Storage for decoding and storing strings associated with an address. More...

#include <stringmanage.hh>

Inheritance diagram for ghidra::StringManager:

Collaboration diagram for ghidra::StringManager:

Classes
class	StringData
	String data (a sequence of bytes) stored by StringManager. More...

Public Member Functions
	StringManager (int4 max)
	Constructor.

virtual	~StringManager (void)
	Destructor.

void	clear (void)
	Clear out any cached strings.

bool	isString (const Address &addr, Datatype *charType)

virtual const vector< uint1 > &	getStringData (const Address &addr, Datatype *charType, bool &isTrunc)=0
	Retrieve string data at the given address as a UTF8 byte array.

uint8	registerInternalStringData (const Address &addr, const uint1 buf, int4 size, Datatype charType)
	Associate string data at a code address or other location that doesn't hold string data normally.

void	encode (Encoder &encoder) const
	Encode cached strings to a stream.

void	decode (Decoder &decoder)
	Restore string cache from a stream.

Static Public Member Functions
static bool	hasCharTerminator (const uint1 *buffer, int4 size, int4 charsize)
	Check for a unicode string terminator.

static int4	readUtf16 (const uint1 *buf, bool bigend)
	Read a UTF16 code point from a byte array.

static void	writeUtf8 (ostream &s, int4 codepoint)
	Write unicode character to stream in UTF8 encoding.

static int4	checkCharacters (const uint1 *buf, int4 size, int4 charsize, bool bigend)
	Make sure buffer has valid bounded set of unicode.

static int4	getCodepoint (const uint1 *buf, int4 charsize, bool bigend, int4 &skip)
	Extract next unicode codepoint.

Protected Member Functions
bool	writeUnicode (ostream &s, const uint1 *buffer, int4 size, int4 charsize, bool bigend)
	Translate/copy unicode to UTF8.

void	assignStringData (StringData &data, const uint1 *buf, int4 size, int4 charsize, int4 numChars, bool bigend)
	Translate and assign raw string data to a StringData object.

Static Protected Member Functions
static uint8	calcInternalHash (const Address &addr, const uint1 *buf, int4 size)
	Calculate hash of a specific Address and contents of a byte array.

Protected Attributes
map< Address, StringData >	stringMap
	Map from address to string data.

int4	maximumChars
	Maximum characters in a string before truncating.

Detailed Description

Storage for decoding and storing strings associated with an address.

Looks at data in the loadimage to determine if it represents a "string". Decodes the string for presentation in the output. Stores the decoded string until its needed for presentation. Strings are associated with their starting address in memory. An internal string (that is not in the loadimage) can be registered with the manager and will be associated with a constant.

Constructor & Destructor Documentation

◆ StringManager()

ghidra::StringManager::StringManager ( int4 max )

Constructor.

Parameters

max	is the maximum number of characters to allow before truncating string

References maximumChars.

Member Function Documentation

◆ assignStringData()

void ghidra::StringManager::assignStringData	(	StringData &	data,
		const uint1 *	buf,
		int4	size,
		int4	charsize,
		int4	numChars,
		bool	bigend
	)

protected

Translate and assign raw string data to a StringData object.

The string data is provided as raw bytes. The data is translated to UTF-8 and truncated to the maximumChars allowed by the manager. The encoding must be legal unicode as performed by checkCharacters().

Parameters

data	is the StringData object to populate
buf	is the raw byte array
size	is the number of bytes in the array
charsize	is the size of unicode encoding
numChars	is the number of characters in the encoding as returned by checkCharacters()
bigend	is true if UTF-16 and UTF-32 elements are big endian encoded

References ghidra::StringManager::StringData::byteData, ghidra::StringManager::StringData::isTruncated, maximumChars, and writeUnicode().

Referenced by ghidra::StringManagerUnicode::getStringData(), and registerInternalStringData().

◆ calcInternalHash()

uint8 ghidra::StringManager::calcInternalHash	(	const Address &	addr,
		const uint1 *	buf,
		int4	size
	)

staticprotected

Calculate hash of a specific Address and contents of a byte array.

Calculate a 32-bit CRC of the bytes and XOR into the upper part of the Address offset.

Parameters

addr	is the specific Address
buf	is a pointer to the array of bytes
size	is the number of bytes in the array

Returns: the 64-bit hash

References ghidra::crc_update(), and ghidra::Address::getOffset().

Referenced by registerInternalStringData().

◆ checkCharacters()

int4 ghidra::StringManager::checkCharacters	(	const uint1 *	buf,
		int4	size,
		int4	charsize,
		bool	bigend
	)

static

Make sure buffer has valid bounded set of unicode.

Check that the given buffer contains valid unicode. If the string is encoded in UTF8 or ASCII, we get (on average) a bit of check per character. For UTF16, the surrogate reserved area gives at least some check.

Parameters

buf	is the byte array to check
size	is the size of the buffer in bytes
charsize	is the UTF encoding (1=UTF8, 2=UTF16, 4=UTF32)
bigend	is true if the (UTF16 and UTF32) characters are big endian encoded

Returns: the number of characters or -1 if there is an invalid encoding

References getCodepoint().

Referenced by ghidra::StringManagerUnicode::getStringData(), and registerInternalStringData().

◆ decode()

void ghidra::StringManager::decode ( Decoder & decoder )

Restore string cache from a stream.

Parse a <stringmanage> element, with <string> children.

Parameters

decoder is the stream decoder

References ghidra::StringManager::StringData::byteData, ghidra::Decoder::closeElement(), ghidra::Address::decode(), ghidra::StringManager::StringData::isTruncated, ghidra::Decoder::openElement(), ghidra::Decoder::readBool(), ghidra::Decoder::readString(), and stringMap.

Referenced by ghidra::Architecture::restoreXml().

◆ encode()

void ghidra::StringManager::encode ( Encoder & encoder ) const

Encode cached strings to a stream.

Encode <stringmanage> element, with <string> children.

Parameters

encoder is the stream encoder

References ghidra::StringManager::StringData::byteData, ghidra::Encoder::closeElement(), ghidra::StringManager::StringData::isTruncated, ghidra::Encoder::openElement(), stringMap, ghidra::Encoder::writeBool(), and ghidra::Encoder::writeString().

Referenced by ghidra::Architecture::encode().

◆ getCodepoint()

int4 ghidra::StringManager::getCodepoint	(	const uint1 *	buf,
		int4	charsize,
		bool	bigend,
		int4 &	skip
	)

static

Extract next unicode codepoint.

One or more bytes is consumed from the array, and the number of bytes used is passed back.

Parameters

buf	is a pointer to the bytes in the character array
charsize	is 1 for UTF8, 2 for UTF16, or 4 for UTF32
bigend	is true for big endian encoding of the UTF element
skip	is a reference for passing back the number of bytes consumed

Returns: the codepoint or -1 if the encoding is invalid

References readUtf16().

Referenced by checkCharacters(), ghidra::PrintLanguage::escapeCharacterData(), and writeUnicode().

◆ getStringData()

virtual const vector< uint1 > & ghidra::StringManager::getStringData	(	const Address &	addr,
		Datatype *	charType,
		bool &	isTrunc
	)

pure virtual

Retrieve string data at the given address as a UTF8 byte array.

If the address does not represent string data, a zero length vector is returned. Otherwise, the string data is fetched, converted to a UTF8 encoding, cached and returned.

Parameters

addr	is the given address
charType	is a character data-type indicating the encoding
isTrunc	passes back whether the string is truncated

Returns: the byte array of UTF8 data

Implemented in ghidra::StringManagerUnicode, and ghidra::GhidraStringManager.

Referenced by isString(), and ghidra::PrintC::printCharacterConstant().

◆ hasCharTerminator()

bool ghidra::StringManager::hasCharTerminator	(	const uint1 *	buffer,
		int4	size,
		int4	charsize
	)

static

Check for a unicode string terminator.

Parameters

buffer	is the byte buffer
size	is the number of bytes in the buffer
charsize	is the presumed size (in bytes) of character elements

Returns: true if a string terminator is found

Referenced by ghidra::StringManagerUnicode::getStringData().

◆ isString()

bool ghidra::StringManager::isString	(	const Address &	addr,
		Datatype *	charType
	)

Returns true if the data is some kind of complete string. A given character data-type can be used as a hint for the encoding. The string decoding can be cached internally.

Parameters

addr	is the given address
charType	is the given character data-type

Returns: true if the address represents string data

References getStringData().

Referenced by ghidra::RulePtrsubCharConstant::applyOp().

◆ readUtf16()

int4 ghidra::StringManager::readUtf16	(	const uint1 *	buf,
		bool	bigend
	)

inlinestatic

Read a UTF16 code point from a byte array.

Pull the first two bytes from the byte array and combine them in the indicated endian order

Parameters

buf	is the byte array
bigend	is true to request big endian encoding

Returns: the decoded UTF16 element

Referenced by getCodepoint().

◆ registerInternalStringData()

uint8 ghidra::StringManager::registerInternalStringData	(	const Address &	addr,
		const uint1 *	buf,
		int4	size,
		Datatype *	charType
	)

Associate string data at a code address or other location that doesn't hold string data normally.

The given byte buffer is decoded, and if it represents a legal string, a non-zero hash is returned, constructed from an Address associated with the string and the string data itself. The registered string can be retrieved via the getStringData() method using this hash as a constant Address. If the string is not legal, 0 is returned.

Parameters

addr	is the address to associate with the string data
buf	is a pointer to the array of raw bytes encoding the string
size	is the number of bytes in the array
charType	is a character data-type indicating the encoding

Returns: a hash associated with the string or 0

References assignStringData(), ghidra::StringManager::StringData::byteData, calcInternalHash(), checkCharacters(), ghidra::AddrSpaceManager::getConstant(), ghidra::AddrSpace::getManager(), ghidra::Datatype::getSize(), ghidra::Address::getSpace(), ghidra::Address::isBigEndian(), ghidra::StringManager::StringData::isTruncated, and stringMap.

Referenced by ghidra::Funcdata::getInternalString().

◆ writeUnicode()

bool ghidra::StringManager::writeUnicode	(	ostream &	s,
		const uint1 *	buffer,
		int4	size,
		int4	charsize,
		bool	bigend
	)

protected

Translate/copy unicode to UTF8.

Assume the buffer contains a null terminated unicode encoded string. Write the characters out (as UTF8) to the stream.

Parameters

s	is the output stream
buffer	is the given byte buffer
size	is the number of bytes in the buffer
charsize	specifies the encoding (1=UTF8 2=UTF16 4=UTF32)
bigend	is true if (UTF16 and UTF32) are big endian encoded

Returns: true if the byte array contains valid unicode

References getCodepoint(), maximumChars, and writeUtf8().

Referenced by assignStringData().

◆ writeUtf8()

void ghidra::StringManager::writeUtf8	(	ostream &	s,
		int4	codepoint
	)

static

Write unicode character to stream in UTF8 encoding.

Encode the given unicode codepoint as UTF8 (1, 2, 3, or 4 bytes) and write the bytes to the stream.

Parameters

s	is the output stream
codepoint	is the unicode codepoint

Referenced by ghidra::PrintC::printUnicode(), ghidra::PrintJava::printUnicode(), and writeUnicode().

The documentation for this class was generated from the following files:

/builds/appsec/reveng-binrw/ghidraplusplus/src/dec/stringmanage.hh
/builds/appsec/reveng-binrw/ghidraplusplus/src/dec/stringmanage.cc

Classes

Public Member Functions

Static Public Member Functions

Protected Member Functions

Static Protected Member Functions

Protected Attributes

Detailed Description

Constructor & Destructor Documentation

◆ StringManager()

Member Function Documentation

◆ assignStringData()

◆ calcInternalHash()

◆ checkCharacters()

◆ decode()

◆ encode()

◆ getCodepoint()

◆ getStringData()

◆ hasCharTerminator()

◆ isString()

◆ readUtf16()

◆ registerInternalStringData()

◆ writeUnicode()

◆ writeUtf8()