fix: Redact Authorization header before sending events to Sentry

CHANGELOG.md

@@ -2,9 +2,14 @@
 
 ## Unreleased
 
+### Fixes
+
+- Redact Authorization headers before sending events to Sentry ([#4164](https://github.com/getsentry/sentry-dotnet/pull/4164))
+
 ### Features
 
 - New source generator allows Sentry to see true build variables like PublishAot and PublishTrimmed to properly adapt checks in the Sentry SDK ([#4101](https://github.com/getsentry/sentry-dotnet/pull/4101))
+
 ### Dependencies
 
 - Bump CLI from v2.43.1 to v2.44.0 ([#4169](https://github.com/getsentry/sentry-dotnet/pull/4169))

src/Sentry.AspNet/Internal/SystemWebRequestEventProcessor.cs

@@ -1,4 +1,5 @@
 using Sentry.Extensibility;
+using Sentry.Internal;
 using Sentry.Reflection;
 
 namespace Sentry.AspNet.Internal;
@@ -54,12 +55,12 @@ public SystemWebRequestEventProcessor(IRequestPayloadExtractor payloadExtractor,
 
         foreach (var key in context.Request.Headers.AllKeys)
         {
-            if (!_options.SendDefaultPii
-                // Don't add headers which might contain PII
-                && key is "Cookie" or "Authorization")
+            // Don't add cookies that might contain PII
+            if (!_options.SendDefaultPii && key is "Cookie")
             {
                 continue;
             }
+
             @event.Request.Headers[key] = context.Request.Headers[key];
         }
 

src/Sentry.AspNetCore/ScopeExtensions.cs

@@ -4,6 +4,7 @@
 using Microsoft.Net.Http.Headers;
 using Sentry.AspNetCore.Extensions;
 using Sentry.Extensibility;
+using Sentry.Internal;
 using Sentry.Internal.Extensions;
 
 namespace Sentry.AspNetCore;
@@ -135,10 +136,8 @@ private static void SetEnv(Scope scope, HttpContext context, SentryAspNetCoreOpt
         scope.Request.QueryString = context.Request.QueryString.ToString();
         foreach (var requestHeader in context.Request.Headers)
         {
-            if (!options.SendDefaultPii
-                // Don't add headers which might contain PII
-                && (requestHeader.Key == HeaderNames.Cookie
-                    || requestHeader.Key == HeaderNames.Authorization))
+            // Don't add cookies that might contain PII
+            if (!options.SendDefaultPii && requestHeader.Key == HeaderNames.Cookie)
             {
                 continue;
             }

src/Sentry/HttpHeadersExtensions.cs

@@ -1,3 +1,6 @@
+using Sentry.Internal;
+using Sentry.Internal.Extensions;
+
 namespace Sentry;
 
 internal static class HttpHeadersExtensions
@@ -6,4 +9,14 @@ internal static string GetCookies(this HttpHeaders headers) =>
         headers.TryGetValues("Cookie", out var values)
             ? string.Join("; ", values)
             : string.Empty;
+
+    internal static RedactedHeaders? ToRedactedHeaders(this Dictionary<string, string?>? headers)
+    {
+        var items = headers?.WhereNotNullValue();
+        if (items is null || !items.Any())
+        {
+            return null;
+        }
+        return headers!;
+    }
 }

src/Sentry/Internal/RedactedHeaders.cs

@@ -0,0 +1,53 @@
+using Sentry.Internal.Extensions;
+
+namespace Sentry.Internal;
+
+internal class RedactedHeaders : IDictionary<string, string>
+{
+    private static readonly string[] SensitiveKeys = ["Authorization", "Proxy-Authorization"];
+
+    private readonly Dictionary<string, string> _inner = new(StringComparer.OrdinalIgnoreCase);
+
+    private static string Redact(string key, string value) =>
+        SensitiveKeys.Contains(key, StringComparer.OrdinalIgnoreCase) ? "[Filtered]" : value;
+
+    public string this[string key]
+    {
+        get => _inner[key];
+        set => _inner[key] = Redact(key, value);
+    }
+
+    public void Add(string key, string value) => _inner.Add(key, Redact(key, value));
+
+    // Delegate rest to _inner
+    public bool ContainsKey(string key) => _inner.ContainsKey(key);
+    public bool Remove(string key) => _inner.Remove(key);
+#if NET8_0_OR_GREATER
+    public bool TryGetValue(string key, [MaybeNullWhen(false)] out string value) => _inner.TryGetValue(key, out value);
+#else
+    public bool TryGetValue(string key, out string value) => _inner.TryGetValue(key, out value);
+#endif
+    public ICollection<string> Keys => _inner.Keys;
+    public ICollection<string> Values => _inner.Values;
+    public int Count => _inner.Count;
+    public bool IsReadOnly => false;
+
+    public void Add(KeyValuePair<string, string> item) => Add(item.Key, item.Value);
+    public void Clear() => _inner.Clear();
+    public bool Contains(KeyValuePair<string, string> item) => _inner.Contains(item);
+    public void CopyTo(KeyValuePair<string, string>[] array, int arrayIndex) =>
+        ((IDictionary<string, string>)_inner).CopyTo(array, arrayIndex);
+    public bool Remove(KeyValuePair<string, string> item) => _inner.Remove(item.Key);
+    public IEnumerator<KeyValuePair<string, string>> GetEnumerator() => _inner.GetEnumerator();
+    IEnumerator IEnumerable.GetEnumerator() => _inner.GetEnumerator();
+
+    public static implicit operator RedactedHeaders(Dictionary<string, string> source)
+    {
+        var result = new RedactedHeaders();
+        foreach (var kvp in source)
+        {
+            result[kvp.Key] = kvp.Value; // This will sanitize
+        }
+        return result;
+    }
+}

src/Sentry/Protocol/Response.cs

@@ -30,7 +30,7 @@ public sealed class Response : ISentryJsonSerializable, ICloneable<Response>, IU
     /// </summary>
     public const string Type = "response";
 
-    internal Dictionary<string, string>? InternalHeaders { get; private set; }
+    internal RedactedHeaders? InternalHeaders { get; private set; }
 
     /// <summary>
     /// Gets or sets the HTTP response body size.
@@ -57,7 +57,7 @@ public sealed class Response : ISentryJsonSerializable, ICloneable<Response>, IU
     /// <remarks>
     /// If a header appears multiple times it needs to be merged according to the HTTP standard for header merging.
     /// </remarks>
-    public IDictionary<string, string> Headers => InternalHeaders ??= new Dictionary<string, string>();
+    public IDictionary<string, string> Headers => InternalHeaders ??= new();
 
     /// <summary>
     /// Gets or sets the HTTP Status response code
@@ -69,10 +69,13 @@ internal void AddHeaders(IEnumerable<KeyValuePair<string, IEnumerable<string>>>
     {
         foreach (var header in headers)
         {
-            Headers.Add(
-                header.Key,
-                string.Join("; ", header.Value)
-            );
+            // Always redact the Authorization header
+            if (header.Key.Equals("Authorization", StringComparison.OrdinalIgnoreCase))
+            {
+                Headers.Add(header.Key, PiiExtensions.RedactedText);
+                continue;
+            }
+            Headers.Add(header.Key, string.Join("; ", header.Value));
         }
     }
 
@@ -144,7 +147,7 @@ public static Response FromJson(JsonElement json)
             BodySize = bodySize,
             Cookies = cookies,
             Data = data,
-            InternalHeaders = headers?.WhereNotNullValue().ToDict(),
+            InternalHeaders = headers.ToRedactedHeaders(),
             StatusCode = statusCode
         };
     }

src/Sentry/SentryRequest.cs

@@ -1,4 +1,5 @@
 using Sentry.Extensibility;
+using Sentry.Internal;
 using Sentry.Internal.Extensions;
 
 namespace Sentry;
@@ -31,7 +32,7 @@ public sealed class SentryRequest : ISentryJsonSerializable
 
     internal Dictionary<string, string>? InternalOther { get; private set; }
 
-    internal Dictionary<string, string>? InternalHeaders { get; private set; }
+    internal RedactedHeaders? InternalHeaders { get; private set; }
 
     /// <summary>
     /// Gets or sets the full request URL, if available.
@@ -81,7 +82,7 @@ public sealed class SentryRequest : ISentryJsonSerializable
     /// If a header appears multiple times it needs to be merged according to the HTTP standard for header merging.
     /// </remarks>
     /// <value>The headers.</value>
-    public IDictionary<string, string> Headers => InternalHeaders ??= new Dictionary<string, string>();
+    public IDictionary<string, string> Headers => InternalHeaders ??= new();
 
     /// <summary>
     /// Gets or sets the optional environment data.
@@ -102,6 +103,12 @@ internal void AddHeaders(IEnumerable<KeyValuePair<string, IEnumerable<string>>>
     {
         foreach (var header in headers)
         {
+            // Always redact the Authorization header
+            if (header.Key.Equals("Authorization", StringComparison.OrdinalIgnoreCase))
+            {
+                Headers.Add(header.Key, PiiExtensions.RedactedText);
+                continue;
+            }
             Headers.Add(header.Key, string.Join("; ", header.Value));
         }
     }
@@ -176,7 +183,7 @@ public static SentryRequest FromJson(JsonElement json)
         {
             InternalEnv = env?.WhereNotNullValue().ToDict(),
             InternalOther = other?.WhereNotNullValue().ToDict(),
-            InternalHeaders = headers?.WhereNotNullValue().ToDict(),
+            InternalHeaders = headers.ToRedactedHeaders(),
             Url = url,
             Method = method,
             Data = data,

test/Sentry.Tests/Internals/RedactedHeadersTests.cs

@@ -0,0 +1,118 @@
+namespace Sentry.Tests.Internals;
+
+public class RedactedHeadersTests
+{
+    [Fact]
+    public void Add_WithAuthorizationKey_ShouldStoreFilteredValue()
+    {
+        // Arrange
+        var headers = new RedactedHeaders();
+
+        // Act
+        headers.Add("Authorization", "Bearer 123");
+
+        // Assert
+        headers["Authorization"].Should().Be("[Filtered]");
+    }
+
+    [Fact]
+    public void IndexerSet_WithAuthorizationKey_ShouldStoreFilteredValue()
+    {
+        // Arrange
+        var headers = new RedactedHeaders();
+
+        // Act
+        headers["Authorization"] = "Bearer 456";
+
+        // Assert
+        headers["Authorization"].Should().Be("[Filtered]");
+    }
+
+    [Fact]
+    public void Add_WithOtherKey_ShouldStoreOriginalValue()
+    {
+        // Arrange
+        var headers = new RedactedHeaders();
+
+        // Act
+        headers.Add("User-Agent", "TestAgent");
+
+        // Assert
+        headers["User-Agent"].Should().Be("TestAgent");
+    }
+
+    [Fact]
+    public void IndexerGet_WithMissingKey_ShouldThrowKeyNotFoundException()
+    {
+        // Arrange
+        var headers = new RedactedHeaders();
+
+        // Act
+        var act = () => _ = headers["Missing"];
+
+        // Assert
+        act.Should().Throw<KeyNotFoundException>();
+    }
+
+    [Fact]
+    public void TryGetValue_WithExistingKey_ShouldReturnTrueAndValue()
+    {
+        // Arrange
+        var headers = new RedactedHeaders
+        {
+            ["Authorization"] = "secret"
+        };
+
+        // Act
+        var success = headers.TryGetValue("Authorization", out var value);
+
+        // Assert
+        success.Should().BeTrue();
+        value.Should().Be("[Filtered]");
+    }
+
+    [Fact]
+    public void TryGetValue_WithMissingKey_ShouldReturnFalse()
+    {
+        // Arrange
+        var headers = new RedactedHeaders();
+
+        // Act
+        var success = headers.TryGetValue("Nonexistent", out var value);
+
+        // Assert
+        success.Should().BeFalse();
+        value.Should().BeNull(); // nullable context may allow this
+    }
+
+    [Fact]
+    public void ImplicitConversion_FromDictionary_ShouldRedactAuthorization()
+    {
+        // Arrange
+        var dict = new Dictionary<string, string>
+        {
+            { "Authorization", "Token xyz" },
+            { "Custom", "Value" }
+        };
+
+        // Act
+        RedactedHeaders headers = dict;
+
+        // Assert
+        headers["Authorization"].Should().Be("[Filtered]");
+        headers["Custom"].Should().Be("Value");
+    }
+
+    [Fact]
+    public void CaseInsensitiveKeyMatching_ShouldRedactAuthorization()
+    {
+        // Arrange
+        var headers = new RedactedHeaders();
+
+        // Act
+        headers.Add("authorization", "should be filtered");
+
+        // Assert
+        headers["AUTHORIZATION"].Should().Be("[Filtered]");
+    }
+}