

Remarks

The bit alignment performed by this method is to interpret the most significant bit in the first byte of the value as the least significant bit in TFlagsEnum, with bits increasing in value until the least significant bit of the first byte, proceeding with the most significant bit of the second byte, and so on. Under this scheme, the following ASN.1 type declaration and C# enumeration can be used together:

KeyUsage ::= BIT STRING {
    digitalSignature        (0),
    nonRepudiation          (1),
    keyEncipherment         (2),
    dataEncipherment        (3),
    keyAgreement            (4),
    keyCertSign             (5),
    cRLSign                 (6),
    encipherOnly            (7),
    decipherOnly            (8) }

[Flags]
enum KeyUsage
{
    None = 0, DigitalSignature = 1 << (0),
    NonRepudiation = 1 << (1),
    KeyEncipherment = 1 << (2),
    DataEncipherment = 1 << (3),
    KeyAgreement = 1 << (4),
    KeyCertSign = 1 << (5),
    CrlSign = 1 << (6),
    EncipherOnly = 1 << (7),
    DecipherOnly = 1 << (8),
}

While the example here uses the KeyUsage NamedBitList from RFC 3280 (4.2.1.3), the example enum uses values that are different from X509KeyUsageFlags.