internal static bool TryParseHeader(ReadOnlyMemory <byte> utf8Payload, byte[]?buffer, TokenValidationPolicy policy, [NotNullWhen(true)] out JwtHeaderDocument?header, [NotNullWhen(false)] out TokenValidationError?error)
{
ReadOnlySpan <byte> utf8JsonSpan = utf8Payload.Span;
var database = new JsonMetadata(utf8Payload.Length);
int algIdx = -1;
int encIdx = -1;
int kidIdx = -1;
int critIdx = -1;
var reader = new Utf8JsonReader(utf8JsonSpan);
if (reader.Read())
{
JsonTokenType tokenType = reader.TokenType;
if (tokenType == JsonTokenType.StartObject)
{
while (reader.Read())
{
tokenType = reader.TokenType;
int tokenStart = (int)reader.TokenStartIndex;
if (tokenType == JsonTokenType.EndObject)
{
break;
}
else if (tokenType != JsonTokenType.PropertyName)
{
error = TokenValidationError.MalformedToken();
goto Error;
}
// Adding 1 to skip the start quote will never overflow
Debug.Assert(tokenStart < int.MaxValue);
database.Append(JsonTokenType.PropertyName, tokenStart + 1, reader.ValueSpan.Length);
if (reader.ValueSpan.IndexOf((byte)'\\') != -1)
{
database.SetNeedUnescaping(database.Length - JsonRow.Size);
}
ReadOnlySpan <byte> memberName = reader.ValueSpan;
reader.Read();
tokenType = reader.TokenType;
tokenStart = (int)reader.TokenStartIndex;
// Since the input payload is contained within a Span,
// token start index can never be larger than int.MaxValue (i.e. utf8JsonSpan.Length).
Debug.Assert(reader.TokenStartIndex <= int.MaxValue);
if (tokenType == JsonTokenType.String)
{
if (memberName.Length == 3)
{
switch ((JwtHeaderParameters)IntegerMarshal.ReadUInt24(memberName))
{
case JwtHeaderParameters.Alg:
algIdx = database.Length;
break;
case JwtHeaderParameters.Enc:
encIdx = database.Length;
break;
case JwtHeaderParameters.Kid:
kidIdx = database.Length;
break;
}
}
// Adding 1 to skip the start quote will never overflow
Debug.Assert(tokenStart < int.MaxValue);
database.Append(JsonTokenType.String, tokenStart + 1, reader.ValueSpan.Length);
}
else if (tokenType == JsonTokenType.StartObject)
{
int count = Utf8JsonReaderHelper.SkipObject(ref reader);
int index = database.Length;
int tokenEnd = (int)reader.TokenStartIndex;
database.Append(JsonTokenType.StartObject, tokenStart, tokenEnd - tokenStart + 1);
database.SetNumberOfRows(index, count);
}
else if (tokenType == JsonTokenType.StartArray)
{
int count;
if (memberName.Length == 4 &&
(JwtHeaderParameters)IntegerMarshal.ReadUInt32(memberName) == JwtHeaderParameters.Crit &&
!policy.IgnoreCriticalHeader)
{
critIdx = database.Length;
if (!TryCheckCrit(ref reader, out count))
{
error = TokenValidationError.MalformedToken("The 'crit' header parameter must be an array of string.");
goto Error;
}
}
else
{
count = Utf8JsonReaderHelper.SkipArray(ref reader);
}
int index = database.Length;
int tokenEnd = (int)reader.TokenStartIndex;
database.Append(JsonTokenType.StartArray, tokenStart, tokenEnd - tokenStart + 1);
database.SetNumberOfRows(index, count);
}
else
{
Debug.Assert(tokenType >= JsonTokenType.Number && tokenType <= JsonTokenType.Null);
database.Append(tokenType, tokenStart, reader.ValueSpan.Length);
}
}
}
}
Debug.Assert(reader.BytesConsumed == utf8JsonSpan.Length);
database.CompleteAllocations();
header = new JwtHeaderDocument(new JwtDocument(utf8Payload, database, buffer), algIdx, encIdx, kidIdx, critIdx);
#if NET5_0_OR_GREATER
Unsafe.SkipInit(out error);
#else
error = default;
#endif
return(true);
Error:
#if NET5_0_OR_GREATER
Unsafe.SkipInit(out header);
#else
header = default;
#endif
return(false);
}
internal static bool TryParsePayload(ReadOnlyMemory <byte> utf8Payload, byte[]?buffer, TokenValidationPolicy policy, [NotNullWhen(true)] out JwtPayloadDocument?payload, [NotNullWhen(false)] out TokenValidationError?error)
{
ReadOnlySpan <byte> utf8JsonSpan = utf8Payload.Span;
var database = new JsonMetadata(utf8Payload.Length);
byte control = policy.Control;
int issIdx = -1;
var reader = new Utf8JsonReader(utf8JsonSpan);
if (reader.Read())
{
JsonTokenType tokenType = reader.TokenType;
if (tokenType == JsonTokenType.StartObject)
{
while (reader.Read())
{
tokenType = reader.TokenType;
int tokenStart = (int)reader.TokenStartIndex;
if (tokenType == JsonTokenType.EndObject)
{
break;
}
else if (tokenType != JsonTokenType.PropertyName)
{
error = TokenValidationError.MalformedToken();
goto Error;
}
Debug.Assert(tokenStart < int.MaxValue);
database.Append(JsonTokenType.PropertyName, tokenStart + 1, reader.ValueSpan.Length);
ReadOnlySpan <byte> memberName = reader.ValueSpan;
if (memberName.IndexOf((byte)'\\') != -1)
{
database.SetNeedUnescaping(database.Length - JsonRow.Size);
}
reader.Read();
tokenType = reader.TokenType;
tokenStart = (int)reader.TokenStartIndex;
Debug.Assert(reader.TokenStartIndex <= int.MaxValue);
if (tokenType == JsonTokenType.String)
{
if (memberName.Length == 3)
{
switch ((JwtClaims)IntegerMarshal.ReadUInt24(memberName))
{
case JwtClaims.Aud:
CheckStringAudience(ref reader, ref control, policy);
break;
case JwtClaims.Iss:
issIdx = database.Length;
CheckIssuer(ref reader, ref control, policy);
break;
}
}
Debug.Assert(tokenStart < int.MaxValue);
database.Append(JsonTokenType.String, tokenStart + 1, reader.ValueSpan.Length);
}
else if (tokenType == JsonTokenType.Number)
{
if (memberName.Length == 3)
{
switch ((JwtClaims)IntegerMarshal.ReadUInt24(memberName))
{
case JwtClaims.Exp:
if (!TryCheckExpirationTime(ref reader, ref control, policy))
{
error = TokenValidationError.MalformedToken("The claim 'exp' must be an integral number.");
goto Error;
}
break;
case JwtClaims.Nbf:
if (!TryCheckNotBefore(ref reader, ref control, policy))
{
error = TokenValidationError.MalformedToken("The claim 'nbf' must be an integral number.");
goto Error;
}
break;
}
}
database.Append(JsonTokenType.Number, tokenStart, reader.ValueSpan.Length);
}
else if (tokenType == JsonTokenType.StartObject)
{
int itemCount = Utf8JsonReaderHelper.SkipObject(ref reader);
int tokenEnd = (int)reader.TokenStartIndex;
int index = database.Length;
database.Append(JsonTokenType.StartObject, tokenStart, tokenEnd - tokenStart + 1);
database.SetNumberOfRows(index, itemCount);
}
else if (tokenType == JsonTokenType.StartArray)
{
int itemCount;
if (memberName.Length == 3 && (JwtClaims)IntegerMarshal.ReadUInt24(memberName) == JwtClaims.Aud)
{
itemCount = CheckArrayAudience(ref reader, ref control, policy);
}
else
{
itemCount = Utf8JsonReaderHelper.SkipArray(ref reader);
}
int index = database.Length;
int tokenEnd = (int)reader.TokenStartIndex;
database.Append(JsonTokenType.StartArray, tokenStart, tokenEnd - tokenStart + 1);
database.SetNumberOfRows(index, itemCount);
}
else
{
Debug.Assert(tokenType >= JsonTokenType.True && tokenType <= JsonTokenType.Null);
database.Append(tokenType, tokenStart, reader.ValueSpan.Length);
}
}
}
}
Debug.Assert(reader.BytesConsumed == utf8JsonSpan.Length);
database.CompleteAllocations();
payload = new JwtPayloadDocument(new JwtDocument(utf8Payload, database, buffer), control, issIdx);
#if NET5_0_OR_GREATER
Unsafe.SkipInit(out error);
#else
error = default;
#endif
return(true);
Error:
#if NET5_0_OR_GREATER
Unsafe.SkipInit(out payload);
#else
payload = default;
#endif
return(false);
}