return str;
}
+function stringToBytes(str) {
+ var length = str.length;
+ var bytes = new Uint8Array(length);
+ for (var n = 0; n < length; ++n)
+ bytes[n] = str.charCodeAt(n) & 0xFF;
+ return bytes;
+}
+
var Stream = (function() {
function constructor(arrayBuffer, start, length, dict) {
this.bytes = Uint8Array(arrayBuffer);
})();
var DecryptStream = (function() {
- function constructor(str, fileKey, encAlgorithm, keyLength) {
- TODO("decrypt stream is not implemented");
+ function constructor(str, decrypt) {
+ this.str = str;
+ this.dict = str.dict;
+ this.decrypt = decrypt;
+
+ DecodeStream.call(this);
}
- constructor.prototype = Stream.prototype;
+ const chunkSize = 512;
+
+ constructor.prototype = Object.create(DecodeStream.prototype);
+ constructor.prototype.readBlock = function() {
+ var chunk = this.str.getBytes(chunkSize);
+ if (!chunk || chunk.length == 0) {
+ this.eof = true;
+ return;
+ }
+ var decrypt = this.decrypt;
+ chunk = decrypt(chunk);
+
+ var bufferLength = this.bufferLength;
+ var i, n = chunk.length;
+ var buffer = this.ensureBuffer(bufferLength + n);
+ for (i = 0; i < n; i++)
+ buffer[bufferLength++] = chunk[i];
+ this.bufferLength = n;
+ this.eof = n < chunkSize;
+ };
return constructor;
})();
function ToHexDigit(ch) {
if (ch >= "0" && ch <= "9")
- return ch - "0";
- ch = ch.toLowerCase();
- if (ch >= "a" && ch <= "f")
- return ch - "a";
+ return ch.charCodeAt(0) - 48;
+ ch = ch.toUpperCase();
+ if (ch >= "A" && ch <= "F")
+ return ch.charCodeAt(0) - 55;
return -1;
}
// don't buffer inline image data
this.buf2 = (this.inlineImg > 0) ? null : this.lexer.getObj();
},
- getObj: function() {
+ getObj: function(cipherTransform) {
// refill buffer after inline image data
if (this.inlineImg == 2)
this.refill();
this.shift();
if (IsEOF(this.buf1))
break;
- dict.set(key, this.getObj());
+ dict.set(key, this.getObj(cipherTransform));
}
}
if (IsEOF(this.buf1))
// stream objects are not allowed inside content streams or
// object streams
if (this.allowStreams && IsCmd(this.buf2, "stream")) {
- return this.makeStream(dict);
+ return this.makeStream(dict, cipherTransform);
} else {
this.shift();
}
} else if (IsString(this.buf1)) { // string
var str = this.buf1;
this.shift();
- if (this.fileKey) {
- var decrypt = new DecryptStream(new StringStream(str),
- this.fileKey,
- this.encAlgorithm,
- this.keyLength);
- var str = "";
- var pos = decrypt.pos;
- var length = decrypt.length;
- while (pos++ > length)
- str += decrypt.getChar();
- }
+ if (cipherTransform)
+ str = cipherTransform.decryptString(str);
return str;
}
this.shift();
return obj;
},
- makeStream: function(dict) {
+ makeStream: function(dict, cipherTransform) {
var lexer = this.lexer;
var stream = lexer.stream;
this.shift();
stream = stream.makeSubStream(pos, length, dict);
- if (this.fileKey) {
- stream = new DecryptStream(stream,
- this.fileKey,
- this.encAlgorithm,
- this.keyLength);
- }
+ if (cipherTransform)
+ stream = cipherTransform.createString(stream);
stream = this.filter(stream, dict, length);
stream.parameters = dict;
return stream;
this.xrefstms = {};
var trailerDict = this.readXRef(startXRef);
+ // prepare the XRef cache
+ this.cache = [];
+
+ var encrypt = trailerDict.get("Encrypt");
+ if (encrypt) {
+ var fileId = trailerDict.get("ID");
+ this.encrypt = new CipherTransformFactory(this.fetch(encrypt), fileId[0] /*, password */);
+ }
+
// get the root dictionary (catalog) object
if (!IsRef(this.root = trailerDict.get("Root")))
error("Invalid root reference");
-
- // prepare the XRef cache
- this.cache = [];
}
constructor.prototype = {
}
error("bad XRef entry");
}
- e = parser.getObj();
+ e = parser.getObj(this.encrypt);
// Don't cache streams since they are mutable.
if (!IsStream(e))
this.cache[num] = e;
}
}
} else if (cmd == "Tf") { // eagerly collect all fonts
- var fontRes = resources.get("Font");
+ var fontRes; // = resources.get("Font");
if (fontRes) {
fontRes = xref.fetchIfRef(fontRes);
var font = xref.fetchIfRef(fontRes.get(args[0].name));
--- /dev/null
+/* -*- Mode: Java; tab-width: s; indent-tabs-mode: nil; c-basic-offset: 2 -*- /
+/* vim: set shiftwidth=s tabstop=2 autoindent cindent expandtab: */
+
+"use strict";
+
+var ARCFourCipher = (function() {
+ function constructor(key) {
+ var key = this.key;
+ this.a = 0;
+ this.b = 0;
+ var s = new Uint8Array(256);
+ var i, j = 0, tmp, keyLength = key.length;
+ for (i = 0; i < 256; ++i)
+ s[i] = i;
+ for (i = 0; i < 256; ++i) {
+ tmp = s[i];
+ j = (j + tmp + key[i % keyLength]) & 0xFF;
+ s[i] = s[j];
+ s[j] = tmp;
+ }
+ this.s = s;
+ }
+
+ constructor.prototype = {
+ encryptBlock: function(data) {
+ var i, n = data.length, tmp, tmp2;
+ var a = this.a, b = this.b, s = this.s;
+ var output = new Uint8Array(n);
+ for (i = 0; i < n; ++i) {
+ var tmp;
+ a = (a + 1) & 0xFF;
+ tmp = s[a];
+ b = (b + tmp) & 0xFF;
+ tmp2 = s[b]
+ s[a] = tmp2;
+ s[b] = tmp;
+ output[i] = data[i] ^ s[(tmp + tmp2) & 0xFF];
+ }
+ this.a = a;
+ this.b = b;
+ return output;
+ }
+ };
+
+ return constructor;
+})();
+
+var md5 = (function() {
+ const r = new Uint8Array([
+ 7, 12, 17, 22, 7, 12, 17, 22, 7, 12, 17, 22, 7, 12, 17, 22,
+ 5, 9, 14, 20, 5, 9, 14, 20, 5, 9, 14, 20, 5, 9, 14, 20,
+ 4, 11, 16, 23, 4, 11, 16, 23, 4, 11, 16, 23, 4, 11, 16, 23,
+ 6, 10, 15, 21, 6, 10, 15, 21, 6, 10, 15, 21, 6, 10, 15, 21]);
+ const k = new Int32Array([
+ -680876936, -389564586, 606105819, -1044525330, -176418897, 1200080426,
+ -1473231341, -45705983, 1770035416, -1958414417, -42063, -1990404162,
+ 1804603682, -40341101, -1502002290, 1236535329, -165796510, -1069501632,
+ 643717713, -373897302, -701558691, 38016083, -660478335, -405537848, 568446438,
+ -1019803690, -187363961, 1163531501, -1444681467, -51403784, 1735328473,
+ -1926607734, -378558, -2022574463, 1839030562, -35309556, -1530992060,
+ 1272893353, -155497632, -1094730640, 681279174, -358537222, -722521979,
+ 76029189, -640364487, -421815835, 530742520, -995338651, -198630844, 1126891415,
+ -1416354905, -57434055, 1700485571, -1894986606, -1051523, -2054922799,
+ 1873313359, -30611744, -1560198380, 1309151649, -145523070, -1120210379,
+ 718787259, -343485551]);
+
+ function hash(data, offset, length) {
+ var h0 = 1732584193, h1 = -271733879, h2 = -1732584194, h3 = 271733878;
+ // pre-processing
+ var paddedLength = (length + 72) & ~63; // data + 9 extra bytes
+ var padded = new Uint8Array(paddedLength);
+ var i, j, n;
+ for (i = 0; i < length; ++i)
+ padded[i] = data[offset++];
+ padded[i++] = 0x80;
+ n = paddedLength - 8;
+ for (; i < n; ++i)
+ padded[i] = 0;
+ padded[i++] = (length << 3) & 0xFF;
+ padded[i++] = (length >> 5) & 0xFF;
+ padded[i++] = (length >> 13) & 0xFF;
+ padded[i++] = (length >> 21) & 0xFF;
+ padded[i++] = (length >>> 29) & 0xFF;
+ padded[i++] = 0;
+ padded[i++] = 0;
+ padded[i++] = 0;
+ // chunking
+ // TODO ArrayBuffer ?
+ var w = new Int32Array(16);
+ for (i = 0; i < paddedLength;) {
+ for (j = 0; j < 16; ++j, i += 4)
+ w[j] = padded[i] | (padded[i + 1] << 8) | (padded[i + 2] << 16) | (padded[i + 3] << 24);
+ var a = h0, b = h1, c = h2, d = h3, f, g;
+ for (j = 0; j < 64; ++j) {
+ if (j < 16) {
+ f = (b & c) | ((~b) & d);
+ g = j;
+ } else if (j < 32) {
+ f = (d & b) | ((~d) & c);
+ g = (5 * j + 1) & 15;
+ } else if (j < 48) {
+ f = b ^ c ^ d;
+ g = (3 * j + 5) & 15;
+ } else {
+ f = c ^ (b | (~d));
+ g = (7 * j) & 15;
+ }
+ var tmp = d, rotateArg = (a + f + k[j] + w[g]) | 0, rotate = r[j];
+ d = c;
+ c = b;
+ b = (b + ((rotateArg << rotate) | (rotateArg >>> (32 - rotate)))) | 0;
+ a = tmp;
+ }
+ h0 = (h0 + a) | 0;
+ h1 = (h1 + b) | 0;
+ h2 = (h2 + c) | 0;
+ h3 = (h3 + d) | 0;
+ }
+ return new Uint8Array([
+ h0 & 0xFF, (h0 >> 8) & 0xFF, (h0 >> 16) & 0xFF, (h0 >>> 24) & 0xFF,
+ h1 & 0xFF, (h1 >> 8) & 0xFF, (h1 >> 16) & 0xFF, (h1 >>> 24) & 0xFF,
+ h2 & 0xFF, (h2 >> 8) & 0xFF, (h2 >> 16) & 0xFF, (h2 >>> 24) & 0xFF,
+ h3 & 0xFF, (h3 >> 8) & 0xFF, (h3 >> 16) & 0xFF, (h3 >>> 24) & 0xFF
+ ]);
+ }
+ return hash;
+})();
+
+var CipherTransform = (function() {
+ function constructor(stringCipherConstructor, streamCipherConstructor) {
+ this.stringCipherConstructor = stringCipherConstructor;
+ this.streamCipherConstructor = streamCipherConstructor;
+ }
+ constructor.prototype = {
+ createStream: function (stream) {
+ var cipher = new streamCipherConstructor();
+ return new DecryptStream(stream, function(data) {
+ return cipher.encryptBlock(data);
+ });
+ },
+ decryptString: function(s) {
+ var cipher = new stringCipherConstructor();
+ var data = string2bytes(s);
+ data = cipher.encryptBlock(data);
+ return bytes2string(data);
+ }
+ };
+ return constructor;
+})();
+
+var CipherTransformFactory = (function() {
+ function prepareKeyData(fileId, password, ownerPassword, userPassword, flags, revision, keyLength) {
+ const defaultPasswordBytes = new Uint8Array([
+ 0x28, 0xBF, 0x4E, 0x5E, 0x4E, 0x75, 0x8A, 0x41, 0x64, 0x00, 0x4E, 0x56, 0xFF, 0xFA, 0x01, 0x08,
+ 0x2E, 0x2E, 0x00, 0xB6, 0xD0, 0x68, 0x3E, 0x80, 0x2F, 0x0C, 0xA9, 0xFE, 0x64, 0x53, 0x69, 0x7A]);
+ var hashData = new Uint8Array(88), i = 0, j, n;
+ if (password) {
+ n = Math.min(32, password.length);
+ for (; i < n; ++i)
+ hashData[i] = password[i];
+ }
+ j = 0;
+ while (i < 32) {
+ hashData[i++] = defaultPasswordBytes[j++];
+ }
+ // as now the padded password in the hashData[0..i]
+ for (j = 0, n = ownerPassword.length; j < n; ++j)
+ hashData[i++] = ownerPassword[j];
+ hashData[i++] = flags & 0xFF;
+ hashData[i++] = (flags >> 8) & 0xFF;
+ hashData[i++] = (flags >> 16) & 0xFF;
+ hashData[i++] = (flags >>> 24) & 0xFF;
+ for (j = 0, n = fileId.length; j < n; ++j)
+ hashData[i++] = fileId[j];
+ // TODO rev 4, if metadata is not encrypted pass 0xFFFFFF also
+ var hash = md5(hashData, 0, i);
+ var keyLengthInBytes = keyLength >> 3;
+ if (revision >= 3) {
+ for (j = 0; j < 50; ++j) {
+ hash = md5(hash, 0, keyLengthInBytes);
+ }
+ }
+ var encryptionKey = hash.subarray(0, keyLengthInBytes);
+ var cipher, checkData;
+
+ if (revision >= 3) {
+ // padded password in hashData, we can use this array for user password check
+ i = 32;
+ for(j = 0, n = fileId.length; j < n; ++j)
+ hashData[i++] = fileId[j];
+ cipher = new ARCFourCipher(encryptionKey);
+ var checkData = cipher.encryptBlock(md5(hashData, 0, i));
+ n = encryptionKey.length;
+ var derrivedKey = new Uint8Array(n), k;
+ for (j = 1; j <= 19; ++j) {
+ for (k = 0; k < n; ++k)
+ derrivedKey[k] = encryptionKey[k] ^ j;
+ cipher = new ARCFourCipher(derrivedKey);
+ checkData = cipher.encryptBlock(checkData);
+ }
+ } else {
+ cipher = new ARCFourCipher(encryptionKey);
+ checkData = cipher.encryptBlock(hashData.subarray(0, 32));
+ }
+ for (j = 0, n = checkData.length; j < n; ++j) {
+ if (userPassword[j] != checkData[j])
+ error("incorrect password");
+ }
+ return encryptionKey;
+ }
+
+ function constructor(dict, fileId, password) {
+ var filter = dict.get("Filter");
+ if (!IsName(filter) || filter.name != "Standard")
+ error("unknown encryption method");
+ this.dict = dict;
+ var algorithm = dict.get("V");
+ if (!IsInt(algorithm) ||
+ (algorithm != 1 && algorithm != 2))
+ error("unsupported encryption algorithm");
+ // TODO support algorithm 4
+ var keyLength = dict.get("Length") || 40;
+ if (!IsInt(keyLength) ||
+ keyLength < 40 || (keyLength % 8) != 0)
+ error("invalid key length");
+ // prepare keys
+ var ownerPassword = stringToBytes(dict.get("O"));
+ var userPassword = stringToBytes(dict.get("U"));
+ var flags = dict.get("P");
+ var revision = dict.get("R");
+ var fileIdBytes = stringToBytes(fileId);
+ var passwordBytes;
+ if (password)
+ passwordBytes = stringToBytes(password);
+
+ this.encryptionKey = prepareKeyData(fileIdBytes, passwordBytes,
+ ownerPassword, userPassword, flags, revision, keyLength);
+ }
+
+ constructor.prototype = {
+ createCipherTransform: function(num, gen) {
+ var encryptionKey = this.encryptionKey;
+ var key = new Uint8Array(encryptionKey.length + 5), i, j, n;
+ for (j = 0, n = encryptionKey.length; j < n; ++j)
+ key[j] = encryptionKey[j];
+ key[i++] = num & 0xFF;
+ key[i++] = (num >> 8) & 0xFF;
+ key[i++] = (num >> 16) & 0xFF;
+ key[i++] = gen & 0xFF;
+ key[i++] = (gen >> 8) & 0xFF;
+ var hash = md5(key, 0, i);
+ key = hash.subarray(0, Math.min(key.length, 16));
+ var cipherConstructor = function() {
+ return new ARCFourCipher(key);
+ };
+ return new CipherTransform(cipherConstructor, cipherConstructor);
+ }
+ };
+
+ return constructor;
+})();
projects / pdf.js.git / commitdiff