Problem opening certain encrypted spreadsheets in Excel

[pbowyer]

I've been testing the encryption feature to add encryption to existing workbooks a web app generates. Some work brilliantly, but with more complex workbooks they encrypt without any error but won't open in Excel.

Excel then shows the dialog:

If I click 'Yes' Excel hangs and has to be force-closed.

I thought our spreadsheets could be the issue (they are generated with box/spout) so tested encrypting with herumi/msoffice. Excel is able to decrypt these ones without issue.

xlsx-populate setup

I installed it yesterday via npm:

`-- xlsx-populate@1.14.1
  +-- cfb@1.0.7
  | +-- commander@2.15.1
  | `-- printj@1.1.2
  +-- jszip@3.1.5
  | +-- core-js@2.3.0
  | +-- es6-promise@3.0.2
  | +-- lie@3.1.1
  | | `-- immediate@3.0.6
  | +-- pako@1.0.6
  | `-- readable-stream@2.0.6
  |   +-- core-util-is@1.0.2
  |   +-- inherits@2.0.3
  |   +-- isarray@1.0.0
  |   +-- process-nextick-args@1.0.7
  |   +-- string_decoder@0.10.31
  |   `-- util-deprecate@1.0.2
  +-- lodash@4.17.10
  `-- sax@1.2.4

My code to encrypt the file is:

const XlsxPopulate = require("xlsx-populate");
XlsxPopulate.fromFileAsync("./nta-anonymised.xlsx", {})
.then(workbook => {
    workbook.toFileAsync("./nta-enc-xlsxpopulate.xlsx", { password: "testing123" });
});

Excel

Microsoft Excel 2016 MSO (16.0.8431.2110) 32-bit
Running on Windows 10 Pro

msoffice-crypto

Built yesterday from Git, on Ubuntu 16.04. When run on the file outputs:

$ msoffice-crypt -e -p testing123 nta-anonymised.xlsx nta-enc-msoffice-crypt.xlsx -v
inFile=nta-anonymised.xlsx, outFile=nta-enc-msoffice-crypt.xlsx, mode=enc, encMode=0
encryptionInfoStr size=1056
miniFatNum=26
miniFatDataSectorNum=4
encryptionPackageSectorNum=21
contentSectorNum=29
fatSectorNum=1
difatSectorNum=0
allSectorNum=30
data.size=15872

Sample files

File	Purpose
nta-anonymised.xlsx	The raw, unencrypted file
nta-enc-xlsxpopulate.xlsx	Encrypted with xlsx-populate, does not open in Excel
nta-enc-msoffice-crypt.xlsx	Encrypted with herumi/msoffice and opens in Excel