diff --git a/libwvdrmengine/cdm/core/include/crypto_session.h b/libwvdrmengine/cdm/core/include/crypto_session.h
index ee891692..80566042 100644
--- a/libwvdrmengine/cdm/core/include/crypto_session.h
+++ b/libwvdrmengine/cdm/core/include/crypto_session.h
@@ -89,7 +89,20 @@ class CryptoSession {
   virtual bool GetApiMinorVersion(SecurityLevel requested_level,
                                   uint32_t* minor_version);
 
+  // This method will return, for devices with a
+  // * keybox: the 32 byte device ID from the keybox.
+  // * OEM certificate:
+  //   - that implements |OEMCrypto_GetDeviceID|: the (1 to 64 byte) device ID.
+  //   - that does not implement |OEMCrypto_GetDeviceID|: the OEM public
+  //     certificate.
   virtual CdmResponseType GetInternalDeviceUniqueId(std::string* device_id);
+
+  // This method will return, for devices with a
+  // * keybox: the 32 byte device ID from the keybox.
+  // * OEM certificate:
+  //   - that implements |OEMCrypto_GetDeviceID|: the (1 to 64 byte) device ID.
+  //   - that does not implement |OEMCrypto_GetDeviceID|: the 32 byte hash
+  //     of the OEM public certificate.
   virtual CdmResponseType GetExternalDeviceUniqueId(std::string* device_id);
   virtual bool GetSystemId(uint32_t* system_id);
   virtual CdmResponseType GetProvisioningId(std::string* provisioning_id);
diff --git a/libwvdrmengine/cdm/test/request_license_test.cpp b/libwvdrmengine/cdm/test/request_license_test.cpp
index f49f4e02..8d78c804 100644
--- a/libwvdrmengine/cdm/test/request_license_test.cpp
+++ b/libwvdrmengine/cdm/test/request_license_test.cpp
@@ -4795,6 +4795,7 @@ TEST_F(WvCdmRequestLicenseTest, QueryStatus) {
             decryptor_->QueryStatus(kLevelDefault, wvcdm::QUERY_KEY_DEVICE_ID,
                                     &value));
   EXPECT_LT(0u, value.size());
+  EXPECT_LE(value.size(), 64u) << "device id size: " << value.size();
 
   EXPECT_EQ(wvcdm::NO_ERROR,
             decryptor_->QueryStatus(kLevelDefault, wvcdm::QUERY_KEY_SYSTEM_ID,
@@ -4808,8 +4809,8 @@ TEST_F(WvCdmRequestLicenseTest, QueryStatus) {
   EXPECT_EQ(wvcdm::NO_ERROR,
             decryptor_->QueryStatus(kLevelDefault,
                                     wvcdm::QUERY_KEY_PROVISIONING_ID, &value));
-  EXPECT_TRUE(16u == value.size() || 32u == value.size())
-      << "provisioning id size: " << value.size();
+  EXPECT_LT(0u, value.size());
+  EXPECT_LE(value.size(), 64u) << "provisioning id size: " << value.size();
 
   EXPECT_EQ(wvcdm::NO_ERROR,
             decryptor_->QueryStatus(
@@ -4942,6 +4943,7 @@ TEST_F(WvCdmRequestLicenseTest, QueryStatusL3) {
   EXPECT_EQ(wvcdm::NO_ERROR, decryptor_->QueryStatus(
                                  kLevel3, wvcdm::QUERY_KEY_DEVICE_ID, &value));
   EXPECT_LT(0u, value.size());
+  EXPECT_LE(value.size(), 64u) << "device id size: " << value.size();
 
   EXPECT_EQ(wvcdm::NO_ERROR,
             decryptor_->QueryStatus(kLevelDefault, wvcdm::QUERY_KEY_SYSTEM_ID,
@@ -4972,8 +4974,8 @@ TEST_F(WvCdmRequestLicenseTest, QueryStatusL3) {
   EXPECT_EQ(wvcdm::NO_ERROR,
             decryptor_->QueryStatus(kLevel3, wvcdm::QUERY_KEY_PROVISIONING_ID,
                                     &value));
-  EXPECT_TRUE(16u == value.size() || 32u == value.size())
-      << "provisioning id size: " << value.size();
+  EXPECT_LT(0u, value.size());
+  EXPECT_LE(value.size(), 64u) << "provisioning id size: " << value.size();
 
   EXPECT_EQ(wvcdm::NO_ERROR,
             decryptor_->QueryStatus(