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P11KitPin * | p11_kit_pin_new () |
P11KitPin * | p11_kit_pin_new_for_buffer () |
P11KitPin * | p11_kit_pin_new_for_string () |
const unsigned char * | p11_kit_pin_get_value () |
size_t | p11_kit_pin_get_length () |
P11KitPin * | p11_kit_pin_ref () |
void | p11_kit_pin_unref () |
int | p11_kit_pin_register_callback () |
void | p11_kit_pin_unregister_callback () |
P11KitPin * | (*p11_kit_pin_callback) () |
P11KitPin * | p11_kit_pin_request () |
void | (*p11_kit_pin_destroy_func) () |
P11KitPin * | p11_kit_pin_file_callback () |
Applications can register a callback which will be called to provide a password associated with a given pin source.
PKCS#11 URIs can contain a 'pin-source' attribute. The value of this attribute is application dependent, but often references a file containing a PIN to use.
Using these functions, an applications or libraries can register a
callback with p11_kit_pin_register_callback()
to be called when a given
'pin-source' attribute value is requested. The application can then prompt
the user or retrieve a PIN for the given context. These registered
callbacks are only relevant and valid within the current process.
A fallback callback can be registered by passing the P11_KIT_PIN_FALLBACK
value to p11_kit_pin_register_callback()
. This fallback callback will be
called for every 'pin-source' attribute request for which no callback has been
directly registered.
To request a PIN for a given 'pin-source' attribute, use the
p11_kit_pin_request()
function. If this function returns NULL
then either
no callbacks were registered or none of them could handle the request.
If multiple callbacks are registered for the same PIN source, then they are called in last-registered-first-called order. They are called in turn until one of them can handle the request. Fallback callbacks are not called if a callback was registered specifically for a requested 'pin-source' attribute.
PINs themselves are handled inside of P11KitPin structures. These are thread
safe and allow the callback to specify how the PIN is stored in memory
and freed. A callback can use p11_kit_pin_new_for_string()
or related
functions to create a PIN to be returned.
For example in order to handle the following PKCS#11 URI with a 'pin-source' attribute
pkcs11:id=\%69\%95\%3e\%5c\%f4\%bd\%ec\%91;pin-source=my-application
an application could register a callback like this:
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static P11KitPin* my_application_pin_callback (const char *pin_source, P11KitUri *pin_uri, const char *pin_description, P11KitPinFlags pin_flags, void *callback_data) { return p11_kit_pin_new_from_string ("pin-value"); } p11_kit_pin_register_callback ("my-application", my_application_pin_callback, NULL, NULL); |
P11KitPin * p11_kit_pin_new (const unsigned char *value
,size_t length
);
Create a new P11KitPin with the given PIN value. This function is usually used from within registered PIN callbacks.
Exactly length
bytes from value
are used. Null terminated strings,
or encodings are not considered. A copy of the value
will be made.
The newly allocated P11KitPin, which should be freed with
p11_kit_pin_unref()
when no longer needed.
P11KitPin * p11_kit_pin_new_for_buffer (unsigned char *buffer
,size_t length
,p11_kit_pin_destroy_func destroy
);
Create a new P11KitPin which will use buffer
for the PIN value.
This function is usually used from within registered PIN callbacks.
The buffer will not be copied. String encodings and null characters are not considered.
When the last reference to this PIN is lost, then the destroy
callback
function will be called passing buffer
as an argument. This allows the
caller to use a buffer as a PIN without copying it.
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char *buffer = malloc (128); P11KitPin *pin; .... pin = p11_kit_pin_new_for_buffer (buffer, 128, free); |
buffer |
the value of the PIN |
|
length |
the length of |
|
destroy |
if not |
The newly allocated P11KitPin, which should be freed with
p11_kit_pin_unref()
when no longer needed.
P11KitPin *
p11_kit_pin_new_for_string (const char *value
);
Create a new P11KitPin for the given null-terminated string, such as a password. This function is usually used from within registered PIN callbacks.
The PIN will consist of the string not including the null terminator.
String encoding is not considered. A copy of the value
will be made.
The newly allocated P11KitPin, which should be freed with
p11_kit_pin_unref()
when no longer needed.
const unsigned char * p11_kit_pin_get_value (P11KitPin *pin
,size_t *length
);
Get the PIN value from a P11KitPin. length
will be set to the
length of the value.
The value returned is owned by the P11KitPin and should not be modified. It remains valid as long as a reference to the PIN is held. The PIN value will not contain an extra null-terminator character.
size_t
p11_kit_pin_get_length (P11KitPin *pin
);
Get the length of the PIN value from a P11KitPin.
P11KitPin *
p11_kit_pin_ref (P11KitPin *pin
);
Add a reference to a P11KitPin. This should be matched with a later call
to p11_kit_pin_unref()
. As long as at least one reference is held, the PIN
will remain valid and in memory.
void
p11_kit_pin_unref (P11KitPin *pin
);
Remove a reference from a P11KitPin. When all references have been removed then the PIN will be freed and will no longer be in memory.
int p11_kit_pin_register_callback (const char *pin_source
,p11_kit_pin_callback callback
,void *callback_data
,p11_kit_pin_destroy_func callback_destroy
);
Register a callback to handle PIN requests for a given 'pin-source' attribute.
If pin_source
is set to P11_KIT_PIN_FALLBACK then this will be a fallback
callback and will be called for requests for which no other callback has
been specifically registered.
If multiple callbacks are registered for the same pin_source
value, then
the last registered callback will be the first to be called.
void p11_kit_pin_unregister_callback (const char *pin_source
,p11_kit_pin_callback callback
,void *callback_data
);
Unregister a callback that was previously registered with the
p11_kit_pin_register_callback()
function. If more than one registered
callback matches the given arguments, then only one of those will be
removed.
P11KitPin * (*p11_kit_pin_callback) (const char *pin_source
,P11KitUri *pin_uri
,const char *pin_description
,P11KitPinFlags pin_flags
,void *callback_data
);
Represents a PIN callback function.
The various arguments are the same as the ones passed to
p11_kit_pin_request()
. The callback_data
argument was the one passed to
p11_kit_pin_register_callback()
when registering this callback.
The function should return NULL
if it could not provide a PIN, either
because of an error or a user cancellation.
If a PIN is returned, it will be unreferenced by the caller. So it should be either newly allocated, or referenced before returning.
pin_source |
a 'pin-source' attribute string |
|
pin_uri |
a PKCS#11 URI that the PIN is for, or |
|
pin_description |
a descrption of what the PIN is for |
|
pin_flags |
flags describing the PIN request |
|
callback_data |
data that was provided when registering this callback |
P11KitPin * p11_kit_pin_request (const char *pin_source
,P11KitUri *pin_uri
,const char *pin_description
,P11KitPinFlags pin_flags
);
Request a PIN for a given 'pin-source' attribute. The result depends on the registered callbacks.
If not NULL
, then the pin_uri
attribute should point to the thing that the
PIN is being requested for. In most use cases this should be a PKCS#11 URI
pointing to a token.
The pin_description
should always be specified. It is a string describing
what the PIN is for. For example this would be the token label, if the PIN
is for a token.
If more than one callback is registered for the pin_source
, then the latest
registered one will be called first. If that callback does not return a
PIN, then the next will be called in turn.
If no callback is registered for pin_source
, then the fallback callbacks will
be invoked in the same way. The fallback callbacks will not be called if any
callback has been registered specifically for pin_source
.
The PIN returned should be released with p11_kit_pin_unref()
.
the PIN which should be released with p11_kit_pin_unref()
, or NULL
if no callback was registered or could proivde a PIN
void
(*p11_kit_pin_destroy_func) (void *data
);
A function called to free or cleanup data
.
P11KitPin * p11_kit_pin_file_callback (const char *pin_source
,P11KitUri *pin_uri
,const char *pin_description
,P11KitPinFlags pin_flags
,void *callback_data
);
This is a PIN callback function that looks up the 'pin-source' attribute in a file with that name. This can be used to enable the normal PKCS#11 URI behavior described in the RFC.
If pin_flags
contains the P11_KIT_PIN_FLAGS_RETRY
flag, then this
callback will always return NULL
. This is to prevent endless loops
where an application is expecting to interact with a prompter, but
instead is interacting with this callback reading a file over and over.
This callback fails on files larger than 4 Kilobytes.
This callback is not registered by default. It may have security implications depending on the source of the PKCS#11 URI and the PKCS#11 in use. To register it, use code like the following:
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p11_kit_pin_register_callback (P11_KIT_PIN_FALLBACK, p11_kit_pin_file_callback, NULL, NULL); |
A structure representing a PKCS#11 PIN. There are no public fields visible in this structure. Use the various accessor functions.
Flags that are passed to p11_kit_pin_request()
and registered callbacks.
The PIN is for a PKCS#11 user type login. |
||
The PIN is for a PKCS#11 security officer type login. |
||
The PIN is for a PKCS#11 contect specific type login. |
||
The PIN is being requested again, due to an invalid previous PIN. |
||
The PIN has failed too many times, and few tries are left. |
||
The PIN has failed too many times, and this is the last try. |
#define P11_KIT_PIN_FALLBACK
Used with p11_kit_pin_register_callback()
to register a fallback callback.
This callback will be called if no other callback is registered for a 'pin-source'.