NAME¶
EVP_PKEY_encrypt_init, EVP_PKEY_encrypt - encrypt using a public key algorithm
SYNOPSIS¶
#include <openssl/evp.h>
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);
DESCRIPTION¶
The
EVP_PKEY_encrypt_init() function initializes a public key algorithm
context using key
pkey for an encryption operation.
The
EVP_PKEY_encrypt() function performs a public key encryption
operation using
ctx. The data to be encrypted is specified using the
in and
inlen parameters. If
out is
NULL then the
maximum size of the output buffer is written to the
outlen parameter.
If
out is not
NULL then before the call the
outlen
parameter should contain the length of the
out buffer, if the call is
successful the encrypted data is written to
out and the amount of data
written to
outlen.
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.
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.
EXAMPLE¶
Encrypt data using OAEP (for RSA keys):
#include <openssl/evp.h>
#include <openssl/rsa.h>
EVP_PKEY_CTX *ctx;
unsigned char *out, *in;
size_t outlen, inlen;
EVP_PKEY *key;
/* NB: assumes key in, inlen are already set up
* and that key is an RSA public key
*/
ctx = EVP_PKEY_CTX_new(key);
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 */
SEE ALSO¶
EVP_PKEY_CTX_new(3),
EVP_PKEY_decrypt(3),
EVP_PKEY_sign(3),
EVP_PKEY_verify(3),
EVP_PKEY_verify_recover(3),
EVP_PKEY_derive(3)
HISTORY¶
These functions were first added to OpenSSL 1.0.0.