Add defuse/php-encryption 2.0 to Composer dependencies

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

@@ -0,0 +1,117 @@
+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.