fonttools/Lib/fontTools/t1Lib/__init__.py

"""fontTools.t1Lib.py -- Tools for PostScript Type 1 fonts.

Functions for reading and writing raw Type 1 data:

read(path)
	reads any Type 1 font file, returns the raw data and a type indicator:
	'LWFN', 'PFB' or 'OTHER', depending on the format of the file pointed
	to by 'path'.
	Raises an error when the file does not contain valid Type 1 data.

write(path, data, kind='OTHER', dohex=False)
	writes raw Type 1 data to the file pointed to by 'path'.
	'kind' can be one of 'LWFN', 'PFB' or 'OTHER'; it defaults to 'OTHER'.
	'dohex' is a flag which determines whether the eexec encrypted
	part should be written as hexadecimal or binary, but only if kind
	is 'OTHER'.
"""

import fontTools
from fontTools.misc import eexec
from fontTools.misc.macCreatorType import getMacCreatorAndType
from fontTools.misc.textTools import bytechr, byteord, bytesjoin, tobytes
from fontTools.misc.psOperators import (
    _type1_pre_eexec_order,
    _type1_fontinfo_order,
    _type1_post_eexec_order,
)
from fontTools.encodings.StandardEncoding import StandardEncoding
import os
import re

__author__ = "jvr"
__version__ = "1.0b3"
DEBUG = 0


try:
    try:
        from Carbon import Res
    except ImportError:
        import Res  # MacPython < 2.2
except ImportError:
    haveMacSupport = 0
else:
    haveMacSupport = 1


class T1Error(Exception):
    pass


class T1Font(object):
    """Type 1 font class.

    Uses a minimal interpeter that supports just about enough PS to parse
    Type 1 fonts.
    """

    def __init__(self, path, encoding="ascii", kind=None):
        if kind is None:
            self.data, _ = read(path)
        elif kind == "LWFN":
            self.data = readLWFN(path)
        elif kind == "PFB":
            self.data = readPFB(path)
        elif kind == "OTHER":
            self.data = readOther(path)
        else:
            raise ValueError(kind)
        self.encoding = encoding

    def saveAs(self, path, type, dohex=False):
        write(path, self.getData(), type, dohex)

    def getData(self):
        if not hasattr(self, "data"):
            self.data = self.createData()
        return self.data

    def getGlyphSet(self):
        """Return a generic GlyphSet, which is a dict-like object
        mapping glyph names to glyph objects. The returned glyph objects
        have a .draw() method that supports the Pen protocol, and will
        have an attribute named 'width', but only *after* the .draw() method
        has been called.

        In the case of Type 1, the GlyphSet is simply the CharStrings dict.
        """
        return self["CharStrings"]

    def __getitem__(self, key):
        if not hasattr(self, "font"):
            self.parse()
        return self.font[key]

    def parse(self):
        from fontTools.misc import psLib
        from fontTools.misc import psCharStrings

        self.font = psLib.suckfont(self.data, self.encoding)
        charStrings = self.font["CharStrings"]
        lenIV = self.font["Private"].get("lenIV", 4)
        assert lenIV >= 0
        subrs = self.font["Private"]["Subrs"]
        for glyphName, charString in charStrings.items():
            charString, R = eexec.decrypt(charString, 4330)
            charStrings[glyphName] = psCharStrings.T1CharString(
                charString[lenIV:], subrs=subrs
            )
        for i in range(len(subrs)):
            charString, R = eexec.decrypt(subrs[i], 4330)
            subrs[i] = psCharStrings.T1CharString(charString[lenIV:], subrs=subrs)
        del self.data

    def createData(self):
        sf = self.font

        eexec_began = False
        eexec_dict = {}
        lines = []
        lines.extend(
            [
                self._tobytes(f"%!FontType1-1.1: {sf['FontName']}"),
                self._tobytes(f"%t1Font: ({fontTools.version})"),
                self._tobytes(f"%%BeginResource: font {sf['FontName']}"),
            ]
        )
        # follow t1write.c:writeRegNameKeyedFont
        size = 3  # Headroom for new key addition
        size += 1  # FontMatrix is always counted
        size += 1 + 1  # Private, CharStings
        for key in font_dictionary_keys:
            size += int(key in sf)
        lines.append(self._tobytes(f"{size} dict dup begin"))

        for key, value in sf.items():
            if eexec_began:
                eexec_dict[key] = value
                continue

            if key == "FontInfo":
                fi = sf["FontInfo"]
                # follow t1write.c:writeFontInfoDict
                size = 3  # Headroom for new key addition
                for subkey in FontInfo_dictionary_keys:
                    size += int(subkey in fi)
                lines.append(self._tobytes(f"/FontInfo {size} dict dup begin"))

                for subkey, subvalue in fi.items():
                    lines.extend(self._make_lines(subkey, subvalue))
                lines.append(b"end def")
            elif key in _type1_post_eexec_order:  # usually 'Private'
                eexec_dict[key] = value
                eexec_began = True
            else:
                lines.extend(self._make_lines(key, value))
        lines.append(b"end")
        eexec_portion = self.encode_eexec(eexec_dict)
        lines.append(bytesjoin([b"currentfile eexec ", eexec_portion]))

        for _ in range(8):
            lines.append(self._tobytes("0" * 64))
        lines.extend([b"cleartomark", b"%%EndResource", b"%%EOF"])

        data = bytesjoin(lines, "\n")
        return data

    def encode_eexec(self, eexec_dict):
        lines = []

        # '-|', '|-', '|'
        RD_key, ND_key, NP_key = None, None, None
        lenIV = 4
        subrs = std_subrs

        # Ensure we look at Private first, because we need RD_key, ND_key, NP_key and lenIV
        sortedItems = sorted(eexec_dict.items(), key=lambda item: item[0] != "Private")

        for key, value in sortedItems:
            if key == "Private":
                pr = eexec_dict["Private"]
                # follow t1write.c:writePrivateDict
                size = 3  # for RD, ND, NP
                for subkey in Private_dictionary_keys:
                    size += int(subkey in pr)
                lines.append(b"dup /Private")
                lines.append(self._tobytes(f"{size} dict dup begin"))
                for subkey, subvalue in pr.items():
                    if not RD_key and subvalue == RD_value:
                        RD_key = subkey
                    elif not ND_key and subvalue in ND_values:
                        ND_key = subkey
                    elif not NP_key and subvalue in PD_values:
                        NP_key = subkey

                    if subkey == "lenIV":
                        lenIV = subvalue

                    if subkey == "OtherSubrs":
                        # XXX: assert that no flex hint is used
                        lines.append(self._tobytes(hintothers))
                    elif subkey == "Subrs":
                        for subr_bin in subvalue:
                            subr_bin.compile()
                        subrs = [subr_bin.bytecode for subr_bin in subvalue]
                        lines.append(f"/Subrs {len(subrs)} array".encode("ascii"))
                        for i, subr_bin in enumerate(subrs):
                            encrypted_subr, R = eexec.encrypt(
                                bytesjoin([char_IV[:lenIV], subr_bin]), 4330
                            )
                            lines.append(
                                bytesjoin(
                                    [
                                        self._tobytes(
                                            f"dup {i} {len(encrypted_subr)} {RD_key} "
                                        ),
                                        encrypted_subr,
                                        self._tobytes(f" {NP_key}"),
                                    ]
                                )
                            )
                        lines.append(b"def")

                        lines.append(b"put")
                    else:
                        lines.extend(self._make_lines(subkey, subvalue))
            elif key == "CharStrings":
                lines.append(b"dup /CharStrings")
                lines.append(
                    self._tobytes(f"{len(eexec_dict['CharStrings'])} dict dup begin")
                )
                for glyph_name, char_bin in eexec_dict["CharStrings"].items():
                    char_bin.compile()
                    encrypted_char, R = eexec.encrypt(
                        bytesjoin([char_IV[:lenIV], char_bin.bytecode]), 4330
                    )
                    lines.append(
                        bytesjoin(
                            [
                                self._tobytes(
                                    f"/{glyph_name} {len(encrypted_char)} {RD_key} "
                                ),
                                encrypted_char,
                                self._tobytes(f" {ND_key}"),
                            ]
                        )
                    )
                lines.append(b"end put")
            else:
                lines.extend(self._make_lines(key, value))

        lines.extend(
            [
                b"end",
                b"dup /FontName get exch definefont pop",
                b"mark",
                b"currentfile closefile\n",
            ]
        )

        eexec_portion = bytesjoin(lines, "\n")
        encrypted_eexec, R = eexec.encrypt(bytesjoin([eexec_IV, eexec_portion]), 55665)

        return encrypted_eexec

    def _make_lines(self, key, value):
        if key == "FontName":
            return [self._tobytes(f"/{key} /{value} def")]
        if key in ["isFixedPitch", "ForceBold", "RndStemUp"]:
            return [self._tobytes(f"/{key} {'true' if value else 'false'} def")]
        elif key == "Encoding":
            if value == StandardEncoding:
                return [self._tobytes(f"/{key} StandardEncoding def")]
            else:
                # follow fontTools.misc.psOperators._type1_Encoding_repr
                lines = []
                lines.append(b"/Encoding 256 array")
                lines.append(b"0 1 255 {1 index exch /.notdef put} for")
                for i in range(256):
                    name = value[i]
                    if name != ".notdef":
                        lines.append(self._tobytes(f"dup {i} /{name} put"))
                lines.append(b"def")
                return lines
        if isinstance(value, str):
            return [self._tobytes(f"/{key} ({value}) def")]
        elif isinstance(value, bool):
            return [self._tobytes(f"/{key} {'true' if value else 'false'} def")]
        elif isinstance(value, list):
            return [self._tobytes(f"/{key} [{' '.join(str(v) for v in value)}] def")]
        elif isinstance(value, tuple):
            return [self._tobytes(f"/{key} {{{' '.join(str(v) for v in value)}}} def")]
        else:
            return [self._tobytes(f"/{key} {value} def")]

    def _tobytes(self, s, errors="strict"):
        return tobytes(s, self.encoding, errors)


# low level T1 data read and write functions


def read(path, onlyHeader=False):
    """reads any Type 1 font file, returns raw data"""
    _, ext = os.path.splitext(path)
    ext = ext.lower()
    creator, typ = getMacCreatorAndType(path)
    if typ == "LWFN":
        return readLWFN(path, onlyHeader), "LWFN"
    if ext == ".pfb":
        return readPFB(path, onlyHeader), "PFB"
    else:
        return readOther(path), "OTHER"


def write(path, data, kind="OTHER", dohex=False):
    assertType1(data)
    kind = kind.upper()
    try:
        os.remove(path)
    except os.error:
        pass
    err = 1
    try:
        if kind == "LWFN":
            writeLWFN(path, data)
        elif kind == "PFB":
            writePFB(path, data)
        else:
            writeOther(path, data, dohex)
        err = 0
    finally:
        if err and not DEBUG:
            try:
                os.remove(path)
            except os.error:
                pass


# -- internal --

LWFNCHUNKSIZE = 2000
HEXLINELENGTH = 80


def readLWFN(path, onlyHeader=False):
    """reads an LWFN font file, returns raw data"""
    from fontTools.misc.macRes import ResourceReader

    reader = ResourceReader(path)
    try:
        data = []
        for res in reader.get("POST", []):
            code = byteord(res.data[0])
            if byteord(res.data[1]) != 0:
                raise T1Error("corrupt LWFN file")
            if code in [1, 2]:
                if onlyHeader and code == 2:
                    break
                data.append(res.data[2:])
            elif code in [3, 5]:
                break
            elif code == 4:
                with open(path, "rb") as f:
                    data.append(f.read())
            elif code == 0:
                pass  # comment, ignore
            else:
                raise T1Error("bad chunk code: " + repr(code))
    finally:
        reader.close()
    data = bytesjoin(data)
    assertType1(data)
    return data


def readPFB(path, onlyHeader=False):
    """reads a PFB font file, returns raw data"""
    data = []
    with open(path, "rb") as f:
        while True:
            if f.read(1) != bytechr(128):
                raise T1Error("corrupt PFB file")
            code = byteord(f.read(1))
            if code in [1, 2]:
                chunklen = stringToLong(f.read(4))
                chunk = f.read(chunklen)
                assert len(chunk) == chunklen
                data.append(chunk)
            elif code == 3:
                break
            else:
                raise T1Error("bad chunk code: " + repr(code))
            if onlyHeader:
                break
    data = bytesjoin(data)
    assertType1(data)
    return data


def readOther(path):
    """reads any (font) file, returns raw data"""
    with open(path, "rb") as f:
        data = f.read()
    assertType1(data)
    chunks = findEncryptedChunks(data)
    data = []
    for isEncrypted, chunk in chunks:
        if isEncrypted and isHex(chunk[:4]):
            data.append(deHexString(chunk))
        else:
            data.append(chunk)
    return bytesjoin(data)


# file writing tools


def writeLWFN(path, data):
    # Res.FSpCreateResFile was deprecated in OS X 10.5
    Res.FSpCreateResFile(path, "just", "LWFN", 0)
    resRef = Res.FSOpenResFile(path, 2)  # write-only
    try:
        Res.UseResFile(resRef)
        resID = 501
        chunks = findEncryptedChunks(data)
        for isEncrypted, chunk in chunks:
            if isEncrypted:
                code = 2
            else:
                code = 1
            while chunk:
                res = Res.Resource(bytechr(code) + "\0" + chunk[: LWFNCHUNKSIZE - 2])
                res.AddResource("POST", resID, "")
                chunk = chunk[LWFNCHUNKSIZE - 2 :]
                resID = resID + 1
        res = Res.Resource(bytechr(5) + "\0")
        res.AddResource("POST", resID, "")
    finally:
        Res.CloseResFile(resRef)


def writePFB(path, data):
    chunks = findEncryptedChunks(data)
    with open(path, "wb") as f:
        for isEncrypted, chunk in chunks:
            if isEncrypted:
                code = 2
            else:
                code = 1
            f.write(bytechr(128) + bytechr(code))
            f.write(longToString(len(chunk)))
            f.write(chunk)
        f.write(bytechr(128) + bytechr(3))


def writeOther(path, data, dohex=False):
    chunks = findEncryptedChunks(data)
    with open(path, "wb") as f:
        hexlinelen = HEXLINELENGTH // 2
        for isEncrypted, chunk in chunks:
            if isEncrypted:
                code = 2
            else:
                code = 1
            if code == 2 and dohex:
                while chunk:
                    f.write(eexec.hexString(chunk[:hexlinelen]))
                    f.write(b"\r")
                    chunk = chunk[hexlinelen:]
            else:
                f.write(chunk)


# decryption tools

EEXECBEGIN = b"currentfile eexec"
# The spec allows for 512 ASCII zeros interrupted by arbitrary whitespace to
# follow eexec
EEXECEND = re.compile(b"(0[ \t\r\n]*){512}", flags=re.M)
EEXECINTERNALEND = b"currentfile closefile"
EEXECBEGINMARKER = b"%-- eexec start\r"
EEXECENDMARKER = b"%-- eexec end\r"

_ishexRE = re.compile(b"[0-9A-Fa-f]*$")


def isHex(text):
    return _ishexRE.match(text) is not None


def decryptType1(data):
    chunks = findEncryptedChunks(data)
    data = []
    for isEncrypted, chunk in chunks:
        if isEncrypted:
            if isHex(chunk[:4]):
                chunk = deHexString(chunk)
            decrypted, R = eexec.decrypt(chunk, 55665)
            decrypted = decrypted[4:]
            if (
                decrypted[-len(EEXECINTERNALEND) - 1 : -1] != EEXECINTERNALEND
                and decrypted[-len(EEXECINTERNALEND) - 2 : -2] != EEXECINTERNALEND
            ):
                raise T1Error("invalid end of eexec part")
            decrypted = decrypted[: -len(EEXECINTERNALEND) - 2] + b"\r"
            data.append(EEXECBEGINMARKER + decrypted + EEXECENDMARKER)
        else:
            if chunk[-len(EEXECBEGIN) - 1 : -1] == EEXECBEGIN:
                data.append(chunk[: -len(EEXECBEGIN) - 1])
            else:
                data.append(chunk)
    return bytesjoin(data)


def findEncryptedChunks(data):
    chunks = []
    while True:
        eBegin = data.find(EEXECBEGIN)
        if eBegin < 0:
            break
        eBegin = eBegin + len(EEXECBEGIN) + 1
        endMatch = EEXECEND.search(data, eBegin)
        if endMatch is None:
            raise T1Error("can't find end of eexec part")
        eEnd = endMatch.start()
        cypherText = data[eBegin : eEnd + 2]
        if isHex(cypherText[:4]):
            cypherText = deHexString(cypherText)
        plainText, R = eexec.decrypt(cypherText, 55665)
        eEndLocal = plainText.find(EEXECINTERNALEND)
        if eEndLocal < 0:
            raise T1Error("can't find end of eexec part")
        chunks.append((0, data[:eBegin]))
        chunks.append((1, cypherText[: eEndLocal + len(EEXECINTERNALEND) + 1]))
        data = data[eEnd:]
    chunks.append((0, data))
    return chunks


def deHexString(hexstring):
    return eexec.deHexString(bytesjoin(hexstring.split()))


# Type 1 assertion

_fontType1RE = re.compile(rb"/FontType\s+1\s+def")


def assertType1(data):
    for head in [b"%!PS-AdobeFont", b"%!FontType1"]:
        if data[: len(head)] == head:
            break
    else:
        raise T1Error("not a PostScript font")
    if not _fontType1RE.search(data):
        raise T1Error("not a Type 1 font")
    if data.find(b"currentfile eexec") < 0:
        raise T1Error("not an encrypted Type 1 font")
    # XXX what else?
    return data


# pfb helpers


def longToString(long):
    s = b""
    for i in range(4):
        s += bytechr((long & (0xFF << (i * 8))) >> i * 8)
    return s


def stringToLong(s):
    if len(s) != 4:
        raise ValueError("string must be 4 bytes long")
    l = 0
    for i in range(4):
        l += byteord(s[i]) << (i * 8)
    return l


# PS stream helpers

font_dictionary_keys = list(_type1_pre_eexec_order)
# t1write.c:writeRegNameKeyedFont
# always counts following keys
font_dictionary_keys.remove("FontMatrix")

FontInfo_dictionary_keys = list(_type1_fontinfo_order)
# extend because AFDKO tx may use following keys
FontInfo_dictionary_keys.extend(
    [
        "FSType",
        "Copyright",
    ]
)

Private_dictionary_keys = [
    # We don't know what names will be actually used.
    # "RD",
    # "ND",
    # "NP",
    "Subrs",
    "OtherSubrs",
    "UniqueID",
    "BlueValues",
    "OtherBlues",
    "FamilyBlues",
    "FamilyOtherBlues",
    "BlueScale",
    "BlueShift",
    "BlueFuzz",
    "StdHW",
    "StdVW",
    "StemSnapH",
    "StemSnapV",
    "ForceBold",
    "LanguageGroup",
    "password",
    "lenIV",
    "MinFeature",
    "RndStemUp",
]

# t1write_hintothers.h
hintothers = """/OtherSubrs[{}{}{}{systemdict/internaldict known not{pop 3}{1183615869
systemdict/internaldict get exec dup/startlock known{/startlock get exec}{dup
/strtlck known{/strtlck get exec}{pop 3}ifelse}ifelse}ifelse}executeonly]def"""
# t1write.c:saveStdSubrs
std_subrs = [
    # 3 0 callother pop pop setcurrentpoint return
    b"\x8e\x8b\x0c\x10\x0c\x11\x0c\x11\x0c\x21\x0b",
    # 0 1 callother return
    b"\x8b\x8c\x0c\x10\x0b",
    # 0 2 callother return
    b"\x8b\x8d\x0c\x10\x0b",
    # return
    b"\x0b",
    # 3 1 3 callother pop callsubr return
    b"\x8e\x8c\x8e\x0c\x10\x0c\x11\x0a\x0b",
]
# follow t1write.c:writeRegNameKeyedFont
eexec_IV = b"cccc"
char_IV = b"\x0c\x0c\x0c\x0c"
RD_value = ("string", "currentfile", "exch", "readstring", "pop")
ND_values = [("def",), ("noaccess", "def")]
PD_values = [("put",), ("noaccess", "put")]