.\" Copyright (c) 1999 Kungliga Tekniska Högskolan .\" $Id: krb5_create_checksum.3,v 1.2 2001/01/26 22:43:21 assar Exp $ .Dd April 7, 1999 .Dt NAME 3 .Os HEIMDAL .Sh NAME .Nm krb5_checksum_is_collision_proof , .Nm krb5_checksum_is_keyed , .Nm krb5_checksumsize , .Nm krb5_create_checksum , .Nm krb5_verify_checksum .Nd creates and verifies checksums .Sh SYNOPSIS .Fd #include .Ft krb5_error_code .Fn krb5_create_checksum "krb5_context context" "krb5_crypto crypto" "unsigned usage_or_type" "void *data" "size_t len" "Checksum *result" .Ft krb5_error_code .Fn krb5_verify_checksum "krb5_context context" "krb5_crypto crypto" "krb5_key_usage usage" "void *data" "size_t len" "Checksum *cksum" .Ft krb5_boolean .Fn krb5_checksum_is_collision_proof "krb5_context context" "krb5_cksumtype type" .Ft krb5_boolean .Fn krb5_checksum_is_keyed "krb5_context context" "krb5_cksumtype type" .Sh DESCRIPTION These functions are used to create and verify checksums. .Fn krb5_create_checksum creates a checksum of the specified data, and puts it in .Fa result . If .Fa crypto is .Dv NULL , .Fa usage_or_type specifies the checksum type to use; it must not be keyed. Otherwise .Fa crypto is an encryption context created by .Fn krb5_crypto_init , and .Fa usage_or_type specifies a key-usage. .Pp .Fn krb5_verify_checksum verifies the .Fa checksum , against the provided data. .Pp .Fn krb5_checksum_is_collision_proof returns true is the specified checksum is collision proof (that it's very unlikely that two strings has the same hash value, and that it's hard to find two strings that has the same hash). Examples of collision proof checksums are MD5, and SHA1, while CRC32 is not. .Pp .Fn krb5_checksum_is_keyed returns true if the specified checksum type is keyed (that the hash value is a function of both the data, and a separate key). Examples of keyed hash algorithms are HMAC-SHA1-DES3, and RSA-MD5-DES. The .Dq plain hash functions MD5, and SHA1 are not keyed. .\" .Sh EXAMPLE .\" .Sh BUGS .Sh SEE ALSO .Xr krb5_crypto_init 3 , .Xr krb5_encrypt 3