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 context created by krb5_crypto_init(), and usage_or_type specifies a key-usage.

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)