NAME(3)                   OpenBSD Programmer's Manual                  NAME(3)

NAME
     krb5_checksum_is_collision_proof, krb5_checksum_is_keyed,
     krb5_checksumsize, krb5_create_checksum, krb5_verify_checksum - creates
     and verifies checksums

LIBRARY
     Kerberos 5 Library (libkrb5, -lkrb5)

SYNOPSIS
     #include <krb5.h>

     krb5_error_code
     krb5_create_checksum(krb5_context context, krb5_crypto crypto,
             unsigned usage_or_type, void *data, size_t len,
             Checksum *result);

     krb5_error_code
     krb5_verify_checksum(krb5_context context, krb5_crypto crypto,
             krb5_key_usage usage, void *data, size_t len, Checksum *cksum);

     krb5_boolean
     krb5_checksum_is_collision_proof(krb5_context context,
             krb5_cksumtype type);

     krb5_boolean
     krb5_checksum_is_keyed(krb5_context context, krb5_cksumtype type);

DESCRIPTION
     These functions are used to create and verify checksums.
     krb5_create_checksum() creates a checksum of the specified data, and puts
     it in result.  If crypto is NULL, usage_or_type specifies the checksum
     type to use; it must not be keyed. Otherwise crypto is an encryption con-
     text created by krb5_crypto_init(), and usage_or_type specifies a key-us-
     age.

     krb5_verify_checksum() verifies the checksum, against the provided data.

     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.

     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 ``plain'' hash functions MD5, and SHA1 are not keyed.

SEE ALSO
     krb5_crypto_init(3), krb5_encrypt(3)

 HEIMDAL                         April 7, 1999                               1
