diff --git a/libwvdrmengine/cdm/core/include/crypto_session.h b/libwvdrmengine/cdm/core/include/crypto_session.h
index 139bb466..b9a56391 100644
--- a/libwvdrmengine/cdm/core/include/crypto_session.h
+++ b/libwvdrmengine/cdm/core/include/crypto_session.h
@@ -325,14 +325,6 @@ class CryptoSession {
   CdmResponseType SelectKey(const std::string& key_id,
                             CdmCipherMode cipher_mode);
 
-  static const OEMCrypto_Algorithm kInvalidAlgorithm =
-      static_cast<OEMCrypto_Algorithm>(-1);
-
-  OEMCrypto_Algorithm GenericSigningAlgorithm(CdmSigningAlgorithm algorithm);
-  OEMCrypto_Algorithm GenericEncryptionAlgorithm(
-      CdmEncryptionAlgorithm algorithm);
-  size_t GenericEncryptionBlockSize(CdmEncryptionAlgorithm algorithm);
-
   // These methods fall back into each other in the order given, depending on
   // how much data they were given and how much data OEMCrypto can accept in one
   // call.
@@ -408,10 +400,6 @@ class CryptoSession {
 
   static bool IsInitialized();
 
-  // Constants
-  static const size_t kAes128BlockSize = 16;  // Block size for AES_CBC_128
-  static const size_t kSignatureSize = 32;    // size for HMAC-SHA256 signature
-
   // The locking methods above should be used in preference to taking these
   // mutexes directly. If code takes these manually and needs to take more
   // than one, it must *always* take them in the order they are defined here.
diff --git a/libwvdrmengine/cdm/core/src/crypto_session.cpp b/libwvdrmengine/cdm/core/src/crypto_session.cpp
index e5e468ac..21ad78a7 100644
--- a/libwvdrmengine/cdm/core/src/crypto_session.cpp
+++ b/libwvdrmengine/cdm/core/src/crypto_session.cpp
@@ -57,6 +57,7 @@ constexpr size_t MiB = 1024 * 1024;
 
 constexpr uint32_t kRsaSignatureLength = 256;
 constexpr size_t kEstimatedInitialUsageTableHeader = 40;
+const size_t kAes128BlockSize = 16;
 
 // Constants and utility objects relating to OEM Certificates
 constexpr const char* kWidevineSystemIdExtensionOid = "1.3.6.1.4.1.11129.4.1.1";
@@ -128,6 +129,36 @@ void AdvanceDestBuffer(OEMCrypto_DestBufferDesc* dest_buffer, size_t bytes) {
   LOGE("Unrecognized OEMCryptoBufferType %u - doing nothing",
        dest_buffer->type);
 }
+
+bool GetGenericSigningAlgorithm(CdmSigningAlgorithm algorithm,
+                                OEMCrypto_Algorithm* oec_algorithm) {
+  RETURN_IF_NULL(oec_algorithm, false);
+  if (kSigningAlgorithmHmacSha256 != algorithm) {
+    LOGW("Unrecognized signing algorithm: %d", algorithm);
+    return false;
+  }
+  *oec_algorithm = OEMCrypto_HMAC_SHA256;
+  return true;
+}
+
+bool GetGenericEncryptionAlgorithm(CdmEncryptionAlgorithm algorithm,
+                                   OEMCrypto_Algorithm* oec_algorithm) {
+  RETURN_IF_NULL(oec_algorithm, false);
+  if (kEncryptionAlgorithmAesCbc128 != algorithm) {
+    LOGW("Unrecognized encryption algorithm: %d", algorithm);
+    return false;
+  }
+  *oec_algorithm = OEMCrypto_AES_CBC_128_NO_PADDING;
+  return true;
+}
+
+size_t GenericEncryptionBlockSize(CdmEncryptionAlgorithm algorithm) {
+  if (kEncryptionAlgorithmAesCbc128 != algorithm) {
+    LOGW("Unrecognized encryption algorithm: %d", algorithm);
+    return 0;
+  }
+  return kAes128BlockSize;
+}
 }  // namespace
 
 shared_mutex CryptoSession::static_field_mutex_;
@@ -2121,9 +2152,9 @@ CdmResponseType CryptoSession::GenericEncrypt(const std::string& in_buffer,
   LOGV("Generic encrypt: id = %u", oec_session_id_);
   RETURN_IF_NULL(out_buffer, PARAMETER_NULL);
 
-  OEMCrypto_Algorithm oec_algorithm = GenericEncryptionAlgorithm(algorithm);
+  OEMCrypto_Algorithm oec_algorithm = OEMCrypto_AES_CBC_128_NO_PADDING;
   if (iv.size() != GenericEncryptionBlockSize(algorithm) ||
-      oec_algorithm == kInvalidAlgorithm) {
+      !GetGenericEncryptionAlgorithm(algorithm, &oec_algorithm)) {
     return INVALID_PARAMETERS_ENG_13;
   }
 
@@ -2182,9 +2213,9 @@ CdmResponseType CryptoSession::GenericDecrypt(const std::string& in_buffer,
   LOGV("Generic decrypt: id = %u", oec_session_id_);
   RETURN_IF_NULL(out_buffer, PARAMETER_NULL);
 
-  OEMCrypto_Algorithm oec_algorithm = GenericEncryptionAlgorithm(algorithm);
+  OEMCrypto_Algorithm oec_algorithm = OEMCrypto_AES_CBC_128_NO_PADDING;
   if (iv.size() != GenericEncryptionBlockSize(algorithm) ||
-      oec_algorithm == kInvalidAlgorithm) {
+      !GetGenericEncryptionAlgorithm(algorithm, &oec_algorithm)) {
     return INVALID_PARAMETERS_ENG_14;
   }
 
@@ -2242,8 +2273,8 @@ CdmResponseType CryptoSession::GenericSign(const std::string& message,
   LOGV("Generic sign: id = %u", oec_session_id_);
   RETURN_IF_NULL(signature, PARAMETER_NULL);
 
-  OEMCrypto_Algorithm oec_algorithm = GenericSigningAlgorithm(algorithm);
-  if (oec_algorithm == kInvalidAlgorithm) {
+  OEMCrypto_Algorithm oec_algorithm = OEMCrypto_HMAC_SHA256;
+  if (!GetGenericSigningAlgorithm(algorithm, &oec_algorithm)) {
     return INVALID_PARAMETERS_ENG_15;
   }
 
@@ -2308,8 +2339,8 @@ CdmResponseType CryptoSession::GenericVerify(const std::string& message,
                                              const std::string& signature) {
   LOGV("Generic verify: id = %u", oec_session_id_);
 
-  OEMCrypto_Algorithm oec_algorithm = GenericSigningAlgorithm(algorithm);
-  if (oec_algorithm == kInvalidAlgorithm) {
+  OEMCrypto_Algorithm oec_algorithm = OEMCrypto_HMAC_SHA256;
+  if (!GetGenericSigningAlgorithm(algorithm, &oec_algorithm)) {
     return INVALID_PARAMETERS_ENG_16;
   }
 
@@ -2660,33 +2691,6 @@ bool CryptoSession::GetAnalogOutputCapabilities(bool* can_support_output,
   return true;
 }
 
-OEMCrypto_Algorithm CryptoSession::GenericSigningAlgorithm(
-    CdmSigningAlgorithm algorithm) {
-  if (kSigningAlgorithmHmacSha256 == algorithm) {
-    return OEMCrypto_HMAC_SHA256;
-  } else {
-    return kInvalidAlgorithm;
-  }
-}
-
-OEMCrypto_Algorithm CryptoSession::GenericEncryptionAlgorithm(
-    CdmEncryptionAlgorithm algorithm) {
-  if (kEncryptionAlgorithmAesCbc128 == algorithm) {
-    return OEMCrypto_AES_CBC_128_NO_PADDING;
-  } else {
-    return kInvalidAlgorithm;
-  }
-}
-
-size_t CryptoSession::GenericEncryptionBlockSize(
-    CdmEncryptionAlgorithm algorithm) {
-  if (kEncryptionAlgorithmAesCbc128 == algorithm) {
-    return kAes128BlockSize;
-  } else {
-    return 0;
-  }
-}
-
 // OEMCryptoResult OEMCrypto_DecryptCENC(
 //     OEMCrypto_SESSION session,
 //     const OEMCrypto_SampleDescription* samples,  // an array of samples.