Fix #23937 - fix rahash2 JSON ssdeep output ##json ##print

[mattunleashed]

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Description

This should be a straight-forward code change to ensure > rahash2 -a ssdeep -j /path/to/bin actually prints the correct ssdeep hash as expected.

This is my first PR. I believe I followed everything correctly and expect this to be good to go, but I'm happy to learn and make updates if needed. Specifically, I:

• Recompiled and tested the expected output locally
• Added a test and reran the r2r test suite. Everything finished and I didn't see my test throw an error but I was unclear on how to specifically confirm that my new test actually ran.

I tracked some of my analysis to identify the fix on my personal fork here.

[trufae]

[main] CC rahash2.c
rahash2.c: In function ‘do_hash_print’:
rahash2.c:151:23: error: pointer targets in passing argument 3 of ‘pj_ks’ differ in signedness [-Werror=pointer-sign]
  151 |    pj_ks (pj, "hash", c);
      |                       ^
      |                       |
      |                       const uint8_t * {aka const unsigned char *}
In file included from /home/runner/work/radare2/radare2/libr/include/r_cons.h:10,
                 from /home/runner/work/radare2/radare2/libr/include/r_util/r_diff.h:6,
                 from /home/runner/work/radare2/radare2/libr/include/r_util.h:58,
                 from /home/runner/work/radare2/radare2/libr/include/r_io.h:7,
                 from rahash2.c:5:
/home/runner/work/radare2/radare2/libr/include/r_util/pj.h:70:11: note: expected ‘const char *’ but argument is of type ‘const uint8_t *’ {aka ‘const unsigned char *’}
   70 | R_API PJ *pj_ks(PJ *j, const char *k, const char *v);
      |           ^~~~~
cc1: all warnings being treated as errors

[trufae]

i would suggest to print the hash as an array of numbers or an hexpair string (that's probably more common representation) you can use the r_hex_bin2strdup function which takes c and dlen and returns a heap allocated string that can be passed instead of c to the pjks

[trufae]

in that case..for ssdeep. this is actually a binary printable buffer.. so maybe asuming that its null terminated you can just cast it to (const char *)

[mattunleashed]

Yup - found a similar cast elsewhere so figured that was an acceptable option. I was hoping to wake up this morning and make that code change but thanks for the assist!