Updated: 2021/Apr/14


EVP_PKEY_encrypt(3)                 OpenSSL                EVP_PKEY_encrypt(3)



NAME
       EVP_PKEY_encrypt_init, EVP_PKEY_encrypt - encrypt using a public key
       algorithm

LIBRARY
       libcrypto, -lcrypto

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.

EXAMPLES
       Encrypt data using OAEP (for RSA keys). See also PEM_read_PUBKEY(3) or
       d2i_X509(3) for means to load a public key. You may also simply set
       'eng = NULL;' to start with the default OpenSSL RSA implementation:

        #include <openssl/evp.h>
        #include <openssl/rsa.h>
        #include <openssl/engine.h>

        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 */

SEE ALSO
       d2i_X509(3), ENGINE_by_id(3), 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 added in OpenSSL 1.0.0.

COPYRIGHT
       Copyright 2006-2019 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
       <https://www.openssl.org/source/license.html>.



1.1.1i                            2020-01-23               EVP_PKEY_encrypt(3)