=pod
=head1 NAME
EVP_PKEY_encrypt_init, EVP_PKEY_encrypt - encrypt using a public key algorithm
=head1 SYNOPSIS
#include
int EVP_PKEY_encrypt_init(EVP_PKEY_CTX *ctx);
int EVP_PKEY_encrypt(EVP_PKEY_CTX *ctx,
unsigned char *out, size_t *outlen,
const unsigned char *in, size_t inlen);
=head1 DESCRIPTION
The EVP_PKEY_encrypt_init() function initializes a public key algorithm
context using key B for an encryption operation.
The EVP_PKEY_encrypt() function performs a public key encryption operation
using B. The data to be encrypted is specified using the B and
B parameters. If B is B then the maximum size of the output
buffer is written to the B parameter. If B is not B then
before the call the B parameter should contain the length of the
B buffer, if the call is successful the encrypted data is written to
B and the amount of data written to B.
=head1 NOTES
After the call to EVP_PKEY_encrypt_init() algorithm specific control
operations can be performed to set any appropriate parameters for the
operation.
The function EVP_PKEY_encrypt() can be called more than once on the same
context if several operations are performed using the same parameters.
=head1 RETURN VALUES
EVP_PKEY_encrypt_init() and EVP_PKEY_encrypt() return 1 for success and 0
or a negative value for failure. In particular a return value of -2
indicates the operation is not supported by the public key algorithm.
=head1 EXAMPLE
Encrypt data using OAEP (for RSA keys). See also L or
L for means to load a public key. You may also simply
set 'eng = NULL;' to start with the default OpenSSL RSA implementation:
#include
#include
#include
EVP_PKEY_CTX *ctx;
ENGINE *eng;
unsigned char *out, *in;
size_t outlen, inlen;
EVP_PKEY *key;
/* NB: assumes eng, key, in, inlen are already set up,
* and that key is an RSA public key
*/
ctx = EVP_PKEY_CTX_new(key,eng);
if (!ctx)
/* Error occurred */
if (EVP_PKEY_encrypt_init(ctx) <= 0)
/* Error */
if (EVP_PKEY_CTX_set_rsa_padding(ctx, RSA_OAEP_PADDING) <= 0)
/* Error */
/* Determine buffer length */
if (EVP_PKEY_encrypt(ctx, NULL, &outlen, in, inlen) <= 0)
/* Error */
out = OPENSSL_malloc(outlen);
if (!out)
/* malloc failure */
if (EVP_PKEY_encrypt(ctx, out, &outlen, in, inlen) <= 0)
/* Error */
/* Encrypted data is outlen bytes written to buffer out */
=head1 SEE ALSO
L,
L,
L,
L,
L,
L,
L,
L
=head1 HISTORY
These functions were first added to OpenSSL 1.0.0.
=cut