Manual Pages for UNIX Operating System command usage for man dhparam

OpenSSL                                         DHPARAM(1openssl)



NNNNAAAAMMMMEEEE
     dhparam - DH parameter manipulation and generation

SSSSYYYYNNNNOOOOPPPPSSSSIIIISSSS
     ooooppppeeeennnnssssssssllll ddddhhhhppppaaaarrrraaaammmm [---iiinnnnffffoooorrrrmmmm DDDDEEEERRRR||||PPPPEEEEMMMM] [---ooouuuuttttffffoooorrrrmmmm DDDDEEEERRRR||||PPPPEEEEMMMM] [---iiinnnn
     filename] [---ooouuuutttt filename] [---dddssssaaaappppaaaarrrraaaammmm] [---nnnoooooooouuuutttt] [---ttteeeexxxxtttt] [---CCC]
     [----2222] [----5555] [---rrraaaannnndddd file(s)] [---eeennnnggggiiiinnnneeee iiiidddd] [numbits]

DDDDEEEESSSSCCCCRRRRIIIIPPPPTTTTIIIIOOOONNNN
     This command is used to manipulate DH parameter files.

OOOOPPPPTTTTIIIIOOOONNNNSSSS
     -iiiinnnnffffoooorrrrmmmm DDDDEEEERRRR||||PPPPEEEEMMMM
         This specifies the input format. The DDDDEEEERRRR option uses an
         ASN1 DER encoded form compatible with the PKCS#3
         DHparameter structure. The PEM form is the default
         format: it consists of the DDDDEEEERRRR format base64 encoded
         with additional header and footer lines.

     -oooouuuuttttffffoooorrrrmmmm DDDDEEEERRRR||||PPPPEEEEMMMM
         This specifies the output format, the options have the
         same meaning as the ---iiinnnnffffoooorrrrmmmm option.

     -iiiinnnn filename
         This specifies the input filename to read parameters
         from or standard input if this option is not specified.

     -oooouuuutttt filename
         This specifies the output filename parameters to.
         Standard output is used if this option is not present.
         The output filename should nnnnooootttt be the same as the input
         filename.

     -ddddssssaaaappppaaaarrrraaaammmm
         If this option is used, DSA rather than DH parameters
         are read or created; they are converted to DH format.
         Otherwise, "strong" primes (such that (p-1)/2 is also
         prime) will be used for DH parameter generation.

         DH parameter generation with the ---dddssssaaaappppaaaarrrraaaammmm option is
         much faster, and the recommended exponent length is
         shorter, which makes DH key exchange more efficient.
         Beware that with such DSA-style DH parameters, a fresh
         DH key should be created for each use to avoid small-
         subgroup attacks that may be possible otherwise.

     -2222, -5555
         The generator to use, either 2 or 5. 2 is the default.
         If present then the input file is ignored and parameters
         are generated instead.





30/Jan/2003            Last change: 0.9.8o                      1






OpenSSL                                         DHPARAM(1openssl)



     -rrrraaaannnndddd file(s)
         a file or files containing random data used to seed the
         random number generator, or an EGD socket (see
         RAND_egd(3)).  Multiple files can be specified separated
         by a OS-dependent character.  The separator is ;;;; for
         MS-Windows, ,,,, for OpenVMS, and :::: for all others.

     numbits
         this option specifies that a parameter set should be
         generated of size numbits. It must be the last option.
         If not present then a value of 512 is used. If this
         option is present then the input file is ignored and
         parameters are generated instead.

     -nnnnoooooooouuuutttt
         this option inhibits the output of the encoded version
         of the parameters.

     -tttteeeexxxxtttt
         this option prints out the DH parameters in human
         readable form.

     -CCCC  this option converts the parameters into C code. The
         parameters can then be loaded by calling the
         ggggeeeetttt_ddddhhhhnumbits(((()))) function.

     -eeeennnnggggiiiinnnneeee iiiidddd
         specifying an engine (by it's unique iiiidddd string) will
         cause rrrreeeeqqqq 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.

WWWWAAAARRRRNNNNIIIINNNNGGGGSSSS
     The program ddddhhhhppppaaaarrrraaaammmm combines the functionality of the
     programs ddddhhhh and ggggeeeennnnddddhhhh in previous versions of OpenSSL and
     SSLeay. The ddddhhhh and ggggeeeennnnddddhhhh programs are retained for now but
     may have different purposes in future versions of OpenSSL.

NNNNOOOOTTTTEEEESSSS
     PEM format DH parameters use the header and footer lines:

      -----BEGIN DH PARAMETERS-----
      -----END DH PARAMETERS-----

     OpenSSL currently only supports the older PKCS#3 DH, not the
     newer X9.42 DH.

     This program manipulates DH parameters not keys.

BBBBUUUUGGGGSSSS
     There should be a way to generate and manipulate DH keys.



30/Jan/2003            Last change: 0.9.8o                      2






OpenSSL                                         DHPARAM(1openssl)



SSSSEEEEEEEE AAAALLLLSSSSOOOO
     dsaparam(1)

HHHHIIIISSSSTTTTOOOORRRRYYYY
     The ddddhhhhppppaaaarrrraaaammmm command was added in OpenSSL 0.9.5.  The
     ---dddssssaaaappppaaaarrrraaaammmm option was added in OpenSSL 0.9.6.

















































30/Jan/2003            Last change: 0.9.8o                      3