3 This engine provides implementation of Russian cryptography standard.
4 This is also an example of adding new cryptoalgorithms into OpenSSL
5 without changing its core. If OpenSSL is compiled with dynamic engine
6 support, new algorithms can be added even without recompilation of
7 OpenSSL and applications which use it.
11 GOST R 34.10-2001 and GOST R 34.10-2012 - digital signature algorithms.
12 Also support key exchange based on public keys. See RFC 4357 for
13 details of VKO key exchange algorithm. These algorithms use
14 256 bit private keys. Public keys are 1024 bit for 94 and 512 bit for
15 2001 (which is elliptic-curve based). Key exchange algorithms
16 (VKO R 34.10) are supported on these keys too.
18 GOST R 34.11-2012 Message digest algorithm. 256- and 512-bit hash values.
20 GOST 28147-89 - Symmetric cipher with 256-bit key. Various modes are
21 defined in the standard, but only CFB and CNT modes are implemented
22 in the engine. To make statistical analysis more difficult, key
23 meshing is supported (see RFC 4357).
25 GOST 28147-89 MAC mode. Message authentication code. While most MAC
26 algorithms out there are based on hash functions using HMAC
27 algorithm, this algoritm is based on symmetric cipher.
28 It has 256-bit symmetric key and only 32 bits of MAC value
29 (while HMAC has same key size and value size).
31 Really, this algorithm supports from 8 to 64 bits of the MAC value
33 It is implemented as combination of EVP_PKEY type and EVP_MD type.
35 GOST R 34.13–2015 - Symmetric cypher Grasshopper ("Kuznechik")
37 USAGE OF THESE ALGORITHMS
39 This engine is designed to allow usage of this algorithms in the
40 high-level openssl functions, such as PKI, S/MIME and TLS.
42 See RFC 4490 for S/MIME with GOST algorithms and RFC 4491 for PKI.
43 TLS support is implemented according IETF
44 draft-chudov-cryptopro-cptls-03.txt and is compatible with
45 CryptoPro CSP 3.0 and 3.6 as well as with MagPro CSP.
46 GOST ciphersuites implemented in CryptoPro CSP 2.0 are not supported
47 because they use ciphersuite numbers used now by AES ciphersuites.
49 To use the engine you have to load it via openssl configuration
50 file. Applications should read openssl configuration file or provide
51 their own means to load engines. Also, applications which operate with
52 private keys, should use generic EVP_PKEY API instead of using RSA or
53 other algorithm-specific API.
57 Configuration file should include following statement in the global
58 section, i.e. before first bracketed section header (see config(5) for details)
60 openssl_conf = openssl_def
62 where openssl_def is name of the section in configuration file which
63 describes global defaults.
65 This section should contain following statement:
68 engines = engine_section
70 which points to the section which describes list of the engines to be
71 loaded. This section should contain:
76 And section which describes configuration of the engine should contain
80 dynamic_path = /usr/lib/ssl/engines/libgost.so
81 default_algorithms = ALL
82 CRYPT_PARAMS = id-Gost28147-89-CryptoPro-A-ParamSet
84 Where engine_id parameter specifies name of engine (should be "gost").
85 dynamic_path is a location of the loadable shared library implementing the
86 engine. If the engine is compiled statically or is located in the OpenSSL
87 engines directory, this line can be omitted.
88 default_algorithms parameter specifies that all algorithms, provided by
89 engine, should be used.
91 The CRYPT_PARAMS parameter is engine-specific. It allows the user to choose
92 between different parameter sets of symmetric cipher algorithm. RFC 4357
93 specifies several parameters for the GOST 28147-89 algorithm, but OpenSSL
94 doesn't provide user interface to choose one when encrypting. So use engine
95 configuration parameter instead.
97 Value of this parameter can be either short name, defined in OpenSSL
98 obj_dat.h header file or numeric representation of OID, defined in RFC
101 USAGE WITH COMMAND LINE openssl UTILITY
103 1. Generation of private key
105 openssl genpkey -algorithm gost2001 -pkeyopt paramset:A -out seckey.pem
107 Use -algorithm option to specify algorithm.
108 Use -pkeyopt option to pass paramset to algorithm. The following paramsets
110 gost94: 0,A,B,C,D,XA,XB,XC
111 gost2001: 0,A,B,C,XA,XB
112 You can also use numeric representation of OID as to destinate
115 Paramsets starting with X are intended to use for key exchange keys.
116 Paramsets without X are for digital signature keys.
118 Paramset for both algorithms 0 is the test paramset which should be used
119 only for test purposes.
121 There are no algorithm-specific things with generation of certificate
122 request once you have a private key.
124 2. Generation of certificate request along with private/public keypar
126 openssl req -newkey gost2001 -pkeyopt paramset:A
128 Syntax of -pkeyopt parameter is identical with genpkey command.
130 You can also use oldstyle syntax -newkey gost2001:paramfile, but in
131 this case you should create parameter file first.
133 It can be created with
135 openssl genpkey -genparam -algorithm gost2001 -pkeyopt paramset:A\
140 If you want to send encrypted mail using GOST algorithms, don't forget
141 to specify -gost89 as encryption algorithm for OpenSSL smime command.
142 While OpenSSL is clever enough to find out that GOST R 34.11-94 digest
143 must be used for digital signing with GOST private key, it have no way
144 to derive symmetric encryption algorithm from key exchange keys.
148 OpenSSL supports all four ciphersuites defined in the IETF draft.
149 Once you've loaded GOST key and certificate into your TLS server,
150 ciphersuites which use GOST 28147-89 encryption are enabled.
152 Ciphersuites with NULL encryption should be enabled explicitely if
155 GOST2001-GOST89-GOST89 Uses GOST R 34.10-2001 for auth and key exchange
156 GOST 28147-89 for encryption and GOST 28147-89 MAC
157 GOST94-GOST89-GOST89 Uses GOST R 34.10-94 for auth and key exchange
158 GOST 28147-89 for encryption and GOST 28147-89 MAC
159 GOST2001-NULL-GOST94 Uses GOST R 34.10-2001 for auth and key exchange,
160 no encryption and HMAC, based on GOST R 34.11-94
161 GOST94-NULL-GOST94 Uses GOST R 34.10-94 for auth and key exchange,
162 no encryption and HMAC, based on GOST R 34.11-94
164 Gost 94 and gost 2001 keys can be used simultaneously in the TLS server.
165 RSA, DSA and EC keys can be used simultaneously with GOST keys, if
166 server implementation supports loading more than two private
167 key/certificate pairs. In this case ciphersuites which use any of loaded
168 keys would be supported and clients can negotiate ones they wish.
170 This allows creation of TLS servers which use GOST ciphersuites for
171 Russian clients and RSA/DSA ciphersuites for foreign clients.
173 5. Calculation of digests and symmetric encryption
174 OpenSSL provides specific commands (like sha1, aes etc) for calculation
175 of digests and symmetric encryption. Since such commands cannot be
176 added dynamically, no such commands are provided for GOST algorithms.
177 Use generic commands 'dgst' and 'enc'.
179 Calculation of GOST R 34.11-94 message digest
181 openssl dgst -md_gost94 datafile
183 Note that GOST R 34.11-94 specifies that digest value should be
184 interpreted as little-endian number, but OpenSSL outputs just hex dump
187 So, to obtain correct digest value, such as produced by gostsum utility
188 included in the engine distribution, bytes of output should be
191 Calculation of HMAC based on GOST R 34.11-94
193 openssl dgst -md_gost94 -mac hmac -macopt key:<32 bytes of key> datafile
195 (or use hexkey if key contain NUL bytes)
196 Calculation of GOST 28147 MAC
198 openssl dgst -mac gost-mac -macopt key:<32 bytes of key> datafile
200 Note absence of an option that specifies digest algorithm. gost-mac
201 algorithm supports only one digest (which is actually part of
202 implementation of this mac) and OpenSSL is clever enough to find out
205 Following mac options are supported:
207 key:(32 bytes of key)
209 hexkey:(64 hexadecimal digits of key)
211 Engine support calculation of mac with size different from default 32
212 bits. You can set mac size to any value from 1 to 8 bytes using
214 -sigopt size:(number from 1 to 8 - mac size in bytes)
216 (dgst command uses different EVP_PKEY_CTX for initialization and for
217 finalization of MAC. Option of first are set via -macopt, and for
218 second via -sigopt. Key should be set during initialization and size
219 during finalization. If you use API functions
220 EVP_DigestSignInit/EVP_DigestSignFinal, you can set both options at
223 Encryption with GOST 28147 CFB mode
224 openssl enc -gost89 -out encrypted-file -in plain-text-file -k <passphrase>
225 Encryption with GOST 28147 CNT mode
226 openssl enc -gost89-cnt -out encrypted-file -in plain-text-file -k <passphrase>
227 Encryption with GOST 28147 CBC mode
228 openssl enc -gost89-cbc -out encrypted-file -in plain-text-file -k <passphrase>
230 6. Encrypting private keys and PKCS12
232 To produce PKCS12 files compatible with MagPro CSP, you need to use
233 GOST algorithm for encryption of PKCS12 file and also GOST R 34.11-94
234 hash to derive key from password.
236 openssl pksc12 -export -inkey gost.pem -in gost_cert.pem -keypbe gost89\
237 -certpbe gost89 -macalg md_gost94
239 7. Testing speed of symmetric ciphers.
241 To test performance of GOST symmetric ciphers you should use -evp switch
242 of the openssl speed command. Engine-provided ciphers couldn't be
243 accessed by cipher-specific functions, only via generic evp interface
245 openssl speed -evp gost89
246 openssl speed -evp gost89-cnt
247 openssl speed -evp gost89-cbc
250 PROGRAMMING INTERFACES DETAILS
252 Applications never should access engine directly. They only use provided
253 EVP_PKEY API. But there are some details, which should be taken into
256 EVP provides two kinds of API for key exchange:
258 1. EVP_PKEY_encrypt/EVP_PKEY_decrypt functions, intended to use with
259 RSA-like public key encryption algorithms
261 2. EVP_PKEY_derive, intended to use with Diffie-Hellman-like shared key
262 computing algorithms.
264 Although VKO R 34.10 algorithms, described in the RFC 4357 are
265 definitely second case, engine provides BOTH API for GOST R 34.10 keys.
267 EVP_PKEY_derive just invokes appropriate VKO algorithm and computes
268 256 bit shared key. VKO R 34.10-2001 requires 64 bits of random user key
269 material (UKM). This UKM should be transmitted to other party, so it is
270 not generated inside derive function.
272 It should be set by EVP_PKEY_CTX_ctrl function using
273 EVP_PKEY_CTRL_SET_IV command after call of EVP_PKEY_derive_init, but
274 before EVP_PKEY_derive.
275 unsigned char ukm[8];
277 EVP_PKEY_CTX_ctrl(ctx, -1, EVP_PKEY_OP_DERIVE, 8, ukm)
279 EVP_PKEY_encrypt encrypts provided session key with VKO shared key and
280 packs it into GOST key transport structure, described in the RFC 4490.
282 It typically uses ephemeral key pair to compute shared key and packs its
283 public part along with encrypted key. So, for most cases use of
284 EVP_PKEY_encrypt/EVP_PKEY_decrypt with GOST keys is almost same as with
287 However, if peerkey field in the EVP_PKEY_CTX structure is set (using
288 EVP_PKEY_derive_set_peerkey function) to EVP_PKEY structure which has private
289 key and uses same parameters as the public key from which this EVP_PKEY_CTX is
290 created, EVP_PKEY_encrypt will use this private key to compute shared key and
291 set ephemeral key in the GOST_key_transport structure to NULL. In this case
292 pkey and peerkey fields in the EVP_PKEY_CTX are used upside-down.
294 If EVP_PKEY_decrypt encounters GOST_key_transport structure with NULL
295 public key field, it tries to use peerkey field from the context to
296 compute shared key. In this case peerkey field should really contain
299 Encrypt operation supports EVP_PKEY_CTRL_SET_IV operation as well.
300 It can be used when some specific restriction on UKM are imposed by
301 higher level protocol. For instance, description of GOST ciphersuites
302 requires UKM to be derived from shared secret.
304 If UKM is not set by this control command, encrypt operation would
308 This sources include implementation of GOST 28147-89 and GOST R 34.11-94
309 which are completely indepentent from OpenSSL and can be used separately
310 (files gost89.c, gost89.h, gosthash.c, gosthash.h) Utility gostsum (file
311 gostsum.c) is provided as example of such separate usage. This is
312 program, simular to md5sum and sha1sum utilities, but calculates GOST R
315 Makefile doesn't include rule for compiling gostsum.
318 $(CC) -o gostsum gostsum.c gost89.c gosthash.c
319 where $(CC) is name of your C compiler.
321 Implementations of GOST R 34.10-xx, including VKO algorithms heavily
322 depends on OpenSSL BIGNUM and Elliptic Curve libraries.