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Obsoleted by:
Keywords: GSSAPI, CAT, GSS
Network Working Group J. Wray
Request for Comments: 1509 Digital Equipment Corporation
September 1993
Generic Security Service API : C-bindings
Status of this Memo
This RFC specifies an Internet standards track protocol for the
Internet community, and requests discussion and suggestions for
improvements. Please refer to the current edition of the "Internet
Official Protocol Standards" for the standardization state and status
of this protocol. Distribution of this memo is unlimited.
Abstract
This document specifies C language bindings for the Generic Security
Service Application Program Interface (GSS-API), which is described
at a language-independent conceptual level in other documents.
The Generic Security Service Application Programming Interface (GSS-
API) provides security services to its callers, and is intended for
implementation atop alternative underlying cryptographic mechanisms.
Typically, GSS-API callers will be application protocols into which
security enhancements are integrated through invocation of services
provided by the GSS-API. The GSS-API allows a caller application to
authenticate a principal identity associated with a peer application,
to delegate rights to a peer, and to apply security services such as
confidentiality and integrity on a per-message basis.
1. INTRODUCTION
The Generic Security Service Application Programming Interface [1]
provides security services to calling applications. It allows a
communicating application to authenticate the user associated with
another application, to delegate rights to another application, and
to apply security services such as confidentiality and integrity on a
per-message basis.
There are four stages to using the GSSAPI:
(a) The application acquires a set of credentials with which it may
prove its identity to other processes. The application's
credentials vouch for its global identity, which may or may not
be related to the local username under which it is running.
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(b) A pair of communicating applications establish a joint security
context using their credentials. The security context is a
pair of GSSAPI data structures that contain shared state
information, which is required in order that per-message
security services may be provided. As part of the
establishment of a security context, the context initiator is
authenticated to the responder, and may require that the
responder is authenticated in turn. The initiator may
optionally give the responder the right to initiate further
security contexts. This transfer of rights is termed
delegation, and is achieved by creating a set of credentials,
similar to those used by the originating application, but which
may be used by the responder. To establish and maintain the
shared information that makes up the security context, certain
GSSAPI calls will return a token data structure, which is a
cryptographically protected opaque data type. The caller of
such a GSSAPI routine is responsible for transferring the token
to the peer application, which should then pass it to a
corresponding GSSAPI routine which will decode it and extract
the information.
(c) Per-message services are invoked to apply either:
(i) integrity and data origin authentication, or
(ii) confidentiality, integrity and data origin authentication
to application data, which are treated by GSSAPI as
arbitrary octet-strings. The application transmitting a
message that it wishes to protect will call the appropriate
GSSAPI routine (sign or seal) to apply protection, specifying
the appropriate security context, and send the result to the
receiving application. The receiver will pass the received
data to the corresponding decoding routine (verify or unseal)
to remove the protection and validate the data.
(d) At the completion of a communications session (which may extend
across several connections), the peer applications call GSSAPI
routines to delete the security context. Multiple contexts may
also be used (either successively or simultaneously) within a
single communications association.
2. GSSAPI Routines
This section lists the functions performed by each of the GSSAPI
routines and discusses their major parameters, describing how they
are to be passed to the routines. The routines are listed in figure
4-1.
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Figure 4-1 GSSAPI Routines
Routine Function
gss_acquire_cred Assume a global identity
gss_release_cred Discard credentials
gss_init_sec_context Initiate a security context
with a peer application
gss_accept_sec_context Accept a security context
initiated by a peer
application
gss_process_context_token Process a token on a security
context from a peer
application
gss_delete_sec_context Discard a security context
gss_context_time Determine for how long a
context will remain valid
gss_sign Sign a message; integrity
service
gss_verify Check signature on a message
gss_seal Sign (optionally encrypt) a
message; confidentiality
service
gss_unseal Verify (optionally decrypt)
message
gss_display_status Convert an API status code
to text
gss_indicate_mechs Determine underlying
authentication mechanism
gss_compare_name Compare two internal-form
names
gss_display_name Convert opaque name to text
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gss_import_name Convert a textual name to
internal-form
gss_release_name Discard an internal-form
name
gss_release_buffer Discard a buffer
gss_release_oid_set Discard a set of object
identifiers
gss_inquire_cred Determine information about
a credential
Individual GSSAPI implementations may augment these routines by
providing additional mechanism-specific routines if required
functionality is not available from the generic forms. Applications
are encouraged to use the generic routines wherever possible on
portability grounds.
2.1. Data Types and Calling Conventions
The following conventions are used by the GSSAPI:
2.1.1. Structured data types
Wherever these GSSAPI C-bindings describe structured data, only
fields that must be provided by all GSSAPI implementation are
documented. Individual implementations may provide additional
fields, either for internal use within GSSAPI routines, or for use by
non-portable applications.
2.1.2. Integer types
GSSAPI defines the following integer data type:
OM_uint32 32-bit unsigned integer
Where guaranteed minimum bit-count is important, this portable data
type is used by the GSSAPI routine definitions. Individual GSSAPI
implementations will include appropriate typedef definitions to map
this type onto a built-in data type.
2.1.3. String and similar data
Many of the GSSAPI routines take arguments and return values that
describe contiguous multiple-byte data. All such data is passed
between the GSSAPI and the caller using the gss_buffer_t data type.
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This data type is a pointer to a buffer descriptor, which consists of
a length field that contains the total number of bytes in the datum,
and a value field which contains a pointer to the actual datum:
typedef struct gss_buffer_desc_struct {
size_t length;
void *value;
} gss_buffer_desc, *gss_buffer_t;
Storage for data passed to the application by a GSSAPI routine using
the gss_buffer_t conventions is allocated by the GSSAPI routine. The
application may free this storage by invoking the gss_release_buffer
routine. Allocation of the gss_buffer_desc object is always the
responsibility of the application; Unused gss_buffer_desc objects
may be initialized to the value GSS_C_EMPTY_BUFFER.
2.1.3.1. Opaque data types
Certain multiple-word data items are considered opaque data types at
the GSSAPI, because their internal structure has no significance
either to the GSSAPI or to the caller. Examples of such opaque data
types are the input_token parameter to gss_init_sec_context (which is
opaque to the caller), and the input_message parameter to gss_seal
(which is opaque to the GSSAPI). Opaque data is passed between the
GSSAPI and the application using the gss_buffer_t datatype.
2.1.3.2. Character strings
Certain multiple-word data items may be regarded as simple ISO
Latin-1 character strings. An example of this is the
input_name_buffer parameter to gss_import_name. Some GSSAPI routines
also return character strings. Character strings are passed between
the application and the GSSAPI using the gss_buffer_t datatype,
defined earlier.
2.1.4. Object Identifiers
Certain GSSAPI procedures take parameters of the type gss_OID, or
Object identifier. This is a type containing ISO-defined tree-
structured values, and is used by the GSSAPI caller to select an
underlying security mechanism. A value of type gss_OID has the
following structure:
typedef struct gss_OID_desc_struct {
OM_uint32 length;
void *elements;
} gss_OID_desc, *gss_OID;
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The elements field of this structure points to the first byte of an
octet string containing the ASN.1 BER encoding of the value of the
gss_OID. The length field contains the number of bytes in this
value. For example, the gss_OID value corresponding to {iso(1)
identified- oganization(3) icd-ecma(12) member-company(2) dec(1011)
cryptoAlgorithms(7) SPX(5)} meaning SPX (Digital's X.509
authentication mechanism) has a length field of 7 and an elements
field pointing to seven octets containing the following octal values:
53,14,2,207,163,7,5. GSSAPI implementations should provide constant
gss_OID values to allow callers to request any supported mechanism,
although applications are encouraged on portability grounds to accept
the default mechanism. gss_OID values should also be provided to
allow applications to specify particular name types (see section
2.1.10). Applications should treat gss_OID_desc values returned by
GSSAPI routines as read-only. In particular, the application should
not attempt to deallocate them. The gss_OID_desc datatype is
equivalent to the X/Open OM_object_identifier datatype [2].
2.1.5. Object Identifier Sets
Certain GSSAPI procedures take parameters of the type gss_OID_set.
This type represents one or more object identifiers (section 2.1.4).
A gss_OID_set object has the following structure:
typedef struct gss_OID_set_desc_struct {
int count;
gss_OID elements;
} gss_OID_set_desc, *gss_OID_set;
The count field contains the number of OIDs within the set. The
elements field is a pointer to an array of gss_OID_desc objects, each
of which describes a single OID. gss_OID_set values are used to name
the available mechanisms supported by the GSSAPI, to request the use
of specific mechanisms, and to indicate which mechanisms a given
credential supports. Storage associated with gss_OID_set values
returned to the application by the GSSAPI may be deallocated by the
gss_release_oid_set routine.
2.1.6. Credentials
A credential handle is a caller-opaque atomic datum that identifies a
GSSAPI credential data structure. It is represented by the caller-
opaque type gss_cred_id_t, which may be implemented as either an
arithmetic or a pointer type. Credentials describe a principal, and
they give their holder the ability to act as that principal. The
GSSAPI does not make the actual credentials available to
applications; instead the credential handle is used to identify a
particular credential, held internally by GSSAPI or underlying
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mechanism. Thus the credential handle contains no security-relavent
information, and requires no special protection by the application.
Depending on the implementation, a given credential handle may refer
to different credentials when presented to the GSSAPI by different
callers. Individual GSSAPI implementations should define both the
scope of a credential handle and the scope of a credential itself
(which must be at least as wide as that of a handle). Possibilities
for credential handle scope include the process that acquired the
handle, the acquiring process and its children, or all processes
sharing some local identification information (e.g., UID). If no
handles exist by which a given credential may be reached, the GSSAPI
may delete the credential.
Certain routines allow credential handle parameters to be omitted to
indicate the use of a default credential. The mechanism by which a
default credential is established and its scope should be defined by
the individual GSSAPI implementation.
2.1.7. Contexts
The gss_ctx_id_t data type contains a caller-opaque atomic value that
identifies one end of a GSSAPI security context. It may be
implemented as either an arithmetic or a pointer type. Depending on
the implementation, a given gss_ctx_id_t value may refer to different
GSSAPI security contexts when presented to the GSSAPI by different
callers. The security context holds state information about each end
of a peer communication, including cryptographic state information.
Individual GSSAPI implementations should define the scope of a
context. Since no way is provided by which a new gss_ctx_id_t value
may be obtained for an existing context, the scope of a context
should be the same as the scope of a gss_ctx_id_t.
2.1.8. Authentication tokens
A token is a caller-opaque type that GSSAPI uses to maintain
synchronization between the context data structures at each end of a
GSSAPI security context. The token is a cryptographically protected
bit-string, generated by the underlying mechanism at one end of a
GSSAPI security context for use by the peer mechanism at the other
end. Encapsulation (if required) and transfer of the token are the
responsibility of the peer applications. A token is passed between
the GSSAPI and the application using the gss_buffer_t conventions.
2.1.9. Status values
One or more status codes are returned by each GSSAPI routine. Two
distinct sorts of status codes are returned. These are termed GSS
status codes and Mechanism status codes.
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2.1.9.1. GSS status codes
GSSAPI routines return GSS status codes as their OM_uint32 function
value. These codes indicate errors that are independent of the
underlying mechanism used to provide the security service. The
errors that can be indicated via a GSS status code are either generic
API routine errors (errors that are defined in the GSSAPI
specification) or calling errors (errors that are specific to these
bindings).
A GSS status code can indicate a single fatal generic API error from
the routine and a single calling error. In addition, supplementary
status information may be indicated via the setting of bits in the
supplementary info field of a GSS status code.
These errors are encoded into the 32-bit GSS status code as follows:
MSB LSB
|------------------------------------------------------------|
| Calling Error | Routine Error | Supplementary Info |
|------------------------------------------------------------|
Bit 31 24 23 16 15 0
Hence if a GSSAPI routine returns a GSS status code whose upper 16
bits contain a non-zero value, the call failed. If the calling error
field is non-zero, the invoking application's call of the routine was
erroneous. Calling errors are defined in table 5-1. If the routine
error field is non-zero, the routine failed for one of the routine-
specific reasons listed below in table 5-2. Whether or not the upper
16 bits indicate a failure or a success, the routine may indicate
additional information by setting bits in the supplementary info
field of the status code. The meaning of individual bits is listed
below in table 5-3.
Table 5-1 Calling Errors
Name Value in Meaning
Field
GSS_S_CALL_INACCESSIBLE_READ 1 A required input
parameter could
not be read.
GSS_S_CALL_INACCESSIBLE_WRITE 2 A required output
parameter could
not be written.
GSS_S_CALL_BAD_STRUCTURE 3 A parameter was
malformed
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Table 5-2 Routine Errors
Name Value in Meaning
Field
GSS_S_BAD_MECH 1 An unsupported mechanism was
requested
GSS_S_BAD_NAME 2 An invalid name was supplied
GSS_S_BAD_NAMETYPE 3 A supplied name was of an
unsupported type
GSS_S_BAD_BINDINGS 4 Incorrect channel bindings
were supplied
GSS_S_BAD_STATUS 5 An invalid status code was
supplied
GSS_S_BAD_SIG 6 A token had an invalid
signature
GSS_S_NO_CRED 7 No credentials were supplied
GSS_S_NO_CONTEXT 8 No context has been
established
GSS_S_DEFECTIVE_TOKEN 9 A token was invalid
GSS_S_DEFECTIVE_CREDENTIAL 10 A credential was invalid
GSS_S_CREDENTIALS_EXPIRED 11 The referenced credentials
have expired
GSS_S_CONTEXT_EXPIRED 12 The context has expired
GSS_S_FAILURE 13 Miscellaneous failure
(see text)
Table 5-3 Supplementary Status Bits
Name Bit Number Meaning
GSS_S_CONTINUE_NEEDED 0 (LSB) The routine must be called
again to complete its
function.
See routine documentation for
detailed description.
GSS_S_DUPLICATE_TOKEN 1 The token was a duplicate of
an earlier token
GSS_S_OLD_TOKEN 2 The token's validity period
has expired
GSS_S_UNSEQ_TOKEN 3 A later token has already been
processed
The routine documentation also uses the name GSS_S_COMPLETE, which is
a zero value, to indicate an absence of any API errors or
supplementary information bits.
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All GSS_S_xxx symbols equate to complete OM_uint32 status codes,
rather than to bitfield values. For example, the actual value of the
symbol GSS_S_BAD_NAMETYPE (value 3 in the routine error field) is 3
<< 16.
The macros GSS_CALLING_ERROR(), GSS_ROUTINE_ERROR() and
GSS_SUPPLEMENTARY_INFO() are provided, each of which takes a GSS
status code and removes all but the relevant field. For example, the
value obtained by applying GSS_ROUTINE_ERROR to a status code removes
the calling errors and supplementary info fields, leaving only the
routine errors field. The values delivered by these macros may be
directly compared with a GSS_S_xxx symbol of the appropriate type.
The macro GSS_ERROR() is also provided, which when applied to a GSS
status code returns a non-zero value if the status code indicated a
calling or routine error, and a zero value otherwise.
A GSSAPI implementation may choose to signal calling errors in a
platform-specific manner instead of, or in addition to the routine
value; routine errors and supplementary info should be returned via
routine status values only.
2.1.9.2. Mechanism-specific status codes
GSSAPI routines return a minor_status parameter, which is used to
indicate specialized errors from the underlying security mechanism.
This parameter may contain a single mechanism-specific error,
indicated by a OM_uint32 value.
The minor_status parameter will always be set by a GSSAPI routine,
even if it returns a calling error or one of the generic API errors
indicated above as fatal, although other output parameters may remain
unset in such cases. However, output parameters that are expected to
return pointers to storage allocated by a routine must always set set
by the routine, even in the event of an error, although in such cases
the GSSAPI routine may elect to set the returned parameter value to
NULL to indicate that no storage was actually allocated. Any length
field associated with such pointers (as in a gss_buffer_desc
structure) should also be set to zero in such cases.
The GSS status code GSS_S_FAILURE is used to indicate that the
underlying mechanism detected an error for which no specific GSS
status code is defined. The mechanism status code will provide more
details about the error.
2.1.10. Names
A name is used to identify a person or entity. GSSAPI authenticates
the relationship between a name and the entity claiming the name.
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Two distinct representations are defined for names:
(a) A printable form, for presentation to a user
(b) An internal form, for presentation at the API
The syntax of a printable name is defined by the GSSAPI
implementation, and may be dependent on local system configuration,
or on individual user preference. The internal form provides a
canonical representation of the name that is independent of
configuration.
A given GSSAPI implementation may support names drawn from multiple
namespaces. In such an implementation, the internal form of the name
must include fields that identify the namespace from which the name
is drawn. The namespace from which a printable name is drawn is
specified by an accompanying object identifier.
Routines (gss_import_name and gss_display_name) are provided to
convert names between their printable representations and the
gss_name_t type. gss_import_name may support multiple syntaxes for
each supported namespace, allowing users the freedom to choose a
preferred name representation. gss_display_name should use an
implementation-chosen preferred syntax for each supported name-type.
Comparison of internal-form names is accomplished via the
gss_compare_names routine. This removes the need for the application
program to understand the syntaxes of the various printable names
that a given GSSAPI implementation may support.
Storage is allocated by routines that return gss_name_t values. A
procedure, gss_release_name, is provided to free storage associated
with a name.
2.1.11. Channel Bindings
GSSAPI supports the use of user-specified tags to identify a given
context to the peer application. These tags are used to identify the
particular communications channel that carries the context. Channel
bindings are communicated to the GSSAPI using the following
structure:
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typedef struct gss_channel_bindings_struct {
OM_uint32 initiator_addrtype;
gss_buffer_desc initiator_address;
OM_uint32 acceptor_addrtype;
gss_buffer_desc acceptor_address;
gss_buffer_desc application_data;
} *gss_channel_bindings_t;
The initiator_addrtype and acceptor_addrtype fields denote the type
of addresses contained in the initiator_address and acceptor_address
buffers. The address type should be one of the following:
GSS_C_AF_UNSPEC Unspecified address type
GSS_C_AF_LOCAL Host-local address type
GSS_C_AF_INET DARPA Internet address type
GSS_C_AF_IMPLINK ARPAnet IMP address type (eg IP)
GSS_C_AF_PUP pup protocols (eg BSP) address type
GSS_C_AF_CHAOS MIT CHAOS protocol address type
GSS_C_AF_NS XEROX NS address type
GSS_C_AF_NBS nbs address type
GSS_C_AF_ECMA ECMA address type
GSS_C_AF_DATAKIT datakit protocols address type
GSS_C_AF_CCITT CCITT protocols (eg X.25)
GSS_C_AF_SNA IBM SNA address type
GSS_C_AF_DECnet DECnet address type
GSS_C_AF_DLI Direct data link interface address type
GSS_C_AF_LAT LAT address type
GSS_C_AF_HYLINK NSC Hyperchannel address type
GSS_C_AF_APPLETALK AppleTalk address type
GSS_C_AF_BSC BISYNC 2780/3780 address type
GSS_C_AF_DSS Distributed system services address type
GSS_C_AF_OSI OSI TP4 address type
GSS_C_AF_X25 X25
GSS_C_AF_NULLADDR No address specified
Note that these name address families rather than specific addressing
formats. For address families that contain several alternative
address forms, the initiator_address and acceptor_address fields must
contain sufficient information to determine which address form is
used. When not otherwise specified, addresses should be specified in
network byte-order.
Conceptually, the GSSAPI concatenates the initiator_addrtype,
initiator_address, acceptor_addrtype, acceptor_address and
application_data to form an octet string. The mechanism signs this
octet string, and binds the signature to the context establishment
token emitted by gss_init_sec_context. The same bindings are
presented by the context acceptor to gss_accept_sec_context, and a
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signature is calculated in the same way. The calculated signature is
compared with that found in the token, and if the signatures differ,
gss_accept_sec_context will return a GSS_S_BAD_BINDINGS error, and
the context will not be established. Some mechanisms may include the
actual channel binding data in the token (rather than just a
signature); applications should therefore not use confidential data
as channel-binding components. Individual mechanisms may impose
additional constraints on addresses and address types that may appear
in channel bindings. For example, a mechanism may verify that the
initiator_address field of the channel bindings presented to
gss_init_sec_context contains the correct network address of the host
system.
2.1.12. Optional parameters
Various parameters are described as optional. This means that they
follow a convention whereby a default value may be requested. The
following conventions are used for omitted parameters. These
conventions apply only to those parameters that are explicitly
documented as optional.
2.1.12.1. gss_buffer_t types
Specify GSS_C_NO_BUFFER as a value. For an input parameter this
signifies that default behavior is requested, while for an output
parameter it indicates that the information that would be returned
via the parameter is not required by the application.
2.1.12.2. Integer types (input)
Individual parameter documentation lists values to be used to
indicate default actions.
2.1.12.3. Integer types (output)
Specify NULL as the value for the pointer.
2.1.12.4. Pointer types
Specify NULL as the value.
2.1.12.5. Object IDs
Specify GSS_C_NULL_OID as the value.
2.1.12.6. Object ID Sets
Specify GSS_C_NULL_OID_SET as the value.
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2.1.12.7. Credentials
Specify GSS_C_NO_CREDENTIAL to use the default credential handle.
2.1.12.8. Channel Bindings
Specify GSS_C_NO_CHANNEL_BINDINGS to indicate that channel bindings
are not to be used.
3. GSSAPI routine descriptions
2.1. gss_acquire_cred
OM_uint32 gss_acquire_cred (
OM_uint32 * minor_status,
gss_name_t desired_name,
OM_uint32 time_req,
gss_OID_set desired_mechs,
int cred_usage,
gss_cred_id_t * output_cred_handle,
gss_OID_set * actual_mechs,
OM_int32 * time_rec)
Purpose:
Allows an application to acquire a handle for a pre-existing
credential by name. GSSAPI implementations must impose a local
access-control policy on callers of this routine to prevent
unauthorized callers from acquiring credentials to which they are not
entitled. This routine is not intended to provide a "login to the
network" function, as such a function would result in the creation of
new credentials rather than merely acquiring a handle to existing
credentials. Such functions, if required, should be defined in
implementation-specific extensions to the API.
If credential acquisition is time-consuming for a mechanism, the
mechanism may chooses to delay the actual acquisition until the
credential is required (e.g., by gss_init_sec_context or
gss_accept_sec_context). Such mechanism-specific implementation
decisions should be invisible to the calling application; thus a call
of gss_inquire_cred immediately following the call of
gss_acquire_cred must return valid credential data, and may therefore
incur the overhead of a deferred credential acquisition.
Parameters:
desired_name gss_name_t, read
Name of principal whose credential
should be acquired
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time_req integer, read
number of seconds that credentials
should remain valid
desired_mechs Set of Object IDs, read
set of underlying security mechanisms that
may be used. GSS_C_NULL_OID_SET may be used
to obtain an implementation-specific default.
cred_usage integer, read
GSS_C_BOTH - Credentials may be used
either to initiate or accept
security contexts.
GSS_C_INITIATE - Credentials will only be
used to initiate security
contexts.
GSS_C_ACCEPT - Credentials will only be used to
accept security contexts.
output_cred_handle gss_cred_id_t, modify
The returned credential handle.
actual_mechs Set of Object IDs, modify, optional
The set of mechanisms for which the
credential is valid. Specify NULL
if not required.
time_rec Integer, modify, optional
Actual number of seconds for which the
returned credentials will remain valid. If the
implementation does not support expiration of
credentials, the value GSS_C_INDEFINITE will
be returned. Specify NULL if not required
minor_status Integer, modify
Mechanism specific status code.
Function value:
GSS status code:
GSS_S_COMPLETE Successful completion
GSS_S_BAD_MECH Unavailable mechanism requested
GSS_S_BAD_NAMETYPE Type contained within desired_name parameter is
not supported
GSS_S_BAD_NAME Value supplied for desired_name parameter is
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ill-formed.
GSS_S_FAILURE Unspecified failure. The minor_status parameter
contains more detailed information
3.2. gss_release_cred
OM_uint32 gss_release_cred (
OM_uint32 * minor_status,
gss_cred_id_t * cred_handle)
Purpose:
Informs GSSAPI that the specified credential handle is no longer
required by the process. When all processes have released a
credential, it will be deleted.
Parameters:
cred_handle gss_cred_id_t, modify, optional
buffer containing opaque credential
handle. If GSS_C_NO_CREDENTIAL is supplied,
the default credential will be released
minor_status integer, modify
Mechanism specific status code.
Function value:
GSS status code:
GSS_S_COMPLETE Successful completion
GSS_S_NO_CRED Credentials could not be accessed.
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3.3. gss_init_sec_context
OM_uint32 gss_init_sec_context (
OM_uint32 * minor_status,
gss_cred_id_t claimant_cred_handle,
gss_ctx_id_t * context_handle,
gss_name_t target_name,
gss_OID mech_type,
int req_flags,
int time_req,
gss_channel_bindings_t
input_chan_bindings,
gss_buffer_t input_token
gss_OID * actual_mech_type,
gss_buffer_t output_token,
int * ret_flags,
OM_uint32 * time_rec )
Purpose:
Initiates the establishment of a security context between the
application and a remote peer. Initially, the input_token parameter
should be specified as GSS_C_NO_BUFFER. The routine may return a
output_token which should be transferred to the peer application,
where the peer application will present it to gss_accept_sec_context.
If no token need be sent, gss_init_sec_context will indicate this by
setting the length field of the output_token argument to zero. To
complete the context establishment, one or more reply tokens may be
required from the peer application; if so, gss_init_sec_context will
return a status indicating GSS_S_CONTINUE_NEEDED in which case it
should be called again when the reply token is received from the peer
application, passing the token to gss_init_sec_context via the
input_token parameters.
The values returned via the ret_flags and time_rec parameters are not
defined unless the routine returns GSS_S_COMPLETE.
Parameters:
claimant_cred_handle gss_cred_id_t, read, optional
handle for credentials claimed. Supply
GSS_C_NO_CREDENTIAL to use default
credentials.
context_handle gss_ctx_id_t, read/modify
context handle for new context. Supply
GSS_C_NO_CONTEXT for first call; use value
returned by first call in continuation calls.
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target_name gss_name_t, read
Name of target
mech_type OID, read, optional
Object ID of desired mechanism. Supply
GSS_C_NULL_OID to obtain an implementation
specific default
req_flags bit-mask, read
Contains four independent flags, each of
which requests that the context support a
specific service option. Symbolic
names are provided for each flag, and the
symbolic names corresponding to the required
flags should be logically-ORed
together to form the bit-mask value. The
flags are:
GSS_C_DELEG_FLAG
True - Delegate credentials to remote peer
False - Don't delegate
GSS_C_MUTUAL_FLAG
True - Request that remote peer
authenticate itself
False - Authenticate self to remote peer
only
GSS_C_REPLAY_FLAG
True - Enable replay detection for signed
or sealed messages
False - Don't attempt to detect
replayed messages
GSS_C_SEQUENCE_FLAG
True - Enable detection of out-of-sequence
signed or sealed messages
False - Don't attempt to detect
out-of-sequence messages
time_req integer, read
Desired number of seconds for which context
should remain valid. Supply 0 to request a
default validity period.
input_chan_bindings channel bindings, read
Application-specified bindings. Allows
application to securely bind channel
identification information to the security
context.
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input_token buffer, opaque, read, optional (see text)
Token received from peer application.
Supply GSS_C_NO_BUFFER on initial call.
actual_mech_type OID, modify
actual mechanism used.
output_token buffer, opaque, modify
token to be sent to peer application. If
the length field of the returned buffer is
zero, no token need be sent to the peer
application.
ret_flags bit-mask, modify
Contains six independent flags, each of which
indicates that the context supports a specific
service option. Symbolic names are provided
for each flag, and the symbolic names
corresponding to the required flags should be
logically-ANDed with the ret_flags value to test
whether a given option is supported by the
context. The flags are:
GSS_C_DELEG_FLAG
True - Credentials were delegated to
the remote peer
False - No credentials were delegated
GSS_C_MUTUAL_FLAG
True - Remote peer has been asked to
authenticated itself
False - Remote peer has not been asked to
authenticate itself
GSS_C_REPLAY_FLAG
True - replay of signed or sealed messages
will be detected
False - replayed messages will not be
detected
GSS_C_SEQUENCE_FLAG
True - out-of-sequence signed or sealed
messages will be detected
False - out-of-sequence messages will not
be detected
GSS_C_CONF_FLAG
True - Confidentiality service may be
invoked by calling seal routine
False - No confidentiality service (via
seal) available. seal will provide
message encapsulation, data-origin
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authentication and integrity
services only.
GSS_C_INTEG_FLAG
True - Integrity service may be invoked by
calling either gss_sign or gss_seal
routines.
False - Per-message integrity service
unavailable.
time_rec integer, modify, optional
number of seconds for which the context
will remain valid. If the implementation does
not support credential expiration, the value
GSS_C_INDEFINITE will be returned. Specify
NULL if not required.
minor_status integer, modify
Mechanism specific status code.
Function value:
GSS status code:
GSS_S_COMPLETE Successful completion
GSS_S_CONTINUE_NEEDED Indicates that a token from the peer
application is required to complete thecontext, and
that gss_init_sec_context must be called again with
that token.
GSS_S_DEFECTIVE_TOKEN Indicates that consistency checks performed on
the input_token failed
GSS_S_DEFECTIVE_CREDENTIAL Indicates that consistency checks
performed on the credential failed.
GSS_S_NO_CRED The supplied credentials were not valid for context
initiation, or the credential handle did not
reference any credentials.
GSS_S_CREDENTIALS_EXPIRED The referenced credentials have expired
GSS_S_BAD_BINDINGS The input_token contains different channel
bindings to those specified via the
input_chan_bindings parameter
GSS_S_BAD_SIG The input_token contains an invalid signature, or a
signature that could not be verified
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GSS_S_OLD_TOKEN The input_token was too old. This is a fatal error
during context establishment
GSS_S_DUPLICATE_TOKEN The input_token is valid, but is a duplicate of
a token already processed. This is a fatal error
during context establishment.
GSS_S_NO_CONTEXT Indicates that the supplied context handle did not
refer to a valid context
GSS_S_BAD_NAMETYPE The provided target_name parameter contained an
invalid or unsupported type of name
GSS_S_BAD_NAME The provided target_name parameter was ill-formed.
GSS_S_FAILURE Failure. See minor_status for more information
3.4. gss_accept_sec_context
OM_uint32 gss_accept_sec_context (
OM_uint32 * minor_status,
gss_ctx_id_t * context_handle,
gss_cred_id_t verifier_cred_handle,
gss_buffer_t input_token_buffer
gss_channel_bindings_t
input_chan_bindings,
gss_name_t * src_name,
gss_OID * mech_type,
gss_buffer_t output_token,
int * ret_flags,
OM_uint32 * time_rec,
gss_cred_id_t * delegated_cred_handle)
Purpose:
Allows a remotely initiated security context between the application
and a remote peer to be established. The routine may return a
output_token which should be transferred to the peer application,
where the peer application will present it to gss_init_sec_context.
If no token need be sent, gss_accept_sec_context will indicate this
by setting the length field of the output_token argument to zero. To
complete the context establishment, one or more reply tokens may be
required from the peer application; if so, gss_accept_sec_context
will return a status flag of GSS_S_CONTINUE_NEEDED, in which case it
should be called again when the reply token is received from the peer
application, passing the token to gss_accept_sec_context via the
input_token parameters.
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The values returned via the src_name, ret_flags, time_rec, and
delegated_cred_handle parameters are not defined unless the routine
returns GSS_S_COMPLETE.
Parameters:
context_handle gss_ctx_id_t, read/modify
context handle for new context. Supply
GSS_C_NO_CONTEXT for first call; use value
returned in subsequent calls.
verifier_cred_handle gss_cred_id_t, read, optional
Credential handle claimed by context
acceptor.
Specify GSS_C_NO_CREDENTIAL to use default
credentials. If GSS_C_NO_CREDENTIAL is
specified, but the caller has no default
credentials established, an
implementation-defined default credential
may be used.
input_token_buffer buffer, opaque, read
token obtained from remote application
input_chan_bindings channel bindings, read
Application-specified bindings. Allows
application to securely bind channel
identification information to the security
context.
src_name gss_name_t, modify, optional
Authenticated name of context initiator.
After use, this name should be deallocated by
passing it to gss_release_name. If not required,
specify NULL.
mech_type Object ID, modify
Security mechanism used. The returned
OID value will be a pointer into static
storage, and should be treated as read-only
by the caller.
output_token buffer, opaque, modify
Token to be passed to peer application. If the
length field of the returned token buffer is 0,
then no token need be passed to the peer
application.
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ret_flags bit-mask, modify
Contains six independent flags, each of
which indicates that the context supports a
specific service option. Symbolic names are
provided for each flag, and the symbolic names
corresponding to the required flags
should be logically-ANDed with the ret_flags
value to test whether a given option is
supported by the context. The flags are:
GSS_C_DELEG_FLAG
True - Delegated credentials are available
via the delegated_cred_handle
parameter
False - No credentials were delegated
GSS_C_MUTUAL_FLAG
True - Remote peer asked for mutual
authentication
False - Remote peer did not ask for mutual
authentication
GSS_C_REPLAY_FLAG
True - replay of signed or sealed messages
will be detected
False - replayed messages will not be
detected
GSS_C_SEQUENCE_FLAG
True - out-of-sequence signed or sealed
messages will be detected
False - out-of-sequence messages will not
be detected
GSS_C_CONF_FLAG
True - Confidentiality service may be
invoked by calling seal routine
False - No confidentiality service (via
seal) available. seal will
provide message encapsulation,
data-origin authentication and
integrity services only.
GSS_C_INTEG_FLAG
True - Integrity service may be invoked
by calling either gss_sign or
gss_seal routines.
False - Per-message integrity service
unavailable.
time_rec integer, modify, optional
number of seconds for which the context
will remain valid. Specify NULL if not required.
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delegated_cred_handle
gss_cred_id_t, modify
credential handle for credentials received from
context initiator. Only valid if deleg_flag in
ret_flags is true.
minor_status integer, modify
Mechanism specific status code.
Function value:
GSS status code:
GSS_S_COMPLETE Successful completion
GSS_S_CONTINUE_NEEDED Indicates that a token from the peer
application is required to complete the context,
and that gss_accept_sec_context must be called
again with that token.
GSS_S_DEFECTIVE_TOKEN Indicates that consistency checks
performed on the input_token failed.
GSS_S_DEFECTIVE_CREDENTIAL Indicates that consistency checks
performed on the credential failed.
GSS_S_NO_CRED The supplied credentials were not valid for
context acceptance, or the credential handle
did not reference any credentials.
GSS_S_CREDENTIALS_EXPIRED The referenced credentials have
expired.
GSS_S_BAD_BINDINGS The input_token contains different channel
bindings to those specified via the
input_chan_bindings parameter.
GSS_S_NO_CONTEXT Indicates that the supplied context handle did
not refer to a valid context.
GSS_S_BAD_SIG The input_token contains an invalid signature.
GSS_S_OLD_TOKEN The input_token was too old. This is a fatal
error during context establishment.
GSS_S_DUPLICATE_TOKEN The input_token is valid, but is a
duplicate of a token already processed. This
is a fatal error during context establishment.
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GSS_S_FAILURE Failure. See minor_status for more information.
3.5. gss_process_context_token
OM_uint32 gss_process_context_token (
OM_uint32 * minor_status,
gss_ctx_id_t context_handle,
gss_buffer_t token_buffer)
Purpose:
Provides a way to pass a token to the security service. Usually,
tokens are associated either with context establishment (when they
would be passed to gss_init_sec_context or gss_accept_sec_context) or
with per-message security service (when they would be passed to
gss_verify or gss_unseal). Occasionally, tokens may be received at
other times, and gss_process_context_token allows such tokens to be
passed to the underlying security service for processing. At
present, such additional tokens may only be generated by
gss_delete_sec_context. GSSAPI implementation may use this service
to implement deletion of the security context.
Parameters:
context_handle gss_ctx_id_t, read
context handle of context on which token is to
be processed
token_buffer buffer, opaque, read
pointer to first byte of token to process
minor_status integer, modify
Implementation specific status code.
Function value:
GSS status code:
GSS_S_COMPLETE Successful completion
GSS_S_DEFECTIVE_TOKEN Indicates that consistency checks
performed on the token failed
GSS_S_FAILURE Failure. See minor_status for more information
GSS_S_NO_CONTEXT The context_handle did not refer to a valid
context
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3.6. gss_delete_sec_context
OM_uint32 gss_delete_sec_context (
OM_uint32 * minor_status,
gss_ctx_id_t * context_handle,
gss_buffer_t output_token)
Purpose:
Delete a security context. gss_delete_sec_context will delete the
local data structures associated with the specified security context,
and generate an output_token, which when passed to the peer
gss_process_context_token will instruct it to do likewise. No
further security services may be obtained using the context specified
by context_handle.
Parameters:
minor_status integer, modify
Mechanism specific status code.
context_handle gss_ctx_id_t, modify
context handle identifying context to delete.
output_token buffer, opaque, modify
token to be sent to remote application to
instruct it to also delete the context
Function value:
GSS status code:
GSS_S_COMPLETE Successful completion
GSS_S_FAILURE Failure, see minor_status for more information
GSS_S_NO_CONTEXT No valid context was supplied
3.7. gss_context_time
OM_uint32 gss_context_time (
OM_uint32 * minor_status,
gss_ctx_id_t context_handle,
OM_uint32 * time_rec)
Purpose:
Determines the number of seconds for which the specified context will
remain valid.
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Parameters:
minor_status integer, modify
Implementation specific status code.
context_handle gss_ctx_id_t, read
Identifies the context to be interrogated.
time_rec integer, modify
Number of seconds that the context will remain
valid. If the context has already expired,
zero will be returned.
Function value:
GSS status code:
GSS_S_COMPLETE Successful completion
GSS_S_CONTEXT_EXPIRED The context has already expired
GSS_S_CREDENTIALS_EXPIRED The context is recognized, but
associated credentials have expired
GSS_S_NO_CONTEXT The context_handle parameter did not identify a
valid context
3.8. gss_sign
OM_uint32 gss_sign (
OM_uint32 * minor_status,
gss_ctx_id_t context_handle,
int qop_req,
gss_buffer_t message_buffer,
gss_buffer_t msg_token)
Purpose:
Generates a cryptographic signature for the supplied message, and
places the signature in a token for transfer to the peer application.
The qop_req parameter allows a choice between several cryptographic
algorithms, if supported by the chosen mechanism.
Parameters:
minor_status integer, modify
Implementation specific status code.
context_handle gss_ctx_id_t, read
identifies the context on which the message
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will be sent
qop_req integer, read, optional
Specifies requested quality of protection.
Callers are encouraged, on portability grounds,
to accept the default quality of protection
offered by the chosen mechanism, which may be
requested by specifying GSS_C_QOP_DEFAULT for
this parameter. If an unsupported protection
strength is requested, gss_sign will return a
major_status of GSS_S_FAILURE.
message_buffer buffer, opaque, read
message to be signed
msg_token buffer, opaque, modify
buffer to receive token
Function value:
GSS status code:
GSS_S_COMPLETE Successful completion
GSS_S_CONTEXT_EXPIRED The context has already expired
GSS_S_CREDENTIALS_EXPIRED The context is recognized, but
associated credentials have expired
GSS_S_NO_CONTEXT The context_handle parameter did not identify a
valid context
GSS_S_FAILURE Failure. See minor_status for more information.
3.9. gss_verify
OM_uint32 gss_verify (
OM_uint32 * minor_status,
gss_ctx_id_t context_handle,
gss_buffer_t message_buffer,
gss_buffer_t token_buffer,
int * qop_state)
Purpose:
Verifies that a cryptographic signature, contained in the token
parameter, fits the supplied message. The qop_state parameter allows
a message recipient to determine the strength of protection that was
applied to the message.
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Parameters:
minor_status integer, modify
Mechanism specific status code.
context_handle gss_ctx_id_t, read
identifies the context on which the message
arrived
message_buffer buffer, opaque, read
message to be verified
token_buffer buffer, opaque, read
token associated with message
qop_state integer, modify
quality of protection gained from signature
Function value:
GSS status code:
GSS_S_COMPLETE Successful completion
GSS_S_DEFECTIVE_TOKEN The token failed consistency checks
GSS_S_BAD_SIG The signature was incorrect
GSS_S_DUPLICATE_TOKEN The token was valid, and contained a correct
signature for the message, but it had already
been processed
GSS_S_OLD_TOKEN The token was valid, and contained a correct
signature for the message, but it is too old
GSS_S_UNSEQ_TOKEN The token was valid, and contained a correct
signature for the message, but has been
verified out of sequence; an earlier token has
been signed or sealed by the remote
application, but not yet been processed
locally.
GSS_S_CONTEXT_EXPIRED The context has already expired
GSS_S_CREDENTIALS_EXPIRED The context is recognized, but
associated credentials have expired
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GSS_S_NO_CONTEXT The context_handle parameter did not identify a
valid context
GSS_S_FAILURE Failure. See minor_status for more information.
3.10. gss_seal
OM_uint32 gss_seal (
OM_uint32 * minor_status,
gss_ctx_id_t context_handle,
int conf_req_flag,
int qop_req
gss_buffer_t input_message_buffer,
int * conf_state,
gss_buffer_t output_message_buffer)
Purpose:
Cryptographically signs and optionally encrypts the specified
input_message. The output_message contains both the signature and
the message. The qop_req parameter allows a choice between several
cryptographic algorithms, if supported by the chosen mechanism.
Parameters:
minor_status integer, modify
Mechanism specific status code.
context_handle gss_ctx_id_t, read
identifies the context on which the message
will be sent
conf_req_flag boolean, read
True - Both confidentiality and integrity
services are requested
False - Only integrity service is requested
qop_req integer, read, optional
Specifies required quality of protection. A
mechanism-specific default may be requested by
setting qop_req to GSS_C_QOP_DEFAULT. If an
unsupported protection strength is requested,
gss_seal will return a major_status of
GSS_S_FAILURE.
input_message_buffer buffer, opaque, read
message to be sealed
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conf_state boolean, modify
True - Confidentiality, data origin
authentication and integrity services
have been applied
False - Integrity and data origin services only
has been applied.
output_message_buffer buffer, opaque, modify
buffer to receive sealed message
Function value:
GSS status code:
GSS_S_COMPLETE Successful completion
GSS_S_CONTEXT_EXPIRED The context has already expired
GSS_S_CREDENTIALS_EXPIRED The context is recognized, but
associated credentials have expired
GSS_S_NO_CONTEXT The context_handle parameter did not identify a
valid context
GSS_S_FAILURE Failure. See minor_status for more information.
3.11. gss_unseal
OM_uint32 gss_unseal (
OM_uint32 * minor_status,
gss_ctx_id_t context_handle,
gss_buffer_t input_message_buffer,
gss_buffer_t output_message_buffer,
int * conf_state,
int * qop_state)
Purpose:
Converts a previously sealed message back to a usable form, verifying
the embedded signature. The conf_state parameter indicates whether
the message was encrypted; the qop_state parameter indicates the
strength of protection that was used to provide the confidentiality
and integrity services.
Parameters:
minor_status integer, modify
Mechanism specific status code.
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context_handle gss_ctx_id_t, read
identifies the context on which the message
arrived
input_message_buffer buffer, opaque, read
sealed message
output_message_buffer buffer, opaque, modify
buffer to receive unsealed message
conf_state boolean, modify
True - Confidentiality and integrity protection
were used
False - Inteegrity service only was used
qop_state integer, modify
quality of protection gained from signature
Function value:
GSS status code:
GSS_S_COMPLETE Successful completion
GSS_S_DEFECTIVE_TOKEN The token failed consistency checks
GSS_S_BAD_SIG The signature was incorrect
GSS_S_DUPLICATE_TOKEN The token was valid, and contained a
correct signature for the message, but it had
already been processed
GSS_S_OLD_TOKEN The token was valid, and contained a correct
signature for the message, but it is too old
GSS_S_UNSEQ_TOKEN The token was valid, and contained a correct
signature for the message, but has been
verified out of sequence; an earlier token has
been signed or sealed by the remote
application, but not yet been processed
locally.
GSS_S_CONTEXT_EXPIRED The context has already expired
GSS_S_CREDENTIALS_EXPIRED The context is recognized, but
associated credentials have expired
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GSS_S_NO_CONTEXT The context_handle parameter did not identify a
valid context
GSS_S_FAILURE Failure. See minor_status for more information.
3.12. gss_display_status
OM_uint32 gss_display_status (
OM_uint32 * minor_status,
int status_value,
int status_type,
gss_OID mech_type,
int * message_context,
gss_buffer_t status_string)
Purpose:
Allows an application to obtain a textual representation of a GSSAPI
status code, for display to the user or for logging purposes. Since
some status values may indicate multiple errors, applications may
need to call gss_display_status multiple times, each call generating
a single text string. The message_context parameter is used to
indicate which error message should be extracted from a given
status_value; message_context should be initialized to 0, and
gss_display_status will return a non-zero value if there are further
messages to extract.
Parameters:
minor_status integer, modify
Mechanism specific status code.
status_value integer, read
Status value to be converted
status_type integer, read
GSS_C_GSS_CODE - status_value is a GSS status
code
GSS_C_MECH_CODE - status_value is a mechanism
status code
mech_type Object ID, read, optional
Underlying mechanism (used to interpret a
minor status value) Supply GSS_C_NULL_OID to
obtain the system default.
message_context integer, read/modify
Should be initialized to zero by caller
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on first call. If further messages are
contained in the status_value parameter,
message_context will be non-zero on return,
and this value should be passed back to
subsequent calls, along with the same
status_value, status_type and mech_type
parameters.
status_string buffer, character string, modify
textual interpretation of the status_value
Function value:
GSS status code:
GSS_S_COMPLETE Successful completion
GSS_S_BAD_MECH Indicates that translation in accordance with
an unsupported mechanism type was requested
GSS_S_BAD_STATUS The status value was not recognized, or the
status type was neither GSS_C_GSS_CODE nor
GSS_C_MECH_CODE.
3.13. gss_indicate_mechs
OM_uint32 gss_indicate_mechs (
OM_uint32 * minor_status,
gss_OID_set * mech_set)
Purpose:
Allows an application to determine which underlying security
mechanisms are available.
Parameters:
minor_status integer, modify
Mechanism specific status code.
mech_set set of Object IDs, modify
set of implementation-supported mechanisms.
The returned gss_OID_set value will be a
pointer into static storage, and should be
treated as read-only by the caller.
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Function value:
GSS status code:
GSS_S_COMPLETE Successful completion
3.14. gss_compare_name
OM_uint32 gss_compare_name (
OM_uint32 * minor_status,
gss_name_t name1,
gss_name_t name2,
int * name_equal)
Purpose:
Allows an application to compare two internal-form names to determine
whether they refer to the same entity.
Parameters:
minor_status integer, modify
Mechanism specific status code.
name1 gss_name_t, read
internal-form name
name2 gss_name_t, read
internal-form name
name_equal boolean, modify
True - names refer to same entity
False - names refer to different entities
(strictly, the names are not known to
refer to the same identity).
Function value:
GSS status code:
GSS_S_COMPLETE Successful completion
GSS_S_BAD_NAMETYPE The type contained within either name1 or
name2 was unrecognized, or the names were of
incomparable types.
GSS_S_BAD_NAME One or both of name1 or name2 was ill-formed
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3.15. gss_display_name
OM_uint32 gss_display_name (
OM_uint32 * minor_status,
gss_name_t input_name,
gss_buffer_t output_name_buffer,
gss_OID * output_name_type)
Purpose:
Allows an application to obtain a textual representation of an opaque
internal-form name for display purposes. The syntax of a printable
name is defined by the GSSAPI implementation.
Parameters:
minor_status integer, modify
Mechanism specific status code.
input_name gss_name_t, read
name to be displayed
output_name_buffer buffer, character-string, modify
buffer to receive textual name string
output_name_type Object ID, modify
The type of the returned name. The returned
gss_OID will be a pointer into static storage,
and should be treated as read-only by the caller
Function value:
GSS status code:
GSS_S_COMPLETE Successful completion
GSS_S_BAD_NAMETYPE The type of input_name was not recognized
GSS_S_BAD_NAME input_name was ill-formed
3.16. gss_import_name
OM_uint32 gss_import_name (
OM_uint32 * minor_status,
gss_buffer_t input_name_buffer,
gss_OID input_name_type,
gss_name_t * output_name)
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Purpose:
Convert a printable name to internal form.
Parameters:
minor_status integer, modify
Mechanism specific status code
input_name_buffer buffer, character-string, read
buffer containing printable name to convert
input_name_type Object ID, read, optional
Object Id specifying type of printable
name. Applications may specify either
GSS_C_NULL_OID to use a local system-specific
printable syntax, or an OID registered by the
GSSAPI implementation to name a particular
namespace.
output_name gss_name_t, modify
returned name in internal form
Function value:
GSS status code
GSS_S_COMPLETE Successful completion
GSS_S_BAD_NAMETYPE The input_name_type was unrecognized
GSS_S_BAD_NAME The input_name parameter could not be
interpreted as a name of the specified type
3.17. gss_release_name
OM_uint32 gss_release_name (
OM_uint32 * minor_status,
gss_name_t * name)
Purpose:
Free GSSAPI-allocated storage associated with an internal form name.
Parameters:
minor_status integer, modify
Mechanism specific status code
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name gss_name_t, modify
The name to be deleted
Function value:
GSS status code
GSS_S_COMPLETE Successful completion
GSS_S_BAD_NAME The name parameter did not contain a valid name
3.18. gss_release_buffer
OM_uint32 gss_release_buffer (
OM_uint32 * minor_status,
gss_buffer_t buffer)
Purpose:
Free storage associated with a buffer format name. The storage must
have been allocated by a GSSAPI routine. In addition to freeing the
associated storage, the routine will zero the length field in the
buffer parameter.
Parameters:
minor_status integer, modify
Mechanism specific status code
buffer buffer, modify
The storage associated with the buffer will be
deleted. The gss_buffer_desc object will not
be freed, but its length field will be zeroed.
Function value:
GSS status code
GSS_S_COMPLETE Successful completion
3.19. gss_release_oid_set
OM_uint32 gss_release_oid_set (
OM_uint32 * minor_status,
gss_OID_set * set)
Purpose:
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Free storage associated with a gss_OID_set object. The storage must
have been allocated by a GSSAPI routine.
Parameters:
minor_status integer, modify
Mechanism specific status code
set Set of Object IDs, modify
The storage associated with the gss_OID_set
will be deleted.
Function value:
GSS status code
GSS_S_COMPLETE Successful completion
3.20. gss_inquire_cred
OM_uint32 gss_inquire_cred (
OM_uint32 * minor_status,
gss_cred_id_t cred_handle,
gss_name_t * name,
OM_uint32 * lifetime,
int * cred_usage,
gss_OID_set * mechanisms )
Purpose:
Obtains information about a credential. The caller must already have
obtained a handle that refers to the credential.
Parameters:
minor_status integer, modify
Mechanism specific status code
cred_handle gss_cred_id_t, read
A handle that refers to the target credential.
Specify GSS_C_NO_CREDENTIAL to inquire about
the default credential.
name gss_name_t, modify
The name whose identity the credential asserts.
Specify NULL if not required.
lifetime Integer, modify
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The number of seconds for which the credential
will remain valid. If the credential has
expired, this parameter will be set to zero.
If the implementation does not support
credential expiration, the value
GSS_C_INDEFINITE will be returned. Specify
NULL if not required.
cred_usage Integer, modify
How the credential may be used. One of the
following:
GSS_C_INITIATE
GSS_C_ACCEPT
GSS_C_BOTH
Specify NULL if not required.
mechanisms gss_OID_set, modify
Set of mechanisms supported by the credential.
Specify NULL if not required.
Function value:
GSS status code
GSS_S_COMPLETE Successful completion
GSS_S_NO_CRED The referenced credentials could not be
accessed.
GSS_S_DEFECTIVE_CREDENTIAL The referenced credentials were
invalid.
GSS_S_CREDENTIALS_EXPIRED The referenced credentials have expired.
If the lifetime parameter was not passed as
NULL, it will be set to 0.
#ifndef GSSAPI_H_
#define GSSAPI_H_
/*
* First, define the platform-dependent types.
*/
typedef <platform-specific> OM_uint32;
typedef <platform-specific> gss_ctx_id_t;
typedef <platform-specific> gss_cred_id_t;
typedef <platform-specific> gss_name_t;
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RFC 1509 GSSAPI - Overview and C bindings September 1993
/*
* Note that a platform supporting the xom.h X/Open header file
* may make use of that header for the definitions of OM_uint32
* and the structure to which gss_OID_desc equates.
*/
typedef struct gss_OID_desc_struct {
OM_uint32 length;
void *elements;
} gss_OID_desc, *gss_OID;
typedef struct gss_OID_set_desc_struct {
int count;
gss_OID elements;
} gss_OID_set_desc, *gss_OID_set;
typedef struct gss_buffer_desc_struct {
size_t length;
void *value;
} gss_buffer_desc, *gss_buffer_t;
typedef struct gss_channel_bindings_struct {
OM_uint32 initiator_addrtype;
gss_buffer_desc initiator_address;
OM_uint32 acceptor_addrtype;
gss_buffer_desc acceptor_address;
gss_buffer_desc application_data;
} *gss_channel_bindings_t;
/*
* Six independent flags each of which indicates that a context
* supports a specific service option.
*/
#define GSS_C_DELEG_FLAG 1
#define GSS_C_MUTUAL_FLAG 2
#define GSS_C_REPLAY_FLAG 4
#define GSS_C_SEQUENCE_FLAG 8
#define GSS_C_CONF_FLAG 16
#define GSS_C_INTEG_FLAG 32
/*
* Credential usage options
*/
#define GSS_C_BOTH 0
#define GSS_C_INITIATE 1
#define GSS_C_ACCEPT 2
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/*
* Status code types for gss_display_status
*/
#define GSS_C_GSS_CODE 1
#define GSS_C_MECH_CODE 2
/*
* The constant definitions for channel-bindings address families
*/
#define GSS_C_AF_UNSPEC 0;
#define GSS_C_AF_LOCAL 1;
#define GSS_C_AF_INET 2;
#define GSS_C_AF_IMPLINK 3;
#define GSS_C_AF_PUP 4;
#define GSS_C_AF_CHAOS 5;
#define GSS_C_AF_NS 6;
#define GSS_C_AF_NBS 7;
#define GSS_C_AF_ECMA 8;
#define GSS_C_AF_DATAKIT 9;
#define GSS_C_AF_CCITT 10;
#define GSS_C_AF_SNA 11;
#define GSS_C_AF_DECnet 12;
#define GSS_C_AF_DLI 13;
#define GSS_C_AF_LAT 14;
#define GSS_C_AF_HYLINK 15;
#define GSS_C_AF_APPLETALK 16;
#define GSS_C_AF_BSC 17;
#define GSS_C_AF_DSS 18;
#define GSS_C_AF_OSI 19;
#define GSS_C_AF_X25 21;
#define GSS_C_AF_NULLADDR 255;
#define GSS_C_NO_BUFFER ((gss_buffer_t) 0)
#define GSS_C_NULL_OID ((gss_OID) 0)
#define GSS_C_NULL_OID_SET ((gss_OID_set) 0)
#define GSS_C_NO_CONTEXT ((gss_ctx_id_t) 0)
#define GSS_C_NO_CREDENTIAL ((gss_cred_id_t) 0)
#define GSS_C_NO_CHANNEL_BINDINGS ((gss_channel_bindings_t) 0)
#define GSS_C_EMPTY_BUFFER {0, NULL}
/*
* Define the default Quality of Protection for per-message
* services. Note that an implementation that offers multiple
* levels of QOP may either reserve a value (for example zero,
* as assumed here) to mean "default protection", or alternatively
* may simply equate GSS_C_QOP_DEFAULT to a specific explicit QOP
* value.
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*/
#define GSS_C_QOP_DEFAULT 0
/*
* Expiration time of 2^32-1 seconds means infinite lifetime for a
* credential or security context
*/
#define GSS_C_INDEFINITE 0xfffffffful
/* Major status codes */
#define GSS_S_COMPLETE 0
/*
* Some "helper" definitions to make the status code macros obvious.
*/
#define GSS_C_CALLING_ERROR_OFFSET 24
#define GSS_C_ROUTINE_ERROR_OFFSET 16
#define GSS_C_SUPPLEMENTARY_OFFSET 0
#define GSS_C_CALLING_ERROR_MASK 0377ul
#define GSS_C_ROUTINE_ERROR_MASK 0377ul
#define GSS_C_SUPPLEMENTARY_MASK 0177777ul
/*
* The macros that test status codes for error conditions
*/
#define GSS_CALLING_ERROR(x) \
(x & (GSS_C_CALLING_ERROR_MASK << GSS_C_CALLING_ERROR_OFFSET))
#define GSS_ROUTINE_ERROR(x) \
(x & (GSS_C_ROUTINE_ERROR_MASK << GSS_C_ROUTINE_ERROR_OFFSET))
#define GSS_SUPPLEMENTARY_INFO(x) \
(x & (GSS_C_SUPPLEMENTARY_MASK << GSS_C_SUPPLEMENTARY_OFFSET))
#define GSS_ERROR(x) \
((GSS_CALLING_ERROR(x) != 0) || (GSS_ROUTINE_ERROR(x) != 0))
/*
* Now the actual status code definitions
*/
/*
* Calling errors:
*/
#define GSS_S_CALL_INACCESSIBLE_READ \
(1ul << GSS_C_CALLING_ERROR_OFFSET)
#define GSS_S_CALL_INACCESSIBLE_WRITE \
(2ul << GSS_C_CALLING_ERROR_OFFSET)
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#define GSS_S_CALL_BAD_STRUCTURE \
(3ul << GSS_C_CALLING_ERROR_OFFSET)
/*
* Routine errors:
*/
#define GSS_S_BAD_MECH (1ul << GSS_C_ROUTINE_ERROR_OFFSET)
#define GSS_S_BAD_NAME (2ul << GSS_C_ROUTINE_ERROR_OFFSET)
#define GSS_S_BAD_NAMETYPE (3ul << GSS_C_ROUTINE_ERROR_OFFSET)
#define GSS_S_BAD_BINDINGS (4ul << GSS_C_ROUTINE_ERROR_OFFSET)
#define GSS_S_BAD_STATUS (5ul << GSS_C_ROUTINE_ERROR_OFFSET)
#define GSS_S_BAD_SIG (6ul << GSS_C_ROUTINE_ERROR_OFFSET)
#define GSS_S_NO_CRED (7ul << GSS_C_ROUTINE_ERROR_OFFSET)
#define GSS_S_NO_CONTEXT (8ul << GSS_C_ROUTINE_ERROR_OFFSET)
#define GSS_S_DEFECTIVE_TOKEN (9ul << GSS_C_ROUTINE_ERROR_OFFSET)
#define GSS_S_DEFECTIVE_CREDENTIAL (10ul << GSS_C_ROUTINE_ERROR_OFFSET)
#define GSS_S_CREDENTIALS_EXPIRED (11ul << GSS_C_ROUTINE_ERROR_OFFSET)
#define GSS_S_CONTEXT_EXPIRED (12ul << GSS_C_ROUTINE_ERROR_OFFSET)
#define GSS_S_FAILURE (13ul << GSS_C_ROUTINE_ERROR_OFFSET)
/*
* Supplementary info bits:
*/
#define GSS_S_CONTINUE_NEEDED (1ul << (GSS_C_SUPPLEMENTARY_OFFSET + 0))
#define GSS_S_DUPLICATE_TOKEN (1ul << (GSS_C_SUPPLEMENTARY_OFFSET + 1))
#define GSS_S_OLD_TOKEN (1ul << (GSS_C_SUPPLEMENTARY_OFFSET + 2))
#define GSS_S_UNSEQ_TOKEN (1ul << (GSS_C_SUPPLEMENTARY_OFFSET + 3))
/*
* Finally, function prototypes for the GSSAPI routines.
*/
OM_uint32 gss_acquire_cred
(OM_uint32*, /* minor_status */
gss_name_t, /* desired_name */
OM_uint32, /* time_req */
gss_OID_set, /* desired_mechs */
int, /* cred_usage */
gss_cred_id_t*, /* output_cred_handle */
gss_OID_set*, /* actual_mechs */
OM_uint32* /* time_rec */
);
OM_uint32 gss_release_cred,
(OM_uint32*, /* minor_status */
gss_cred_id_t* /* cred_handle */
);
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OM_uint32 gss_init_sec_context
(OM_uint32*, /* minor_status */
gss_cred_id_t, /* claimant_cred_handle */
gss_ctx_id_t*, /* context_handle */
gss_name_t, /* target_name */
gss_OID, /* mech_type */
int, /* req_flags */
OM_uint32, /* time_req */
gss_channel_bindings_t,
/* input_chan_bindings */
gss_buffer_t, /* input_token */
gss_OID*, /* actual_mech_type */
gss_buffer_t, /* output_token */
int*, /* ret_flags */
OM_uint32* /* time_rec */
);
OM_uint32 gss_accept_sec_context
(OM_uint32*, /* minor_status */
gss_ctx_id_t*, /* context_handle */
gss_cred_id_t, /* verifier_cred_handle */
gss_buffer_t, /* input_token_buffer */
gss_channel_bindings_t,
/* input_chan_bindings */
gss_name_t*, /* src_name */
gss_OID*, /* mech_type */
gss_buffer_t, /* output_token */
int*, /* ret_flags */
OM_uint32*, /* time_rec */
gss_cred_id_t* /* delegated_cred_handle */
);
OM_uint32 gss_process_context_token
(OM_uint32*, /* minor_status */
gss_ctx_id_t, /* context_handle */
gss_buffer_t /* token_buffer */
);
OM_uint32 gss_delete_sec_context
(OM_uint32*, /* minor_status */
gss_ctx_id_t*, /* context_handle */
gss_buffer_t /* output_token */
);
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OM_uint32 gss_context_time
(OM_uint32*, /* minor_status */
gss_ctx_id_t, /* context_handle */
OM_uint32* /* time_rec */
);
OM_uint32 gss_sign
(OM_uint32*, /* minor_status */
gss_ctx_id_t, /* context_handle */
int, /* qop_req */
gss_buffer_t, /* message_buffer */
gss_buffer_t /* message_token */
);
OM_uitn32 gss_verify
(OM_uint32*, /* minor_status */
gss_ctx_id_t, /* context_handle */
gss_buffer_t, /* message_buffer */
gss_buffer_t, /* token_buffer */
int* /* qop_state */
);
OM_uint32 gss_seal
(OM_uint32*, /* minor_status */
gss_ctx_id_t, /* context_handle */
int, /* conf_req_flag */
int, /* qop_req */
gss_buffer_t, /* input_message_buffer */
int*, /* conf_state */
gss_buffer_t /* output_message_buffer */
);
OM_uint32 gss_unseal
(OM_uint32*, /* minor_status */
gss_ctx_id_t, /* context_handle */
gss_buffer_t, /* input_message_buffer */
gss_buffer_t, /* output_message_buffer */
int*, /* conf_state */
int* /* qop_state */
);
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OM_uint32 gss_display_status
(OM_uint32*, /* minor_status */
OM_uint32, /* status_value */
int, /* status_type */
gss_OID, /* mech_type */
int*, /* message_context */
gss_buffer_t /* status_string */
);
OM_uint32 gss_indicate_mechs
(OM_uint32*, /* minor_status */
gss_OID_set* /* mech_set */
);
OM_uint32 gss_compare_name
(OM_uint32*, /* minor_status */
gss_name_t, /* name1 */
gss_name_t, /* name2 */
int* /* name_equal */
);
OM_uint32 gss_display_name,
(OM_uint32*, /* minor_status */
gss_name_t, /* input_name */
gss_buffer_t, /* output_name_buffer */
gss_OID* /* output_name_type */
);
OM_uint32 gss_import_name
(OM_uint32*, /* minor_status */
gss_buffer_t, /* input_name_buffer */
gss_OID, /* input_name_type */
gss_name_t* /* output_name */
);
OM_uint32 gss_release_name
(OM_uint32*, /* minor_status */
gss_name_t* /* input_name */
);
OM_uint32 gss_release_buffer
(OM_uint32*, /* minor_status */
gss_buffer_t /* buffer */
);
OM_uint32 gss_release_oid_set
(OM_uint32*, /* minor_status */
gss_OID_set* /* set */
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);
OM_uint32 gss_inquire_cred
(OM_uint32 *, /* minor_status */
gss_cred_id_t, /* cred_handle */
gss_name_t *, /* name */
OM_uint32 *, /* lifetime */
int *, /* cred_usage */
gss_OID_set * /* mechanisms */
);
#endif /* GSSAPI_H_ */
References
[1] Linn, J., "Generic Security Service Application Program
Interface", RFC 1508, Geer Zolot Associate, September 1993.
[2] "OSI Object Management API Specification, Version 2.0 t", X.400
API Association & X/Open Company Limited, August 24, 1990.
Specification of datatypes and routines for manipulating
information objects.
Security Considerations
Security issues are discussed throughout this memo.
Author's Address
John Wray
Digital Equipment Corporation
550 King Street, LKG2-2/AA6
Littleton, MA 01460
USA
Phone: +1-508-486-5210
EMail: Wray@tuxedo.enet.dec.com
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