Polish API `unsigned long outlen` vs. `unsigned long *outlen` #176

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opened 2017-03-23 14:01:18 -05:00 by karel-m · 3 comments

karel-m commented

2017-03-23 14:01:18 -05:00

(Migrated from github.com)

based on discussion in #171 I have found the following places where we IMO handle incosistently outlen

pelican_done(pelican_state *pelmac, unsigned char *out);  /* missing outlen*/
crc32_finish(.... void *hash, unsigned long size);        /* should be: unsigned long *size */
adler32_finish(.... void *hash, unsigned long size);      /* should be: unsigned long *size */

based on discussion in #171 I have found the following places where we IMO handle incosistently `outlen` ```C pelican_done(pelican_state *pelmac, unsigned char *out); /* missing outlen*/ crc32_finish(.... void *hash, unsigned long size); /* should be: unsigned long *size */ adler32_finish(.... void *hash, unsigned long size); /* should be: unsigned long *size */ ```

sjaeckel commented

2017-03-23 18:04:47 -05:00

(Migrated from github.com)

Looking at these it also became obvious to me that there's different paradigms used for different classes of algorithms... like the XXhash_done() functions always use the same signature as pelican_done() and TBH I'm not sure yet how much I (dis)like that type of signature...

Looking at these it also became obvious to me that there's different paradigms used for different classes of algorithms... like the `XXhash_done()` functions always use the same signature as `pelican_done()` and TBH I'm not sure yet how much I (dis)like that type of signature...

rofl0r commented

2017-03-23 18:16:03 -05:00

(Migrated from github.com)

well i suppose in the case of crc32_finish it's clear that the result len will be 4 bytes, so there's no need to pass a pointer-to where the size is being written to by the callee.

karel-m commented

2017-03-24 01:25:02 -05:00

(Migrated from github.com)

well i suppose in the case of crc32_finish it's clear that the result len will be 4 bytes, so there's no need to pass a pointer-to where the size is being written to by the callee.

But it is exactly the same case in many mac/authenc functions returning a tag of fixed length (where we utilize unsigned long *outlen parameter)

> well i suppose in the case of crc32_finish it's clear that the result len will be 4 bytes, so there's no need to pass a pointer-to where the size is being written to by the callee. But it is exactly the same case in many mac/authenc functions returning a tag of fixed length (where we utilize `unsigned long *outlen` parameter)