1.\" Copyright (c) 1999 Kungliga Tekniska H�gskolan 2.\" (Royal Institute of Technology, Stockholm, Sweden). 3.\" All rights reserved. 4.\" 5.\" Redistribution and use in source and binary forms, with or without 6.\" modification, are permitted provided that the following conditions 7.\" are met: 8.\" 9.\" 1. Redistributions of source code must retain the above copyright 10.\" notice, this list of conditions and the following disclaimer. 11.\" 12.\" 2. Redistributions in binary form must reproduce the above copyright 13.\" notice, this list of conditions and the following disclaimer in the 14.\" documentation and/or other materials provided with the distribution. 15.\" 16.\" 3. Neither the name of the Institute nor the names of its contributors 17.\" may be used to endorse or promote products derived from this software 18.\" without specific prior written permission. 19.\" 20.\" THIS SOFTWARE IS PROVIDED BY THE INSTITUTE AND CONTRIBUTORS ``AS IS'' AND 21.\" ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE 22.\" IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE 23.\" ARE DISCLAIMED. IN NO EVENT SHALL THE INSTITUTE OR CONTRIBUTORS BE LIABLE 24.\" FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL 25.\" DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS 26.\" OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) 27.\" HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT 28.\" LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY 29.\" OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF 30.\" SUCH DAMAGE. 31.\" 32.\" $Id: krb5_create_checksum.3,v 1.6 2003/04/16 13:58:14 lha Exp $ 33.\" 34.Dd April 7, 1999 35.Dt NAME 3 36.Os HEIMDAL 37.Sh NAME 38.Nm krb5_checksum_is_collision_proof , 39.Nm krb5_checksum_is_keyed , 40.Nm krb5_checksumsize , 41.Nm krb5_create_checksum , 42.Nm krb5_verify_checksum 43.Nd creates and verifies checksums 44.Sh LIBRARY 45Kerberos 5 Library (libkrb5, -lkrb5) 46.Sh SYNOPSIS 47.In krb5.h 48.Ft krb5_error_code 49.Fn krb5_create_checksum "krb5_context context" "krb5_crypto crypto" "unsigned usage_or_type" "void *data" "size_t len" "Checksum *result" 50.Ft krb5_error_code 51.Fn krb5_verify_checksum "krb5_context context" "krb5_crypto crypto" "krb5_key_usage usage" "void *data" "size_t len" "Checksum *cksum" 52.Ft krb5_boolean 53.Fn krb5_checksum_is_collision_proof "krb5_context context" "krb5_cksumtype type" 54.Ft krb5_boolean 55.Fn krb5_checksum_is_keyed "krb5_context context" "krb5_cksumtype type" 56.Sh DESCRIPTION 57These functions are used to create and verify checksums. 58.Fn krb5_create_checksum 59creates a checksum of the specified data, and puts it in 60.Fa result . 61If 62.Fa crypto 63is 64.Dv NULL , 65.Fa usage_or_type 66specifies the checksum type to use; it must not be keyed. Otherwise 67.Fa crypto 68is an encryption context created by 69.Fn krb5_crypto_init , 70and 71.Fa usage_or_type 72specifies a key-usage. 73.Pp 74.Fn krb5_verify_checksum 75verifies the 76.Fa checksum , 77against the provided data. 78.Pp 79.Fn krb5_checksum_is_collision_proof 80returns true is the specified checksum is collision proof (that it's 81very unlikely that two strings has the same hash value, and that it's 82hard to find two strings that has the same hash). Examples of 83collision proof checksums are MD5, and SHA1, while CRC32 is not. 84.Pp 85.Fn krb5_checksum_is_keyed 86returns true if the specified checksum type is keyed (that the hash 87value is a function of both the data, and a separate key). Examples of 88keyed hash algorithms are HMAC-SHA1-DES3, and RSA-MD5-DES. The 89.Dq plain 90hash functions MD5, and SHA1 are not keyed. 91.\" .Sh EXAMPLE 92.\" .Sh BUGS 93.Sh SEE ALSO 94.Xr krb5_crypto_init 3 , 95.Xr krb5_encrypt 3 96