FreeCalypso > hg > freecalypso-tools
view rvinterf/etmsync/cl_des.h @ 465:003e48f8ebe1
rvinterf/etmsync/fsnew.c: cast 0 to (char *) for execl sentinel
I generally don't use NULL and use plain 0 instead, based on a "NULL
considered harmful" discussion on the classiccmp mailing list many aeons
ago (I couldn't find it, and I reason that it must have been 2005 or
earlier), but a recent complaint by a packager sent me searching, and I
found this:
https://ewontfix.com/11/
While I don't give a @#$% about "modern" systems and code-nazi tools,
I realized that passing a plain 0 as a pointer sentinel in execl is wrong
because it will break on systems where pointers are longer than the plain
int type. Again, I don't give a @#$% about the abomination of x86_64 and
the like, but if anyone ever manages to port my code to something like a
PDP-11 (16-bit int, 32-bit long and pointers), then passing a plain 0
as a function argument where a pointer is expected most definitely won't
work: if the most natural stack slot and SP alignment unit is 16 bits,
fitting an int, with longs and pointers taking up two such slots, then
the call stack will be totally wrong with a plain 0 passed for a pointer.
Casting the 0 to (char *) ought to be the most kosher solution for the
most retro systems possible.
| author | Mychaela Falconia <falcon@freecalypso.org> |
|---|---|
| date | Mon, 11 Feb 2019 00:00:19 +0000 |
| parents | 3d148edb87c2 |
| children |
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/* * This DES implementation is used for the purpose of decrypting * Pirelli's factory IMEI record; it has been lifted out of TI's * reference GSM firmware source. */ #ifndef CL_DES_H #define CL_DES_H /**********************************************************************************/ #define CL_DES_BUFFER_SIZE 8 #define CL_DES_KEY_SIZE 8 #define CL_DES_ENCRYPTION 1 #define CL_DES_DECRYPTION 2 /* +------------------------------------------------------------------------------ | Function : cl_des +------------------------------------------------------------------------------ | Description : The function performs DES encrypting or decrypting | | Parameters : inMsgPtr : pointer to input message M. The length of message | has to be min. 8 bytes e.g. M = 0123456789abcdef | desKeyPtr : pointer to DES key. Length has to be 8 bytes | outMsgPtr : output encrypted/decrypted message. The length is 8 b. | code : CL_DES_ENCRYPTION, CL_DES_DECRYPTION +------------------------------------------------------------------------------ */ extern void cl_des(unsigned char *inMsgPtr, unsigned char *desKeyPtr, unsigned char *outMsgPtr, unsigned char code); /**********************************************************************************/ #endif /* CL_DES_H */