keeping old logic for API < 28

Author: somalaya

common/src/main/java/com/microsoft/identity/common/crypto/AndroidWrappedKeyLoader.java

@@ -273,50 +273,61 @@ public void deleteSecretKeyFromStorage() throws ClientException {
     /**
      * Generate a self-signed cert and derive an AlgorithmParameterSpec from that.
      * This is for the key to be generated in {@link KeyStore} via {@link KeyPairGenerator}
+     * Note : This is now only for API level < 28
      *
      * @param context an Android {@link Context} object.
      * @return a {@link AlgorithmParameterSpec} for the keystore key (that we'll use to wrap the secret key).
      */
-//    @RequiresApi(api = Build.VERSION_CODES.JELLY_BEAN_MR2)
-//    private static AlgorithmParameterSpec getLegacySpecForKeyStoreKey(@NonNull final Context context,
-//                                                                @NonNull final String alias) {
-//        // Generate a self-signed cert.
-//        final String certInfo = String.format(Locale.ROOT, "CN=%s, OU=%s",
-//                alias,
-//                context.getPackageName());
-//
-//        final Calendar start = Calendar.getInstance();
-//        final Calendar end = Calendar.getInstance();
-//        final int certValidYears = 100;
-//        end.add(Calendar.YEAR, certValidYears);
-//
-//        return new KeyPairGeneratorSpec.Builder(context)
-//                .setAlias(alias)
-//                .setSubject(new X500Principal(certInfo))
-//                .setSerialNumber(BigInteger.ONE)
-//                .setStartDate(start.getTime())
-//                .setEndDate(end.getTime())
-//                .build();
-//    }
-
-
-    private static AlgorithmParameterSpec getSpecForKeyStoreKey(@NonNull final Context context, @NonNull final String alias) {
+    @RequiresApi(api = Build.VERSION_CODES.JELLY_BEAN_MR2)
+    private static AlgorithmParameterSpec getLegacySpecForKeyStoreKey(@NonNull final Context context,
+                                                                @NonNull final String alias) {
         // Generate a self-signed cert.
         final String certInfo = String.format(Locale.ROOT, "CN=%s, OU=%s",
                 alias,
                 context.getPackageName());
+
+        final Calendar start = Calendar.getInstance();
+        final Calendar end = Calendar.getInstance();
         final int certValidYears = 100;
-        return new KeyGenParameterSpec.Builder(alias, KeyProperties.PURPOSE_WRAP_KEY | KeyProperties.PURPOSE_ENCRYPT | KeyProperties.PURPOSE_DECRYPT)
-                .setCertificateSubject(new X500Principal(certInfo))
-                .setCertificateSerialNumber(BigInteger.ONE)
-                .setCertificateNotBefore(new Date())
-                .setCertificateNotAfter(new Date(System.currentTimeMillis() + TimeUnit.DAYS.toMillis(365 * certValidYears)))
-                .setKeySize(2048)
-                .setDigests(KeyProperties.DIGEST_SHA256, KeyProperties.DIGEST_SHA512)
-                .setEncryptionPaddings(KeyProperties.ENCRYPTION_PADDING_RSA_PKCS1)
+        end.add(Calendar.YEAR, certValidYears);
+
+        return new KeyPairGeneratorSpec.Builder(context)
+                .setAlias(alias)
+                .setSubject(new X500Principal(certInfo))
+                .setSerialNumber(BigInteger.ONE)
+                .setStartDate(start.getTime())
+                .setEndDate(end.getTime())
                 .build();
     }
 
+    /**
+     * Generate a self-signed cert and derive an AlgorithmParameterSpec from that.
+     * This is for the key to be generated in {@link KeyStore} via {@link KeyPairGenerator}
+     *
+     * @param context an Android {@link Context} object.
+     * @return a {@link AlgorithmParameterSpec} for the keystore key (that we'll use to wrap the secret key).
+     */
+    private static AlgorithmParameterSpec getSpecForKeyStoreKey(@NonNull final Context context, @NonNull final String alias) {
+        if (Build.VERSION.SDK_INT < Build.VERSION_CODES.P) {
+            return getLegacySpecForKeyStoreKey(context, alias);
+        } else {
+            final String certInfo = String.format(Locale.ROOT, "CN=%s, OU=%s",
+                    alias,
+                    context.getPackageName());
+            final int certValidYears = 100;
+            int purposes = KeyProperties.PURPOSE_WRAP_KEY | KeyProperties.PURPOSE_ENCRYPT | KeyProperties.PURPOSE_DECRYPT;
+            return new KeyGenParameterSpec.Builder(alias, purposes)
+                    .setCertificateSubject(new X500Principal(certInfo))
+                    .setCertificateSerialNumber(BigInteger.ONE)
+                    .setCertificateNotBefore(new Date())
+                    .setCertificateNotAfter(new Date(System.currentTimeMillis() + TimeUnit.DAYS.toMillis(365 * certValidYears)))
+                    .setKeySize(2048)
+                    .setDigests(KeyProperties.DIGEST_SHA256, KeyProperties.DIGEST_SHA512)
+                    .setEncryptionPaddings(KeyProperties.ENCRYPTION_PADDING_RSA_PKCS1)
+                    .build();
+        }
+    }
+
     /**
      * Get the file that stores the wrapped key.
      */