Add end-to-end decryption test with vectors

Added a test_mode flag to the libwvdrmengine plugin
to support verifying decryption results.

Change-Id: I9edbd6279d54fc495b5bbad8273c179106cad474

libwvdrmengine/mediacrypto/Android.mk

@@ -7,6 +7,7 @@ LOCAL_SRC_FILES := \
 LOCAL_C_INCLUDES := \
   bionic \
   external/stlport/stlport \
+  external/openssl/include \
   frameworks/av/include \
   frameworks/native/include \
   vendor/widevine/libwvdrmengine/cdm/core/include \

libwvdrmengine/mediacrypto/include/WVCryptoPlugin.h

@@ -29,7 +29,8 @@ class WVCryptoPlugin : public android::CryptoPlugin {
   DISALLOW_EVIL_CONSTRUCTORS(WVCryptoPlugin);
 
   wvcdm::WvContentDecryptionModule* const mCDM;
-  const wvcdm::CdmSessionId mSessionId;
+  wvcdm::CdmSessionId mSessionId;
+  bool mTestMode;
 };
 
 } // namespace wvdrm

libwvdrmengine/mediacrypto/src/WVCryptoPlugin.cpp

@@ -10,9 +10,12 @@
 
 #include <string>
 #include <vector>
+#include <openssl/sha.h>
 
 #include "utils/Errors.h"
+#include "utils/String8.h"
 #include "wv_cdm_constants.h"
+#include "media/stagefright/MediaErrors.h"
 
 namespace wvdrm {
 
@@ -23,7 +26,14 @@ using namespace wvcdm;
 WVCryptoPlugin::WVCryptoPlugin(const void* data, size_t size,
                                WvContentDecryptionModule* cdm)
     : mCDM(cdm),
-      mSessionId(static_cast<const char*>(data), size) {}
+      mSessionId(static_cast<const char*>(data), size),
+      mTestMode(false) {
+  size_t index = mSessionId.find("test_mode");
+  if (index != string::npos) {
+    mSessionId = mSessionId.substr(0, index);
+    mTestMode = true;
+  }
+}
 
 bool WVCryptoPlugin::requiresSecureDecoderComponent(const char *mime) const {
   // TODO: Determine if we are using L1 or L3 and return an appropriate value.
@@ -100,6 +110,27 @@ ssize_t WVCryptoPlugin::decrypt(bool secure, const uint8_t key[KEY_ID_SIZE],
     }
   }
 
+  // In test mode, we return an error that causes a detailed error
+  // message string containing a SHA256 hash of the decrypted data
+  // to get passed to the java app via CryptoException.  The test app
+  // can then use the hash to verify that decryption was successful.
+
+  if (mTestMode) {
+      SHA256_CTX ctx;
+      uint8_t digest[SHA256_DIGEST_LENGTH];
+      SHA256_Init(&ctx);
+      SHA256_Update(&ctx, dstPtr, offset);
+      SHA256_Final(digest, &ctx);
+      String8 buf;
+      for (size_t i = 0; i < sizeof(digest); i++) {
+          buf.appendFormat("%02x", digest[i]);
+      }
+
+      *errorDetailMsg = AString(buf.string());
+      return ERROR_DRM_VENDOR_MIN;
+  }
+
+
   return static_cast<ssize_t>(offset);
 }