git-svn-id: svn://svn.h5l.se/heimdal/trunk/heimdal@5975 ec53bebd-3082-4978-b11e-865c3cabbd6b
		
			
				
	
	
		
			69 lines
		
	
	
		
			2.0 KiB
		
	
	
	
		
			Groff
		
	
	
	
	
	
			
		
		
	
	
			69 lines
		
	
	
		
			2.0 KiB
		
	
	
	
		
			Groff
		
	
	
	
	
	
.\" Copyright (c) 1999 Kungliga Tekniska Högskolan
 | 
						|
.\" $Id$
 | 
						|
.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 <krb5.h>
 | 
						|
 | 
						|
.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
 |