=pod =head1 NAME RSA_public_encrypt, RSA_private_decrypt - RSA public key cryptography =head1 SYNOPSIS #include int RSA_public_encrypt(int flen, const unsigned char *from, unsigned char *to, RSA *rsa, int padding); int RSA_private_decrypt(int flen, const unsigned char *from, unsigned char *to, RSA *rsa, int padding); =head1 DESCRIPTION RSA_public_encrypt() encrypts the B bytes at B (usually a session key) using the public key B and stores the ciphertext in B. B must point to RSA_size(B) bytes of memory. B denotes one of the following modes: =over 4 =item RSA_PKCS1_PADDING PKCS #1 v1.5 padding. This currently is the most widely used mode. =item 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 recommended for all new applications. =item RSA_SSLV23_PADDING PKCS #1 v1.5 padding with an SSL-specific modification that denotes that the server is SSL3 capable. =item RSA_NO_PADDING Raw RSA encryption. This mode should I be used to implement cryptographically sound padding modes in the application code. Encrypting user data directly with RSA is insecure. =back B must be less than RSA_size(B) - 11 for the PKCS #1 v1.5 based padding modes, less than RSA_size(B) - 41 for RSA_PKCS1_OAEP_PADDING and exactly RSA_size(B) for RSA_NO_PADDING. The random number generator must be seeded prior to calling RSA_public_encrypt(). RSA_private_decrypt() decrypts the B bytes at B using the private key B and stores the plaintext in B. B must point to a memory section large enough to hold the decrypted data (which is smaller than RSA_size(B)). B is the padding mode that was used to encrypt the data. =head1 RETURN VALUES RSA_public_encrypt() returns the size of the encrypted data (i.e., RSA_size(B)). RSA_private_decrypt() returns the size of the recovered plaintext. On error, -1 is returned; the error codes can be obtained by L. =head1 CONFORMING TO SSL, PKCS #1 v2.0 =head1 SEE ALSO L, L, L =head1 COPYRIGHT Copyright 2000-2016 The OpenSSL Project Authors. All Rights Reserved. Licensed under the OpenSSL license (the "License"). You may not use this file except in compliance with the License. You can obtain a copy in the file LICENSE in the source distribution or at L. =cut