RSApublicencrypt(3) OpenSSL RSApublicencrypt(3)

NAME
       RSApublicencrypt, RSAprivatedecrypt - RSA public key cryptography

SYNOPSIS
        #include 

        int RSApublicencrypt(int flen, unsigned char *from,
           unsigned char *to, RSA *rsa, int padding);

        int RSAprivatedecrypt(int flen, unsigned char *from,
            unsigned char *to, RSA *rsa, int padding);

DESCRIPTION
       RSApublicencrypt() encrypts the fflleenn bytes at ffrroomm (usually a session
       key) using the public key rrssaa and stores the ciphertext in ttoo. ttoo must
       point to RSAsize(rrssaa) bytes of memory.

       ppaaddddiinngg denotes one of the following modes:

       RSAPKCS1PADDING
           PKCS #1 v1.5 padding. This currently is the most widely used mode.

       RSAPKCS1OAEPPADDING
           EME-OAEP as defined in PKCS #1 v2.0 with SHA-1, MGF1 and an empty
           encoding parameter. This mode is recommended for all new
           applications.

       RSASSLV23PADDING
           PKCS #1 v1.5 padding with an SSL-specific modification that denotes
           that the server is SSL3 capable.

       RSANOPADDING
           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.

       fflleenn must be less than RSAsize(rrssaa) - 11 for the PKCS #1 v1.5 based
       padding modes, less than RSAsize(rrssaa) - 41 for RSAPKCS1OAEPPADDING
       and exactly RSAsize(rrssaa) for RSANOPADDING.  The random number
       generator must be seeded prior to calling RSApublicencrypt().

       RSAprivatedecrypt() decrypts the fflleenn bytes at ffrroomm using the private
       key rrssaa and stores the plaintext in ttoo. ttoo must point to a memory
       section large enough to hold the decrypted data (which is smaller than
       RSAsize(rrssaa)). ppaaddddiinngg is the padding mode that was used to encrypt
       the data.

RETURN VALUES
       RSApublicencrypt() returns the size of the encrypted data (i.e.,
       RSAsize(rrssaa)). RSAprivatedecrypt() returns the size of the recovered
       plaintext.

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

CCOONNFFOORRMMIINNGG TTOO
       SSL, PKCS #1 v2.0

SEE ALSO
       ERRgeterror(3), rand(3), rsa(3), RSAsize(3)

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



0.9.7l                            2004-03-23             RSApublicencrypt(3)