Commit fbaedfdd authored by Matt Caswell's avatar Matt Caswell
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Document functions added as a result of DSA opacity changes 



A number of getters/setters have been added for examining DSA objects, as
well as a whole set of functions for creating and buildingup DSA_METHODs.

Reviewed-by: default avatarRichard Levitte <levitte@openssl.org>
Reviewed-by: default avatarStephen Henson <steve@openssl.org>
parent 6e9fa57c

doc/crypto/DSA_get0_pqg.pod

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=pod



=head1 NAME



DSA_get0_pqg, DSA_set0_pgg, DSA_get0_key, DSA_set0_key, DSA_clear_flags,

DSA_test_flags, DSA_set_flags, DSA_get0_engine - Routines for getting and

setting data in a DSA object



=head1 SYNOPSIS



 #include <openssl/dsa.h>



 void DSA_get0_pqg(const DSA *d, BIGNUM **p, BIGNUM **q, BIGNUM **g);

 int DSA_set0_pqg(DSA *d, BIGNUM *p, BIGNUM *q, BIGNUM *g);

 void DSA_get0_key(const DSA *d, BIGNUM **pub_key, BIGNUM **priv_key);

 int DSA_set0_key(DSA *d, BIGNUM *pub_key, BIGNUM *priv_key);

 void DSA_clear_flags(DSA *d, int flags);

 int DSA_test_flags(const DSA *d, int flags);

 void DSA_set_flags(DSA *d, int flags);

 ENGINE *DSA_get0_engine(DSA *d);



=head1 DESCRIPTION



A DSA object contains the parameters B<p>, B<q> and B<g>. It also contains a

public key (B<pub_key>) and (optionally) a private key (B<priv_key>).



The B<p>, B<q> and B<g> parameters can be obtained by calling DSA_get0_pqg().

If the parameters have not yet been set then B<*p>, B<*q> and B<*g> will be set

to NULL. Otherwise they are set to pointers to their respective values. These

point directly to the internal representations of the values and therefore

should not be freed directly.



The B<p>, B<q> and B<g> values can be set by calling DSA_set0_pqg() and passing

the new values for B<p>, B<q> and B<g> as parameters to the function. Calling

this function transfers the memory management of the values to the DSA object,

and therefore the values that have been passed in should not be freed directly

after this function has been called.



To get the public and private key values use the DSA_get0_key() function. A

pointer to the public key will be stored in B<*pub_key>, and a pointer to the

private key will be stored in B<*priv_key>. Either may be NULL if they have not

been set yet, although if the private key has been set then the public key must

be. The values point to the internal representation of the public key and

private key values. This memory should not be freed directly.



The public and private key values can be set using DSA_set0_key(). The public

key must always be non-NULL. The private key may be NULL. As for DSA_set0_pqg()

this function transfers the memory management of the key values to the DSA

object, and therefore they should not be freed directly after this function has

been called.



DSA_set_flags() sets the flags in the B<flags> parameter on the DSA object.

Multiple flags can be passed in one go (bitwise ORed together). Any flags that

are already set are left set. DSA_test_flags() tests to see whether the flags

passed in the B<flags> parameter are currently set in the DSA object. Multple

flags can be tested in one go. All flags that are currently set are returned, or

zero if none of the flags are set. DSA_clear_flags() clears the specified flags

within the DSA object.



DSA_get0_engine() returns a handle to the ENGINE that has been set for this DSA

object, or NULL if no such ENGINE has been set.



=head1 RETURN VALUES



DSA_set0_pqg() and DSA_set0_key() return 1 on success or 0 on failure.



DSA_test_flags() returns the current state of the flags in the DSA object.



DSA_get0_engine() returns the ENGINE set for the DSA object or NULL if no ENGINE

has been set.



=head1 SEE ALSO



L<dsa>, L<DSA_new>, L<DSA_generate_parameters>, L<DSA_generate_key>,

L<DSA_dup_DH>, L<DSA_do_sign>, L<DSA_set_method>, L<DSA_SIG_new>, L<DSA_sign>,

L<DSA_size>, L<DSA_meth_new>



=head1 HISTORY



The functions described here were added in OpenSSL version 1.1.0.



=cut

doc/crypto/DSA_meth_new.pod

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=pod



=head1 NAME



DSA_meth_new, DSA_meth_free, DSA_meth_dup, DSA_meth_get_name, DSA_meth_set_name,

DSA_meth_get_flags, DSA_meth_set_flags, DSA_meth_get_app_data,

DSA_meth_set_app_data, DSA_meth_get_sign, DSA_meth_set_sign,

DSA_meth_get_sign_setup, DSA_meth_set_sign_setup, DSA_meth_get_verify,

DSA_meth_set_verify, DSA_meth_get_mod_exp, DSA_meth_set_mod_exp,

DSA_meth_get_bn_mod_exp, DSA_meth_set_bn_mod_exp, DSA_meth_get_init,

DSA_meth_set_init, DSA_meth_get_finish, DSA_meth_set_finish,

DSA_meth_get_paramgen, DSA_meth_set_paramgen, DSA_meth_get_keygen,

DSA_meth_set_keygen  - Routines to build up DSA methods



=head1 SYNOPSIS



 #include <openssl/bio.h>



 DSA_METHOD *DSA_meth_new(const char *name, int flags);

 void DSA_meth_free(DSA_METHOD *dsam);

 DSA_METHOD *DSA_meth_dup(const DSA_METHOD *meth);

 const char *DSA_meth_get_name(const DSA_METHOD *dsam);

 int DSA_meth_set_name(DSA_METHOD *dsam, const char *name);

 int DSA_meth_get_flags(DSA_METHOD *dsam);

 int DSA_meth_set_flags(DSA_METHOD *dsam, int flags);

 void *DSA_meth_get_app_data(const DSA_METHOD *dsam);

 int DSA_meth_set_app_data(DSA_METHOD *dsam, void *app_data);

 DSA_SIG *(*DSA_meth_get_sign(const DSA_METHOD *dsam))

         (const unsigned char *, int, DSA *);

 int DSA_meth_set_sign(DSA_METHOD *dsam,

                       DSA_SIG *(*sign) (const unsigned char *, int, DSA *));

 int (*DSA_meth_get_sign_setup(const DSA_METHOD *dsam))

         (DSA *, BN_CTX *, BIGNUM **, BIGNUM **);

 int DSA_meth_set_sign_setup(DSA_METHOD *dsam,

         int (*sign_setup) (DSA *, BN_CTX *, BIGNUM **, BIGNUM **));

 int (*DSA_meth_get_verify(const DSA_METHOD *dsam))

         (const unsigned char *, int , DSA_SIG *, DSA *);

 int DSA_meth_set_verify(DSA_METHOD *dsam,

     int (*verify) (const unsigned char *, int, DSA_SIG *, DSA *));

 int (*DSA_meth_get_mod_exp(const DSA_METHOD *dsam))

        (DSA *dsa, BIGNUM *rr, BIGNUM *a1, BIGNUM *p1, BIGNUM *a2, BIGNUM *p2,

         BIGNUM *m, BN_CTX *ctx, BN_MONT_CTX *in_mont);

 int DSA_meth_set_mod_exp(DSA_METHOD *dsam,

     int (*mod_exp) (DSA *dsa, BIGNUM *rr, BIGNUM *a1, BIGNUM *p1, BIGNUM *a2,

                     BIGNUM *p2, BIGNUM *m, BN_CTX *ctx, BN_MONT_CTX *mont));

 int (*DSA_meth_get_bn_mod_exp(const DSA_METHOD *dsam))

     (DSA *dsa, BIGNUM *r, BIGNUM *a, const BIGNUM *p, const BIGNUM *m,

      BN_CTX *ctx, BN_MONT_CTX *mont);

 int DSA_meth_set_bn_mod_exp(DSA_METHOD *dsam,

     int (*bn_mod_exp) (DSA *dsa, BIGNUM *r, BIGNUM *a, const BIGNUM *p,

                        const BIGNUM *m, BN_CTX *ctx, BN_MONT_CTX *mont));

 int (*DSA_meth_get_init(const DSA_METHOD *dsam))(DSA *);

 int DSA_meth_set_init(DSA_METHOD *dsam, int (*init)(DSA *));

 int (*DSA_meth_get_finish(const DSA_METHOD *dsam)) (DSA *);

 int DSA_meth_set_finish(DSA_METHOD *dsam, int (*finish) (DSA *));

 int (*DSA_meth_get_paramgen(const DSA_METHOD *dsam))

         (DSA *, int, const unsigned char *, int, int *, unsigned long *,

          BN_GENCB *);

 int DSA_meth_set_paramgen(DSA_METHOD *dsam,

         int (*paramgen) (DSA *, int, const unsigned char *, int, int *,

                          unsigned long *, BN_GENCB *));

 int (*DSA_meth_get_keygen(const DSA_METHOD *dsam)) (DSA *);

 int DSA_meth_set_keygen(DSA_METHOD *dsam, int (*keygen) (DSA *));



=head1 DESCRIPTION



The B<DSA_METHOD> type is a structure used for the provision of custom DSA

implementations. It provides a set of of functions used by OpenSSL for the

implementation of the various DSA capabilities. See the L<dsa> page for more

information.



DSA_meth_new() creates a new B<DSA_METHOD> structure. It should be given a

unique B<name> and a set of B<flags>. The B<name> should be a NULL terminated

string, which will be duplicated and stored in the B<DSA_METHOD> object. It is

the callers responsibility to free the original string. The flags will be used

during the construction of a new B<DSA> object based on this B<DSA_METHOD>. Any

new B<DSA> object will have those flags set by default.



DSA_meth_dup() creates a duplicate copy of the B<DSA_METHOD> object passed as a

parameter. This might be useful for creating a new B<DSA_METHOD> based on an

existing one, but with some differences.



DSA_meth_free() destroys a B<DSA_METHOD> structure and frees up any memory

associated with it.



DSA_meth_get_flags() returns the current value of the flags associated with this

DSA_METHOD. DSA_meth_set_flags() provides the ability to set these flags.



The functions DSA_meth_get_app_data() and DSA_meth_set_app_data() provide the

ability to associate implementation specific data with the DSA_METHOD. It is

the application's responsibility to free this data before the DSA_METHOD is

freed via a call to DSA_meth_free().



DSA_meth_get_sign() and DSA_meth_set_sign() get and set the function used for

creating a DSA signature respectively. This function will be

called in response to the application calling DSA_do_sign() (or DSA_sign()). The

parameters for the function have the same meaning as for DSA_do_sign().



DSA_meth_get_sign_setup() and DSA_meth_set_sign_setup() get and set the function

used for precalculating the DSA signature values B<k^-1> and B<r>. This function

will be called in response to the application calling DSA_sign_setup(). The

parameters for the function have the same meaning as for DSA_sign_setup().



DSA_meth_get_verify() and DSA_meth_set_verify() get and set the function used

for verifying a DSA signature respectively. This function will be called in

response to the application calling DSA_do_verify() (or DSA_verify()). The

parameters for the function have the same meaning as for DSA_do_verify().



DSA_meth_get_mod_exp() and DSA_meth_set_mod_exp() get and set the function used

for computing the following value:



 rr = a1^p1 * a2^p2 mod m



This function will be called by the default OpenSSL method during verification

of a DSA signature. The result is stored in the B<rr> parameter. This function

may be NULL.



DSA_meth_get_bn_mod_exp() and DSA_meth_set_bn_mod_exp() get and set the function

used for computing the following value:



 r = a ^ p mod m



This function will be called by the default OpenSSL function for

DSA_sign_setup(). The result is stored in the B<r> parameter. This function

may be NULL.



DSA_meth_get_init() and DSA_meth_set_init() get and set the function used

for creating a new DSA instance respectively. This function will be

called in response to the application calling DSA_new() (if the current default

DSA_METHOD is this one) or DSA_new_method(). The DSA_new() and DSA_new_method()

functions will allocate the memory for the new DSA object, and a pointer to this

newly allocated structure will be passed as a parameter to the function. This

function may be NULL.



DSA_meth_get_finish() and DSA_meth_set_finish() get and set the function used

for destroying an instance of a DSA object respectively. This function will be

called in response to the application calling DSA_free(). A pointer to the DSA

to be destroyed is passed as a parameter. The destroy function should be used

for DSA implementation specific clean up. The memory for the DSA itself should

not be freed by this function. This function may be NULL.



DSA_meth_get_paramgen() and DSA_meth_set_paramgen() get and set the function

used for generating DSA parameters respectively. This function will be called in

response to the application calling DSA_generate_parameters_ex() (or

DSA_generate_parameters()). The parameters for the function have the same

meaning as for DSA_generate_parameters_ex().



DSA_meth_get_keygen() and DSA_meth_set_keygen() get and set the function

used for generating a new DSA key pair respectively. This function will be

called in response to the application calling DSA_generate_key(). The parameter

for the function has the same meaning as for DSA_generate_key().



=head1 RETURN VALUES



DSA_meth_new() and DSA_meth_dup() return the newly allocated DSA_METHOD object

or NULL on failure.



DSA_meth_get_name() and DSA_meth_get_flags() return the name and flags

associated with the DSA_METHOD respectively.



All other DSA_meth_get_*() functions return the appropriate function pointer

that has been set in the DSA_METHOD, or NULL if no such pointer has yet been

set.



All DSA_meth_set_*() functions return 1 on success or 0 on failure.



=head1 SEE ALSO



L<dsa>, L<DSA_new>, L<DSA_generate_parameters>, L<DSA_generate_key>,

L<DSA_dup_DH>, L<DSA_do_sign>, L<DSA_set_method>, L<DSA_SIG_new>, L<DSA_sign>,

L<DSA_size>, L<DSA_get0_p>



=head1 HISTORY



The functions described here were added in OpenSSL version 1.1.0.



=cut

doc/crypto/DSA_set_method.pod

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@@ -47,55 +47,14 @@ be released during the change. It is possible to have DSA keys that only 
work with certain DSA_METHOD implementations (eg. from an ENGINE module

that supports embedded hardware-protected keys), and in such cases

attempting to change the DSA_METHOD for the key can have unexpected

results.

results. See L<DSA_meth_new> for information on constructing custom DSA_METHOD

objects;



DSA_new_method() allocates and initializes a DSA structure so that B<engine>

will be used for the DSA operations. If B<engine> is NULL, the default engine

for DSA operations is used, and if no default ENGINE is set, the DSA_METHOD

controlled by DSA_set_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 for some

                                          implementations) */

	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 for some implementations) */

        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() and DSA_get_default_method() return pointers to the respective
@@ -113,6 +72,6 @@ fails. Otherwise it returns a pointer to the newly allocated structure. 


=head1 SEE ALSO



L<dsa(3)>, L<DSA_new(3)>

L<dsa(3)>, L<DSA_new(3)>, L<DSA_meth_new(3)>



=cut