KRB5_AUTH_CONTEXT(3)

NAME
krb5_auth_context, krb5_auth_con_init, krb5_auth_con_free, krb5_auth_con_setflags, krb5_auth_con_getflags, krb5_auth_con_setaddrs, krb5_auth_con_setaddrs_from_fd, krb5_auth_con_getaddrs, krb5_auth_con_genaddrs, krb5_auth_con_getkey, krb5_auth_con_setkey, krb5_auth_con_getuserkey, krb5_auth_con_setuserkey, krb5_auth_con_getlocalsubkey, krb5_auth_con_setlocalsubkey, krb5_auth_con_getremotesubkey, krb5_auth_con_setremotesubkey, krb5_auth_setcksumtype, krb5_auth_getcksumtype, krb5_auth_setkeytype, krb5_auth_getkeytype, krb5_auth_getlocalseqnumber, krb5_auth_setlocalseqnumber, krb5_auth_getremoteseqnumber, krb5_auth_setremoteseqnumber, krb5_auth_getauthenticator, krb5_auth_con_getrcache, krb5_auth_con_setrcache, krb5_auth_con_initivector, krb5_auth_con_setivector - manage authentication on connection level

LIBRARY
Kerberos 5 Library (libkrb5, -lkrb5)

SYNOPSIS
#include <krb5/krb5.h>
krb5_error_code
krb5_auth_con_init(krb5_context context, krb5_auth_context *auth_context);
void
krb5_auth_con_free(krb5_context context, krb5_auth_context auth_context);
krb5_error_code
krb5_auth_con_setflags(krb5_context context, krb5_auth_context auth_context, int32_t flags);
krb5_error_code
krb5_auth_con_getflags(krb5_context context, krb5_auth_context auth_context, int32_t *flags);
krb5_error_code
krb5_auth_con_setaddrs(krb5_context context, krb5_auth_context auth_context, krb5_address *local_addr, krb5_address *remote_addr);
krb5_error_code
krb5_auth_con_getaddrs(krb5_context context, krb5_auth_context auth_context, krb5_address **local_addr, krb5_address **remote_addr);
krb5_error_code
krb5_auth_con_genaddrs(krb5_context context, krb5_auth_context auth_context, int fd, int flags);
krb5_error_code
krb5_auth_con_setaddrs_from_fd(krb5_context context, krb5_auth_context auth_context, void *p_fd);
krb5_error_code
krb5_auth_con_getkey(krb5_context context, krb5_auth_context auth_context, krb5_keyblock **keyblock);
krb5_error_code
krb5_auth_con_getlocalsubkey(krb5_context context, krb5_auth_context auth_context, krb5_keyblock **keyblock);
krb5_error_code
krb5_auth_con_getremotesubkey(krb5_context context, krb5_auth_context auth_context, krb5_keyblock **keyblock);
krb5_error_code
krb5_auth_con_initivector(krb5_context context, krb5_auth_context auth_context);
krb5_error_code
krb5_auth_con_setivector(krb5_context context, krb5_auth_context *auth_context, krb5_pointer ivector);

DESCRIPTION
The krb5_auth_context structure holds all context related to an authenticated connection, in a similar way to krb5_context that holds the context for the thread or process. krb5_auth_context is used by various functions that are directly related to authentication between the server/client. Example of data that this structure contains are various flags, addresses of client and server, port numbers, keyblocks (and subkeys), sequence numbers, replay cache, and checksum-type.

krb5_auth_con_init() allocates and initializes the krb5_auth_context structure. Default values can be changed with krb5_auth_con_setcksumtype() and krb5_auth_con_setflags(). The auth_context structure must be freed by krb5_auth_con_free().

krb5_auth_con_getflags() and krb5_auth_con_setflags() gets and modifies the flags for a krb5_auth_context structure. Possible flags to set are:

KRB5_AUTH_CONTEXT_DO_TIME
    check timestamp on incoming packets.

KRB5_AUTH_CONTEXT_DO_SEQUENCE
    Generate and check sequence-number on each packet.

krb5_auth_con_setaddrs(), krb5_auth_con_setaddrs_from_fd() and krb5_auth_con_getaddrs() gets and sets the addresses that are checked when a packet is received. It is mandatory to set an address for the remote host. If the local address is not set, it iss deduced from the underlaying operating system. krb5_auth_con_getaddrs() will call krb5_free_address() on any address that is passed in local_addr or remote_addr. krb5_auth_con_setaddr() allows passing in a NULL pointer as local_addr and remote_addr, in that case it will just not set that address.

krb5_auth_con_setaddrs_from_fd() fetches the addresses from a file descriptor.

krb5_auth_con_genaddrs() fetches the address information from the given file descriptor fd depending on the bitmap argument flags.

Possible values on flags are:

KRB5_AUTH_CONTEXT_GENERATE_LOCAL_ADDR
    fetches the local address from fd.

KRB5_AUTH_CONTEXT_GENERATE_REMOTE_ADDR
    fetches the remote address from fd.

krb5_auth_con_setkey(), krb5_auth_con_setuserkey() and krb5_auth_con_getkey() gets and sets the key used for this auth context. The keyblock returned by krb5_auth_con_getkey() should be freed with krb5_free_keyblock(). The keyblock send into krb5_auth_con_setkey() is copied into the krb5_auth_context, and thus no special handling is needed. NULL is not a valid keyblock to krb5_auth_con_setkey().

krb5_auth_con_setuserkey() is only useful when doing user to user authentication. krb5_auth_con_setkey() is equivalent to krb5_auth_con_setuserkey().

krb5_auth_con_getlocalsubkey(), krb5_auth_con_setlocalsubkey(), krb5_auth_con_getremotesubkey() and krb5_auth_con_setremotesubkey() gets and sets the keyblock for the local and remote subkey. The keyblock returned by krb5_auth_con_getlocalsubkey() and krb5_auth_con_getremotesubkey() must be freed with krb5_free_keyblock().

krb5_auth_setcksumtype() and krb5_auth_getcksumtype() sets and gets the checksum type that should be used for this connection.

krb5_auth_getremoteseqnumber() krb5_auth_setremoteseqnumber(), krb5_auth_getlocalseqnumber() and krb5_auth_setlocalseqnumber() gets and sets the sequence-number for the local and remote sequence-number counter.

krb5_auth_setkeytype() and krb5_auth_getkeytype() gets and gets the keytype of the keyblock in krb5_auth_context.

krb5_auth_getauthenticator() Retrieves the authenticator that was used during mutual authentication. The authenticator returned should be freed by calling krb5_free_authenticator().

krb5_auth_con_getrcache() and krb5_auth_con_setrcache() gets and sets the replay-cache.

krb5_auth_con_initivector() allocates memory for and zeros the initial vector in the auth_context keyblock.

krb5_auth_con_setivector() sets the i_vector portion of auth_context to ivector.

SEE ALSO
krb5_context(3), kerberos(8)