1=pod 2 3=head1 NAME 4 5EVP_PKEY_encrypt_init, EVP_PKEY_encrypt - encrypt using a public key algorithm 6 7=head1 SYNOPSIS 8 9 #include <openssl/evp.h> 10 11 int EVP_PKEY_encrypt_init(EVP_PKEY_CTX *ctx); 12 int EVP_PKEY_encrypt(EVP_PKEY_CTX *ctx, 13 unsigned char *out, size_t *outlen, 14 const unsigned char *in, size_t inlen); 15 16=head1 DESCRIPTION 17 18The EVP_PKEY_encrypt_init() function initializes a public key algorithm 19context using key B<pkey> for an encryption operation. 20 21The EVP_PKEY_encrypt() function performs a public key encryption operation 22using B<ctx>. The data to be encrypted is specified using the B<in> and 23B<inlen> parameters. If B<out> is B<NULL> then the maximum size of the output 24buffer is written to the B<outlen> parameter. If B<out> is not B<NULL> then 25before the call the B<outlen> parameter should contain the length of the 26B<out> buffer, if the call is successful the encrypted data is written to 27B<out> and the amount of data written to B<outlen>. 28 29=head1 NOTES 30 31After the call to EVP_PKEY_encrypt_init() algorithm specific control 32operations can be performed to set any appropriate parameters for the 33operation. 34 35The function EVP_PKEY_encrypt() can be called more than once on the same 36context if several operations are performed using the same parameters. 37 38=head1 RETURN VALUES 39 40EVP_PKEY_encrypt_init() and EVP_PKEY_encrypt() return 1 for success and 0 41or a negative value for failure. In particular a return value of -2 42indicates the operation is not supported by the public key algorithm. 43 44=head1 EXAMPLES 45 46Encrypt data using OAEP (for RSA keys). See also L<PEM_read_PUBKEY(3)> or 47L<d2i_X509(3)> for means to load a public key. You may also simply 48set 'eng = NULL;' to start with the default OpenSSL RSA implementation: 49 50 #include <openssl/evp.h> 51 #include <openssl/rsa.h> 52 #include <openssl/engine.h> 53 54 EVP_PKEY_CTX *ctx; 55 ENGINE *eng; 56 unsigned char *out, *in; 57 size_t outlen, inlen; 58 EVP_PKEY *key; 59 60 /* 61 * NB: assumes eng, key, in, inlen are already set up, 62 * and that key is an RSA public key 63 */ 64 ctx = EVP_PKEY_CTX_new(key, eng); 65 if (!ctx) 66 /* Error occurred */ 67 if (EVP_PKEY_encrypt_init(ctx) <= 0) 68 /* Error */ 69 if (EVP_PKEY_CTX_set_rsa_padding(ctx, RSA_OAEP_PADDING) <= 0) 70 /* Error */ 71 72 /* Determine buffer length */ 73 if (EVP_PKEY_encrypt(ctx, NULL, &outlen, in, inlen) <= 0) 74 /* Error */ 75 76 out = OPENSSL_malloc(outlen); 77 78 if (!out) 79 /* malloc failure */ 80 81 if (EVP_PKEY_encrypt(ctx, out, &outlen, in, inlen) <= 0) 82 /* Error */ 83 84 /* Encrypted data is outlen bytes written to buffer out */ 85 86=head1 SEE ALSO 87 88L<d2i_X509(3)>, 89L<ENGINE_by_id(3)>, 90L<EVP_PKEY_CTX_new(3)>, 91L<EVP_PKEY_decrypt(3)>, 92L<EVP_PKEY_sign(3)>, 93L<EVP_PKEY_verify(3)>, 94L<EVP_PKEY_verify_recover(3)>, 95L<EVP_PKEY_derive(3)> 96 97=head1 HISTORY 98 99These functions were added in OpenSSL 1.0.0. 100 101=head1 COPYRIGHT 102 103Copyright 2006-2019 The OpenSSL Project Authors. All Rights Reserved. 104 105Licensed under the OpenSSL license (the "License"). You may not use 106this file except in compliance with the License. You can obtain a copy 107in the file LICENSE in the source distribution or at 108L<https://www.openssl.org/source/license.html>. 109 110=cut 111