[Opendnssec-develop] string handling

[Roland van Rijswijk]

Hi Jakob, Rickard,

I'd like to bail Rickard out a bit here. PKCS #11 uses a lot of
fixed-length strings, one of which is token label. And to make matters
even more confusing: the fixed-length strings in the PKCS #11 spec are
not NULL-terminated...

Cheers,

Roland

Jakob Schlyter wrote:
> On 7 apr 2009, at 12.37, Rickard Bondeson wrote:
> 
>> Author: rb
>> Date: 2009-04-07 12:37:14 +0200 (Tue, 07 Apr 2009)
>> New Revision: 394
>>
>> Modified:
>>   trunk/softHSM/src/lib/SoftDatabase.cpp
>> Log:
>> We do not want to zero fill the token label.
>>
>>
>> Modified: trunk/softHSM/src/lib/SoftDatabase.cpp
>> ===================================================================
>> --- trunk/softHSM/src/lib/SoftDatabase.cpp    2009-04-07 09:56:46 UTC
>> (rev 393)
>> +++ trunk/softHSM/src/lib/SoftDatabase.cpp    2009-04-07 10:37:14 UTC
>> (rev 394)
>> @@ -103,7 +103,12 @@
>>
>>   if(sqlite3_step(select_sql) == SQLITE_ROW) {
>>     const char *tokenLabel = (const
>> char*)sqlite3_column_text(select_sql, 0);
>> -    strncpy(retLabel, tokenLabel, 32);
>> +
>> +    int counter = 0;
>> +    while(tokenLabel[counter] != '\0' && counter < 32) {
>> +      retLabel[counter] = tokenLabel[counter];
>> +      counter++;
>> +    }
>>   }
>>
>>   sqlite3_finalize(select_sql);
>>
> 
> I'd just like to make a more public note regarding string handling in
> OpenDNSSEC; as long as possible we should should strlcpy(3) and
> strlcat(3) instead of home-brewn similar functions. if we need to
> support platforms that does not have those functions, we'll import
> compat-version from OpenSSH.
> 
> also, while we're at this specific example. static lengths (as 32 above)
> should never be used - either #define them if a constant (like the size
> of a token label) or better use sizeof() when possible. I'll make a
> review of stuff like this, but it's better to get rid of them before that
> 
> so Rickard, please fix the stuff above and use strlcpy(3) and #define
> something like MAX_TOKEN_LABEL_LENGTH somewhere.
> 
> 
>     jakob, senior buffer and string management officer
> 
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