public static bool TryCopyIA5StringBytes(
this AsnReader reader,
Span <byte> destination,
out int bytesWritten)
{
return(reader.TryCopyCharacterStringBytes(
UniversalTagNumber.IA5String,
destination,
out bytesWritten));
}
public static void TryCopyUTF8StringBytes(
PublicEncodingRules ruleSet,
string inputHex,
string expectedString)
{
byte[] inputData = inputHex.HexToByteArray();
string expectedHex = Text.Encoding.UTF8.GetBytes(expectedString).ByteArrayToHex();
byte[] output = new byte[expectedHex.Length / 2];
AsnReader reader = new AsnReader(inputData, (AsnEncodingRules)ruleSet);
bool copied;
int bytesWritten;
if (output.Length > 0)
{
output[0] = 32;
copied = reader.TryCopyCharacterStringBytes(
UniversalTagNumber.UTF8String,
output.AsSpan(0, output.Length - 1),
out bytesWritten);
Assert.False(copied, "reader.TryCopyUTF8StringBytes - too short");
Assert.Equal(0, bytesWritten);
Assert.Equal(32, output[0]);
}
copied = reader.TryCopyCharacterStringBytes(
UniversalTagNumber.UTF8String,
output,
out bytesWritten);
Assert.True(copied, "reader.TryCopyUTF8StringBytes");
Assert.Equal(
expectedHex,
new ReadOnlySpan <byte>(output, 0, bytesWritten).ByteArrayToHex());
Assert.Equal(output.Length, bytesWritten);
}
public static void TryCopyUTF8StringBytes_Throws(
string description,
PublicEncodingRules ruleSet,
string inputHex)
{
byte[] inputData = inputHex.HexToByteArray();
byte[] outputData = new byte[inputData.Length + 1];
outputData[0] = 252;
int bytesWritten = -1;
AsnReader reader = new AsnReader(inputData, (AsnEncodingRules)ruleSet);
Assert.Throws <CryptographicException>(
() => reader.TryCopyCharacterStringBytes(UniversalTagNumber.UTF8String, outputData, out bytesWritten));
Assert.Equal(-1, bytesWritten);
Assert.Equal(252, outputData[0]);
}
public static void TryCopyUTF8StringBytes_Success_CER_MaxPrimitiveLength()
{
// CER says that the maximum encoding length for a UTF8String primitive
// is 1000.
//
// So we need 0C [1000] { 1000 anythings }
// 1000 => 0x3E8, so the length encoding is 82 03 E8.
// 1000 + 3 + 1 == 1004
byte[] input = new byte[1004];
input[0] = 0x0C;
input[1] = 0x82;
input[2] = 0x03;
input[3] = 0xE8;
// Content
input[4] = 0x65;
input[5] = 0x65;
input[1002] = 0x61;
input[1003] = 0x61;
byte[] output = new byte[1000];
AsnReader reader = new AsnReader(input, AsnEncodingRules.CER);
bool success = reader.TryCopyCharacterStringBytes(
UniversalTagNumber.UTF8String,
output,
out int bytesWritten);
Assert.True(success, "reader.TryCopyUTF8StringBytes");
Assert.Equal(1000, bytesWritten);
Assert.Equal(
input.AsReadOnlySpan().Slice(4).ByteArrayToHex(),
output.ByteArrayToHex());
}
public static void TryCopyUTF8StringBytes_Success_CER_MinConstructedLength()
{
// CER says that the maximum encoding length for a UTF8String primitive
// is 1000, and that a constructed form must be used for values greater
// than 1000 bytes, with segments dividing up for each thousand
// [1000, 1000, ..., len%1000].
//
// So our smallest constructed form is 1001 bytes, [1000, 1]
//
// 2C 80 (indefinite constructed utf8 string)
// 04 82 03 E9 (primitive octet string, 1000 bytes)
// [1000 content bytes]
// 04 01 (primitive octet string, 1 byte)
// pp
// 00 00 (end of contents, 0 bytes)
// 1011 total.
byte[] input = new byte[1011];
int offset = 0;
// CONSTRUCTED UTF8 STRING (Indefinite)
input[offset++] = 0x2C;
input[offset++] = 0x80;
// OCTET STRING (1000)
input[offset++] = 0x04;
input[offset++] = 0x82;
input[offset++] = 0x03;
input[offset++] = 0xE8;
// Primitive 1: (65 65 :: 61 61) (1000)
input[offset++] = 0x65;
input[offset] = 0x65;
offset += 997;
input[offset++] = 0x61;
input[offset++] = 0x61;
// OCTET STRING (1)
input[offset++] = 0x04;
input[offset++] = 0x01;
// Primitive 2: One more byte
input[offset] = 0x2E;
byte[] expected = new byte[1001];
offset = 0;
expected[offset++] = 0x65;
expected[offset] = 0x65;
offset += 997;
expected[offset++] = 0x61;
expected[offset++] = 0x61;
expected[offset] = 0x2E;
byte[] output = new byte[1001];
AsnReader reader = new AsnReader(input, AsnEncodingRules.CER);
bool success = reader.TryCopyCharacterStringBytes(
UniversalTagNumber.UTF8String,
output,
out int bytesWritten);
Assert.True(success, "reader.TryCopyUTF8StringBytes");
Assert.Equal(1001, bytesWritten);
Assert.Equal(
expected.ByteArrayToHex(),
output.ByteArrayToHex());
}
