jkurwa

GF2m ellipcit curves library in javascript.

• Supports short Weierstrass curves used in Ukrainian standard DSTU 4145;
• Provides key deriviation for DSTU block ciphers (see https://github.com/muromec/em-gost);
• Encypted containers can be parsed and decrypted if respective cipher implementation is passed. See gost89 and dstucrypt/agent for reference;
• Encrypted and signed messages in wicked PKCS#7 format used by tax office (sta.gov.ua) are supported for both read and write (see jk.Box, jk.util.transport);
• Includes parsers for signed and encrypted messages, X509.v3 certificates, JKS and Key-6.dat key containers, TSP, CMP, OCSP requests and responses.

Warning

• Jkurwa does not guarranty constant-time calculcation;
• Jkurwa only verifies signature against public key and does not actually check X.509 certificate validity unless CA list is loaded. See dstucrypt/agent repo readme for details.

Usage

See ./test/ and ./examples/ directories. See dstucrypt/agent repo for example app.

Sister libraries:

• https://github.com/dstucrypt/ukurwa4145 - DSTU 4145 in Python;
• https://github.com/dstucrypt/gost89 - GOST cipher, hash, mac, key wrapper and container loader in pure js;
• https://github.com/dstucrypt/python-gost89 - gost hash for python (2 and 3);
• https://github.com/dstucrypt/jksreader - library to parse java-style key containers used by privatbank;
• https://github.com/muromec/zozol - dumb ASN.1 parser and serialisator for python with X509 and wicked CMS schemas;
• https://github.com/dstucrypt/openssl-dstu - patched OpenSSL with DSTU 4145 and GOST family support (outdated, unmaintained).

Demo site: https://dstucrypt.github.io/signerbox2/

Demo apps:

• https://github.com/dstucrypt/agent -- command line utility and daemon service to sign, encrypt and decrypt files;
• https://github.com/dstucrypt/dstukeys -- web interface with examples of authentication;
• https://github.com/dstucrypt/signerbox2/ -- another web app;
• https://github.com/max1gu/e-rro -- cash register app (прогрманий рро).

To cross-verifiy signatures use https://czo.gov.ua/verify .

References

• Certificate format (in Ukrainian), basically kind of X.509v3: http://zakon4.rada.gov.ua/laws/show/z1398-12
• Private key container format, PBES2-like (effective from 01.01.2016): http://zakon3.rada.gov.ua/laws/show/z2227-13
• See https://github.com/dstucrypt/agent repo for tax report format and implementation details
• Law on Trust Services - http://zakon.rada.gov.ua/laws/show/2155-19

Bonus

First known use of the word Kurwa was recorded in 1415. Happy 600 birthday Kurwa!