NAME
auth_sasl, auth_sasl_ex - SASL implementation
SYNOPSIS
#include <courierauthsasl.h>
int rc=auth_sasl(const char *method, const char *initialresponse,
char *(*conversation_func)(const char *, void *)),
void *callback_arg, char **authtype_ret,
char **authdata_ret);
int rc=auth_sasl_ex(const char *method, const char *initialresponse,
const char *externalauth,
char *(*conversation_func)(const char *, void *)),
void *callback_arg, char **authtype_ret,
char **authdata_ret);
DESCRIPTION
auth_sasl is a generic SASL server implementation. method is the
requested SASL method. At this time auth_sasl knows how to handle the
following SASL methods:
· LOGIN
· PLAIN
· CRAM-MD5
· CRAM-SHA1
initialresponse is a base64-encoded initial response provided in the
client´s SASL request. initialresponse must be NULL if an initial
response was not included in the client´s SASL request.
conversation_func is the application-implemented SASL conversation
callback function. conversation_func receives a base64-encoded SASL
prompt, and the callback_arg argument to auth_sasl. conversation_func
must return a buffer containing the base64-encoded reply from the
client. auth_sasl will free(3) this buffer when it´s done.
conversation_func should return NULL to abort the SASL conversation.
auth_sasl_ex is a version of auth_sasl that recognizes the EXTERNAL
SASL method. It takes an extra parameter, externalauth. This parameter
should be set to indicate an login that was authenticated via some
other means, such as, perhaps, an SSL certificate, or NULL if no
externally-authenticated identity was established.
If method is not EXTERNAL, auth_sasl_ex is identical to auth_sasl, and
externalauth is ignored. Otherwise, if method is EXTERNAL and
externalauth is not NULL, auth_sasl_ex returns AUTHSASL_OK, and sets
*authtype_ret and *authdata_ret accordingly, so that the subsequent
invocation of auth_generic() returns authentication information for the
login ID specified by externalauth.
RETURNS
If the SASL conversation succesfully completes, auth_sasl or
auth_sasl_ex initializes *authtype_ret and *authdata_ret. They will be
set to a malloc(3)-ed buffers that can be directly passed as arguments
to auth_generic(3)[1]. It is the application´s responsibility to
free(3) these buffers when it´s done with them.
auth_sasl or auth_sasl_ex returns AUTHSASL_OK when the SASL
conversation succesfully completes, and *authtype_ret and *authdata_ret
are succesfully assembled. Any other return indicates an error
condition. Right now two error conditions are defined:
AUTHSASL_ABORTED
The SASL conversation was aborted by the client.
AUTHSASL_ERROR
General error (insufficient memory, or some other reason). Check
errno for any clues.
SEE ALSO
authlib(3)[2], auth_generic(3)[1].
NOTES
1. auth_generic(3)
auth_generic.html
2. authlib(3)
authlib.html