1.\" $OpenBSD: crypto.3,v 1.25 2020/06/24 17:00:38 schwarze Exp $ 2.\" OpenSSL a9c85cea Nov 11 09:33:55 2016 +0100 3.\" 4.\" This file was written by Ulf Moeller <ulf@openssl.org> and 5.\" Dr. Stephen Henson <steve@openssl.org>. 6.\" Copyright (c) 2000, 2002 The OpenSSL Project. All rights reserved. 7.\" 8.\" Redistribution and use in source and binary forms, with or without 9.\" modification, are permitted provided that the following conditions 10.\" are met: 11.\" 12.\" 1. Redistributions of source code must retain the above copyright 13.\" notice, this list of conditions and the following disclaimer. 14.\" 15.\" 2. Redistributions in binary form must reproduce the above copyright 16.\" notice, this list of conditions and the following disclaimer in 17.\" the documentation and/or other materials provided with the 18.\" distribution. 19.\" 20.\" 3. All advertising materials mentioning features or use of this 21.\" software must display the following acknowledgment: 22.\" "This product includes software developed by the OpenSSL Project 23.\" for use in the OpenSSL Toolkit. (http://www.openssl.org/)" 24.\" 25.\" 4. The names "OpenSSL Toolkit" and "OpenSSL Project" must not be used to 26.\" endorse or promote products derived from this software without 27.\" prior written permission. For written permission, please contact 28.\" openssl-core@openssl.org. 29.\" 30.\" 5. Products derived from this software may not be called "OpenSSL" 31.\" nor may "OpenSSL" appear in their names without prior written 32.\" permission of the OpenSSL Project. 33.\" 34.\" 6. Redistributions of any form whatsoever must retain the following 35.\" acknowledgment: 36.\" "This product includes software developed by the OpenSSL Project 37.\" for use in the OpenSSL Toolkit (http://www.openssl.org/)" 38.\" 39.\" THIS SOFTWARE IS PROVIDED BY THE OpenSSL PROJECT ``AS IS'' AND ANY 40.\" EXPRESSED OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE 41.\" IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR 42.\" PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE OpenSSL PROJECT OR 43.\" ITS CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, 44.\" SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT 45.\" NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; 46.\" LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) 47.\" HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, 48.\" STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) 49.\" ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED 50.\" OF THE POSSIBILITY OF SUCH DAMAGE. 51.\" 52.Dd $Mdocdate: June 24 2020 $ 53.Dt CRYPTO 3 54.Os 55.Sh NAME 56.Nm crypto 57.Nd OpenSSL cryptographic library 58.Sh DESCRIPTION 59The OpenSSL crypto library implements a wide range of cryptographic 60algorithms used in various Internet standards. 61The services provided by this library are used by the OpenSSL 62implementations of TLS and S/MIME, and they have also been used to 63implement SSH, OpenPGP, and other cryptographic standards. 64.Pp 65.Sy Symmetric ciphers 66including AES, Blowfish, CAST, Chacha20, IDEA, DES, RC2, and RC4 67are provided by the generic interface 68.Xr EVP_EncryptInit 3 . 69Low-level stand-alone interfaces include 70.Xr AES_encrypt 3 , 71.Xr BF_set_key 3 , 72.Xr ChaCha 3 , 73.Xr DES_set_key 3 , 74and 75.Xr RC4 3 . 76.Pp 77.Sy Public key cryptography and key agreement 78are provided by 79.Xr DH_new 3 , 80.Xr ECDH_compute_key 3 , 81.Xr X25519 3 , 82.Xr DSA_new 3 , 83.Xr ECDSA_SIG_new 3 , 84.Xr RSA_new 3 , 85and 86.Xr EVP_PKEY_new 3 . 87.Pp 88.Sy Certificates 89are handled by 90.Xr X509_new 3 91and 92.Xr X509v3_add_ext 3 . 93.Pp 94.Sy Authentication codes and hash functions 95offered include 96.Xr EVP_DigestInit 3 , 97.Xr CMAC_Init 3 , 98.Xr HMAC 3 , 99.Xr MD4 3 , 100.Xr MD5 3 , 101.Xr RIPEMD160 3 , 102.Xr SHA1 3 , 103and 104.Xr SHA256 3 . 105.Pp 106.Sy Input, output, and data encoding 107facilities include 108.Xr ASN1_TYPE_get 3 , 109.Xr BIO_new 3 , 110.Xr CMS_ContentInfo_new 3 , 111.Xr evp 3 , 112.Xr EVP_EncodeInit 3 , 113.Xr PEM_read 3 , 114.Xr PKCS7_encrypt 3 , 115.Xr PKCS7_sign 3 , 116.Xr PKCS12_create 3 , 117and 118.Xr SMIME_write_PKCS7 3 . 119.Pp 120.Sy Auxiliary features include: 121.Bl -dash -compact 122.It 123configuration file handling: see 124.Xr OPENSSL_config 3 125.It 126error reporting: see 127.Xr ERR 3 128.It 129.Xr OCSP_REQUEST_new 3 130.It 131.Xr UI_new 3 132.El 133.Pp 134.Sy Internal utilities 135include 136.Xr BIO_f_buffer 3 , 137.Xr BN_new 3 , 138.Xr EC_GROUP_new 3 , 139.Xr lh_new 3 , 140and 141.Xr STACK_OF 3 . 142.Pp 143Some of the newer functions follow a naming convention using the numbers 144.Sq 0 145and 146.Sq 1 . 147For example consider the names of these functions: 148.Pp 149.Ft int 150.Fo X509_CRL_add0_revoked 151.Fa "X509_CRL *crl" 152.Fa "X509_REVOKED *rev" 153.Fc 154.br 155.Ft int 156.Fo X509_add1_trust_object 157.Fa "X509 *x" 158.Fa "ASN1_OBJECT *obj" 159.Fc 160.Pp 161The 162.Sq 0 163version uses the supplied structure pointer directly in the parent and 164it will be freed up when the parent is freed. 165In the above example 166.Fa crl 167would be freed but 168.Fa rev 169would not. 170.Pp 171The 172.Sq 1 173function uses a copy of the supplied structure pointer (or in some cases 174increases its link count) in the parent and so both 175.Pf ( Fa x 176and 177.Fa obj 178above) should be freed up. 179.Sh SEE ALSO 180.Xr openssl 1 , 181.Xr ssl 3 182