IdentityShroud/IdentityShroud.Api/Apis/DTO/JsonWebKey.cs
2026-02-20 17:35:38 +01:00

73 lines
No EOL
2.5 KiB
C#

using System.Buffers;
using System.Buffers.Text;
using System.Text.Json;
using System.Text.Json.Serialization;
namespace IdentityShroud.Core.Messages;
// https://www.rfc-editor.org/rfc/rfc7517.html
public class JsonWebKey
{
[JsonPropertyName("kty")]
public string KeyType { get; set; } = "RSA";
// Common values sig(nature) enc(ryption)
[JsonPropertyName("use")]
public string? Use { get; set; } = "sig"; // "sig" for signature, "enc" for encryption
// Per standard this field is optional, commented out for now as it seems not
// have any good use in an identity server. Anyone validating tokens should use
// the algorithm specified in the header of the token.
// [JsonPropertyName("alg")]
// public string? Algorithm { get; set; } = "RS256";
[JsonPropertyName("kid")]
public required string KeyId { get; set; }
// RSA Public Key Components
[JsonPropertyName("n")]
public string? Modulus { get; set; }
[JsonPropertyName("e")]
public string? Exponent { get; set; }
// ECdsa
public string? Curve { get; set; }
[JsonConverter(typeof(Base64UrlConverter))]
public byte[]? X { get; set; }
[JsonConverter(typeof(Base64UrlConverter))]
public byte[]? Y { get; set; }
// Optional fields
// [JsonPropertyName("x5c")]
// [JsonIgnore(Condition = JsonIgnoreCondition.WhenWritingNull)]
// public List<string>? X509CertificateChain { get; set; }
//
// [JsonPropertyName("x5t")]
// [JsonIgnore(Condition = JsonIgnoreCondition.WhenWritingNull)]
// public string? X509CertificateThumbprint { get; set; }
}
public class Base64UrlConverter : JsonConverter<byte[]>
{
public override byte[] Read(ref Utf8JsonReader reader, Type typeToConvert, JsonSerializerOptions options)
{
// GetValueSpan gives you the raw UTF-8 bytes of the JSON string value
if (reader.HasValueSequence)
{
var valueSequence = reader.ValueSequence.ToArray();
return Base64Url.DecodeFromUtf8(valueSequence);
}
return Base64Url.DecodeFromUtf8(reader.ValueSpan);
}
public override void Write(Utf8JsonWriter writer, byte[] value, JsonSerializerOptions options)
{
int encodedLength = Base64Url.GetEncodedLength(value.Length);
Span<byte> buffer = encodedLength <= 256 ? stackalloc byte[encodedLength] : new byte[encodedLength];
Base64Url.EncodeToUtf8(value, buffer);
writer.WriteStringValue(buffer);
}
}