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#94 refactor duplicated code
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@totaam
totaam committed Sep 3, 2021
1 parent c09acc7 commit eea3f95
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Showing 2 changed files with 50 additions and 63 deletions.
8 changes: 6 additions & 2 deletions html5/js/Client.js
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Original file line number Diff line number Diff line change
Expand Up @@ -1206,7 +1206,7 @@ XpraClient.prototype._make_hello_base = function() {
"cipher.mode" : mode,
"cipher.iv" : Utilities.getSecureRandomString(16),
"cipher.key_salt" : Utilities.getSecureRandomString(32),
"cipher.key_size" : 32,
"cipher.key_size" : 32, //256 bits
"cipher.key_hash" : "SHA1",
"cipher.key_stretch_iterations" : 1000,
"cipher.padding.options" : ["PKCS#7"],
Expand Down Expand Up @@ -1813,7 +1813,11 @@ XpraClient.prototype._process_hello = function(packet, ctx) {
];
for (let i=0; i<CIPHER_CAPS.length; ++i) {
const cipher_key = "cipher"+CIPHER_CAPS[i];
ctx.cipher_out_caps[cipher_key] = hello[cipher_key];
let value = hello[cipher_key];
if ((typeof value) === 'object' && value.constructor===Uint8Array) {
value = String.fromCharCode.apply(null, value);
}
ctx.cipher_out_caps[cipher_key] = value;
}
ctx.protocol.set_cipher_out(ctx.cipher_out_caps, ctx.encryption_key);
}
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105 changes: 44 additions & 61 deletions html5/js/Protocol.js
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Original file line number Diff line number Diff line change
Expand Up @@ -356,6 +356,17 @@ XpraProtocol.prototype.do_process_receive_queue = function() {
if (proto_crypto) {
this.cipher_in.update(forge.util.createBuffer(uintToString(packet_data)));
const decrypted = this.cipher_in.output.getBytes();
if (!decrypted || decrypted.length<packet_size-padding) {
this.error("error decrypting packet using", this.cipher_in);
if (decrypted.length<packet_size-padding) {
this.error(" expected "+(packet_size-padding)+" bytes, but got "+decrypted.length);
}
else {
this.error(" decrypted:", decrypted);
}
this.raw_packets = [];
return this.rQ.length>0;
}
packet_data = new Uint8Array(packet_size-padding);
for (i=0; i<packet_size-padding; i++) {
packet_data[i] = decrypted[i].charCodeAt(0);
Expand Down Expand Up @@ -574,95 +585,67 @@ XpraProtocol.prototype.set_packet_handler = function(callback, ctx) {
};

XpraProtocol.prototype.set_cipher_in = function(caps, key) {
const me = this;
this.setup_cipher(caps, key, function(cipher, block_size, secret, iv) {
me.cipher_in_block_size = block_size;
me.cipher_in = forge.cipher.createDecipher(cipher, secret);
//me.cipher_in.start({"iv": iv, "tagLength" : 0, "tag" : ""});
me.cipher_in.start({"iv": iv});
});
};

XpraProtocol.prototype.set_cipher_out = function(caps, key) {
const me = this;
this.setup_cipher(caps, key, function(cipher, block_size, secret, iv) {
me.cipher_out_block_size = block_size;
me.cipher_out = forge.cipher.createCipher(cipher, secret);
me.cipher_out.start({"iv": iv});
});
};

XpraProtocol.prototype.setup_cipher = function(caps, key, setup_fn) {
if (!key) {
throw "missing encryption key";
}
// stretch the password
const cipher = caps["cipher"];
const cipher = caps["cipher"] || "AES";
if (cipher!="AES") {
throw "unsupported encryption specified: '"+cipher+"'";
}
const salt = caps["cipher.key_salt"];
const key_salt = caps["cipher.key_salt"];
const iterations = caps["cipher.key_stretch_iterations"];
if (iterations<0) {
throw "invalid number of iterations: "+iterations;
}
const DEFAULT_KEYSIZE = 32;
const key_size = caps["cipher.key_size"] || DEFAULT_KEYSIZE;
if (key_size<=16) {
if ([32, 24, 16].indexOf(key_size)<0) {
throw "invalid key size '"+key_size+"'";
}
const key_stretch = caps["cipher.key_stretch"] || "PBKDF2";
if (key_stretch.toUpperCase()!="PBKDF2") {
throw "invalid key stretching function "+key_stretch;
}
const DEFAULT_KEY_HASH = "SHA1";
const key_hash = (caps["cipher.key_hash"] || DEFAULT_KEY_HASH).toLowerCase();
const secret = forge.pkcs5.pbkdf2(key, salt, iterations, key_size, key_hash);
const secret = forge.pkcs5.pbkdf2(key, key_salt, iterations, key_size, key_hash);
const DEFAULT_MODE = "CBC";
const mode = caps["cipher.mode"] || DEFAULT_MODE;
if (mode=="CBC") {
this.cipher_in_block_size = 32;
let block_size = 0;
if (mode=="CBC") {
block_size = 32;
}
else if (["CFB", "CTR"].indexOf(mode)>=0){
this.cipher_in_block_size = 0;
}
else {
else if (["CFB", "CTR"].indexOf(mode)<0){
throw "unsupported AES mode '"+mode+"'";
}
// start the cipher
this.cipher_in = forge.cipher.createDecipher(cipher+"-"+mode, secret);
const iv = caps["cipher.iv"];
if (!iv) {
throw "missing IV";
}
this.cipher_in.start({iv: iv, tagLength : 0, tag : ""});
//ie: setup_fn("AES-CBC", "THESTRETCHEDKEYVALUE", "THEIVVALUE");
setup_fn(cipher+"-"+mode, block_size, secret, iv);
};

XpraProtocol.prototype.set_cipher_out = function(caps, key) {
if (!key) {
throw "missing encryption key";
}
function cipher_cap(k) {
var value = caps['cipher'+k];
if ((typeof value) === 'object' && value.constructor===Uint8Array) {
value = String.fromCharCode.apply(null, value);
}
return value;
}
const cipher = cipher_cap("") || "AES";
if (cipher!="AES") {
throw "unsupported encryption specified: '"+cipher+"'";
}
const key_salt = cipher_cap('.key_salt');
const iterations = cipher_cap('.key_stretch_iterations');
if (iterations<0) {
throw "invalid number of iterations: "+iterations;
}
const DEFAULT_KEYSIZE = 32;
const key_size = cipher_cap('.key_size') || DEFAULT_KEYSIZE;
if (key_size<=16) {
throw "invalid key size '"+key_size+"'";
}
// stretch the password
const DEFAULT_KEY_HASH = "SHA1";
const key_hash = (cipher_cap(".key_hash") || DEFAULT_KEY_HASH).toLowerCase();
const secret = forge.pkcs5.pbkdf2(key, key_salt, iterations, key_size, key_hash);
const DEFAULT_MODE = "CBC";
const mode = cipher_cap(".mode") || DEFAULT_MODE;
if (mode=="CBC") {
this.cipher_out_block_size = 32;
}
else if (["CFB", "CTR"].indexOf(mode)>=0){
this.cipher_out_block_size = 0;
}
else {
throw "unsupported AES mode '"+mode+"'";
}
// start the cipher
const iv = cipher_cap('.iv');
if (!iv) {
throw "missing IV";
}
this.cipher_out = forge.cipher.createCipher(cipher+"-"+mode, secret);
this.cipher_out.start({iv: iv});
};


/*
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