/// <summary>Returns a new instance of <see cref="Jwks"/>.</summary>
/// <param name="issuer">The issuer of the keys.</param>
/// <param name="json">A string that contains JSON Web Key parameters in JSON format.</param>
public static Jwks FromJson(string issuer, string json)
{
if (json is null)
{
ThrowHelper.ThrowArgumentNullException(ExceptionArgument.json);
}
byte[]? jsonToReturn = null;
try
{
int length = Utf8.GetMaxByteCount(json.Length);
Span <byte> jsonSpan = length <= Constants.MaxStackallocBytes
? stackalloc byte[length]
: (jsonToReturn = ArrayPool <byte> .Shared.Rent(length));
length = Utf8.GetBytes(json, jsonSpan);
return(FromJson(issuer, jsonSpan.Slice(0, length)));
}
finally
{
if (jsonToReturn != null)
{
ArrayPool <byte> .Shared.Return(jsonToReturn);
}
}
}
/// <summary>Decodes a string of UTF-8 base64url-encoded text.</summary>
/// <remarks>This method allocate an array of bytes. Use <see cref="Decode(ReadOnlySpan{byte}, Span{byte})"/> when possible.</remarks>
public static byte[] Decode(string data)
{
if (data is null)
{
ThrowHelper.ThrowArgumentNullException(ExceptionArgument.data);
}
int length = Utf8.GetMaxByteCount(data.Length);
byte[]? utf8ArrayToReturn = null;
try
{
Span <byte> tmp = length > Constants.MaxStackallocBytes
? (utf8ArrayToReturn = ArrayPool <byte> .Shared.Rent(length))
: stackalloc byte[Constants.MaxStackallocBytes];
int written = Utf8.GetBytes(data, tmp);
return(Decode(tmp.Slice(0, written)));
}
finally
{
if (utf8ArrayToReturn != null)
{
ArrayPool <byte> .Shared.Return(utf8ArrayToReturn);
}
}
}
/// <inheritsdoc />
public override void Encode(EncodingContext context)
{
if (Payload != null)
{
int payloadLength = Utf8.GetMaxByteCount(Payload.Length);
byte[]? payloadToReturnToPool = null;
Span <byte> encodedPayload = payloadLength > Constants.MaxStackallocBytes
? (payloadToReturnToPool = ArrayPool <byte> .Shared.Rent(payloadLength))
: stackalloc byte[payloadLength];
try
{
int bytesWritten = Utf8.GetBytes(Payload, encodedPayload);
EncryptToken(encodedPayload.Slice(0, bytesWritten), context);
}
finally
{
if (payloadToReturnToPool != null)
{
ArrayPool <byte> .Shared.Return(payloadToReturnToPool);
}
}
}
else
{
ThrowHelper.ThrowInvalidOperationException_UndefinedPayload();
}
}
internal bool TryGetNamedPropertyValue(ReadOnlySpan <char> propertyName, out JwtElement value)
{
JsonRow row;
int maxBytes = Utf8.GetMaxByteCount(propertyName.Length);
int endIndex = _parsedData.Length;
if (maxBytes < JsonConstants.StackallocThreshold)
{
Span <byte> utf8Name = stackalloc byte[JsonConstants.StackallocThreshold];
int len = JsonReaderHelper.GetUtf8FromText(propertyName, utf8Name);
utf8Name = utf8Name.Slice(0, len);
return(TryGetNamedPropertyValue(
endIndex,
utf8Name,
out value));
}
// Unescaping the property name will make the string shorter (or the same)
// So the first viable candidate is one whose length in bytes matches, or
// exceeds, our length in chars.
//
// The maximal escaping seems to be 6 -> 1 ("\u0030" => "0"), but just transcode
// and switch once one viable long property is found.
int minBytes = propertyName.Length;
for (int candidateIndex = 0; candidateIndex <= endIndex; candidateIndex += JsonRow.Size * 2)
{
row = _parsedData.Get(candidateIndex);
Debug.Assert(row.TokenType == JsonTokenType.PropertyName);
if (row.Length >= minBytes)
{
byte[] tmpUtf8 = ArrayPool <byte> .Shared.Rent(maxBytes);
Span <byte> utf8Name = default;
try
{
int len = JsonReaderHelper.GetUtf8FromText(propertyName, tmpUtf8);
utf8Name = tmpUtf8.AsSpan(0, len);
return(TryGetNamedPropertyValue(
candidateIndex,
utf8Name,
out value));
}
finally
{
ArrayPool <byte> .Shared.Return(tmpUtf8);
}
}
}
// None of the property names were within the range that the UTF-8 encoding would have been.
value = default;
return(false);
}
/// <summary>Parses and validates a JWT encoded as a JWS or JWE in compact serialized format.</summary>
/// <param name="token">The JWT encoded as JWE or JWS</param>
/// <param name="policy">The validation policy.</param>
/// <param name="jwt">The resulting <see cref="Jwt"/>.</param>
public static bool TryParse(string token, TokenValidationPolicy policy, out Jwt jwt)
{
if (token is null)
{
ThrowHelper.ThrowArgumentNullException(ExceptionArgument.token);
}
if (policy is null)
{
ThrowHelper.ThrowArgumentNullException(ExceptionArgument.policy);
}
if (token.Length == 0)
{
jwt = new Jwt(TokenValidationError.MalformedToken());
return(false);
}
int length = Utf8.GetMaxByteCount(token.Length);
if (length > policy.MaximumTokenSizeInBytes)
{
jwt = new Jwt(TokenValidationError.MalformedToken());
return(false);
}
byte[]? utf8ArrayToReturnToPool = null;
var utf8Token = length <= Constants.MaxStackallocBytes
? stackalloc byte[length]
: (utf8ArrayToReturnToPool = ArrayPool <byte> .Shared.Rent(length));
try
{
int bytesWritten = Utf8.GetBytes(token, utf8Token);
return(TryParse(utf8Token.Slice(0, bytesWritten), policy, out jwt));
}
finally
{
if (utf8ArrayToReturnToPool != null)
{
ArrayPool <byte> .Shared.Return(utf8ArrayToReturnToPool);
}
}
}
/// <summary>Encodes a string of UTF-8 text.</summary>
/// <returns>The base64-url encoded string.</returns>
/// <remarks>This method allocate an array of bytes. Use <see cref="Encode(ReadOnlySpan{byte}, Span{byte})"/> when possible.</remarks>
public static byte[] Encode(ReadOnlySpan <char> data)
{
byte[]? utf8ArrayToReturn = null;
try
{
int length = Utf8.GetMaxByteCount(data.Length);
var utf8Data = length > Constants.MaxStackallocBytes
? (utf8ArrayToReturn = ArrayPool <byte> .Shared.Rent(length))
: stackalloc byte[Constants.MaxStackallocBytes];
int written = Utf8.GetBytes(data, utf8Data);
return(Encode(utf8Data.Slice(0, written)));
}
finally
{
if (utf8ArrayToReturn != null)
{
ArrayPool <byte> .Shared.Return(utf8ArrayToReturn);
}
}
}
/// <inheritsdoc />
public override void Encode(EncodingContext context, IBufferWriter <byte> output)
{
int payloadLength = Utf8.GetMaxByteCount(Payload.Length);
byte[]? payloadToReturnToPool = null;
Span <byte> encodedPayload = payloadLength > Constants.MaxStackallocBytes
? (payloadToReturnToPool = ArrayPool <byte> .Shared.Rent(payloadLength))
: stackalloc byte[payloadLength];
try
{
int bytesWritten = Utf8.GetBytes(Payload, encodedPayload);
EncryptToken(context, encodedPayload.Slice(0, bytesWritten), output);
}
finally
{
if (payloadToReturnToPool != null)
{
ArrayPool <byte> .Shared.Return(payloadToReturnToPool);
}
}
}
