VARCHAR truncated to 25 characters when saved through model

Question

Given mysql column is created under a table after extension installation. As mentioned, the size of VARCHAR column is 100.

$table_config->addColumn(
'value',
Varien_Db_Ddl_Table::TYPE_VARCHAR,
100,
array(
    'nullable' => false,
)

);

But when I try to save a created API key through model->save() method. The string gets truncated to 25 characters only.

$key = hash('sha256', 'mm_'.rand());
/save API Key in the configure page
    Mage::getModel('mm_sync/config')->setData(array(
            'name'  => 'api/key',
            'value' => $key,
        ))
        ->save();

The same value in the table:

+-----------+---------+--------------------------+
| config_id | name    | value                    |
+-----------+---------+--------------------------+
|         1 | api/key | 91XVVbiUBMDt40jZgKA51g== |

Any clue ?

Answer 1

Let's take them step by step

$key = hash('sha256', 'mm_'.rand());

this line is useless, because the value of $key is overwritten on the line below:

$key = substr(Mage::helper('core')->encrypt('mm_'.rand()), 0, 49);

this means that $key will contain the first 49 chars of the result of: Mage::helper('core')->encrypt('mm_'.rand());

If you look int the method Mage_Core_Helper_Data::encrypt you will see something like this:

public function encrypt($data)
{
    if (!Mage::isInstalled()) {
        return $data;
    }
    return $this->getEncryptor()->encrypt($data);
}

Assuming you are on community edition $this->getEncryptor()->encrypt($data) translates to Mage_Core_Model_Encryption::encrypt($data). This method looks like this:

public function encrypt($data)
{
    return base64_encode($this->_getCrypt()->encrypt((string)$data));
}

this means you should end up with a base64 encoded string. And the one you posted looks like one to me. the length of the generated string can be anything.