class Aws::WAFV2::Types::TextTransformation

Text transformations eliminate some of the unusual formatting that attackers use in web requests in an effort to bypass detection.

@note When making an API call, you may pass TextTransformation

data as a hash:

    {
      priority: 1, # required
      type: "NONE", # required, accepts NONE, COMPRESS_WHITE_SPACE, HTML_ENTITY_DECODE, LOWERCASE, CMD_LINE, URL_DECODE, BASE64_DECODE, HEX_DECODE, MD5, REPLACE_COMMENTS, ESCAPE_SEQ_DECODE, SQL_HEX_DECODE, CSS_DECODE, JS_DECODE, NORMALIZE_PATH, NORMALIZE_PATH_WIN, REMOVE_NULLS, REPLACE_NULLS, BASE64_DECODE_EXT, URL_DECODE_UNI, UTF8_TO_UNICODE
    }

@!attribute [rw] priority

Sets the relative processing order for multiple transformations that
are defined for a rule statement. WAF processes all transformations,
from lowest priority to highest, before inspecting the transformed
content. The priorities don't need to be consecutive, but they must
all be different.
@return [Integer]

@!attribute [rw] type

You can specify the following transformation types:

**BASE64\_DECODE** - Decode a `Base64`-encoded string.

**BASE64\_DECODE\_EXT** - Decode a `Base64`-encoded string, but use
a forgiving implementation that ignores characters that aren't
valid.

**CMD\_LINE** - Command-line transformations. These are helpful in
reducing effectiveness of attackers who inject an operating system
command-line command and use unusual formatting to disguise some or
all of the command.

* Delete the following characters: `\ " ' ^`

* Delete spaces before the following characters: `/ (`

* Replace the following characters with a space: `, ;`

* Replace multiple spaces with one space

* Convert uppercase letters (A-Z) to lowercase (a-z)

**COMPRESS\_WHITE\_SPACE** - Replace these characters with a space
character (decimal 32):

* `\f`, formfeed, decimal 12

* `\t`, tab, decimal 9

* `\n`, newline, decimal 10

* `\r`, carriage return, decimal 13

* `\v`, vertical tab, decimal 11

* Non-breaking space, decimal 160

`COMPRESS_WHITE_SPACE` also replaces multiple spaces with one space.

**CSS\_DECODE** - Decode characters that were encoded using CSS 2.x
escape rules `syndata.html#characters`. This function uses up to two
bytes in the decoding process, so it can help to uncover ASCII
characters that were encoded using CSS encoding that wouldn’t
typically be encoded. It's also useful in countering evasion, which
is a combination of a backslash and non-hexadecimal characters. For
example, `ja\vascript` for javascript.

**ESCAPE\_SEQ\_DECODE** - Decode the following ANSI C escape
sequences: `\a`, `\b`, `\f`, `\n`, `\r`, `\t`, `\v`, `\`, `\?`,
`'`, `"`, `\xHH` (hexadecimal), `\0OOO` (octal). Encodings that
aren't valid remain in the output.

**HEX\_DECODE** - Decode a string of hexadecimal characters into a
binary.

**HTML\_ENTITY\_DECODE** - Replace HTML-encoded characters with
unencoded characters. `HTML_ENTITY_DECODE` performs these
operations:

* Replaces `(ampersand)quot;` with `"`

* Replaces `(ampersand)nbsp;` with a non-breaking space, decimal 160

* Replaces `(ampersand)lt;` with a "less than" symbol

* Replaces `(ampersand)gt;` with `>`

* Replaces characters that are represented in hexadecimal format,
  `(ampersand)#xhhhh;`, with the corresponding characters

* Replaces characters that are represented in decimal format,
  `(ampersand)#nnnn;`, with the corresponding characters

**JS\_DECODE** - Decode JavaScript escape sequences. If a `` `u`
`HHHH` code is in the full-width ASCII code range of `FF01-FF5E`,
then the higher byte is used to detect and adjust the lower byte. If
not, only the lower byte is used and the higher byte is zeroed,
causing a possible loss of information.

**LOWERCASE** - Convert uppercase letters (A-Z) to lowercase (a-z).

**MD5** - Calculate an MD5 hash from the data in the input. The
computed hash is in a raw binary form.

**NONE** - Specify `NONE` if you don't want any text
transformations.

**NORMALIZE\_PATH** - Remove multiple slashes, directory
self-references, and directory back-references that are not at the
beginning of the input from an input string.

**NORMALIZE\_PATH\_WIN** - This is the same as `NORMALIZE_PATH`, but
first converts backslash characters to forward slashes.

**REMOVE\_NULLS** - Remove all `NULL` bytes from the input.

**REPLACE\_COMMENTS** - Replace each occurrence of a C-style comment
(`/* ... */`) with a single space. Multiple consecutive occurrences
are not compressed. Unterminated comments are also replaced with a
space (ASCII 0x20). However, a standalone termination of a comment
(`*/`) is not acted upon.

**REPLACE\_NULLS** - Replace NULL bytes in the input with space
characters (ASCII `0x20`).

**SQL\_HEX\_DECODE** - Decode SQL hex data. Example (`0x414243`)
will be decoded to (`ABC`).

**URL\_DECODE** - Decode a URL-encoded value.

**URL\_DECODE\_UNI** - Like `URL_DECODE`, but with support for
Microsoft-specific `%u` encoding. If the code is in the full-width
ASCII code range of `FF01-FF5E`, the higher byte is used to detect
and adjust the lower byte. Otherwise, only the lower byte is used
and the higher byte is zeroed.

**UTF8\_TO\_UNICODE** - Convert all UTF-8 character sequences to
Unicode. This helps input normalization, and minimizing
false-positives and false-negatives for non-English languages.
@return [String]

@see docs.aws.amazon.com/goto/WebAPI/wafv2-2019-07-29/TextTransformation AWS API Documentation

Constants

SENSITIVE