GENRSA(1) OpenSSL GENRSA(1)

NAME
       genrsa - generate an RSA private key

SYNOPSIS
       ooppeennssssll ggeennrrssaa [-oouutt ffiilleennaammee] [-ppaassssoouutt aarrgg] [-ddeess] [-ddeess33] [-iiddeeaa]
       [-ff44] [-33] [-rraanndd ffiillee((ss))] [-eennggiinnee iidd] [nnuummbbiittss]

DESCRIPTION
       The ggeennrrssaa command generates an RSA private key.

OOPPTTIIOONNSS
       -oouutt ffiilleennaammee
           the output filename. If this argument is not specified then
           standard output is used.

       -ppaassssoouutt aarrgg
           the output file password source. For more information about the
           format of aarrgg see the PPAASSSS PPHHRRAASSEE AARRGGUUMMEENNTTSS section in openssl(1).

       -ddeess||-ddeess33||-iiddeeaa
           These options encrypt the private key with the DES, triple DES, or
           the IDEA ciphers respectively before outputting it. If none of
           these options is specified no encryption is used. If encryption is
           used a pass phrase is prompted for if it is not supplied via the
           -ppaassssoouutt argument.

       -FF44||-33
           the public exponent to use, either 65537 or 3. The default is
           65537.

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

       -eennggiinnee iidd
           specifying an engine (by it's unique iidd string) will cause rreeqq 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.

       nnuummbbiittss
           the size of the private key to generate in bits. This must be the
           last option specified. The default is 512.

NNOOTTEESS
       RSA private key generation essentially involves the generation of two
       prime numbers. When generating a private key various symbols will be
       output to indicate the progress of the generation. A .. represents each
       number which has passed an initial sieve test, ++ means a number has
       passed a single round of the Miller-Rabin primality test. A newline
       means that the number has passed all the prime tests (the actual number
       depends on the key size).

       Because key generation is a random process the time taken to generate a
       key may vary somewhat.

BUGS
       A quirk of the prime generation algorithm is that it cannot generate
       small primes. Therefore the number of bits should not be less that 64.
       For typical private keys this will not matter because for security
       reasons they will be much larger (typically 1024 bits).

SEE ALSO
       gendsa(1)



0.9.7l                            2003-01-30                         GENRSA(1)