mirror of https://github.com/openssl/openssl.git
				
				
				
			
		
			
				
	
	
		
			112 lines
		
	
	
		
			3.1 KiB
		
	
	
	
		
			Plaintext
		
	
	
	
			
		
		
	
	
			112 lines
		
	
	
		
			3.1 KiB
		
	
	
	
		
			Plaintext
		
	
	
	
=pod
 | 
						|
 | 
						|
=head1 NAME
 | 
						|
 | 
						|
DSA_set_default_method, DSA_get_default_method, DSA_set_method,
 | 
						|
DSA_new_method, DSA_OpenSSL - select RSA method
 | 
						|
 | 
						|
=head1 SYNOPSIS
 | 
						|
 | 
						|
 #include <openssl/DSA.h>
 | 
						|
 | 
						|
 void DSA_set_default_method(DSA_METHOD *meth);
 | 
						|
 | 
						|
 DSA_METHOD *DSA_get_default_method(void);
 | 
						|
 | 
						|
 DSA_METHOD *DSA_set_method(DSA *dsa, DSA_METHOD *meth);
 | 
						|
 | 
						|
 DSA *DSA_new_method(DSA_METHOD *meth);
 | 
						|
 | 
						|
 DSA_METHOD *DSA_OpenSSL(void);
 | 
						|
 | 
						|
=head1 DESCRIPTION
 | 
						|
 | 
						|
A B<DSA_METHOD> specifies the functions that OpenSSL uses for DSA
 | 
						|
operations. By modifying the method, alternative implementations
 | 
						|
such as hardware accelerators may be used.
 | 
						|
 | 
						|
Initially, the default is to use the OpenSSL internal implementation.
 | 
						|
DSA_OpenSSL() returns a pointer to that method.
 | 
						|
 | 
						|
DSA_set_default_method() makes B<meth> the default method for all B<DSA>
 | 
						|
structures created later.
 | 
						|
 | 
						|
DSA_get_default_method() returns a pointer to the current default
 | 
						|
method.
 | 
						|
 | 
						|
DSA_set_method() selects B<meth> for all operations using the structure B<DSA>.
 | 
						|
 | 
						|
DSA_get_method() returns a pointer to the method currently selected
 | 
						|
for B<DSA>.
 | 
						|
 | 
						|
DSA_new_method() allocates and initializes a B<DSA> structure so that
 | 
						|
B<method> will be used for the DSA operations. If B<method> is B<NULL>,
 | 
						|
the default method is used.
 | 
						|
 | 
						|
=head1 THE DSA_METHOD STRUCTURE
 | 
						|
 | 
						|
struct
 | 
						|
 {
 | 
						|
     /* name of the implementation */
 | 
						|
        const char *name;
 | 
						|
 | 
						|
     /* sign */
 | 
						|
	DSA_SIG *(*dsa_do_sign)(const unsigned char *dgst, int dlen,
 | 
						|
                                 DSA *dsa);
 | 
						|
 | 
						|
     /* pre-compute k^-1 and r */
 | 
						|
	int (*dsa_sign_setup)(DSA *dsa, BN_CTX *ctx_in, BIGNUM **kinvp,
 | 
						|
                                 BIGNUM **rp);
 | 
						|
 | 
						|
     /* verify */
 | 
						|
	int (*dsa_do_verify)(const unsigned char *dgst, int dgst_len,
 | 
						|
                                 DSA_SIG *sig, DSA *dsa);
 | 
						|
 | 
						|
     /* compute rr = a1^p1 * a2^p2 mod m. May be NULL */
 | 
						|
	int (*dsa_mod_exp)(DSA *dsa, BIGNUM *rr, BIGNUM *a1, BIGNUM *p1,
 | 
						|
                                 BIGNUM *a2, BIGNUM *p2, BIGNUM *m,
 | 
						|
                                 BN_CTX *ctx, BN_MONT_CTX *in_mont);
 | 
						|
 | 
						|
     /* compute r = a ^ p mod m. May be NULL */
 | 
						|
        int (*bn_mod_exp)(DSA *dsa, BIGNUM *r, BIGNUM *a,
 | 
						|
                                 const BIGNUM *p, const BIGNUM *m,
 | 
						|
                                 BN_CTX *ctx, BN_MONT_CTX *m_ctx);
 | 
						|
 | 
						|
     /* called at DSA_new */
 | 
						|
        int (*init)(DSA *DSA);
 | 
						|
 | 
						|
     /* called at DSA_free */
 | 
						|
        int (*finish)(DSA *DSA);
 | 
						|
 | 
						|
        int flags;
 | 
						|
 | 
						|
        char *app_data; /* ?? */
 | 
						|
 | 
						|
 } DSA_METHOD;
 | 
						|
 | 
						|
=head1 RETURN VALUES
 | 
						|
 | 
						|
DSA_OpenSSL(), DSA_get_default_method() and DSA_get_method() return
 | 
						|
pointers to the respective B<DSA_METHOD>s.
 | 
						|
 | 
						|
DSA_set_default_method() returns no value.
 | 
						|
 | 
						|
DSA_set_method() returns a pointer to the B<DSA_METHOD> previously
 | 
						|
associated with B<dsa>.
 | 
						|
 | 
						|
DSA_new_method() returns B<NULL> and sets an error code that can be
 | 
						|
obtained by L<ERR_get_error(3)|ERR_get_error(3)> if the allocation
 | 
						|
fails. Otherwise it returns a pointer to the newly allocated
 | 
						|
structure.
 | 
						|
 | 
						|
=head1 SEE ALSO
 | 
						|
 | 
						|
L<dsa(3)|dsa(3)>, L<DSA_new(3)|DSA_new(3)>
 | 
						|
 | 
						|
=head1 HISTORY
 | 
						|
 | 
						|
DSA_set_default_method(), DSA_get_default_method(), DSA_set_method(),
 | 
						|
DSA_new_method() and DSA_OpenSSL() were added in OpenSSL 0.9.4.
 | 
						|
 | 
						|
=cut
 |