1.\" Copyright (c) 1999 Kungliga Tekniska H�gskolan 2.\" $Id: krb5_create_checksum.3,v 1.1 1999/04/18 13:47:11 joda Exp $ 3.Dd April 7, 1999 4.Dt NAME 3 5.Os HEIMDAL 6.Sh NAME 7.Nm krb5_checksum_is_collision_proof , 8.Nm krb5_checksum_is_keyed , 9.Nm krb5_checksumsize , 10.Nm krb5_create_checksum , 11.Nm krb5_verify_checksum 12.Nd creates and verifies checksums 13.Sh SYNOPSIS 14.Fd #include <krb5.h> 15 16.Ft krb5_error_code 17.Fn krb5_create_checksum "krb5_context context" "krb5_crypto crypto" "unsigned usage_or_type" "void *data" "size_t len" "Checksum *result" 18 19.Ft krb5_error_code 20.Fn krb5_verify_checksum "krb5_context context" "krb5_crypto crypto" "krb5_key_usage usage" "void *data" "size_t len" "Checksum *cksum" 21 22.Ft krb5_boolean 23.Fn krb5_checksum_is_collision_proof "krb5_context context" "krb5_cksumtype type" 24 25.Ft krb5_boolean 26.Fn krb5_checksum_is_keyed "krb5_context context" "krb5_cksumtype type" 27 28.Sh DESCRIPTION 29These functions are used to create and verify checksums. 30.Fn krb5_create_checksum 31creates a checksum of the specified data, and puts it in 32.Fa result . 33If 34.Fa crypto 35is 36.Dv NULL , 37.Fa usage_or_type 38specifies the checksum type to use; it must not be keyed. Otherwise 39.Fa crypto 40is an encryption context created by 41.Fn krb5_crypto_init , 42and 43.Fa usage_or_type 44specifies a key-usage. 45.Pp 46.Fn krb5_verify_checksum 47verifies the 48.Fa checksum , 49against the provided data. 50.Pp 51.Fn krb5_checksum_is_collision_proof 52returns true is the specified checksum is collision proof (that it's 53very unlikely that two strings has the same hash value, and that it's 54hard to find two strings that has the same hash). Examples of 55collision proof checksums are MD5, and SHA1, while CRC32 is not. 56.Pp 57.Fn krb5_checksum_is_keyed 58returns true if the specified checksum type is keyed (that the hash 59value is a function of both the data, and a separate key). Examples of 60keyed hash algorithms are HMAC-SHA1-DES3, and RSA-MD5-DES. The 61.Dq plain 62hash functions MD5, and SHA1 are not keyed. 63 64.\" .Sh EXAMPLE 65.\" .Sh BUGS 66.Sh SEE ALSO 67.Xr krb5_crypto_init 3 , 68.Xr krb5_encrypt 3 69