RSA_public_encrypt(3)       OpenSSL       RSA_public_encrypt(3)





NAME
       RSA_public_encrypt, RSA_private_decrypt - RSA public key
       cryptography

SYNOPSIS
        #include <openssl/rsa.h>

        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);

DESCRIPTION
       RSA_public_encrypt() encrypts the flen bytes at from
       (usually a session key) using the public key rsa and
       stores the ciphertext in to. to must point to
       RSA_size(rsa) bytes of memory.

       padding denotes one of the following modes:

       RSA_PKCS1_PADDING
           PKCS #1 v1.5 padding. This currently is the most
           widely used mode.

       RSA_PKCS1_OAEP_PADDING
           EME-OAEP as defined in PKCS #1 v2.0 with SHA-1, MGF1
           and an empty encoding parameter. This mode is recom-
           mended for all new applications.

       RSA_SSLV23_PADDING
           PKCS #1 v1.5 padding with an SSL-specific modifica-
           tion that denotes that the server is SSL3 capable.

       RSA_NO_PADDING
           Raw RSA encryption. This mode should only be used to
           implement cryptographically sound padding modes in
           the application code.  Encrypting user data directly
           with RSA is insecure.

       flen must be less than RSA_size(rsa) - 11 for the PKCS
       #1 v1.5 based padding modes, and less than RSA_size(rsa)
       - 41 for RSA_PKCS1_OAEP_PADDING. The random number gen-
       erator must be seeded prior to calling RSA_pub-
       lic_encrypt().

       RSA_private_decrypt() decrypts the flen bytes at from
       using the private key rsa and stores the plaintext in
       to. to must point to a memory section large enough to
       hold the decrypted data (which is smaller than
       RSA_size(rsa)). padding is the padding mode that was
       used to encrypt the data.

RETURN VALUES
       RSA_public_encrypt() returns the size of the encrypted
       data (i.e., RSA_size(rsa)). RSA_private_decrypt()
       returns the size of the recovered plaintext.

       On error, -1 is returned; the error codes can be
       obtained by ERR_get_error(3).

CONFORMING TO
       SSL, PKCS #1 v2.0

SEE ALSO
       ERR_get_error(3), rand(3), rsa(3), RSA_size(3)

HISTORY
       The padding argument was added in SSLeay 0.8.
       RSA_NO_PADDING is available since SSLeay 0.9.0, OAEP was
       added in OpenSSL 0.9.2b.



0.9.7c                     2002-09-25     RSA_public_encrypt(3)
