local white = (lpeg.S'\0\9\10\12\13\32' + '%' * (1 - lpeg.S'\r\n')^0)^1 -- Whitespace local regular = 1-lpeg.S'()<>[]{}/%\0\9\10\12\13\32' local lastbase = '123456789abcdefghiklmnopqrstuvwxyz' local number = lpeg.Cmt(lpeg.R'09'^1/tonumber * '#', function(s, p, base) if base < 2 then return end local pattern if base <= 10 then pattern = lpeg.R('0' .. lastbase:sub(base-1, base-1)) else pattern = lpeg.R'09' + lpeg.R('a' .. lastbase:sub(base-1, base-1)) + lpeg.R('A' .. lastbase:sub(base-1, base-1):upper()) end local num, p = (lpeg.C(pattern^1) * lpeg.Cp()):match(s, p) return p, num and tonumber(num, base) end) + (lpeg.S'+-'^-1 * ('.' * lpeg.R'09'^1 + lpeg.R'09'^1 * lpeg.P'.'^-1 * lpeg.R'09'^0) * (lpeg.S'eE' * lpeg.S'+-'^-1 * lpeg.R'09'^1)^-1)/tonumber local literalstring = lpeg.P{'(' * lpeg.Cs(( lpeg.P'\\n'/'\n'+lpeg.P'\\r'/'\r'+lpeg.P'\\t'/'\t'+lpeg.P'\\b'/'\b'+lpeg.P'\\f'/'\f' +'\\'*lpeg.C(lpeg.R'07'*lpeg.R'07'^-2)/function(n)return string.char(tonumber(n, 8))end +'\\'*('\n' + ('\r' * lpeg.P'\n'^-1))/'' +'\\'*lpeg.C(1)/1 +('\n' + ('\r' * lpeg.P'\n'^-1))/'\n' +(1-lpeg.S'()\\')+lpeg.V(1))^0) * ')'} local hexstring = '<' * lpeg.Cs(( lpeg.C(lpeg.R'09'+lpeg.R'af'+lpeg.R'AF')*(lpeg.C(lpeg.R'09'+lpeg.R'af'+lpeg.R'AF')+lpeg.Cc'0')/function(a,b)return string.char(tonumber(a..b, 16))end)^0) * '>' local name = lpeg.C(regular^1) local lname = '/' * name / 1 local boolean = (lpeg.P'true' + 'false')/{["true"] = true, ["false"] = false} -- Everything above this line works pretty reliable and can be understood by reading the PostScript specs. -- This is Type1 specific. The only thing which might need adjustment is adding alternative spellings for -|, RD, |-, |, etc. local binary_bytes = lpeg.Cmt(number*white^-1*(lpeg.P'-| ' + 'RD '), function(s, p, l)return p+l, s:sub(p, p+l-1) end)*white^-1*(lpeg.P"|-"+"|"+"ND"+"NP") -- Attention: The |-, |, ND, NP already contain an implicit `def` local function decrypt(key, n, cipher) -- Generally you should never implement your own crypto. So we call a well known, peer reviewed, -- high-quality cryptographic library. --- Ha-Ha, of course we are implementing by ourselves. -- That might be completely unsecure, but given that the encryption keys are well known constants -- documented in the T1 Spec, there is no need to worry about it. -- Also I do not think any cryptographic library would implement this anyway, it doesn't even -- really deserve the term encryption. local decoded = {string.byte(cipher, 1,-1)} for i=1,#decoded do local c = decoded[i] decoded[i] = c ~ (key>>8) key = (((c+key)&0xFFFF)*52845+22719)&0xFFFF end return string.char(table.unpack(decoded, n+1)) end local anytype = { hexstring + literalstring + number + lname + boolean + lpeg.V'array' + name, array = lpeg.Ct( '[' * (white^-1 * lpeg.V(1))^0 * white^-1 * ']' -- Arrays have two possible syntaxes + '{' * (white^-1 * lpeg.V(1))^0 * white^-1 * '}') * (white * "executeonly")^-1 } local function skip_until(p) if type(p) == 'string' then p = p * -name end return (white + anytype - p)^0/0 end local skip_to_begin = skip_until'begin' * 'begin' local def_like = (lpeg.P'def' + 'ND' + '|-') * -name local encoding = '/' * lpeg.C'Encoding' * -name * skip_until'dup' * lpeg.Cf(lpeg.Ct'' * lpeg.Cg("dup"*white*number*white^-1*lname*white^-1*"put"*white)^0 , rawset) * ("readonly"*white)^-1 * "def" local charstr = '/' * lpeg.C'CharStrings' * -name * skip_until(lname) -- sometimes we get weird stuff in between. Just make sure that we don't swallow a charname * lpeg.Cf(lpeg.Ct'' * lpeg.Cg(lname*white^-1*binary_bytes*white)^0 -- Remember: binary_bytes includes a `def` , rawset) * lpeg.P"end"*white local subrs = '/' * lpeg.C'Subrs' * -name * skip_until'dup' * lpeg.Cf(lpeg.Ct'' * lpeg.Cg("dup"*white^-1*number*white^-1*binary_bytes*white)^0 , rawset) * (lpeg.P"readonly"*white)^-1 * (lpeg.P"noaccess"*white)^-1*(lpeg.P"def"+"ND"+"|-") -- lpeg.V(2) == dict_entries local dict = skip_to_begin * lpeg.V(2) * white^-1 * 'end' * white * ('readonly' * white)^-1 * ('noaccess' * white)^-1 * def_like local dict_entry = encoding + subrs + '/' * lpeg.C'FontInfo' * dict + lname -- key * white^-1 * anytype -- value * ((white + anytype - (def_like + 'dict' + 'array') * -name)/0 * white^-1)^0 -- Sometimes we get Postscript code in between. * def_like local dict_entries = lpeg.P{ lpeg.Cf(lpeg.Carg(1) * lpeg.Cg(white^-1*lpeg.V(3))^0, rawset), lpeg.Cf(lpeg.Ct'' * lpeg.Cg(white^-1*lpeg.V(3))^0, rawset), dict_entry, } local function parse_private(offset, str) local mydict, found offset = (skip_to_begin * lpeg.Cp()):match(str, offset) -- Scan the dictionary mydict, offset = (dict_entries*lpeg.Cp()):match(str, offset, {}) return mydict, offset end local function continue_maintable(offset, str, mydict) mydict, offset = (dict_entries*lpeg.Cp()):match(str, offset, mydict) local found = (white^-1*lname):match(str, offset) if found == "Private" then -- Scanned separatly because it isn't always ended in a regular way mydict.Private, offset = parse_private(offset, str) return continue_maintable(offset, str, mydict) elseif found == "CharStrings" then -- This could be included in normal scanning, but it is our signal to terminate found, mydict.CharStrings, offset = (charstr*lpeg.Cp()):match(str, offset) return mydict else local newoffset = ((white+name)^1/0*lpeg.Cp()):match(str, offset) if newoffset and offset <= #str then return continue_maintable(newoffset, str, mydict) end end error[[Unable to read Type 1 font]] end local function parse_maintable(offset, str) local found offset = (skip_to_begin * lpeg.Cp()):match(str, offset) return continue_maintable(offset, str, {}) end return function(data) local preface, private = string.unpack("