mirrors/CyberChef
1
0
Fork 0
mirror of https://github.com/gchq/CyberChef.git synced 2025-05-09 07:45:00 -04:00
Code Issues Projects Releases Packages Wiki Activity Actions 1

Working on Mime walking

Browse source
This commit is contained in:
Brian Whitney 2018-11-23 15:00:34 -05:00
parent d8667a67be
commit 189cf337d6
1 changed files with 49 additions and 28 deletions
Download patch file Download diff file Expand all files Collapse all files

77
src/core/operations/ParseIMF.mjs
View file

@ -29,26 +29,6 @@ const IMF_FIELD_ITEM = {
TRANSER_ENCODING: [/\s*([A-Za-z0-9-]+)\s*/, "content-transfer-encoding"],
}
/**
* @constant
* @default
*/
// TODO: should 8 bit and 7 bit be treated the same?
const IMF_DECODER = {
"base64": function (input) {
return fromBase64(input);
},
"quoted-printable": function (input) {
return Utils.byteArrayToUtf8(decodeQuotedPrintable(input));
},
"7bit": function (input) {
return input;
},
"8bit": function (input) {
return input;
},
}
class ParseIMF extends Operation {
/**
@ -93,10 +73,11 @@ class ParseIMF extends Operation {
if (args[0] && headerBody.length > 0) {
headerBody[0] = ParseIMF.replaceDecodeWord(headerBody[0]);
}
let retfiles = ParseIMF.walkMime(headerBody[1], headerArray, input.indexOf("\r") >= 0);
let retval = [];
let i = 0;
headerBody.forEach(function(file){
file = new File([file], "test"+String(i), {type: "text/plain"});
retfiles.forEach(function(file){
file = new File([file.data], "test"+String(i), {type: "text/plain"});
retval.push(file);
i++;
});
@ -120,9 +101,39 @@ class ParseIMF extends Operation {
* @param {object} header
* @returns {object[]}
*/
static walkMime(input, header) {
let output = [];
if header[""]
static walkMime(input, header, rn) {
let new_line_length = rn ? 2 : 1;
const content_type_reg = /([^;]+);\s+boundary\=(['"])(.+?)\2/g;
const inner_content_type_reg = /^([^;]+);\s+type\=(['"])(.+?)\2;\s+boundary\=(['"])(.+?)\4/g;
let output_sections = [];
if (header.hasOwnProperty("mime-version") || (header.hasOwnProperty("content-type") && header["content-type"][0].startsWith("multipart/"))) {
let content_boundary = null;
let idx = 3;
if (header["content-type"][0].indexOf("type=") > 0) {
content_boundary = inner_content_type_reg.exec(header["content-type"][0]);
idx = 5;
} else {
content_boundary = content_type_reg.exec(header["content-type"][0]);
}
const boundary_str = "--".concat(content_boundary[idx]);
let start = input.indexOf(boundary_str) + boundary_str.length + new_line_length;
let end = input.indexOf(boundary_str.concat("--")) - new_line_length;
let output = input.substring(start, end);
let headerBody = ParseIMF.splitHeaderFromBody(output);
let headerArray = ParseIMF.parseHeader(headerBody[0]);
let parts = ParseIMF.walkMime(headerBody[1], headerArray, rn);
parts.forEach(function(part){
output_sections.push(part);
});
} else if (header.hasOwnProperty("content-type") && header.hasOwnProperty("content-transfer-encoding")) {
const cont_type_data_reg = /^([^;]+);\s+charset\=(['"])(.+?)\2/g;
let cont_type = cont_type_data_reg.exec(header["content-type"][0]);
let val = ParseIMF.decodeMimeData(input, cont_type[3], header["content-transfer-encoding"][0]);
return [{type:cont_type[1], data: val}];
} else {
throw new OperationError("Invalid Mime section");
}
return output_sections;
}
/**
@ -190,9 +201,19 @@ class ParseIMF extends Operation {
* @returns {string}
*/
static decodeMimeData(input, charEnc, contEnc) {
//TODO: make exceptions for unknown charEnc and contEnc?
input = IMF_DECODER[contEnc](input);
if (charEnc) {
switch (contEnc) {
case "base64":
input = fromBase64(input);
break;
case "quoted-printable":
input = Utils.byteArrayToUtf8(decodeQuotedPrintable(input));
break;
case "7bit":
case "8bit":
default:
break;
}
if (charEnc && MIME_FORMAT.hasOwnProperty(charEnc.toLowerCase())) {
input = cptable.utils.decode(MIME_FORMAT[charEnc.toLowerCase()], input);
}
return input;