rsa(3)

rsa(3)                       OpenSSL                       rsa(3)

NAME

     rsa - RSA public key cryptosystem

SYNOPSIS

      #include <openssl/rsa.h>
      #include <openssl/engine.h>

      RSA * RSA_new(void);
      void RSA_free(RSA *rsa);

      int RSA_public_encrypt(int flen, unsigned char *from,
         unsigned char *to, RSA *rsa, int padding);
      int RSA_private_decrypt(int flen, unsigned char *from,
         unsigned char *to, RSA *rsa, int padding);
      int RSA_private_encrypt(int flen, unsigned char *from,
         unsigned char *to, RSA *rsa,int padding);
      int RSA_public_decrypt(int flen, unsigned char *from,
         unsigned char *to, RSA *rsa,int padding);

      int RSA_sign(int type, unsigned char *m, unsigned int m_len,
         unsigned char *sigret, unsigned int *siglen, RSA *rsa);
      int RSA_verify(int type, unsigned char *m, unsigned int m_len,
         unsigned char *sigbuf, unsigned int siglen, RSA *rsa);

      int RSA_size(const RSA *rsa);

      RSA *RSA_generate_key(int num, unsigned long e,
         void (*callback)(int,int,void *), void *cb_arg);

      int RSA_check_key(RSA *rsa);

      int RSA_blinding_on(RSA *rsa, BN_CTX *ctx);
      void RSA_blinding_off(RSA *rsa);

      void RSA_set_default_method(const RSA_METHOD *meth);
      const RSA_METHOD *RSA_get_default_method(void);
      int RSA_set_method(RSA *rsa, const RSA_METHOD *meth);
      const RSA_METHOD *RSA_get_method(const RSA *rsa);
      RSA_METHOD *RSA_PKCS1_SSLeay(void);
      RSA_METHOD *RSA_null_method(void);
      int RSA_flags(const RSA *rsa);
      RSA *RSA_new_method(ENGINE *engine);

      int RSA_print(BIO *bp, RSA *x, int offset);
      int RSA_print_fp(FILE *fp, RSA *x, int offset);

      int RSA_get_ex_new_index(long argl, char *argp, int (*new_func)(),
         int (*dup_func)(), void (*free_func)());
      int RSA_set_ex_data(RSA *r,int idx,char *arg);
      char *RSA_get_ex_data(RSA *r, int idx);

1.0.2t               Last change: 2019-09-10                    1

rsa(3)                       OpenSSL                       rsa(3)

      int RSA_sign_ASN1_OCTET_STRING(int dummy, unsigned char *m,
         unsigned int m_len, unsigned char *sigret, unsigned int *siglen,
         RSA *rsa);
      int RSA_verify_ASN1_OCTET_STRING(int dummy, unsigned char *m,
         unsigned int m_len, unsigned char *sigbuf, unsigned int siglen,
         RSA *rsa);

DESCRIPTION

     These functions implement RSA public key encryption and
     signatures as defined in PKCS #1 v2.0 [RFC 2437].

     The RSA structure consists of several BIGNUM components. It
     can contain public as well as private RSA keys:

      struct
             {
             BIGNUM *n;              // public modulus
             BIGNUM *e;              // public exponent
             BIGNUM *d;              // private exponent
             BIGNUM *p;              // secret prime factor
             BIGNUM *q;              // secret prime factor
             BIGNUM *dmp1;           // d mod (p-1)
             BIGNUM *dmq1;           // d mod (q-1)
             BIGNUM *iqmp;           // q^-1 mod p
             // ...
             };
      RSA

     In public keys, the private exponent and the related secret
     values are NULL.

     p, q, dmp1, dmq1 and iqmp may be NULL in private keys, but
     the RSA operations are much faster when these values are
     available.

     Note that RSA keys may use non-standard RSA_METHOD
     implementations, either directly or by the use of ENGINE
     modules. In some cases (eg. an ENGINE providing support for
     hardware-embedded keys), these BIGNUM values will not be
     used by the implementation or may be used for alternative
     data storage. For this reason, applications should generally
     avoid using RSA structure elements directly and instead use
     API functions to query or modify keys.

CONFORMING TO

     SSL, PKCS #1 v2.0

PATENTS

     RSA was covered by a US patent which expired in September
     2000.

1.0.2t               Last change: 2019-09-10                    2

rsa(3)                       OpenSSL                       rsa(3)

SEE ALSO

     rsa(1), bn(3), dsa(3), dh(3), rand(3), engine(3),
     RSA_new(3), RSA_public_encrypt(3), RSA_sign(3), RSA_size(3),
     RSA_generate_key(3), RSA_check_key(3), RSA_blinding_on(3),
     RSA_set_method(3), RSA_print(3), RSA_get_ex_new_index(3),
     RSA_private_encrypt(3), RSA_sign_ASN1_OCTET_STRING(3),
     RSA_padding_add_PKCS1_type_1(3)

1.0.2t               Last change: 2019-09-10                    3