friendica/vendor/defuse/php-encryption/docs/classes/Key.md

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Class: Defuse\Crypto\Key
=========================
The `Key` class represents a secret key used for encrypting and decrypting. Once
you have a `Key` instance, you can use it with the `Crypto` class to encrypt and
decrypt strings and with the `File` class to encrypt and decrypt files.
Instance Methods
-----------------
### saveToAsciiSafeString()
**Description:**
Saves the encryption key to a string of printable ASCII characters, which can be
loaded again into a `Key` instance using `Key::loadFromAsciiSafeString()`.
**Parameters:**
This method does not take any parameters.
**Return value:**
Returns a string of printable ASCII characters representing this `Key` instance,
which can be loaded back into an instance of `Key` using
`Key::loadFromAsciiSafeString()`.
**Exceptions:**
- `Defuse\Crypto\Exception\EnvironmentIsBrokenException` is thrown either when
the platform the code is running on cannot safely perform encryption for some
reason (e.g. it lacks a secure random number generator), or the runtime tests
detected a bug in this library.
**Side-effects and performance:**
None.
**Cautions:**
This method currently returns a hexadecimal string. You should not rely on this
behavior. For example, it may be improved in the future to return a base64
string.
Static Methods
---------------
### Key::createNewRandomKey()
**Description:**
Generates a new random key and returns an instance of `Key`.
**Parameters:**
This method does not take any parameters.
**Return value:**
Returns an instance of `Key` containing a randomly-generated encryption key.
**Exceptions:**
- `Defuse\Crypto\Exception\EnvironmentIsBrokenException` is thrown either when
the platform the code is running on cannot safely perform encryption for some
reason (e.g. it lacks a secure random number generator), or the runtime tests
detected a bug in this library.
**Side-effects and performance:**
None.
**Cautions:**
None.
### Key::loadFromAsciiSafeString($saved\_key\_string, $do\_not\_trim = false)
**Description:**
Loads an instance of `Key` that was saved to a string by
`saveToAsciiSafeString()`.
By default, this function will call `Encoding::trimTrailingWhitespace()`
to remove trailing CR, LF, NUL, TAB, and SPACE characters, which are commonly
appended to files when working with text editors.
**Parameters:**
1. `$saved_key_string` is the string returned from `saveToAsciiSafeString()`
when the original `Key` instance was saved.
2. `$do_not_trim` should be set to `TRUE` if you do not wish for the library
to automatically strip trailing whitespace from the string.
**Return value:**
Returns an instance of `Key` representing the same encryption key as the one
that was represented by the `Key` instance that got saved into
`$saved_key_string` by a call to `saveToAsciiSafeString()`.
**Exceptions:**
- `Defuse\Crypto\Exception\EnvironmentIsBrokenException` is thrown either when
the platform the code is running on cannot safely perform encryption for some
reason (e.g. it lacks a secure random number generator), or the runtime tests
detected a bug in this library.
- `Defuse\Crypto\Exception\BadFormatException` is thrown whenever
`$saved_key_string` does not represent a valid `Key` instance.
**Side-effects and performance:**
None.
**Cautions:**
None.