tor-browser

commit 2a597f21c28345e274cc9ace5e52d73539a7fb9c
parent 50ae8c38460620f59bc33d4f596dc44af742f6be
Author: Tom Ritter <tom@mozilla.com>
Date:   Fri, 19 Dec 2025 14:47:58 +0000

Bug 2005273: Add additional known canvas fingerprinting text and aliases r=timhuang

Differential Revision: https://phabricator.services.mozilla.com/D276877

Diffstat:
M
dom/canvas/CanvasRenderingContext2D.cpp
 | 
18
++++++++++++------
M
toolkit/components/resistfingerprinting/nsRFPService.cpp
 | 
14
++++++++------
M
toolkit/components/resistfingerprinting/nsRFPService.h
 | 
8
++++++--

3 files changed, 26 insertions(+), 14 deletions(-)
diff --git a/dom/canvas/CanvasRenderingContext2D.cpp b/dom/canvas/CanvasRenderingContext2D.cpp
@@ -4583,16 +4583,14 @@ void CanvasRenderingContext2D::FillText(const nsAString& aText, double aX,
   if (mFillTextCalls <= 5) {
     if (aText == u"Cwm fjordbank glyphs vext quiz, 😃"_ns) {
       mFeatureUsage |= CanvasFeatureUsage::KnownText_1;
-    } else if (aText == u"Cwm fjordbank gly 😃"_ns) {
-      mFeatureUsage |= CanvasFeatureUsage::KnownText_1;
     } else if (StringBeginsWith(aText, u"Hel$&?6%"_ns)) {
-      mFeatureUsage |= CanvasFeatureUsage::KnownText_2;
+      mFeatureUsage |= CanvasFeatureUsage::KnownText_2;  // Imperva
     } else if (StringBeginsWith(aText, u"<@nv45. "_ns)) {
       mFeatureUsage |= CanvasFeatureUsage::KnownText_3;
     } else if (aText == u"Cañvas FP 😎 12345"_ns) {
       mFeatureUsage |= CanvasFeatureUsage::KnownText_4;
     } else if (StringBeginsWith(aText, u"❤️🤪🎉👋"_ns)) {
-      mFeatureUsage |= CanvasFeatureUsage::KnownText_5;
+      mFeatureUsage |= CanvasFeatureUsage::KnownText_5;  // hCaptcha
     } else if (aText == u"SomeCanvasFingerPrint.65@345876"_ns) {
       mFeatureUsage |= CanvasFeatureUsage::KnownText_6;
     } else if (aText == u"Browser,Signal <canvas> 2.0"_ns) {
@@ -4606,9 +4604,9 @@ void CanvasRenderingContext2D::FillText(const nsAString& aText, double aX,
     } else if (aText == u"g"_ns) {
       mFeatureUsage |= CanvasFeatureUsage::KnownText_11;
     } else if (aText == u"Soft Ruddy Foothold 2"_ns) {
-      mFeatureUsage |= CanvasFeatureUsage::KnownText_12;
+      mFeatureUsage |= CanvasFeatureUsage::KnownText_12;  // Akamai
     } else if (aText == u"!H71JCaj)]# 1@#"_ns) {
-      mFeatureUsage |= CanvasFeatureUsage::KnownText_13;
+      mFeatureUsage |= CanvasFeatureUsage::KnownText_13;  // Akamai
     } else if (aText == u"oubrg5h56e@!$3t4"_ns) {
       mFeatureUsage |= CanvasFeatureUsage::KnownText_14;
     } else if (aText == u"Cwm fjordbank glyphs vext quiz,"_ns) {
@@ -4631,6 +4629,14 @@ void CanvasRenderingContext2D::FillText(const nsAString& aText, double aX,
       mFeatureUsage |= CanvasFeatureUsage::KnownText_23;
     } else if (aText == u"<@nv45. F1n63r,Pr1n71n6!"_ns) {
       mFeatureUsage |= CanvasFeatureUsage::KnownText_24;
+    } else if (aText == u"Cwm fjordbank gly 😃"_ns) {
+      mFeatureUsage |= CanvasFeatureUsage::KnownText_25;
+    } else if (aText == u"clientgear.com <canvas> 1.0") {
+      mFeatureUsage |= CanvasFeatureUsage::KnownText_26;
+    } else if (aText == u"iO0A🤣💩") {
+      mFeatureUsage |= CanvasFeatureUsage::KnownText_27;
+    } else if (aText == u"Ry"_ns) {
+      mFeatureUsage |= CanvasFeatureUsage::KnownText_28;
     }
   }
   mFillTextCalls++;
diff --git a/toolkit/components/resistfingerprinting/nsRFPService.cpp b/toolkit/components/resistfingerprinting/nsRFPService.cpp
@@ -2006,10 +2006,14 @@ static const char* CanvasFingerprinterToString(
       return "Ozoki";
     case CanvasFingerprinterAlias::ePerimeterX:
       return "PerimeterX";
+    case CanvasFingerprinterAlias::eClientGear:
+      return "ClientGear";
     case CanvasFingerprinterAlias::eSignifyd:
       return "Signifyd";
     case CanvasFingerprinterAlias::eClaydar:
       return "Claydar";
+    case CanvasFingerprinterAlias::eImperva:
+      return "Imperva";
     case CanvasFingerprinterAlias::eForter:
       return "Forter";
     case CanvasFingerprinterAlias::eVariant1:
@@ -2482,6 +2486,10 @@ static void MaybeCurrentCaller(nsACString& aFilename, uint32_t& aLineNum,
     fingerprinter = CanvasFingerprinterAlias::eClaydar;
   } else if (accumulatedFeatureUsage & CanvasFeatureUsage::KnownText_23) {
     fingerprinter = CanvasFingerprinterAlias::eForter;
+  } else if (accumulatedFeatureUsage & CanvasFeatureUsage::KnownText_2) {
+    fingerprinter = CanvasFingerprinterAlias::eImperva;
+  } else if (accumulatedFeatureUsage & CanvasFeatureUsage::KnownText_26) {
+    fingerprinter = CanvasFingerprinterAlias::eClientGear;
   } else if (seenExtracted2D_250x80 &&
              accumulatedFeatureUsage & CanvasFeatureUsage::KnownText_6) {
     fingerprinter = CanvasFingerprinterAlias::eVariant5;
@@ -2494,12 +2502,6 @@ static void MaybeCurrentCaller(nsACString& aFilename, uint32_t& aLineNum,
     fingerprinter = CanvasFingerprinterAlias::eVariant1;
   } else if (extractedWebGL > 0 && extracted2D > 1 && seenExtracted2D_860x6) {
     fingerprinter = CanvasFingerprinterAlias::eVariant2;
-  } else if (extracted2D > 0 &&
-             (accumulatedFeatureUsage & CanvasFeatureUsage::SetFont) &&
-             (accumulatedFeatureUsage &
-              (CanvasFeatureUsage::FillRect | CanvasFeatureUsage::LineTo |
-               CanvasFeatureUsage::Stroke))) {
-    fingerprinter = CanvasFingerprinterAlias::eVariant4;
   }
 
   nsAutoCString uri(aURI);
diff --git a/toolkit/components/resistfingerprinting/nsRFPService.h b/toolkit/components/resistfingerprinting/nsRFPService.h
@@ -228,7 +228,8 @@ enum CanvasFingerprinterAlias {
   eSignifyd = 5,
   eClaydar = 6,
   eForter = 7,
-  // Unknown but distinct types of fingerprinters
+
+  // Variants are unknown but distinct types of fingerprinters
   eVariant1 = 8,
   eVariant2 = 9,
   eVariant3 = 10,
@@ -237,7 +238,10 @@ enum CanvasFingerprinterAlias {
   eVariant6 = 13,
   eVariant7 = 14,
   eVariant8 = 15,
-  eLastAlias = eVariant8
+
+  eClientGear = 16,
+  eImperva = 17,
+  eLastAlias = eImperva
 };
 
 enum CanvasExtractionAPI : uint8_t {