GENPKEY(1) OpenSSL GENPKEY(1) NNAAMMEE genpkey - generate a private key SSYYNNOOPPSSIISS ooppeennssssll ggeennppkkeeyy [--oouutt ffiilleennaammee] [--oouuttffoorrmm PPEEMM||DDEERR] [--ppaassss aarrgg] [--cciipphheerr] [--eennggiinnee iidd] [--ppaarraammffiillee ffiillee] [--aallggoorriitthhmm aallgg] [--ppkkeeyyoopptt oopptt::vvaalluuee] [--ggeennppaarraamm] [--tteexxtt] DDEESSCCRRIIPPTTIIOONN The ggeennppkkeeyy command generates a private key. OOPPTTIIOONNSS --oouutt ffiilleennaammee the output filename. If this argument is not specified then stan- dard output is used. --oouuttffoorrmm DDEERR||PPEEMM This specifies the output format DER or PEM. --ppaassss aarrgg the output file password source. For more information about the format of aarrgg see the PPAASSSS PPHHRRAASSEE AARRGGUUMMEENNTTSS section in _o_p_e_n_s_s_l(1). --cciipphheerr This option encrypts the private key with the supplied cipher. Any algorithm name accepted by _E_V_P___g_e_t___c_i_p_h_e_r_b_y_n_a_m_e_(_) is acceptable such as ddeess33. --eennggiinnee iidd specifying an engine (by its unique iidd string) will cause ggeennppkkeeyy to attempt to obtain a functional reference to the specified engine, thus initialising it if needed. The engine will then be set as the default for all available algorithms. If used this option should precede all other options. --aallggoorriitthhmm aallgg public key algorithm to use such as RSA, DSA or DH. If used this option must precede any --ppkkeeyyoopptt options. The options --ppaarraammffiillee and --aallggoorriitthhmm are mutually exclusive. --ppkkeeyyoopptt oopptt::vvaalluuee set the public key algorithm option oopptt to vvaalluuee. The precise set of options supported depends on the public key algorithm used and its implementation. See KKEEYY GGEENNEERRAATTIIOONN OOPPTTIIOONNSS below for more details. --ggeennppaarraamm generate a set of parameters instead of a private key. If used this option must precede and --aallggoorriitthhmm, --ppaarraammffiillee or --ppkkeeyyoopptt options. --ppaarraammffiillee ffiilleennaammee Some public key algorithms generate a private key based on a set of parameters. They can be supplied using this option. If this option is used the public key algorithm used is determined by the parame- ters. If used this option must precede and --ppkkeeyyoopptt options. The options --ppaarraammffiillee and --aallggoorriitthhmm are mutually exclusive. --tteexxtt Print an (unencrypted) text representation of private and public keys and parameters along with the PEM or DER structure. KKEEYY GGEENNEERRAATTIIOONN OOPPTTIIOONNSS The options supported by each algorith and indeed each implementation of an algorithm can vary. The options for the OpenSSL implementations are detailed below. RRSSAA KKEEYY GGEENNEERRAATTIIOONN OOPPTTIIOONNSS rrssaa__kkeeyyggeenn__bbiittss::nnuummbbiittss The number of bits in the generated key. If not specified 1024 is used. rrssaa__kkeeyyggeenn__ppuubbeexxpp::vvaalluuee The RSA public exponent value. This can be a large decimal or hexa- decimal value if preceded by 00xx. Default value is 65537. DDSSAA PPAARRAAMMEETTEERR GGEENNEERRAATTIIOONN OOPPTTIIOONNSS ddssaa__ppaarraammggeenn__bbiittss::nnuummbbiittss The number of bits in the generated parameters. If not specified 1024 is used. DDHH PPAARRAAMMEETTEERR GGEENNEERRAATTIIOONN OOPPTTIIOONNSS ddhh__ppaarraammggeenn__pprriimmee__lleenn::nnuummbbiittss The number of bits in the prime parameter pp. ddhh__ppaarraammggeenn__ggeenneerraattoorr::vvaalluuee The value to use for the generator gg. EECC PPAARRAAMMEETTEERR GGEENNEERRAATTIIOONN OOPPTTIIOONNSS eecc__ppaarraammggeenn__ccuurrvvee::ccuurrvvee the EC curve to use. GGOOSSTT22000011 KKEEYY GGEENNEERRAATTIIOONN AANNDD PPAARRAAMMEETTEERR OOPPTTIIOONNSS Gost 2001 support is not enabled by default. To enable this algorithm, one should load the ccgost engine in the OpenSSL configuration file. See README.gost file in the engines/ccgost directiry of the source dis- tribution for more details. Use of a parameter file for the GOST R 34.10 algorithm is optional. Parameters can be specified during key generation directly as well as during generation of parameter file. ppaarraammsseett::nnaammee Specifies GOST R 34.10-2001 parameter set according to RFC 4357. Parameter set can be specified using abbreviated name, object short name or numeric OID. Following parameter sets are supported: paramset OID Usage A 1.2.643.2.2.35.1 Signature B 1.2.643.2.2.35.2 Signature C 1.2.643.2.2.35.3 Signature XA 1.2.643.2.2.36.0 Key exchange XB 1.2.643.2.2.36.1 Key exchange test 1.2.643.2.2.35.0 Test purposes NNOOTTEESS The use of the genpkey program is encouraged over the algorithm spe- cific utilities because additional algorithm options and ENGINE pro- vided algorithms can be used. EEXXAAMMPPLLEESS Generate an RSA private key using default parameters: openssl genpkey -algorithm RSA -out key.pem Encrypt output private key using 128 bit AES and the passphrase "hello": openssl genpkey -algorithm RSA -out key.pem -aes-128-cbc -pass pass:hello Generate a 2048 bit RSA key using 3 as the public exponent: openssl genpkey -algorithm RSA -out key.pem -pkeyopt rsa_keygen_bits:2048 \ -pkeyopt rsa_keygen_pubexp:3 Generate 1024 bit DSA parameters: openssl genpkey -genparam -algorithm DSA -out dsap.pem \ -pkeyopt dsa_paramgen_bits:1024 Generate DSA key from parameters: openssl genpkey -paramfile dsap.pem -out dsakey.pem Generate 1024 bit DH parameters: openssl genpkey -genparam -algorithm DH -out dhp.pem \ -pkeyopt dh_paramgen_prime_len:1024 Generate DH key from parameters: openssl genpkey -paramfile dhp.pem -out dhkey.pem 1.0.1u 2016-09-22 GENPKEY(1)