The GOST Eyepiece application has been published, which is a branch of the Okular document viewer developed by the KDE project, expanded with support for GOST hash algorithms in the functions of checking and electronically signing PDF files. The program supports simple (CAdES BES) and advanced (CAdES-X Type 1) CAdES embedded signature formats. Cryptoprovider CryptoPro is used to generate and verify signatures.
In addition, many errors of the original Okular have been corrected in the GOST Eyepiece, including problems with the use of Cyrillic when filling out forms and inserting images in PNG and JPEG format, as well as numerous errors when using non-Latin encodings. The program code is distributed under the GPLv2 license, similar to the Poppler and Okular projects. Some of the corrections implemented during the development of the GOST Eyepiece have already been adopted into the original Okular project, and some will be submitted for inclusion in the near future. Ready-made assemblies are prepared for the operating systems Alt, Astra Linux, Debian, Fedora, ROSA and Ubuntu.
Source: opennet.ru