1.\" $OpenBSD: RSA_new.3,v 1.10 2018/04/18 01:11:45 schwarze Exp $ 2.\" OpenSSL doc/man3/RSA_new.pod 99d63d46 Oct 26 13:56:48 2016 -0400 3.\" OpenSSL doc/crypto/rsa.pod 35d2e327 Jun 3 16:19:49 2016 -0400 4.\" 5.\" This file was written by Ulf Moeller <ulf@openssl.org>. 6.\" Copyright (c) 2000, 2002, 2016 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: April 18 2018 $ 53.Dt RSA_NEW 3 54.Os 55.Sh NAME 56.Nm RSA_new , 57.Nm RSA_up_ref , 58.Nm RSA_free 59.Nd allocate and free RSA objects 60.Sh SYNOPSIS 61.In openssl/rsa.h 62.Ft RSA * 63.Fn RSA_new void 64.Ft int 65.Fo RSA_up_ref 66.Fa "RSA *rsa" 67.Fc 68.Ft void 69.Fo RSA_free 70.Fa "RSA *rsa" 71.Fc 72.Sh DESCRIPTION 73The RSA functions implement RSA public key encryption and signatures 74as defined in PKCS #1 v2.0 (RFC 2437). 75.Pp 76.Fn RSA_new 77allocates and initializes an 78.Vt RSA 79structure, setting the reference count to 1. 80It is equivalent to calling 81.Xr RSA_new_method 3 82with a 83.Dv NULL 84argument. 85.Pp 86.Fn RSA_up_ref 87increments the reference count by 1. 88.Pp 89.Fn RSA_free 90decrements the reference count by 1. 91If it reaches 0, it frees the 92.Vt RSA 93structure and its components. 94The key is erased before the memory is returned to the system. 95If 96.Fa rsa 97is a 98.Dv NULL 99pointer, no action occurs. 100.Pp 101The 102.Vt RSA 103structure consists of several 104.Vt BIGNUM 105components. 106It can contain public as well as private RSA keys: 107.Bd -literal 108typedef struct { 109 BIGNUM *n; // public modulus 110 BIGNUM *e; // public exponent 111 BIGNUM *d; // private exponent 112 BIGNUM *p; // secret prime factor 113 BIGNUM *q; // secret prime factor 114 BIGNUM *dmp1; // d mod (p-1) 115 BIGNUM *dmq1; // d mod (q-1) 116 BIGNUM *iqmp; // q^-1 mod p 117 // ... 118} RSA; 119.Ed 120.Pp 121In public keys, the private exponent 122.Fa d 123and the related secret values 124.Fa p , q , dmp1 , dmp2 , 125and 126.Fa iqmp 127are 128.Dv NULL . 129.Pp 130.Fa p , 131.Fa q , 132.Fa dmp1 , 133.Fa dmq1 , 134and 135.Fa iqmp 136may be 137.Dv NULL 138in private keys, but the RSA operations are much faster when these 139values are available. 140.Pp 141Note that RSA keys may use non-standard 142.Vt RSA_METHOD 143implementations, either directly or by the use of 144.Vt ENGINE 145modules. 146In some cases (e.g. an 147.Vt ENGINE 148providing support for hardware-embedded keys), these 149.Vt BIGNUM 150values will not be used by the implementation or may be used for 151alternative data storage. 152For this reason, applications should generally avoid using 153.Vt RSA 154structure elements directly and instead use API functions to query 155or modify keys. 156.Sh RETURN VALUES 157If the allocation fails, 158.Fn RSA_new 159returns 160.Dv NULL 161and sets an error code that can be obtained by 162.Xr ERR_get_error 3 . 163Otherwise it returns a pointer to the newly allocated structure. 164.Pp 165.Fn RSA_up_ref 166returns 1 for success or 0 for failure. 167.Sh SEE ALSO 168.Xr BN_new 3 , 169.Xr d2i_RSAPublicKey 3 , 170.Xr DH_new 3 , 171.Xr DSA_new 3 , 172.Xr ERR_get_error 3 , 173.Xr EVP_PKEY_set1_RSA 3 , 174.Xr RSA_blinding_on 3 , 175.Xr RSA_check_key 3 , 176.Xr RSA_generate_key 3 , 177.Xr RSA_get0_key 3 , 178.Xr RSA_get_ex_new_index 3 , 179.Xr RSA_meth_new 3 , 180.Xr RSA_padding_add_PKCS1_type_1 3 , 181.Xr RSA_print 3 , 182.Xr RSA_private_encrypt 3 , 183.Xr RSA_public_encrypt 3 , 184.Xr RSA_set_method 3 , 185.Xr RSA_sign 3 , 186.Xr RSA_sign_ASN1_OCTET_STRING 3 , 187.Xr RSA_size 3 188.Sh STANDARDS 189SSL, PKCS #1 v2.0 190.Pp 191RSA was covered by a US patent which expired in September 2000. 192.Sh HISTORY 193.Fn RSA_new 194and 195.Fn RSA_free 196appeared in SSLeay 0.4 or earlier and have been available since 197.Ox 2.4 . 198.Pp 199.Fn RSA_up_ref 200first appeared in OpenSSL 0.9.7 and has been available since 201.Ox 3.2 . 202