1RSA_generate_key(3)                 OpenSSL                RSA_generate_key(3)
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NAME

6       RSA_generate_key - generate RSA key pair
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SYNOPSIS

9        #include <openssl/rsa.h>
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11        RSA *RSA_generate_key(int num, unsigned long e,
12           void (*callback)(int,int,void *), void *cb_arg);
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DESCRIPTION

15       RSA_generate_key() generates a key pair and returns it in a newly allo‐
16       cated RSA structure. The pseudo-random number generator must be seeded
17       prior to calling RSA_generate_key().
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19       The modulus size will be num bits, and the public exponent will be e.
20       Key sizes with num < 1024 should be considered insecure.  The exponent
21       is an odd number, typically 3, 17 or 65537.
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23       A callback function may be used to provide feedback about the progress
24       of the key generation. If callback is not NULL, it will be called as
25       follows:
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27       ·   While a random prime number is generated, it is called as described
28           in BN_generate_prime(3).
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30       ·   When the n-th randomly generated prime is rejected as not suitable
31           for the key, callback(2, n, cb_arg) is called.
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33       ·   When a random p has been found with p-1 relatively prime to e, it
34           is called as callback(3, 0, cb_arg).
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36       The process is then repeated for prime q with callback(3, 1, cb_arg).
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RETURN VALUE

39       If key generation fails, RSA_generate_key() returns NULL; the error
40       codes can be obtained by ERR_get_error(3).
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BUGS

43       callback(2, x, cb_arg) is used with two different meanings.
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45       RSA_generate_key() goes into an infinite loop for illegal input values.
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SEE ALSO

48       ERR_get_error(3), rand(3), rsa(3), RSA_free(3)
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HISTORY

51       The cb_arg argument was added in SSLeay 0.9.0.
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550.9.8b                            2002-09-25               RSA_generate_key(3)