=pod =head1 NAME RSA_set_default_method, RSA_get_default_method, RSA_set_method, RSA_get_method, RSA_PKCS1_SSLeay, RSA_PKCS1_RSAref, RSA_PKCS1_null_method, RSA_flags, RSA_new_method - Select RSA method =head1 SYNOPSIS #include void RSA_set_default_method(RSA_METHOD *meth); RSA_METHOD *RSA_get_default_method(void); RSA_METHOD *RSA_set_method(RSA *rsa, RSA_METHOD *meth); RSA_METHOD *RSA_get_method(RSA *rsa); RSA_METHOD *RSA_PKCS1_SSLeay(void); RSA_METHOD *RSA_PKCS1_RSAref(void); RSA_METHOD *RSA_null_method(void); int RSA_flags(RSA *rsa); RSA *RSA_new_method(RSA_METHOD *method); =head1 DESCRIPTION An B specifies the functions that OpenSSL uses for RSA operations. By modifying the method, alternative implementations such as hardware accelerators may be used. Initially, the default is to use the OpenSSL internal implementation, unless OpenSSL was configured with the C or C<-DRSA_NULL> options. RSA_PKCS1_SSLeay() returns a pointer to that method. RSA_PKCS1_RSAref() returns a pointer to a method that uses the RSAref library. This is the default method in the C configuration; the function is not available in other configurations. RSA_null_method() returns a pointer to a method that does not support the RSA transformation. It is the default if OpenSSL is compiled with C<-DRSA_NULL>. These methods may be useful in the USA because of a patent on the RSA cryptosystem. RSA_set_default_method() makes B the default method for all B structures created later. RSA_get_default_method() returns a pointer to the current default method. RSA_set_method() selects B for all operations using the key B. RSA_get_method() returns a pointer to the method currently selected for B. RSA_flags() returns the B that are set for B's current method. RSA_new_method() allocates and initializes an B structure so that B will be used for the RSA operations. If B is B, the default method is used. =head1 THE RSA_METHOD STRUCTURE typedef struct rsa_meth_st { /* name of the implementation */ const char *name; /* encrypt */ int (*rsa_pub_enc)(int flen, unsigned char *from, unsigned char *to, RSA *rsa, int padding); /* verify arbitrary data */ int (*rsa_pub_dec)(int flen, unsigned char *from, unsigned char *to, RSA *rsa, int padding); /* sign arbitrary data */ int (*rsa_priv_enc)(int flen, unsigned char *from, unsigned char *to, RSA *rsa, int padding); /* decrypt */ int (*rsa_priv_dec)(int flen, unsigned char *from, unsigned char *to, RSA *rsa, int padding); /* compute r0 = r0 ^ I mod rsa->n. May be NULL */ int (*rsa_mod_exp)(BIGNUM *r0, BIGNUM *I, RSA *rsa); /* compute r = a ^ p mod m. May be NULL */ int (*bn_mod_exp)(BIGNUM *r, BIGNUM *a, const BIGNUM *p, const BIGNUM *m, BN_CTX *ctx, BN_MONT_CTX *m_ctx); /* called at RSA_new */ int (*init)(RSA *rsa); /* called at RSA_free */ int (*finish)(RSA *rsa); /* RSA_FLAG_EXT_PKEY - rsa_mod_exp is called for private key * operations, even if p,q,dmp1,dmq1,iqmp * are NULL * RSA_FLAG_SIGN_VER - enable rsa_sign and rsa_verify * RSA_METHOD_FLAG_NO_CHECK - don't check pub/private match */ int flags; char *app_data; /* ?? */ /* sign. For backward compatibility, this is used only * if (flags & RSA_FLAG_SIGN_VER) */ int (*rsa_sign)(int type, unsigned char *m, unsigned int m_len, unsigned char *sigret, unsigned int *siglen, RSA *rsa); /* verify. For backward compatibility, this is used only * if (flags & RSA_FLAG_SIGN_VER) */ int (*rsa_verify)(int type, unsigned char *m, unsigned int m_len, unsigned char *sigbuf, unsigned int siglen, RSA *rsa); } RSA_METHOD; =head1 RETURN VALUES RSA_PKCS1_SSLeay(), RSA_PKCS1_RSAref(), RSA_PKCS1_null_method(), RSA_get_default_method() and RSA_get_method() return pointers to the respective Bs. RSA_set_default_method() returns no value. RSA_set_method() returns a pointer to the B previously associated with B. RSA_new_method() returns B and sets an error code that can be obtained by L if the allocation fails. Otherwise it returns a pointer to the newly allocated structure. =head1 SEE ALSO L, L =head1 HISTORY RSA_new_method() and RSA_set_default_method() appeared in SSLeay 0.8. RSA_get_default_method(), RSA_set_method() and RSA_get_method() as well as the rsa_sign and rsa_verify components of RSA_METHOD were added in OpenSSL 0.9.4. =cut