GENRSA 1 2003-07-24 0.9.9-dev OpenSSL
NAME
genrsa - generate an RSA private key
LIBRARY
libcrypto, -lcrypto
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.
OPTIONS
-
--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 _o_p_e_n_s_s_l(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 _R_A_N_D___e_g_d(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.
NOTES
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
_o_p_e_n_s_s_l___g_e_n_d_s_a(1)