NAME
RSA_meth_new,
RSA_meth_dup, RSA_meth_free,
RSA_meth_get0_name,
RSA_meth_set1_name,
RSA_meth_get_flags,
RSA_meth_set_flags,
RSA_meth_get0_app_data,
RSA_meth_set0_app_data,
RSA_meth_get_init,
RSA_meth_set_init,
RSA_meth_get_finish,
RSA_meth_set_finish,
RSA_meth_get_pub_enc,
RSA_meth_set_pub_enc,
RSA_meth_get_pub_dec,
RSA_meth_set_pub_dec,
RSA_meth_get_priv_enc,
RSA_meth_set_priv_enc,
RSA_meth_get_priv_dec,
RSA_meth_set_priv_dec,
RSA_meth_get_sign,
RSA_meth_set_sign,
RSA_meth_get_verify,
RSA_meth_set_verify,
RSA_meth_get_mod_exp,
RSA_meth_set_mod_exp,
RSA_meth_get_bn_mod_exp,
RSA_meth_set_bn_mod_exp,
RSA_meth_get_keygen,
RSA_meth_set_keygen —
build up RSA methods
SYNOPSIS
#include
<openssl/rsa.h>
RSA_METHOD *
RSA_meth_new(const char *name,
int flags);
RSA_METHOD *
RSA_meth_dup(const RSA_METHOD
*meth);
void
RSA_meth_free(RSA_METHOD
*meth);
const char *
RSA_meth_get0_name(const RSA_METHOD
*meth);
int
RSA_meth_set1_name(RSA_METHOD
*meth, const char *name);
int
RSA_meth_get_flags(const RSA_METHOD
*meth);
int
RSA_meth_set_flags(RSA_METHOD
*meth, int flags);
void *
RSA_meth_get0_app_data(const
RSA_METHOD *meth);
int
RSA_meth_set0_app_data(RSA_METHOD
*meth, void *app_data);
int
(*RSA_meth_get_init(const RSA_METHOD
*meth))(RSA *rsa);
int
RSA_meth_set_init(RSA_METHOD
*meth, int (*init)(RSA *rsa));
int
(*RSA_meth_get_finish(const RSA_METHOD
*meth))(RSA *rsa);
int
RSA_meth_set_finish(RSA_METHOD
*meth, int (*finish)(RSA *rsa));
int
(*RSA_meth_get_pub_enc(const RSA_METHOD
*meth))(int flen, const
unsigned char *from, unsigned char *to,
RSA *rsa, int padding);
int
RSA_meth_set_pub_enc(RSA_METHOD
*meth, int (*pub_enc)(int flen, const unsigned char
*from, unsigned char *to, RSA *rsa, int padding));
int
(*RSA_meth_get_pub_dec(const RSA_METHOD
*meth))(int flen, const
unsigned char *from, unsigned char *to,
RSA *rsa, int padding);
int
RSA_meth_set_pub_dec(RSA_METHOD
*meth, int (*pub_dec)(int flen, const unsigned char
*from, unsigned char *to, RSA *rsa, int padding));
int
(*RSA_meth_get_priv_enc(const RSA_METHOD
*meth))(int flen, const
unsigned char *from, unsigned char *to,
RSA *rsa, int padding);
int
RSA_meth_set_priv_enc(RSA_METHOD
*meth, int (*priv_enc)(int flen, const unsigned char
*from, unsigned char *to, RSA *rsa, int padding));
int
(*RSA_meth_get_priv_dec(const RSA_METHOD
*meth))(int flen, const
unsigned char *from, unsigned char *to,
RSA *rsa, int padding);
int
RSA_meth_set_priv_dec(RSA_METHOD
*meth, int (*priv_dec)(int flen, const unsigned char
*from, unsigned char *to, RSA *rsa, int padding));
int
(*RSA_meth_get_sign(const RSA_METHOD
*meth))(int type, const
unsigned char *m, unsigned int m_length,
unsigned char *sigret, unsigned int
*siglen, const RSA *rsa);
int
RSA_meth_set_sign(RSA_METHOD
*rsa, int (*sign)(int type, const unsigned char *m,
unsigned int m_length, unsigned char *sigret, unsigned int *siglen, const
RSA *rsa));
int
(*RSA_meth_get_verify(const RSA_METHOD
*meth))(int dtype, const
unsigned char *m, unsigned int m_length,
const unsigned char *sigbuf, unsigned
int siglen, const RSA *rsa);
int
RSA_meth_set_verify(RSA_METHOD
*rsa, int (*verify)(int dtype, const unsigned char *m,
unsigned int m_length, const unsigned char *sigbuf, unsigned int siglen,
const RSA *rsa));
int
(*RSA_meth_get_mod_exp(const RSA_METHOD
*meth))(BIGNUM *r0, const
BIGNUM *i, RSA *rsa, BN_CTX
*ctx);
int
RSA_meth_set_mod_exp(RSA_METHOD
*meth, int (*mod_exp)(BIGNUM *r0, const BIGNUM *i, RSA
*rsa, BN_CTX *ctx));
int
(*RSA_meth_get_bn_mod_exp(const RSA_METHOD
*meth))(BIGNUM *r, const BIGNUM
*a, const BIGNUM *p, const
BIGNUM *m, BN_CTX *ctx,
BN_MONT_CTX *m_ctx);
int
RSA_meth_set_bn_mod_exp(RSA_METHOD
*meth, int (*bn_mod_exp)(BIGNUM *r, const BIGNUM *a,
const BIGNUM *p, const BIGNUM *m, BN_CTX *ctx, BN_MONT_CTX
*m_ctx));
int
(*RSA_meth_get_keygen(const RSA_METHOD
*meth))(RSA *rsa, int
bits, BIGNUM *e, BN_GENCB
*cb);
int
RSA_meth_set_keygen(RSA_METHOD
*meth, int (*keygen)(RSA *rsa, int bits, BIGNUM *e,
BN_GENCB *cb));
DESCRIPTION
The RSA_METHOD structure holds function pointers for custom RSA implementations.
RSA_meth_new()
creates a new RSA_METHOD structure. A copy of the
NUL-terminated name is stored in the new
RSA_METHOD object. Any new RSA
object constructed from this RSA_METHOD will have the
given flags set by default, as if they were set with
RSA_set_flags(3).
RSA_meth_dup()
creates a deep copy of meth, except that a pointer
stored into it with
RSA_meth_set0_app_data()
is copied as a pointer without creating a copy of its content. This might be
useful for creating a new RSA_METHOD based on an
existing one, but with some differences.
RSA_meth_free()
destroys meth and frees any memory associated with it,
except that memory pointed to by a pointer set with
RSA_meth_set0_app_data()
is not freed. If meth is NULL,
no action occurs.
RSA_meth_get0_name()
returns an internal pointer to the name of meth.
RSA_meth_set1_name()
stores a copy of the NUL-terminated name in the
RSA_METHOD object after freeing the previously stored
name. Method names are ignored by the default RSA implementation but can be
used by alternative implementations and by the application program.
RSA_meth_get_flags()
retrieves the flags from meth. Flags are documented in
RSA_test_flags(3).
RSA_meth_set_flags()
overwrites all flags in meth. Unlike
RSA_set_flags(3), it does not preserve any flags that were
set before the call.
RSA_meth_get0_app_data()
and
RSA_meth_set0_app_data()
get and set a pointer to implementation-specific data. The function
RSA_meth_free() does not
free(3) the memory pointed to by app_data. The
default RSA implementation does not use app_data.
RSA_meth_get_init()
and
RSA_meth_set_init()
get and set an optional function used when creating a new
RSA object. Unless init is
NULL, it will be called at the end of
RSA_new(3),
RSA_new_method(3), and
RSA_set_method(3), passing a pointer to the newly allocated
or reset RSA object as an argument. The default RSA
implementation,
RSA_PKCS1_SSLeay(3), contains an init
function equivalent to calling
RSA_set_flags(3) with an argument of
RSA_FLAG_CACHE_PUBLIC |
RSA_FLAG_CACHE_PRIVATE.
RSA_meth_get_finish()
and
RSA_meth_set_finish()
get and set an optional function for destroying an RSA
object. Unless finish is NULL,
it will be called from
RSA_set_method(3) and from
RSA_free(3). It takes the same argument as
RSA_free(3) and is intended to do RSA implementation specific
cleanup. The memory used by the RSA object itself
should not be freed by the finish function. The
default RSA implementation contains a finish function
freeing the memory used by the RSA_FLAG_CACHE_PUBLIC
and RSA_FLAG_CACHE_PRIVATE caches.
RSA_meth_get_pub_enc(),
RSA_meth_set_pub_enc(),
RSA_meth_get_pub_dec(),
RSA_meth_set_pub_dec(),
RSA_meth_get_priv_enc(),
RSA_meth_set_priv_enc(),
RSA_meth_get_priv_dec(),
and
RSA_meth_set_priv_dec()
get and set the mandatory functions used for public and private key
encryption and decryption. These functions will be called from
RSA_public_encrypt(3),
RSA_public_decrypt(3),
RSA_private_encrypt(3), and
RSA_private_decrypt(3), respectively, and take the same
parameters as those.
RSA_meth_get_sign(),
RSA_meth_set_sign(),
RSA_meth_get_verify(),
and
RSA_meth_set_verify()
get and set the optional functions used for creating and verifying an RSA
signature. If the flag RSA_FLAG_SIGN_VER is set on
the RSA object in question and
sign or verify is not
NULL, it will be called from
RSA_sign(3) or
RSA_verify(3), respectively, and take the same parameters as
those. Otherwise,
RSA_private_encrypt(3) or
RSA_public_decrypt(3) will be used instead.
RSA_meth_get_mod_exp()
and
RSA_meth_set_mod_exp()
get and set the function used for Chinese Remainder Theorem (CRT)
computations involving the p, q,
dmp1, dmq1, and
iqmp fields of an RSA object. It
is used by the default RSA implementation during
RSA_private_encrypt(3) and
RSA_private_decrypt(3) when the required components of the
private key are available or when the
RSA_FLAG_EXT_PKEY flag is set.
RSA_meth_get_bn_mod_exp()
and
RSA_meth_set_bn_mod_exp()
get and set the function used for CRT computations, specifically the value r
= a ^ p mod
m. It is used by the default RSA implementation during
RSA_public_encrypt(3) and
RSA_public_decrypt(3) and as a fallback during
RSA_private_encrypt(3) and
RSA_private_decrypt(3).
RSA_meth_get_keygen()
and
RSA_meth_set_keygen()
get and set the optional function used for generating a new RSA key pair.
Unless keygen is NULL, it will
be called from
RSA_generate_key_ex(3) and takes the same parameters.
Otherwise, a builtin default implementation is used.
RETURN VALUES
RSA_meth_new() and
RSA_meth_dup() return the newly allocated
RSA_METHOD object or NULL on
failure.
RSA_meth_get0_name() returns an internal
pointer which must not be freed by the caller.
RSA_meth_get_flags() returns zero or more
RSA_FLAG_* constants OR'ed together, or 0 if no
flags are set in meth.
RSA_meth_get0_app_data() returns the
pointer that was earlier passed to
RSA_meth_set0_app_data() or
NULL otherwise.
All other RSA_meth_get_*() functions
return the appropriate function pointer that has been set with the
corresponding RSA_meth_set_*() function, or
NULL if no such pointer has been set in
meth.
All RSA_meth_set*() functions return 1 on
success or 0 on failure. In the current implementation, only
RSA_meth_set1_name() can actually fail.
SEE ALSO
RSA_generate_key_ex(3), RSA_new(3), RSA_private_encrypt(3), RSA_public_encrypt(3), RSA_set_flags(3), RSA_set_method(3), RSA_sign(3)
HISTORY
These functions first appeared in OpenSSL 1.1.0.
RSA_meth_new(),
RSA_meth_dup(),
RSA_meth_free(),
RSA_meth_set_finish(),
RSA_meth_set_priv_enc(), and
RSA_meth_set_priv_dec() have been available since
OpenBSD 6.3,
RSA_meth_set1_name() and
RSA_meth_get_finish() since OpenBSD
6.4, and RSA_meth_get0_name(),
RSA_meth_get_flags(),
RSA_meth_set_flags(),
RSA_meth_get0_app_data(),
RSA_meth_set0_app_data(),
RSA_meth_get_init(),
RSA_meth_set_init(),
RSA_meth_set_finish(),
RSA_meth_get_pub_enc(),
RSA_meth_set_pub_enc(),
RSA_meth_get_pub_dec(),
RSA_meth_set_pub_dec(),
RSA_meth_get_priv_enc(),
RSA_meth_get_priv_dec(),
RSA_meth_get_sign(),
RSA_meth_set_sign(),
RSA_meth_get_verify(),
RSA_meth_set_verify(),
RSA_meth_get_mod_exp(),
RSA_meth_set_mod_exp(),
RSA_meth_get_bn_mod_exp(),
RSA_meth_set_bn_mod_exp(),
RSA_meth_get_keygen(), and
RSA_meth_set_keygen() since OpenBSD
6.6.