Type error: substr() expects parameter 2 to be integer, boolean given

[WouterFlorijn]

When using the decryptedAttribute function on an encrypted value, I get the following error:

Symfony\Component\Debug\Exception\FatalThrowableError : Type error: substr() expects parameter 2 to be integer, boolean given

at C:\wamp\www\lifestream\vendor\austinheap\laravel-database-encryption\src\Traits\HasEncryptedAttributes.php: 171

I am encrypting/decrypting data from a migration to ensure that existing data will still work.

My migration looks like this:

class EncryptData extends Migration
{
    public function up()
    {
        $this->encryptModels(SomeModel::all());
    }

    public function down()
    {
        $this->decryptModels(SomeModel::all());
    }

    private function encryptModels($models)
    {
        foreach ($models as $model)
        {
            if (!property_exists($model, 'encrypted'))
                return;
            foreach ($model->encrypted as $key)
            {
                $value = $model->getAttributeRaw($key);
                $value = $model->encryptedAttribute($value);
                $model->setAttributeRaw($key, $value);
                $model->save();
            }
        }
    }

    private function decryptModels($models)
    {
        foreach ($models as $model)
        {
            if (!property_exists($model, 'encrypted'))
                return;
            foreach ($model->encrypted as $key)
            {
                $value = $model->getAttributeRaw($key);
                $value = $model->decryptedAttribute($value);
                $model->setAttributeRaw($key, $value);
                $model->save();
            }
        }
    }
}

The encryption part works fine, but rolling back the migration throws the exception. Also, the encrypted values look like this:

��__LARAVEL-DATABASE-ENCRYPTED-VERSION-00-01-00__��version�VERSION-00-01-00��type�string[native]��eyJpdiI6IjJEYTJuRkdMeTFTQ1pCNXRCanNvUUE9PSIsInZhbHVlIjoiYlo0d2NIOFwvd1BtNER6OUZIOUpIWGc9PSIsIm1hYyI6IjQ5Mzk2OTNlNTAyZGI1NmJkMmUyZjQyNDZlZWYwYTMzYjM3MzRhOTU2NzAzMDc0OGI1Y2Y4ZjczZTk2ZDdhNjQifQ==

Are the �� characters supposed to look like this?

[austinheap]

Hey @WouterFlorijn --

Are the �� characters supposed to look like this?

Yes, they are character codes used to identify the header and it's various key/value pairs. Do the models function normally when you enable encryption? I.e.: do they encrypt/decrypt automatically to the database correctly? Those headers should never be visible to the model, as they're stripped off before actual cryptographic operations.

It's important to note: all calls to decryptedAttribute($value) must have the header present in the $value argument. Without the header it doesn't know what it's looking at. Based on your error (substr() expects parameter 2 to be integer, boolean given), it seems it's not able to find/parse the header.

[WouterFlorijn]

@austinheap I found out I was decrypting the data twice. I made my own method to get the raw encrypted string, but it didn't work and returned the decrypted string. Then I tried to decrypt that, which obviously failed.

Perhaps a good idea to throw a clear exception like Encryption header missing. instead of something obscure like the error I got. But other than that it's working fine.

[austinheap]

@WouterFlorijn Just pushed a commit that'll throw DecryptException if the header is missing:

laravel-database-encryption/src/Traits/HasEncryptedAttributes.php

Line 173 in b5f9b05

throw_if(! array_key_exists('stop', $characters), DecryptException::class, 'Cannot decrypt model attribute not originally encrypted by this package!');

laravel-database-encryption/src/Traits/HasEncryptedAttributes.php

Line 177 in b5f9b05

throw_if($offset === false, DecryptException::class, 'Cannot decrypt model attribute with no package header!');

Re: migration issues: take a look at src/Console/Commands/MigrateEncryptionCommand.php -- it's heavily unit tested so you should be able to lift any migration logic you need from that.