1=pod 2 3=head1 NAME 4 5EVP_PKEY_encrypt_init_ex, 6EVP_PKEY_encrypt_init, EVP_PKEY_encrypt - encrypt using a public key algorithm 7 8=head1 SYNOPSIS 9 10 #include <openssl/evp.h> 11 12 int EVP_PKEY_encrypt_init(EVP_PKEY_CTX *ctx); 13 int EVP_PKEY_encrypt_init_ex(EVP_PKEY_CTX *ctx, const OSSL_PARAM params[]); 14 int EVP_PKEY_encrypt(EVP_PKEY_CTX *ctx, 15 unsigned char *out, size_t *outlen, 16 const unsigned char *in, size_t inlen); 17 18=head1 DESCRIPTION 19 20The EVP_PKEY_encrypt_init() function initializes a public key algorithm 21context using key B<pkey> for an encryption operation. 22 23The EVP_PKEY_encrypt_init_ex() function initializes a public key algorithm 24context using key B<pkey> for an encryption operation and sets the 25algorithm specific B<params>. 26 27The EVP_PKEY_encrypt() function performs a public key encryption operation 28using B<ctx>. The data to be encrypted is specified using the B<in> and 29B<inlen> parameters. If B<out> is B<NULL> then the maximum size of the output 30buffer is written to the B<outlen> parameter. If B<out> is not B<NULL> then 31before the call the B<outlen> parameter should contain the length of the 32B<out> buffer, if the call is successful the encrypted data is written to 33B<out> and the amount of data written to B<outlen>. 34 35=head1 NOTES 36 37After the call to EVP_PKEY_encrypt_init() algorithm specific control 38operations can be performed to set any appropriate parameters for the 39operation. These operations can be included in the EVP_PKEY_encrypt_init_ex() 40call. 41 42The function EVP_PKEY_encrypt() can be called more than once on the same 43context if several operations are performed using the same parameters. 44 45=head1 RETURN VALUES 46 47EVP_PKEY_encrypt_init(), EVP_PKEY_encrypt_init_ex() and EVP_PKEY_encrypt() 48return 1 for success and 0 or a negative value for failure. In particular a 49return value of -2 indicates the operation is not supported by the public key 50algorithm. 51 52=head1 EXAMPLES 53 54Encrypt data using OAEP (for RSA keys). See also L<PEM_read_PUBKEY(3)> or 55L<d2i_X509(3)> for means to load a public key. You may also simply 56set 'eng = NULL;' to start with the default OpenSSL RSA implementation: 57 58 #include <openssl/evp.h> 59 #include <openssl/rsa.h> 60 #include <openssl/engine.h> 61 62 EVP_PKEY_CTX *ctx; 63 ENGINE *eng; 64 unsigned char *out, *in; 65 size_t outlen, inlen; 66 EVP_PKEY *key; 67 68 /* 69 * NB: assumes eng, key, in, inlen are already set up, 70 * and that key is an RSA public key 71 */ 72 ctx = EVP_PKEY_CTX_new(key, eng); 73 if (!ctx) 74 /* Error occurred */ 75 if (EVP_PKEY_encrypt_init(ctx) <= 0) 76 /* Error */ 77 if (EVP_PKEY_CTX_set_rsa_padding(ctx, RSA_PKCS1_OAEP_PADDING) <= 0) 78 /* Error */ 79 80 /* Determine buffer length */ 81 if (EVP_PKEY_encrypt(ctx, NULL, &outlen, in, inlen) <= 0) 82 /* Error */ 83 84 out = OPENSSL_malloc(outlen); 85 86 if (!out) 87 /* malloc failure */ 88 89 if (EVP_PKEY_encrypt(ctx, out, &outlen, in, inlen) <= 0) 90 /* Error */ 91 92 /* Encrypted data is outlen bytes written to buffer out */ 93 94=head1 SEE ALSO 95 96L<d2i_X509(3)>, 97L<ENGINE_by_id(3)>, 98L<EVP_PKEY_CTX_new(3)>, 99L<EVP_PKEY_decrypt(3)>, 100L<EVP_PKEY_sign(3)>, 101L<EVP_PKEY_verify(3)>, 102L<EVP_PKEY_verify_recover(3)>, 103L<EVP_PKEY_derive(3)> 104 105=head1 HISTORY 106 107These functions were added in OpenSSL 1.0.0. 108 109=head1 COPYRIGHT 110 111Copyright 2006-2021 The OpenSSL Project Authors. All Rights Reserved. 112 113Licensed under the Apache License 2.0 (the "License"). You may not use 114this file except in compliance with the License. You can obtain a copy 115in the file LICENSE in the source distribution or at 116L<https://www.openssl.org/source/license.html>. 117 118=cut 119
