xref: /openssl/apps/dgst.c (revision 7ed6de99)
1 /*
2  * Copyright 1995-2024 The OpenSSL Project Authors. All Rights Reserved.
3  *
4  * Licensed under the Apache License 2.0 (the "License").  You may not use
5  * this file except in compliance with the License.  You can obtain a copy
6  * in the file LICENSE in the source distribution or at
7  * https://www.openssl.org/source/license.html
8  */
9 
10 #include <stdio.h>
11 #include <string.h>
12 #include <stdlib.h>
13 #include "apps.h"
14 #include "progs.h"
15 #include <openssl/bio.h>
16 #include <openssl/err.h>
17 #include <openssl/evp.h>
18 #include <openssl/objects.h>
19 #include <openssl/x509.h>
20 #include <openssl/pem.h>
21 #include <openssl/hmac.h>
22 #include <ctype.h>
23 
24 #undef BUFSIZE
25 #define BUFSIZE 1024*8
26 
27 int do_fp(BIO *out, unsigned char *buf, BIO *bp, int sep, int binout, int xoflen,
28           EVP_PKEY *key, unsigned char *sigin, int siglen,
29           const char *sig_name, const char *md_name,
30           const char *file);
31 static void show_digests(const OBJ_NAME *name, void *bio_);
32 
33 struct doall_dgst_digests {
34     BIO *bio;
35     int n;
36 };
37 
38 typedef enum OPTION_choice {
39     OPT_COMMON,
40     OPT_LIST,
41     OPT_C, OPT_R, OPT_OUT, OPT_SIGN, OPT_PASSIN, OPT_VERIFY,
42     OPT_PRVERIFY, OPT_SIGNATURE, OPT_KEYFORM, OPT_ENGINE, OPT_ENGINE_IMPL,
43     OPT_HEX, OPT_BINARY, OPT_DEBUG, OPT_FIPS_FINGERPRINT,
44     OPT_HMAC, OPT_MAC, OPT_SIGOPT, OPT_MACOPT, OPT_XOFLEN,
45     OPT_DIGEST,
46     OPT_R_ENUM, OPT_PROV_ENUM
47 } OPTION_CHOICE;
48 
49 const OPTIONS dgst_options[] = {
50     {OPT_HELP_STR, 1, '-', "Usage: %s [options] [file...]\n"},
51 
52     OPT_SECTION("General"),
53     {"help", OPT_HELP, '-', "Display this summary"},
54     {"list", OPT_LIST, '-', "List digests"},
55 #ifndef OPENSSL_NO_ENGINE
56     {"engine", OPT_ENGINE, 's', "Use engine e, possibly a hardware device"},
57     {"engine_impl", OPT_ENGINE_IMPL, '-',
58      "Also use engine given by -engine for digest operations"},
59 #endif
60     {"passin", OPT_PASSIN, 's', "Input file pass phrase source"},
61 
62     OPT_SECTION("Output"),
63     {"c", OPT_C, '-', "Print the digest with separating colons"},
64     {"r", OPT_R, '-', "Print the digest in coreutils format"},
65     {"out", OPT_OUT, '>', "Output to filename rather than stdout"},
66     {"keyform", OPT_KEYFORM, 'f', "Key file format (ENGINE, other values ignored)"},
67     {"hex", OPT_HEX, '-', "Print as hex dump"},
68     {"binary", OPT_BINARY, '-', "Print in binary form"},
69     {"xoflen", OPT_XOFLEN, 'p', "Output length for XOF algorithms. To obtain the maximum security strength set this to 32 (or greater) for SHAKE128, and 64 (or greater) for SHAKE256"},
70     {"d", OPT_DEBUG, '-', "Print debug info"},
71     {"debug", OPT_DEBUG, '-', "Print debug info"},
72 
73     OPT_SECTION("Signing"),
74     {"sign", OPT_SIGN, 's', "Sign digest using private key"},
75     {"verify", OPT_VERIFY, 's', "Verify a signature using public key"},
76     {"prverify", OPT_PRVERIFY, 's', "Verify a signature using private key"},
77     {"sigopt", OPT_SIGOPT, 's', "Signature parameter in n:v form"},
78     {"signature", OPT_SIGNATURE, '<', "File with signature to verify"},
79     {"hmac", OPT_HMAC, 's', "Create hashed MAC with key"},
80     {"mac", OPT_MAC, 's', "Create MAC (not necessarily HMAC)"},
81     {"macopt", OPT_MACOPT, 's', "MAC algorithm parameters in n:v form or key"},
82     {"", OPT_DIGEST, '-', "Any supported digest"},
83     {"fips-fingerprint", OPT_FIPS_FINGERPRINT, '-',
84      "Compute HMAC with the key used in OpenSSL-FIPS fingerprint"},
85 
86     OPT_R_OPTIONS,
87     OPT_PROV_OPTIONS,
88 
89     OPT_PARAMETERS(),
90     {"file", 0, 0, "Files to digest (optional; default is stdin)"},
91     {NULL}
92 };
93 
dgst_main(int argc,char ** argv)94 int dgst_main(int argc, char **argv)
95 {
96     BIO *in = NULL, *inp, *bmd = NULL, *out = NULL;
97     ENGINE *e = NULL, *impl = NULL;
98     EVP_PKEY *sigkey = NULL;
99     STACK_OF(OPENSSL_STRING) *sigopts = NULL, *macopts = NULL;
100     char *hmac_key = NULL;
101     char *mac_name = NULL, *digestname = NULL;
102     char *passinarg = NULL, *passin = NULL;
103     EVP_MD *md = NULL;
104     const char *outfile = NULL, *keyfile = NULL, *prog = NULL;
105     const char *sigfile = NULL;
106     const char *md_name = NULL;
107     OPTION_CHOICE o;
108     int separator = 0, debug = 0, keyform = FORMAT_UNDEF, siglen = 0;
109     int i, ret = EXIT_FAILURE, out_bin = -1, want_pub = 0, do_verify = 0;
110     int xoflen = 0;
111     unsigned char *buf = NULL, *sigbuf = NULL;
112     int engine_impl = 0;
113     struct doall_dgst_digests dec;
114 
115     buf = app_malloc(BUFSIZE, "I/O buffer");
116     md = (EVP_MD *)EVP_get_digestbyname(argv[0]);
117     if (md != NULL)
118         digestname = argv[0];
119 
120     opt_set_unknown_name("digest");
121     prog = opt_init(argc, argv, dgst_options);
122     while ((o = opt_next()) != OPT_EOF) {
123         switch (o) {
124         case OPT_EOF:
125         case OPT_ERR:
126  opthelp:
127             BIO_printf(bio_err, "%s: Use -help for summary.\n", prog);
128             goto end;
129         case OPT_HELP:
130             opt_help(dgst_options);
131             ret = EXIT_SUCCESS;
132             goto end;
133         case OPT_LIST:
134             BIO_printf(bio_out, "Supported digests:\n");
135             dec.bio = bio_out;
136             dec.n = 0;
137             OBJ_NAME_do_all_sorted(OBJ_NAME_TYPE_MD_METH,
138                                    show_digests, &dec);
139             BIO_printf(bio_out, "\n");
140             ret = EXIT_SUCCESS;
141             goto end;
142         case OPT_C:
143             separator = 1;
144             break;
145         case OPT_R:
146             separator = 2;
147             break;
148         case OPT_R_CASES:
149             if (!opt_rand(o))
150                 goto end;
151             break;
152         case OPT_OUT:
153             outfile = opt_arg();
154             break;
155         case OPT_SIGN:
156             keyfile = opt_arg();
157             break;
158         case OPT_PASSIN:
159             passinarg = opt_arg();
160             break;
161         case OPT_VERIFY:
162             keyfile = opt_arg();
163             want_pub = do_verify = 1;
164             break;
165         case OPT_PRVERIFY:
166             keyfile = opt_arg();
167             do_verify = 1;
168             break;
169         case OPT_SIGNATURE:
170             sigfile = opt_arg();
171             break;
172         case OPT_KEYFORM:
173             if (!opt_format(opt_arg(), OPT_FMT_ANY, &keyform))
174                 goto opthelp;
175             break;
176         case OPT_ENGINE:
177             e = setup_engine(opt_arg(), 0);
178             break;
179         case OPT_ENGINE_IMPL:
180             engine_impl = 1;
181             break;
182         case OPT_HEX:
183             out_bin = 0;
184             break;
185         case OPT_BINARY:
186             out_bin = 1;
187             break;
188         case OPT_XOFLEN:
189             xoflen = atoi(opt_arg());
190             break;
191         case OPT_DEBUG:
192             debug = 1;
193             break;
194         case OPT_FIPS_FINGERPRINT:
195             hmac_key = "etaonrishdlcupfm";
196             break;
197         case OPT_HMAC:
198             hmac_key = opt_arg();
199             break;
200         case OPT_MAC:
201             mac_name = opt_arg();
202             break;
203         case OPT_SIGOPT:
204             if (!sigopts)
205                 sigopts = sk_OPENSSL_STRING_new_null();
206             if (!sigopts || !sk_OPENSSL_STRING_push(sigopts, opt_arg()))
207                 goto opthelp;
208             break;
209         case OPT_MACOPT:
210             if (!macopts)
211                 macopts = sk_OPENSSL_STRING_new_null();
212             if (!macopts || !sk_OPENSSL_STRING_push(macopts, opt_arg()))
213                 goto opthelp;
214             break;
215         case OPT_DIGEST:
216             digestname = opt_unknown();
217             break;
218         case OPT_PROV_CASES:
219             if (!opt_provider(o))
220                 goto end;
221             break;
222         }
223     }
224 
225     /* Remaining args are files to digest. */
226     argc = opt_num_rest();
227     argv = opt_rest();
228     if (keyfile != NULL && argc > 1) {
229         BIO_printf(bio_err, "%s: Can only sign or verify one file.\n", prog);
230         goto end;
231     }
232     if (!app_RAND_load())
233         goto end;
234 
235     if (digestname != NULL) {
236         if (!opt_md(digestname, &md))
237             goto opthelp;
238     }
239 
240     if (do_verify && sigfile == NULL) {
241         BIO_printf(bio_err,
242                    "No signature to verify: use the -signature option\n");
243         goto end;
244     }
245     if (engine_impl)
246         impl = e;
247 
248     in = BIO_new(BIO_s_file());
249     bmd = BIO_new(BIO_f_md());
250     if (in == NULL || bmd == NULL)
251         goto end;
252 
253     if (debug) {
254         BIO_set_callback_ex(in, BIO_debug_callback_ex);
255         /* needed for windows 3.1 */
256         BIO_set_callback_arg(in, (char *)bio_err);
257     }
258 
259     if (!app_passwd(passinarg, NULL, &passin, NULL)) {
260         BIO_printf(bio_err, "Error getting password\n");
261         goto end;
262     }
263 
264     if (out_bin == -1) {
265         if (keyfile != NULL)
266             out_bin = 1;
267         else
268             out_bin = 0;
269     }
270 
271     out = bio_open_default(outfile, 'w', out_bin ? FORMAT_BINARY : FORMAT_TEXT);
272     if (out == NULL)
273         goto end;
274 
275     if ((!(mac_name == NULL) + !(keyfile == NULL) + !(hmac_key == NULL)) > 1) {
276         BIO_printf(bio_err, "MAC and signing key cannot both be specified\n");
277         goto end;
278     }
279 
280     if (keyfile != NULL) {
281         int type;
282 
283         if (want_pub)
284             sigkey = load_pubkey(keyfile, keyform, 0, NULL, e, "public key");
285         else
286             sigkey = load_key(keyfile, keyform, 0, passin, e, "private key");
287         if (sigkey == NULL) {
288             /*
289              * load_[pub]key() has already printed an appropriate message
290              */
291             goto end;
292         }
293         type = EVP_PKEY_get_id(sigkey);
294         if (type == EVP_PKEY_ED25519 || type == EVP_PKEY_ED448) {
295             /*
296              * We implement PureEdDSA for these which doesn't have a separate
297              * digest, and only supports one shot.
298              */
299             BIO_printf(bio_err, "Key type not supported for this operation\n");
300             goto end;
301         }
302     }
303 
304     if (mac_name != NULL) {
305         EVP_PKEY_CTX *mac_ctx = NULL;
306 
307         if (!init_gen_str(&mac_ctx, mac_name, impl, 0, NULL, NULL))
308             goto end;
309         if (macopts != NULL) {
310             for (i = 0; i < sk_OPENSSL_STRING_num(macopts); i++) {
311                 char *macopt = sk_OPENSSL_STRING_value(macopts, i);
312 
313                 if (pkey_ctrl_string(mac_ctx, macopt) <= 0) {
314                     EVP_PKEY_CTX_free(mac_ctx);
315                     BIO_printf(bio_err, "MAC parameter error \"%s\"\n", macopt);
316                     goto end;
317                 }
318             }
319         }
320 
321         sigkey = app_keygen(mac_ctx, mac_name, 0, 0 /* not verbose */);
322         /* Verbose output would make external-tests gost-engine fail */
323         EVP_PKEY_CTX_free(mac_ctx);
324         if (sigkey == NULL)
325             goto end;
326     }
327 
328     if (hmac_key != NULL) {
329         if (md == NULL) {
330             md = (EVP_MD *)EVP_sha256();
331             digestname = SN_sha256;
332         }
333         sigkey = EVP_PKEY_new_raw_private_key(EVP_PKEY_HMAC, impl,
334                                               (unsigned char *)hmac_key,
335                                               strlen(hmac_key));
336         if (sigkey == NULL)
337             goto end;
338     }
339 
340     if (sigkey != NULL) {
341         EVP_MD_CTX *mctx = NULL;
342         EVP_PKEY_CTX *pctx = NULL;
343         int res;
344 
345         if (BIO_get_md_ctx(bmd, &mctx) <= 0) {
346             BIO_printf(bio_err, "Error getting context\n");
347             goto end;
348         }
349         if (do_verify)
350             if (impl == NULL)
351                 res = EVP_DigestVerifyInit_ex(mctx, &pctx, digestname,
352                                               app_get0_libctx(),
353                                               app_get0_propq(), sigkey, NULL);
354             else
355                 res = EVP_DigestVerifyInit(mctx, &pctx, md, impl, sigkey);
356         else
357             if (impl == NULL)
358                 res = EVP_DigestSignInit_ex(mctx, &pctx, digestname,
359                                             app_get0_libctx(),
360                                             app_get0_propq(), sigkey, NULL);
361             else
362                 res = EVP_DigestSignInit(mctx, &pctx, md, impl, sigkey);
363         if (res == 0) {
364             BIO_printf(bio_err, "Error setting context\n");
365             goto end;
366         }
367         if (sigopts != NULL) {
368             for (i = 0; i < sk_OPENSSL_STRING_num(sigopts); i++) {
369                 char *sigopt = sk_OPENSSL_STRING_value(sigopts, i);
370 
371                 if (pkey_ctrl_string(pctx, sigopt) <= 0) {
372                     BIO_printf(bio_err, "Signature parameter error \"%s\"\n",
373                                sigopt);
374                     goto end;
375                 }
376             }
377         }
378     }
379     /* we use md as a filter, reading from 'in' */
380     else {
381         EVP_MD_CTX *mctx = NULL;
382         if (BIO_get_md_ctx(bmd, &mctx) <= 0) {
383             BIO_printf(bio_err, "Error getting context\n");
384             goto end;
385         }
386         if (md == NULL)
387             md = (EVP_MD *)EVP_sha256();
388         if (!EVP_DigestInit_ex(mctx, md, impl)) {
389             BIO_printf(bio_err, "Error setting digest\n");
390             goto end;
391         }
392     }
393 
394     if (sigfile != NULL && sigkey != NULL) {
395         BIO *sigbio = BIO_new_file(sigfile, "rb");
396 
397         if (sigbio == NULL) {
398             BIO_printf(bio_err, "Error opening signature file %s\n", sigfile);
399             goto end;
400         }
401         siglen = EVP_PKEY_get_size(sigkey);
402         sigbuf = app_malloc(siglen, "signature buffer");
403         siglen = BIO_read(sigbio, sigbuf, siglen);
404         BIO_free(sigbio);
405         if (siglen <= 0) {
406             BIO_printf(bio_err, "Error reading signature file %s\n", sigfile);
407             goto end;
408         }
409     }
410     inp = BIO_push(bmd, in);
411 
412     if (md == NULL) {
413         EVP_MD_CTX *tctx;
414 
415         BIO_get_md_ctx(bmd, &tctx);
416         md = EVP_MD_CTX_get1_md(tctx);
417     }
418     if (md != NULL)
419         md_name = EVP_MD_get0_name(md);
420 
421     if (xoflen > 0) {
422         if (!EVP_MD_xof(md)) {
423             BIO_printf(bio_err, "Length can only be specified for XOF\n");
424             goto end;
425         }
426         /*
427          * Signing using XOF is not supported by any algorithms currently since
428          * each algorithm only calls EVP_DigestFinal_ex() in their sign_final
429          * and verify_final methods.
430          */
431         if (sigkey != NULL) {
432             BIO_printf(bio_err, "Signing key cannot be specified for XOF\n");
433             goto end;
434         }
435     }
436 
437     if (argc == 0) {
438         BIO_set_fp(in, stdin, BIO_NOCLOSE);
439         ret = do_fp(out, buf, inp, separator, out_bin, xoflen, sigkey, sigbuf,
440                     siglen, NULL, md_name, "stdin");
441     } else {
442         const char *sig_name = NULL;
443 
444         if (out_bin == 0) {
445             if (sigkey != NULL)
446                 sig_name = EVP_PKEY_get0_type_name(sigkey);
447         }
448         ret = EXIT_SUCCESS;
449         for (i = 0; i < argc; i++) {
450             if (BIO_read_filename(in, argv[i]) <= 0) {
451                 perror(argv[i]);
452                 ret = EXIT_FAILURE;
453                 continue;
454             } else {
455                 if (do_fp(out, buf, inp, separator, out_bin, xoflen,
456                           sigkey, sigbuf, siglen, sig_name, md_name, argv[i]))
457                     ret = EXIT_FAILURE;
458             }
459             (void)BIO_reset(bmd);
460         }
461     }
462  end:
463     if (ret != EXIT_SUCCESS)
464         ERR_print_errors(bio_err);
465     OPENSSL_clear_free(buf, BUFSIZE);
466     BIO_free(in);
467     OPENSSL_free(passin);
468     BIO_free_all(out);
469     EVP_MD_free(md);
470     EVP_PKEY_free(sigkey);
471     sk_OPENSSL_STRING_free(sigopts);
472     sk_OPENSSL_STRING_free(macopts);
473     OPENSSL_free(sigbuf);
474     BIO_free(bmd);
475     release_engine(e);
476     return ret;
477 }
478 
show_digests(const OBJ_NAME * name,void * arg)479 static void show_digests(const OBJ_NAME *name, void *arg)
480 {
481     struct doall_dgst_digests *dec = (struct doall_dgst_digests *)arg;
482     EVP_MD *md = NULL;
483 
484     /* Filter out signed digests (a.k.a signature algorithms) */
485     if (strstr(name->name, "rsa") != NULL || strstr(name->name, "RSA") != NULL)
486         return;
487 
488     if (!islower((unsigned char)*name->name))
489         return;
490 
491     /* Filter out message digests that we cannot use */
492     md = EVP_MD_fetch(app_get0_libctx(), name->name, app_get0_propq());
493     if (md == NULL) {
494         if (EVP_get_digestbyname(name->name) == NULL)
495             return;
496     }
497 
498     BIO_printf(dec->bio, "-%-25s", name->name);
499     if (++dec->n == 3) {
500         BIO_printf(dec->bio, "\n");
501         dec->n = 0;
502     } else {
503         BIO_printf(dec->bio, " ");
504     }
505 
506     EVP_MD_free(md);
507 }
508 
509 /*
510  * The newline_escape_filename function performs newline escaping for any
511  * filename that contains a newline.  This function also takes a pointer
512  * to backslash. The backslash pointer is a flag to indicating whether a newline
513  * is present in the filename.  If a newline is present, the backslash flag is
514  * set and the output format will contain a backslash at the beginning of the
515  * digest output. This output format is to replicate the output format found
516  * in the '*sum' checksum programs. This aims to preserve backward
517  * compatibility.
518  */
newline_escape_filename(const char * file,int * backslash)519 static const char *newline_escape_filename(const char *file, int *backslash)
520 {
521     size_t i, e = 0, length = strlen(file), newline_count = 0, mem_len = 0;
522     char *file_cpy = NULL;
523 
524     for (i = 0; i < length; i++)
525         if (file[i] == '\n')
526             newline_count++;
527 
528     mem_len = length + newline_count + 1;
529     file_cpy = app_malloc(mem_len, file);
530     i = 0;
531 
532     while (e < length) {
533         const char c = file[e];
534         if (c == '\n') {
535             file_cpy[i++] = '\\';
536             file_cpy[i++] = 'n';
537             *backslash = 1;
538         } else {
539             file_cpy[i++] = c;
540         }
541         e++;
542     }
543     file_cpy[i] = '\0';
544     return (const char*)file_cpy;
545 }
546 
547 
do_fp(BIO * out,unsigned char * buf,BIO * bp,int sep,int binout,int xoflen,EVP_PKEY * key,unsigned char * sigin,int siglen,const char * sig_name,const char * md_name,const char * file)548 int do_fp(BIO *out, unsigned char *buf, BIO *bp, int sep, int binout, int xoflen,
549           EVP_PKEY *key, unsigned char *sigin, int siglen,
550           const char *sig_name, const char *md_name,
551           const char *file)
552 {
553     size_t len = BUFSIZE;
554     int i, backslash = 0, ret = EXIT_FAILURE;
555     unsigned char *allocated_buf = NULL;
556 
557     while (BIO_pending(bp) || !BIO_eof(bp)) {
558         i = BIO_read(bp, (char *)buf, BUFSIZE);
559         if (i < 0) {
560             BIO_printf(bio_err, "Read error in %s\n", file);
561             goto end;
562         }
563         if (i == 0)
564             break;
565     }
566     if (sigin != NULL) {
567         EVP_MD_CTX *ctx;
568         BIO_get_md_ctx(bp, &ctx);
569         i = EVP_DigestVerifyFinal(ctx, sigin, (unsigned int)siglen);
570         if (i > 0) {
571             BIO_printf(out, "Verified OK\n");
572         } else if (i == 0) {
573             BIO_printf(out, "Verification failure\n");
574             goto end;
575         } else {
576             BIO_printf(bio_err, "Error verifying data\n");
577             goto end;
578         }
579         ret = EXIT_SUCCESS;
580         goto end;
581     }
582     if (key != NULL) {
583         EVP_MD_CTX *ctx;
584         size_t tmplen;
585 
586         BIO_get_md_ctx(bp, &ctx);
587         if (!EVP_DigestSignFinal(ctx, NULL, &tmplen)) {
588             BIO_printf(bio_err, "Error getting maximum length of signed data\n");
589             goto end;
590         }
591         if (tmplen > BUFSIZE) {
592             len = tmplen;
593             allocated_buf = app_malloc(len, "Signature buffer");
594             buf = allocated_buf;
595         }
596         if (!EVP_DigestSignFinal(ctx, buf, &len)) {
597             BIO_printf(bio_err, "Error signing data\n");
598             goto end;
599         }
600     } else if (xoflen > 0) {
601         EVP_MD_CTX *ctx;
602 
603         len = xoflen;
604         if (len > BUFSIZE) {
605             allocated_buf = app_malloc(len, "Digest buffer");
606             buf = allocated_buf;
607         }
608 
609         BIO_get_md_ctx(bp, &ctx);
610 
611         if (!EVP_DigestFinalXOF(ctx, buf, len)) {
612             BIO_printf(bio_err, "Error Digesting Data\n");
613             goto end;
614         }
615     } else {
616         len = BIO_gets(bp, (char *)buf, BUFSIZE);
617         if ((int)len < 0)
618             goto end;
619     }
620 
621     if (binout) {
622         BIO_write(out, buf, len);
623     } else if (sep == 2) {
624         file = newline_escape_filename(file, &backslash);
625 
626         if (backslash == 1)
627             BIO_puts(out, "\\");
628 
629         for (i = 0; i < (int)len; i++)
630             BIO_printf(out, "%02x", buf[i]);
631 
632         BIO_printf(out, " *%s\n", file);
633         OPENSSL_free((char *)file);
634     } else {
635         if (sig_name != NULL) {
636             BIO_puts(out, sig_name);
637             if (md_name != NULL)
638                 BIO_printf(out, "-%s", md_name);
639             BIO_printf(out, "(%s)= ", file);
640         } else if (md_name != NULL) {
641             BIO_printf(out, "%s(%s)= ", md_name, file);
642         } else {
643             BIO_printf(out, "(%s)= ", file);
644         }
645         for (i = 0; i < (int)len; i++) {
646             if (sep && (i != 0))
647                 BIO_printf(out, ":");
648             BIO_printf(out, "%02x", buf[i]);
649         }
650         BIO_printf(out, "\n");
651     }
652 
653     ret = EXIT_SUCCESS;
654  end:
655     if (allocated_buf != NULL)
656         OPENSSL_clear_free(allocated_buf, len);
657 
658     return ret;
659 }
660