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 34.10-94 and GOST R 34.10-2001 - 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 34.11-94 Message digest algorithm. 256-bit hash value
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 It is implemented as combination of EVP_PKEY type and EVP_MD type.
33 USAGE OF THESE ALGORITHMS
35 This engine is designed to allow usage of this algorithms in the
36 high-level openssl functions, such as PKI, S/MIME and TLS.
38 See RFC 4490 for S/MIME with GOST algorithms and RFC 4491 for PKI.
39 TLS support is implemented according IETF
40 draft-chudov-cryptopro-cptls-03.txt and is compatible with
41 CryptoPro CSP 3.0 and 3.6 as well as with MagPro CSP.
42 GOST ciphersuites implemented in CryptoPro CSP 2.0 are not supported
43 because they use ciphersuite numbers used now by AES ciphersuites.
45 To use the engine you have to load it via openssl configuration
46 file. Applications should read openssl configuration file or provide
47 their own means to load engines. Also, applications which operate with
48 private keys, should use generic EVP_PKEY API instead of using RSA or
49 other algorithm-specific API.
53 Configuration file should include following statement in the global
54 section, i.e. before first bracketed section header (see config(5) for details)
56 openssl_conf = openssl_def
58 where openssl_def is name of the section in configuration file which
59 describes global defaults.
61 This section should contain following statement:
64 engines = engine_section
66 which points to the section which describes list of the engines to be
67 loaded. This section should contain:
72 And section which describes configuration of the engine should contain
76 dynamic_path = /usr/lib/ssl/engines/libgost.so
77 default_algorithms = ALL
78 crypt_params = id-Gost28147-89-CryptoPro-A-ParamSet
80 Where engine_id parameter specifies name of engine (should be "gost").
81 dynamic_path is a location of the loadable shared library implementing the
82 engine. If the engine is compiled statically or is located in the OpenSSL
83 engines directory, this line can be omitted. But as of October 2007 there is
84 some bug in OpenSSL engine initialization code which prevents engine from
85 correct initialization if it is loaded without explicit dynamic_path.
86 default_algorithms parameter specifies that all algorithms, provided by
87 engine, should be used.
89 The crypt_params parameter is engine-specific. It allows the user to choose
90 between different parameter sets of symmetric cipher algorithm. RFC 4357
91 specifies several parameters for the GOST 28147-89 algorithm, but OpenSSL
92 doesn't provide user interface to choose one when encrypting. So use engine
93 configuration parameter instead.
95 Value of this parameter can be either short name, defined in OpenSSL
96 obj_dat.h header file or numeric representation of OID, defined in RFC
99 USAGE WITH COMMAND LINE openssl UTILITY
101 1. Generation of private key
103 openssl genpkey -algorithm gost2001 -pkeyopt paramset:A -out seckey.pem
105 Use -algorithm option to specify algorithm.
106 Use -pkeyopt option to pass paramset to algorithm. The following paramsets
108 gost94: 0,A,B,C,D,XA,XB,XC
109 gost2001: 0,A,B,C,XA,XB
110 You can also use numeric representation of OID as to destinate
113 Paramsets starting with X are intended to use for key exchange keys.
114 Paramsets without X are for digital signature keys.
116 Paramset for both algorithms 0 is the test paramset which should be used
117 only for test purposes.
119 There are no algorithm-specific things with generation of certificate
120 request once you have a private key.
124 If you want to send encrypted mail using GOST algorithms, don't forget
125 to specify -gost89 as encryption algorithm for OpenSSL smime command.
126 While OpenSSL is clever enough to find out that GOST R 34.11-94 digest
127 must be used for digital signing with GOST private key, it have no way
128 to derive symmetric encryption algorithm from key exchange keys.
132 OpenSSL supports all four ciphersuites defined in the IETF draft.
133 Once you've loaded GOST key and certificate into your TLS server,
134 ciphersuites which use GOST 28147-89 encryption are enabled.
136 Ciphersuites with NULL encryption should be enabled explicitely if
139 GOST2001-GOST89-GOST89 Uses GOST R 34.10-2001 for auth and key exchange
140 GOST 28147-89 for encryption and GOST 28147-89 MAC
141 GOST94-GOST89-GOST89 Uses GOST R 34.10-94 for auth and key exchange
142 GOST 28147-89 for encryption and GOST 28147-89 MAC
143 GOST2001-NULL-GOST94 Uses GOST R 34.10-2001 for auth and key exchange,
144 no encryption and HMAC, based on GOST R 34.11-94
145 GOST94-NULL-GOST94 Uses GOST R 34.10-94 for auth and key exchange,
146 no encryption and HMAC, based on GOST R 34.11-94
148 Gost 94 and gost 2001 keys can be used simultaneously in the TLS server.
149 RSA, DSA and EC keys can be used simultaneously with GOST keys, if
150 server implementation supports loading more than two private
151 key/certificate pairs. In this case ciphersuites which use any of loaded
152 keys would be supported and clients can negotiate ones they wish.
154 This allows creation of TLS servers which use GOST ciphersuites for
155 Russian clients and RSA/DSA ciphersuites for foreign clients.
157 4. Calculation of digests and symmetric encryption
158 OpenSSL provides specific commands (like sha1, aes etc) for calculation
159 of digests and symmetric encryption. Since such commands cannot be
160 added dynamically, no such commands are provided for GOST algorithms.
161 Use generic commands 'dgst' and 'enc'.
163 Calculation of GOST R 34.11-94 message digest
165 openssl dgst -md_gost94 datafile
167 Note that GOST R 34.11-94 specifies that digest value should be
168 interpreted as little-endian number, but OpenSSL outputs just hex dump
171 So, to obtain correct digest value, such as produced by gostsum utility
172 included in the engine distribution, bytes of output should be
175 Calculation of HMAC based on GOST R 34.11-94
177 openssl dgst -md_gost94 -mac hmac -macopt key:<32 bytes of key> datafile
179 (or use hexkey if key contain NUL bytes)
180 Calculation of GOST 28147 MAC
182 openssl dgst -mac gost-mac -macopt key:<32 bytes of key> datafile
184 Note absense of an option that specifies digest algorithm. gost-mac
185 algorithm supports only one digest (which is actually part of
186 implementation of this mac) and OpenSSL is clever enough to find out
189 Encryption with GOST 28147 CFB mode
190 openssl enc -gost89 -out encrypted-file -in plain-text-file -k <passphrase>
191 Encryption with GOST 28147 CNT mode
192 openssl enc -gost89-cnt -out encrypted-file -in plain-text-file -k <passphrase>
195 5. Encrypting private keys and PKCS12
197 To produce PKCS12 files compatible with MagPro CSP, you need to use
198 GOST algorithm for encryption of PKCS12 file and also GOST R 34.11-94
199 hash to derive key from password.
201 openssl pksc12 -export -inkey gost.pem -in gost_cert.pem -keypbe gost89\
202 -certpbe gost89 -macalg md_gost94
206 PROGRAMMING INTERFACES DETAILS
208 Applications never should access engine directly. They only use provided
209 EVP_PKEY API. But there are some details, which should be taken into
212 EVP provides two kinds of API for key exchange:
214 1. EVP_PKEY_encrypt/EVP_PKEY_decrypt functions, intended to use with
215 RSA-like public key encryption algorithms
217 2. EVP_PKEY_derive, intended to use with Diffie-Hellman-like shared key
218 computing algorithms.
220 Although VKO R 34.10 algorithms, described in the RFC 4357 are
221 definitely second case, engine provides BOTH API for GOST R 34.10 keys.
223 EVP_PKEY_derive just invokes appropriate VKO algorithm and computes
224 256 bit shared key. VKO R 34.10-2001 requires 64 bits of random user key
225 material (UKM). This UKM should be transmitted to other party, so it is
226 not generated inside derive function.
228 It should be set by EVP_PKEY_CTX_ctrl function using
229 EVP_PKEY_CTRL_SET_IV command after call of EVP_PKEY_derive_init, but
230 before EVP_PKEY_derive.
231 unsigned char ukm[8];
233 EVP_PKEY_CTX_ctrl(ctx, -1, EVP_PKEY_OP_DERIVE, 8, ukm)
235 EVP_PKEY_encrypt encrypts provided session key with VKO shared key and
236 packs it into GOST key transport structure, described in the RFC 4490.
238 It typically uses ephemeral key pair to compute shared key and packs its
239 public part along with encrypted key. So, for most cases use of
240 EVP_PKEY_encrypt/EVP_PKEY_decrypt with GOST keys is almost same as with
243 However, if peerkey field in the EVP_PKEY_CTX structure is set (using
244 EVP_PKEY_derive_set_peerkey function) to EVP_PKEY structure which has private
245 key and uses same parameters as the public key from which this EVP_PKEY_CTX is
246 created, EVP_PKEY_encrypt will use this private key to compute shared key and
247 set ephemeral key in the GOST_key_transport structure to NULL. In this case
248 pkey and peerkey fields in the EVP_PKEY_CTX are used upside-down.
250 If EVP_PKEY_decrypt encounters GOST_key_transport structure with NULL
251 public key field, it tries to use peerkey field from the context to
252 compute shared key. In this case peerkey field should really contain
255 Encrypt operation supports EVP_PKEY_CTRL_SET_IV operation as well.
256 It can be used when some specific restriction on UKM are imposed by
257 higher level protocol. For instance, description of GOST ciphersuites
258 requires UKM to be derived from shared secret.
260 If UKM is not set by this control command, encrypt operation would
264 This sources include implementation of GOST 28147-89 and GOST R 34.11-94
265 which are completely indepentent from OpenSSL and can be used separately
266 (files gost89.c, gost89.h, gosthash.c, gosthash.h) Utility gostsum (file
267 gostsum.c) is provided as example of such separate usage. This is
268 program, simular to md5sum and sha1sum utilities, but calculates GOST R
271 Makefile doesn't include rule for compiling gostsum.
274 $(CC) -o gostsum gostsum.c gost89.c gosthash.c
275 where $(CC) is name of your C compiler.
277 Implementations of GOST R 34.10-xx, including VKO algorithms heavily
278 depends on OpenSSL BIGNUM and Elliptic Curve libraries.