Using the PKCS #11 Module Logger
NSS Technical Note: 2
The logger displays all activity between NSS and a specified PKCS #11 module. It works by inserting a special set of entry points between NSS and the module.
To enable the module logger, you must set the environment variable NSS_DEBUG_PKCS11_MODULE to the name of the target module. For example, to log the softoken, use:
NSS_DEBUG_PKCS11_MODULE="NSS Internal PKCS #11 Module"
Note: In the Command Prompt on Windows, do not quote the name of the target module, otherwise the quotes are considered part of the name. For example, to log the softoken on Windows, use:
set NSS_DEBUG_PKCS11_MODULE=NSS Internal PKCS #11 Module
The logger is available by default in debug builds. For optimized builds, NSS must be built with the variable DEBUG_PKCS11 set.
Modes of Operation
The logger has several modes of operation:
1. Only display the sequence of PKCS #11 calls. To enable this mode, set:
NSPR_LOG_MODULES=nss_mod_log:1 NSPR_LOG_FILE=<logfile>
The output format is:
OSThreadID[NSPRThreadID]: C_XXX OSThreadID[NSPRThreadID]: rv = 0xYYYYYYYY
For example,
1024[805ef10]: C_Initialize 1024[805ef10]: rv = 0x0 1024[805ef10]: C_GetInfo 1024[805ef10]: rv = 0x0 1024[805ef10]: C_GetSlotList 1024[805ef10]: rv = 0x0
2. Display the sequence of PKCS #11 calls, and the parameters given to them. To enable this mode, set:
NSPR_LOG_MODULES=nss_mod_log:3 NSPR_LOG_FILE=<logfile>
The output format is:
OSThreadID[NSPRThreadID]: C_XXX OSThreadID[NSPRThreadID]: arg1 = 0xAAAAAAAA ... OSThreadID[NSPRThreadID]: argN = 0xAAAAAAAA OSThreadID[NSPRThreadID]: rv = 0xYYYYYYYY
For example,
1024[805ef10]: C_Initialize 1024[805ef10]: pInitArgs = 0x4010c938 1024[805ef10]: rv = 0x0 1024[805ef10]: C_GetInfo 1024[805ef10]: pInfo = 0xbffff340 1024[805ef10]: rv = 0x0 1024[805ef10]: C_GetSlotList 1024[805ef10]: tokenPresent = 0x0 1024[805ef10]: pSlotList = 0x0 1024[805ef10]: pulCount = 0xbffff33c 1024[805ef10]: *pulCount = 0x2 1024[805ef10]: rv = 0x0
Note that when a PKCS #11 function takes a pointer argument for which it will set a value (C_GetSlotList above), this mode will display the value upon return.
3. Display verbose information, including template values, array values, etc. To enable this mode, set:
NSPR_LOG_MODULES=nss_mod_log:4 NSPR_LOG_FILE=<logfile>
The output format is the same as above, but with more information. For example,
1024[805ef10]: C_FindObjectsInit 1024[805ef10]: hSession = 0x1000001 1024[805ef10]: pTemplate = 0xbffff410 1024[805ef10]: ulCount = 3 1024[805ef10]: CKA_LABEL = localhost.nyc.rr.com [20] 1024[805ef10]: CKA_TOKEN = CK_TRUE [1] 1024[805ef10]: CKA_CLASS = CKO_CERTIFICATE [4] 1024[805ef10]: rv = 0x0 1024[805ef10]: C_FindObjects 1024[805ef10]: hSession = 0x1000001 1024[805ef10]: phObject = 0x806d810 1024[805ef10]: ulMaxObjectCount = 16 1024[805ef10]: pulObjectCount = 0xbffff38c 1024[805ef10]: *pulObjectCount = 0x1 1024[805ef10]: phObject[0] = 0xf6457d04 1024[805ef10]: rv = 0x0 1024[805ef10]: C_FindObjectsFinal 1024[805ef10]: hSession = 0x1000001 1024[805ef10]: rv = 0x0 1024[805ef10]: C_GetAttributeValue 1024[805ef10]: hSession = 0x1000001 1024[805ef10]: hObject = 0xf6457d04 1024[805ef10]: pTemplate = 0xbffff2d0 1024[805ef10]: ulCount = 2 1024[805ef10]: CKA_TOKEN = 0 [1] 1024[805ef10]: CKA_LABEL = 0 [20] 1024[805ef10]: rv = 0x0 1024[805ef10]: C_GetAttributeValue 1024[805ef10]: hSession = 0x1000001 1024[805ef10]: hObject = 0xf6457d04 1024[805ef10]: pTemplate = 0xbffff2d0 1024[805ef10]: ulCount = 2 1024[805ef10]: CKA_TOKEN = CK_TRUE [1] 1024[805ef10]: CKA_LABEL = localhost.nyc.rr.com [20] 1024[805ef10]: rv = 0x0
4. Collect performance data. This mode is most useful in optimized builds. The number of calls to each PKCS #11 function will be counted, and the time spent in each function as well. A summary of performance data is dumped during NSS shutdown.
No additional environment variables are required for this mode. If the environment variable NSS_OUTPUT_FILE is set, its value will be used as the path name of the file to which the final output will be written. Otherwise, the output will be written to stdout.