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Fix trace state key parsing in W3C propagator to support digits #119778

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merged 2 commits into from
Sep 17, 2025
Merged

Fix trace state key parsing in W3C propagator to support digits #119778

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419599d
Fix trace state key parsing in W3C propagator to support digits
tarekgh Sep 16, 2025
f143912
Merge branch 'main' into FixTraceStateKeyParsingInW3CPropagator
tarekgh Sep 16, 2025
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11 changes: 7 additions & 4 deletions src/libraries/System.Diagnostics.DiagnosticSource/src/System/Diagnostics/W3CPropagator.cs
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Original file line number Diff line number Diff line change
Expand Up @@ -130,6 +130,7 @@ internal static bool TryExtractBaggage(string? baggageString, out IEnumerable<Ke
// key = ( lcalpha / DIGIT ) 0*255 ( keychar )
// keychar = lcalpha / DIGIT / "_" / "-"/ "*" / "/" / "@"
// lcalpha = %x61-7A ; a-z
// DIGIT = %x30-39 ; 0-9
//
// value = 0*255(chr) nblk-chr
// nblk-chr = %x21-2B / %x2D-3C / %x3E-7E
Expand Down Expand Up @@ -421,26 +422,28 @@ private static bool IsInvalidBaggageKey(ReadOnlySpan<char> span)
}
#endif

// https://www.w3.org/TR/trace-context-2/#key
// key = ( lcalpha / DIGIT ) 0*255 ( keychar )
// keychar = lcalpha / DIGIT / "_" / "-"/ "*" / "/" / "@"
// lcalpha = %x61-7A ; a-z
// DIGIT = %x30-39 ; 0-9

#if NET
private const string TraceStateKeyValidChars = "*-/@_abcdefghijklmnopqrstuvwxyz";
private const string TraceStateKeyValidChars = "*-/0123456789@_abcdefghijklmnopqrstuvwxyz";
private static readonly SearchValues<char> s_validTraceStateChars = SearchValues.Create(TraceStateKeyValidChars);

private static bool IsInvalidTraceStateKey(ReadOnlySpan<char> key) => key.IsEmpty || (key[0] < 'a' || key[0] > 'z') || key.ContainsAnyExcept(s_validTraceStateChars);
private static bool IsInvalidTraceStateKey(ReadOnlySpan<char> key) => key.IsEmpty || ((uint)('z' - key[0]) > (uint)('z' - 'a') && (uint)('9' - key[0]) > (uint)('9' - '0')) || key.ContainsAnyExcept(s_validTraceStateChars);

private const string TraceStateValueValidChars = "!\"#$%&'()*+-./0123456789:;<>?@ABCDEFGHIJKLMNOPQRSTUVWXYZ[\\]^_`abcdefghijklmnopqrstuvwxyz{|}~";
private static readonly SearchValues<char> s_validTraceStateValueChars = SearchValues.Create(TraceStateValueValidChars);

private static bool IsInvalidTraceStateValue(ReadOnlySpan<char> value) => value.IsEmpty || value.ContainsAnyExcept(s_validTraceStateValueChars);
#else
private static ulong[] ValidTraceStateKeyCharsMask = [0x0000A40000000000, 0x07FFFFFE80000001];
private static ulong[] ValidTraceStateKeyCharsMask = [0x03FFA40000000000, 0x07FFFFFE80000001];

private static bool IsInvalidTraceStateKey(ReadOnlySpan<char> key)
{
if (key.IsEmpty || (key[0] < 'a' || key[0] > 'z')) // Key has to start with a lowercase letter
if (key.IsEmpty || ((uint)('z' - key[0]) > (uint)('z' - 'a') && (uint)('9' - key[0]) > (uint)('9' - '0'))) // Key has to start with a lowercase letter or digit
{
return true; // invalid key character, skip current entry
}
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13 changes: 8 additions & 5 deletions src/libraries/System.Diagnostics.DiagnosticSource/tests/W3CPropagatorTests.cs
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Expand Up @@ -31,16 +31,19 @@ public static IEnumerable<object[]> W3CTestData()
yield return new object[] { "state=1", "state=1", new[] { new KeyValuePair<string, string>("b1", "v1") }, "b1 = v1", new[] { new KeyValuePair<string, string>("b1", "v1") } };

// Invalid trace state
yield return new object[] { "PassThroughW3CState=1", null, null, null, null }; // trace state key has to be lowercase
yield return new object[] { "PassThroughW3CState=1", null, null, null, null }; // trace state key has to be lowercase or digit

// Invalid trace state
yield return new object[] { "1start=1", null, null, null, null }; // trace state key has to start with lowercase
// valid trace state, the key can have digits https://www.w3.org/TR/trace-context-2/#key
yield return new object[] { "1start=1", "1start=1", null, null, null }; // trace state key has to start with lowercase or digit

// valid trace state, the key can have digits https://www.w3.org/TR/trace-context-2/#key
yield return new object[] { "123@456=1", "123@456=1", null, null, null }; // trace state key has to start with lowercase or digit

// Tabs is not allowed in trace state values. use only the valid entry
yield return new object[] { "start=1, end=\t1", "start=1", null, null, null }; // trace state key has to start with lowercase
yield return new object[] { "start=1, end=\t1", "start=1", null, null, null }; // trace state key has to start with lowercase or digit

// multiple trace states
yield return new object[] { "start=1, end=1", "start=1, end=1", null, null, null }; // trace state key has to start with lowercase
yield return new object[] { "start=1, end=1", "start=1, end=1", null, null, null }; // trace state key has to start with lowercase or digit

// trace state longer than the max limit
yield return new object[] { $"{new string('a', 255)}=1", null, null, null, null }; // trace state length max is 256
Expand Down
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