Relax colorspace checks in CPDF_DIBSource::CreateDecoder().chromium/2917

Previously the log just made sure the colorspace and the image have
exact matches for the number of colorspace components. Now, for some
colorspace types, check the type and make sure the number of
components meets or exceeds what is required by the spec.

Also do some refactoring.

BUG=chromium:650230

Review-Url: https://codereview.chromium.org/2486123002

1 files changed, 66 insertions, 30 deletions

diff --git a/core/fpdfapi/render/fpdf_render_loadimage.cpp b/core/fpdfapi/render/fpdf_render_loadimage.cpp
index c3fe99018c..118f7849a9 100644
--- a/core/fpdfapi/render/fpdf_render_loadimage.cpp
+++ b/core/fpdfapi/render/fpdf_render_loadimage.cpp
@@ -58,6 +58,10 @@ bool IsAllowedBPCValue(int bpc) {
   return bpc == 1 || bpc == 2 || bpc == 4 || bpc == 8 || bpc == 16;
 }
 
+bool IsAllowedICCComponents(int nComp) {
+  return nComp == 1 || nComp == 3 || nComp == 4;
+}
+
 template <typename T>
 T ClampValue(T value, T max_value) {
   value = std::min(value, max_value);
@@ -536,18 +540,43 @@ CCodec_ScanlineDecoder* FPDFAPI_CreateFlateDecoder(
 
 int CPDF_DIBSource::CreateDecoder() {
   const CFX_ByteString& decoder = m_pStreamAcc->GetImageDecoder();
-  if (decoder.IsEmpty()) {
+  if (decoder.IsEmpty())
     return 1;
-  }
-  if (m_bDoBpcCheck && m_bpc == 0) {
+
+  if (m_bDoBpcCheck && m_bpc == 0)
     return 0;
+
+  if (decoder == "JPXDecode") {
+    LoadJpxBitmap();
+    return m_pCachedBitmap ? 1 : 0;
+  }
+  if (decoder == "JBIG2Decode") {
+    m_pCachedBitmap = pdfium::MakeUnique<CFX_DIBitmap>();
+    if (!m_pCachedBitmap->Create(
+            m_Width, m_Height, m_bImageMask ? FXDIB_1bppMask : FXDIB_1bppRgb)) {
+      m_pCachedBitmap.reset();
+      return 0;
+    }
+    m_Status = 1;
+    return 2;
   }
+
   const uint8_t* src_data = m_pStreamAcc->GetData();
   uint32_t src_size = m_pStreamAcc->GetSize();
   const CPDF_Dictionary* pParams = m_pStreamAcc->GetImageParam();
   if (decoder == "CCITTFaxDecode") {
     m_pDecoder.reset(FPDFAPI_CreateFaxDecoder(src_data, src_size, m_Width,
                                               m_Height, pParams));
+  } else if (decoder == "FlateDecode") {
+    m_pDecoder.reset(FPDFAPI_CreateFlateDecoder(
+        src_data, src_size, m_Width, m_Height, m_nComponents, m_bpc, pParams));
+  } else if (decoder == "RunLengthDecode") {
+    m_pDecoder.reset(CPDF_ModuleMgr::Get()
+                         ->GetCodecModule()
+                         ->GetBasicModule()
+                         ->CreateRunLengthDecoder(src_data, src_size, m_Width,
+                                                  m_Height, m_nComponents,
+                                                  m_bpc));
   } else if (decoder == "DCTDecode") {
     m_pDecoder.reset(CPDF_ModuleMgr::Get()->GetJpegModule()->CreateDecoder(
         src_data, src_size, m_Width, m_Height, m_nComponents,
@@ -563,12 +592,41 @@ int CPDF_DIBSource::CreateDecoder() {
           FX_Free(m_pCompData);
           m_pCompData = nullptr;
           m_nComponents = static_cast<uint32_t>(comps);
-          if (m_pColorSpace &&
-              m_pColorSpace->CountComponents() != m_nComponents) {
-            return 0;
+          if (m_pColorSpace) {
+            switch (m_Family) {
+              case PDFCS_DEVICEGRAY:
+              case PDFCS_DEVICERGB:
+              case PDFCS_DEVICECMYK: {
+                uint32_t dwMinComps = ComponentsForFamily(m_Family);
+                if (m_pColorSpace->CountComponents() < dwMinComps ||
+                    m_nComponents < dwMinComps) {
+                  return 0;
+                }
+                break;
+              }
+              case PDFCS_LAB: {
+                if (m_nComponents != 3 || m_pColorSpace->CountComponents() < 3)
+                  return 0;
+                break;
+              }
+              case PDFCS_ICCBASED: {
+                if (!IsAllowedICCComponents(m_nComponents) ||
+                    !IsAllowedICCComponents(m_pColorSpace->CountComponents()) ||
+                    m_pColorSpace->CountComponents() < m_nComponents) {
+                  return 0;
+                }
+                break;
+              }
+              default: {
+                if (m_pColorSpace->CountComponents() != m_nComponents)
+                  return 0;
+                break;
+              }
+            }
+          } else {
+            if (m_Family == PDFCS_LAB && m_nComponents != 3)
+              return 0;
           }
-          if (m_Family == PDFCS_LAB && m_nComponents != 3)
-            return 0;
           m_pCompData = GetDecodeAndMaskArray(m_bDefaultDecode, m_bColorKey);
           if (!m_pCompData)
             return 0;
@@ -578,28 +636,6 @@ int CPDF_DIBSource::CreateDecoder() {
             src_data, src_size, m_Width, m_Height, m_nComponents, bTransform));
       }
     }
-  } else if (decoder == "FlateDecode") {
-    m_pDecoder.reset(FPDFAPI_CreateFlateDecoder(
-        src_data, src_size, m_Width, m_Height, m_nComponents, m_bpc, pParams));
-  } else if (decoder == "JPXDecode") {
-    LoadJpxBitmap();
-    return m_pCachedBitmap ? 1 : 0;
-  } else if (decoder == "JBIG2Decode") {
-    m_pCachedBitmap.reset(new CFX_DIBitmap);
-    if (!m_pCachedBitmap->Create(
-            m_Width, m_Height, m_bImageMask ? FXDIB_1bppMask : FXDIB_1bppRgb)) {
-      m_pCachedBitmap.reset();
-      return 0;
-    }
-    m_Status = 1;
-    return 2;
-  } else if (decoder == "RunLengthDecode") {
-    m_pDecoder.reset(CPDF_ModuleMgr::Get()
-                         ->GetCodecModule()
-                         ->GetBasicModule()
-                         ->CreateRunLengthDecoder(src_data, src_size, m_Width,
-                                                  m_Height, m_nComponents,
-                                                  m_bpc));
   }
   if (!m_pDecoder)
     return 0;