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Command: EVP_PKEY_encrypt | Section: 3 | Source: OpenBSD | File: EVP_PKEY_encrypt.3
EVP_PKEY_ENCRYPT(3) FreeBSD Library Functions Manual EVP_PKEY_ENCRYPT(3)
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 ctx->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.
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.
EXAMPLES
Encrypt data using OAEP (for RSA keys). See also PEM_read_PUBKEY(3) and
d2i_X509(3) for means to load a public key. You may also simply set
"eng" to NULL to start with the default OpenSSL RSA implementation:
#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 that key, in, inlen are already set up
* and that key is an RSA public key
*/
ctx = EVP_PKEY_CTX_new(key, NULL);
if (!ctx)
/* Error occurred */
if (EVP_PKEY_encrypt_init(ctx) <= 0)
/* Error */
if (EVP_PKEY_CTX_set_rsa_padding(ctx, RSA_PKCS1_OAEP_PADDING) <= 0)
/* Error */
/* Determine buffer length */
if (EVP_PKEY_encrypt(ctx, NULL, &outlen, in, inlen) <= 0)
/* Error */
out = 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_derive(3),
EVP_PKEY_sign(3), EVP_PKEY_verify(3), EVP_PKEY_verify_recover(3)
HISTORY
EVP_PKEY_encrypt_init() and EVP_PKEY_encrypt() first appeared in OpenSSL
1.0.0 and have been available since OpenBSD 4.9.
FreeBSD 14.1-RELEASE-p8 December 6, 2024 FreeBSD 14.1-RELEASE-p8