there might be other variants out there in practice, but this works for default encrypted xls of excel 2013
1473ce0 implement CryptoAPI RC4+SHA1 encryption scheme for xls import
filter/source/msfilter/mscodec.cxx | 142 +++++++++++++++++++++++++---------
include/filter/msfilter/mscodec.hxx | 122 +++++++++++++++++------------
sc/source/filter/excel/xicontent.cxx | 80 ++++++++++++++++---
sc/source/filter/excel/xistream.cxx | 70 +++++++++++------
sc/source/filter/inc/xistream.hxx | 67 ++++++++++++----
5 files changed, 347 insertions(+), 134 deletions(-)
Upstream: cgit.freedesktop.org