MAN page from Trustix openssl-0.9.7m-1tr.i586.rpm
Section: OpenSSL (1)
genrsa - generate an RSA private key
command generates an RSA
- -out filename
- the output filename. If this argument is not specified then standard output isused.
- -passout arg
- the output file password source. For more information about the format of argsee the PASS PHRASE ARGUMENTS section in openssl(1).
- These options encrypt the private key with the DES, triple DES, or the IDEA ciphers respectively before outputting it. If none of these options isspecified no encryption is used. If encryption is used a pass phrase is promptedfor if it is not supplied via the -passout argument.
- the public exponent to use, either 65537 or 3. The default is 65537.
- -rand file(s)
- a file or files containing random data used to seed the random numbergenerator, 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 : forall others.
- -engine id
- specifying an engine (by it's unique id string) will cause reqto attempt to obtain a functional reference to the specified engine,thus initialising it if needed. The engine will then be set as the defaultfor all available algorithms.
- the size of the private key to generate in bits. This must be the last optionspecified. The default is 512.
private key generation essentially involves the generation of two primenumbers. When generating a private key various symbols will be output toindicate the progress of the generation. A .
represents each number whichhas passed an initial sieve test, +
means a number has passed a singleround of the Miller-Rabin primality test. A newline means that the number haspassed 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 keymay vary somewhat.
A quirk of the prime generation algorithm is that it cannot generate smallprimes. Therefore the number of bits should not be less that 64. For typicalprivate keys this will not matter because for security reasons they willbe much larger (typically 1024 bits).
- SEE ALSO
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