1 /*
2  * validator/val_secalgo.c - validator security algorithm functions.
3  *
4  * Copyright (c) 2012, NLnet Labs. All rights reserved.
5  *
6  * This software is open source.
7  *
8  * Redistribution and use in source and binary forms, with or without
9  * modification, are permitted provided that the following conditions
10  * are met:
11  *
12  * Redistributions of source code must retain the above copyright notice,
13  * this list of conditions and the following disclaimer.
14  *
15  * Redistributions in binary form must reproduce the above copyright notice,
16  * this list of conditions and the following disclaimer in the documentation
17  * and/or other materials provided with the distribution.
18  *
19  * Neither the name of the NLNET LABS nor the names of its contributors may
20  * be used to endorse or promote products derived from this software without
21  * specific prior written permission.
22  *
23  * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
24  * "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT
25  * LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR
26  * A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT
27  * HOLDER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL,
28  * SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED
29  * TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR
30  * PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF
31  * LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING
32  * NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF THIS
33  * SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
34  */
35 
36 /**
37  * \file
38  *
39  * This file contains helper functions for the validator module.
40  * These functions take raw data buffers, formatted for crypto verification,
41  * and do the library calls (for the crypto library in use).
42  */
43 #include "config.h"
44 /* packed_rrset on top to define enum types (forced by c99 standard) */
45 #include "util/data/packed_rrset.h"
46 #include "validator/val_secalgo.h"
47 #include "validator/val_nsec3.h"
48 #include "util/log.h"
49 #include "sldns/rrdef.h"
50 #include "sldns/keyraw.h"
51 #include "sldns/sbuffer.h"
52 
53 #if !defined(HAVE_SSL) && !defined(HAVE_NSS) && !defined(HAVE_NETTLE)
54 #error "Need crypto library to do digital signature cryptography"
55 #endif
56 
57 /* OpenSSL implementation */
58 #ifdef HAVE_SSL
59 #ifdef HAVE_OPENSSL_ERR_H
60 #include <openssl/err.h>
61 #endif
62 
63 #ifdef HAVE_OPENSSL_RAND_H
64 #include <openssl/rand.h>
65 #endif
66 
67 #ifdef HAVE_OPENSSL_CONF_H
68 #include <openssl/conf.h>
69 #endif
70 
71 #ifdef HAVE_OPENSSL_ENGINE_H
72 #include <openssl/engine.h>
73 #endif
74 
75 /** fake DSA support for unit tests */
76 int fake_dsa = 0;
77 /** fake SHA1 support for unit tests */
78 int fake_sha1 = 0;
79 
80 /**
81  * Output a libcrypto openssl error to the logfile.
82  * @param str: string to add to it.
83  * @param e: the error to output, error number from ERR_get_error().
84  */
85 static void
86 log_crypto_error(const char* str, unsigned long e)
87 {
88 	char buf[128];
89 	/* or use ERR_error_string if ERR_error_string_n is not avail TODO */
90 	ERR_error_string_n(e, buf, sizeof(buf));
91 	/* buf now contains */
92 	/* error:[error code]:[library name]:[function name]:[reason string] */
93 	log_err("%s crypto %s", str, buf);
94 }
95 
96 /* return size of digest if supported, or 0 otherwise */
97 size_t
98 nsec3_hash_algo_size_supported(int id)
99 {
100 	switch(id) {
101 	case NSEC3_HASH_SHA1:
102 		return SHA_DIGEST_LENGTH;
103 	default:
104 		return 0;
105 	}
106 }
107 
108 /* perform nsec3 hash. return false on failure */
109 int
110 secalgo_nsec3_hash(int algo, unsigned char* buf, size_t len,
111         unsigned char* res)
112 {
113 	switch(algo) {
114 	case NSEC3_HASH_SHA1:
115 #ifdef OPENSSL_FIPS
116 		if(!sldns_digest_evp(buf, len, res, EVP_sha1()))
117 			log_crypto_error("could not digest with EVP_sha1",
118 				ERR_get_error());
119 #else
120 		(void)SHA1(buf, len, res);
121 #endif
122 		return 1;
123 	default:
124 		return 0;
125 	}
126 }
127 
128 void
129 secalgo_hash_sha256(unsigned char* buf, size_t len, unsigned char* res)
130 {
131 #ifdef OPENSSL_FIPS
132 	if(!sldns_digest_evp(buf, len, res, EVP_sha256()))
133 		log_crypto_error("could not digest with EVP_sha256",
134 			ERR_get_error());
135 #else
136 	(void)SHA256(buf, len, res);
137 #endif
138 }
139 
140 /**
141  * Return size of DS digest according to its hash algorithm.
142  * @param algo: DS digest algo.
143  * @return size in bytes of digest, or 0 if not supported.
144  */
145 size_t
146 ds_digest_size_supported(int algo)
147 {
148 	switch(algo) {
149 		case LDNS_SHA1:
150 #if defined(HAVE_EVP_SHA1) && defined(USE_SHA1)
151 			return SHA_DIGEST_LENGTH;
152 #else
153 			if(fake_sha1) return 20;
154 			return 0;
155 #endif
156 #ifdef HAVE_EVP_SHA256
157 		case LDNS_SHA256:
158 			return SHA256_DIGEST_LENGTH;
159 #endif
160 #ifdef USE_GOST
161 		case LDNS_HASH_GOST:
162 			/* we support GOST if it can be loaded */
163 			(void)sldns_key_EVP_load_gost_id();
164 			if(EVP_get_digestbyname("md_gost94"))
165 				return 32;
166 			else	return 0;
167 #endif
168 #ifdef USE_ECDSA
169 		case LDNS_SHA384:
170 			return SHA384_DIGEST_LENGTH;
171 #endif
172 		default: break;
173 	}
174 	return 0;
175 }
176 
177 #ifdef USE_GOST
178 /** Perform GOST hash */
179 static int
180 do_gost94(unsigned char* data, size_t len, unsigned char* dest)
181 {
182 	const EVP_MD* md = EVP_get_digestbyname("md_gost94");
183 	if(!md)
184 		return 0;
185 	return sldns_digest_evp(data, (unsigned int)len, dest, md);
186 }
187 #endif
188 
189 int
190 secalgo_ds_digest(int algo, unsigned char* buf, size_t len,
191 	unsigned char* res)
192 {
193 	switch(algo) {
194 #if defined(HAVE_EVP_SHA1) && defined(USE_SHA1)
195 		case LDNS_SHA1:
196 #ifdef OPENSSL_FIPS
197 			if(!sldns_digest_evp(buf, len, res, EVP_sha1()))
198 				log_crypto_error("could not digest with EVP_sha1",
199 					ERR_get_error());
200 #else
201 			(void)SHA1(buf, len, res);
202 #endif
203 			return 1;
204 #endif
205 #ifdef HAVE_EVP_SHA256
206 		case LDNS_SHA256:
207 #ifdef OPENSSL_FIPS
208 			if(!sldns_digest_evp(buf, len, res, EVP_sha256()))
209 				log_crypto_error("could not digest with EVP_sha256",
210 					ERR_get_error());
211 #else
212 			(void)SHA256(buf, len, res);
213 #endif
214 			return 1;
215 #endif
216 #ifdef USE_GOST
217 		case LDNS_HASH_GOST:
218 			if(do_gost94(buf, len, res))
219 				return 1;
220 			break;
221 #endif
222 #ifdef USE_ECDSA
223 		case LDNS_SHA384:
224 #ifdef OPENSSL_FIPS
225 			if(!sldns_digest_evp(buf, len, res, EVP_sha384()))
226 				log_crypto_error("could not digest with EVP_sha384",
227 					ERR_get_error());
228 #else
229 			(void)SHA384(buf, len, res);
230 #endif
231 			return 1;
232 #endif
233 		default:
234 			verbose(VERB_QUERY, "unknown DS digest algorithm %d",
235 				algo);
236 			break;
237 	}
238 	return 0;
239 }
240 
241 /** return true if DNSKEY algorithm id is supported */
242 int
243 dnskey_algo_id_is_supported(int id)
244 {
245 	switch(id) {
246 	case LDNS_RSAMD5:
247 		/* RFC 6725 deprecates RSAMD5 */
248 		return 0;
249 	case LDNS_DSA:
250 	case LDNS_DSA_NSEC3:
251 #if defined(USE_DSA) && defined(USE_SHA1)
252 		return 1;
253 #else
254 		if(fake_dsa || fake_sha1) return 1;
255 		return 0;
256 #endif
257 
258 	case LDNS_RSASHA1:
259 	case LDNS_RSASHA1_NSEC3:
260 #ifdef USE_SHA1
261 		return 1;
262 #else
263 		if(fake_sha1) return 1;
264 		return 0;
265 #endif
266 
267 #if defined(HAVE_EVP_SHA256) && defined(USE_SHA2)
268 	case LDNS_RSASHA256:
269 #endif
270 #if defined(HAVE_EVP_SHA512) && defined(USE_SHA2)
271 	case LDNS_RSASHA512:
272 #endif
273 #ifdef USE_ECDSA
274 	case LDNS_ECDSAP256SHA256:
275 	case LDNS_ECDSAP384SHA384:
276 #endif
277 #ifdef USE_ED25519
278 	case LDNS_ED25519:
279 #endif
280 #ifdef USE_ED448
281 	case LDNS_ED448:
282 #endif
283 #if (defined(HAVE_EVP_SHA256) && defined(USE_SHA2)) || (defined(HAVE_EVP_SHA512) && defined(USE_SHA2)) || defined(USE_ECDSA) || defined(USE_ED25519) || defined(USE_ED448)
284 		return 1;
285 #endif
286 
287 #ifdef USE_GOST
288 	case LDNS_ECC_GOST:
289 		/* we support GOST if it can be loaded */
290 		return sldns_key_EVP_load_gost_id();
291 #endif
292 	default:
293 		return 0;
294 	}
295 }
296 
297 #ifdef USE_DSA
298 /**
299  * Setup DSA key digest in DER encoding ...
300  * @param sig: input is signature output alloced ptr (unless failure).
301  * 	caller must free alloced ptr if this routine returns true.
302  * @param len: input is initial siglen, output is output len.
303  * @return false on failure.
304  */
305 static int
306 setup_dsa_sig(unsigned char** sig, unsigned int* len)
307 {
308 	unsigned char* orig = *sig;
309 	unsigned int origlen = *len;
310 	int newlen;
311 	BIGNUM *R, *S;
312 	DSA_SIG *dsasig;
313 
314 	/* extract the R and S field from the sig buffer */
315 	if(origlen < 1 + 2*SHA_DIGEST_LENGTH)
316 		return 0;
317 	R = BN_new();
318 	if(!R) return 0;
319 	(void) BN_bin2bn(orig + 1, SHA_DIGEST_LENGTH, R);
320 	S = BN_new();
321 	if(!S) return 0;
322 	(void) BN_bin2bn(orig + 21, SHA_DIGEST_LENGTH, S);
323 	dsasig = DSA_SIG_new();
324 	if(!dsasig) return 0;
325 
326 #ifdef HAVE_DSA_SIG_SET0
327 	if(!DSA_SIG_set0(dsasig, R, S)) return 0;
328 #else
329 #  ifndef S_SPLINT_S
330 	dsasig->r = R;
331 	dsasig->s = S;
332 #  endif /* S_SPLINT_S */
333 #endif
334 	*sig = NULL;
335 	newlen = i2d_DSA_SIG(dsasig, sig);
336 	if(newlen < 0) {
337 		DSA_SIG_free(dsasig);
338 		free(*sig);
339 		return 0;
340 	}
341 	*len = (unsigned int)newlen;
342 	DSA_SIG_free(dsasig);
343 	return 1;
344 }
345 #endif /* USE_DSA */
346 
347 #ifdef USE_ECDSA
348 /**
349  * Setup the ECDSA signature in its encoding that the library wants.
350  * Converts from plain numbers to ASN formatted.
351  * @param sig: input is signature, output alloced ptr (unless failure).
352  * 	caller must free alloced ptr if this routine returns true.
353  * @param len: input is initial siglen, output is output len.
354  * @return false on failure.
355  */
356 static int
357 setup_ecdsa_sig(unsigned char** sig, unsigned int* len)
358 {
359         /* convert from two BIGNUMs in the rdata buffer, to ASN notation.
360 	 * ASN preamble: 30440220 <R 32bytefor256> 0220 <S 32bytefor256>
361 	 * the '20' is the length of that field (=bnsize).
362 i	 * the '44' is the total remaining length.
363 	 * if negative, start with leading zero.
364 	 * if starts with 00s, remove them from the number.
365 	 */
366         uint8_t pre[] = {0x30, 0x44, 0x02, 0x20};
367         int pre_len = 4;
368         uint8_t mid[] = {0x02, 0x20};
369         int mid_len = 2;
370         int raw_sig_len, r_high, s_high, r_rem=0, s_rem=0;
371 	int bnsize = (int)((*len)/2);
372         unsigned char* d = *sig;
373 	uint8_t* p;
374 	/* if too short or not even length, fails */
375 	if(*len < 16 || bnsize*2 != (int)*len)
376 		return 0;
377 
378         /* strip leading zeroes from r (but not last one) */
379         while(r_rem < bnsize-1 && d[r_rem] == 0)
380                 r_rem++;
381         /* strip leading zeroes from s (but not last one) */
382         while(s_rem < bnsize-1 && d[bnsize+s_rem] == 0)
383                 s_rem++;
384 
385         r_high = ((d[0+r_rem]&0x80)?1:0);
386         s_high = ((d[bnsize+s_rem]&0x80)?1:0);
387         raw_sig_len = pre_len + r_high + bnsize - r_rem + mid_len +
388                 s_high + bnsize - s_rem;
389 	*sig = (unsigned char*)malloc((size_t)raw_sig_len);
390 	if(!*sig)
391 		return 0;
392 	p = (uint8_t*)*sig;
393 	p[0] = pre[0];
394 	p[1] = (uint8_t)(raw_sig_len-2);
395 	p[2] = pre[2];
396 	p[3] = (uint8_t)(bnsize + r_high - r_rem);
397 	p += 4;
398 	if(r_high) {
399 		*p = 0;
400 		p += 1;
401 	}
402 	memmove(p, d+r_rem, (size_t)bnsize-r_rem);
403 	p += bnsize-r_rem;
404 	memmove(p, mid, (size_t)mid_len-1);
405 	p += mid_len-1;
406 	*p = (uint8_t)(bnsize + s_high - s_rem);
407 	p += 1;
408         if(s_high) {
409 		*p = 0;
410 		p += 1;
411 	}
412 	memmove(p, d+bnsize+s_rem, (size_t)bnsize-s_rem);
413 	*len = (unsigned int)raw_sig_len;
414 	return 1;
415 }
416 #endif /* USE_ECDSA */
417 
418 #ifdef USE_ECDSA_EVP_WORKAROUND
419 static EVP_MD ecdsa_evp_256_md;
420 static EVP_MD ecdsa_evp_384_md;
421 void ecdsa_evp_workaround_init(void)
422 {
423 	/* openssl before 1.0.0 fixes RSA with the SHA256
424 	 * hash in EVP.  We create one for ecdsa_sha256 */
425 	ecdsa_evp_256_md = *EVP_sha256();
426 	ecdsa_evp_256_md.required_pkey_type[0] = EVP_PKEY_EC;
427 	ecdsa_evp_256_md.verify = (void*)ECDSA_verify;
428 
429 	ecdsa_evp_384_md = *EVP_sha384();
430 	ecdsa_evp_384_md.required_pkey_type[0] = EVP_PKEY_EC;
431 	ecdsa_evp_384_md.verify = (void*)ECDSA_verify;
432 }
433 #endif /* USE_ECDSA_EVP_WORKAROUND */
434 
435 /**
436  * Setup key and digest for verification. Adjust sig if necessary.
437  *
438  * @param algo: key algorithm
439  * @param evp_key: EVP PKEY public key to create.
440  * @param digest_type: digest type to use
441  * @param key: key to setup for.
442  * @param keylen: length of key.
443  * @return false on failure.
444  */
445 static int
446 setup_key_digest(int algo, EVP_PKEY** evp_key, const EVP_MD** digest_type,
447 	unsigned char* key, size_t keylen)
448 {
449 #if defined(USE_DSA) && defined(USE_SHA1)
450 	DSA* dsa;
451 #endif
452 	RSA* rsa;
453 
454 	switch(algo) {
455 #if defined(USE_DSA) && defined(USE_SHA1)
456 		case LDNS_DSA:
457 		case LDNS_DSA_NSEC3:
458 			*evp_key = EVP_PKEY_new();
459 			if(!*evp_key) {
460 				log_err("verify: malloc failure in crypto");
461 				return 0;
462 			}
463 			dsa = sldns_key_buf2dsa_raw(key, keylen);
464 			if(!dsa) {
465 				verbose(VERB_QUERY, "verify: "
466 					"sldns_key_buf2dsa_raw failed");
467 				return 0;
468 			}
469 			if(EVP_PKEY_assign_DSA(*evp_key, dsa) == 0) {
470 				verbose(VERB_QUERY, "verify: "
471 					"EVP_PKEY_assign_DSA failed");
472 				return 0;
473 			}
474 #ifdef HAVE_EVP_DSS1
475 			*digest_type = EVP_dss1();
476 #else
477 			*digest_type = EVP_sha1();
478 #endif
479 
480 			break;
481 #endif /* USE_DSA && USE_SHA1 */
482 
483 #if defined(USE_SHA1) || (defined(HAVE_EVP_SHA256) && defined(USE_SHA2)) || (defined(HAVE_EVP_SHA512) && defined(USE_SHA2))
484 #ifdef USE_SHA1
485 		case LDNS_RSASHA1:
486 		case LDNS_RSASHA1_NSEC3:
487 #endif
488 #if defined(HAVE_EVP_SHA256) && defined(USE_SHA2)
489 		case LDNS_RSASHA256:
490 #endif
491 #if defined(HAVE_EVP_SHA512) && defined(USE_SHA2)
492 		case LDNS_RSASHA512:
493 #endif
494 			*evp_key = EVP_PKEY_new();
495 			if(!*evp_key) {
496 				log_err("verify: malloc failure in crypto");
497 				return 0;
498 			}
499 			rsa = sldns_key_buf2rsa_raw(key, keylen);
500 			if(!rsa) {
501 				verbose(VERB_QUERY, "verify: "
502 					"sldns_key_buf2rsa_raw SHA failed");
503 				return 0;
504 			}
505 			if(EVP_PKEY_assign_RSA(*evp_key, rsa) == 0) {
506 				verbose(VERB_QUERY, "verify: "
507 					"EVP_PKEY_assign_RSA SHA failed");
508 				return 0;
509 			}
510 
511 			/* select SHA version */
512 #if defined(HAVE_EVP_SHA256) && defined(USE_SHA2)
513 			if(algo == LDNS_RSASHA256)
514 				*digest_type = EVP_sha256();
515 			else
516 #endif
517 #if defined(HAVE_EVP_SHA512) && defined(USE_SHA2)
518 				if(algo == LDNS_RSASHA512)
519 				*digest_type = EVP_sha512();
520 			else
521 #endif
522 #ifdef USE_SHA1
523 				*digest_type = EVP_sha1();
524 #else
525 				{ verbose(VERB_QUERY, "no digest available"); return 0; }
526 #endif
527 			break;
528 #endif /* defined(USE_SHA1) || (defined(HAVE_EVP_SHA256) && defined(USE_SHA2)) || (defined(HAVE_EVP_SHA512) && defined(USE_SHA2)) */
529 
530 		case LDNS_RSAMD5:
531 			*evp_key = EVP_PKEY_new();
532 			if(!*evp_key) {
533 				log_err("verify: malloc failure in crypto");
534 				return 0;
535 			}
536 			rsa = sldns_key_buf2rsa_raw(key, keylen);
537 			if(!rsa) {
538 				verbose(VERB_QUERY, "verify: "
539 					"sldns_key_buf2rsa_raw MD5 failed");
540 				return 0;
541 			}
542 			if(EVP_PKEY_assign_RSA(*evp_key, rsa) == 0) {
543 				verbose(VERB_QUERY, "verify: "
544 					"EVP_PKEY_assign_RSA MD5 failed");
545 				return 0;
546 			}
547 			*digest_type = EVP_md5();
548 
549 			break;
550 #ifdef USE_GOST
551 		case LDNS_ECC_GOST:
552 			*evp_key = sldns_gost2pkey_raw(key, keylen);
553 			if(!*evp_key) {
554 				verbose(VERB_QUERY, "verify: "
555 					"sldns_gost2pkey_raw failed");
556 				return 0;
557 			}
558 			*digest_type = EVP_get_digestbyname("md_gost94");
559 			if(!*digest_type) {
560 				verbose(VERB_QUERY, "verify: "
561 					"EVP_getdigest md_gost94 failed");
562 				return 0;
563 			}
564 			break;
565 #endif
566 #ifdef USE_ECDSA
567 		case LDNS_ECDSAP256SHA256:
568 			*evp_key = sldns_ecdsa2pkey_raw(key, keylen,
569 				LDNS_ECDSAP256SHA256);
570 			if(!*evp_key) {
571 				verbose(VERB_QUERY, "verify: "
572 					"sldns_ecdsa2pkey_raw failed");
573 				return 0;
574 			}
575 #ifdef USE_ECDSA_EVP_WORKAROUND
576 			*digest_type = &ecdsa_evp_256_md;
577 #else
578 			*digest_type = EVP_sha256();
579 #endif
580 			break;
581 		case LDNS_ECDSAP384SHA384:
582 			*evp_key = sldns_ecdsa2pkey_raw(key, keylen,
583 				LDNS_ECDSAP384SHA384);
584 			if(!*evp_key) {
585 				verbose(VERB_QUERY, "verify: "
586 					"sldns_ecdsa2pkey_raw failed");
587 				return 0;
588 			}
589 #ifdef USE_ECDSA_EVP_WORKAROUND
590 			*digest_type = &ecdsa_evp_384_md;
591 #else
592 			*digest_type = EVP_sha384();
593 #endif
594 			break;
595 #endif /* USE_ECDSA */
596 #ifdef USE_ED25519
597 		case LDNS_ED25519:
598 			*evp_key = sldns_ed255192pkey_raw(key, keylen);
599 			if(!*evp_key) {
600 				verbose(VERB_QUERY, "verify: "
601 					"sldns_ed255192pkey_raw failed");
602 				return 0;
603 			}
604 			*digest_type = NULL;
605 			break;
606 #endif /* USE_ED25519 */
607 #ifdef USE_ED448
608 		case LDNS_ED448:
609 			*evp_key = sldns_ed4482pkey_raw(key, keylen);
610 			if(!*evp_key) {
611 				verbose(VERB_QUERY, "verify: "
612 					"sldns_ed4482pkey_raw failed");
613 				return 0;
614 			}
615 			*digest_type = NULL;
616 			break;
617 #endif /* USE_ED448 */
618 		default:
619 			verbose(VERB_QUERY, "verify: unknown algorithm %d",
620 				algo);
621 			return 0;
622 	}
623 	return 1;
624 }
625 
626 /**
627  * Check a canonical sig+rrset and signature against a dnskey
628  * @param buf: buffer with data to verify, the first rrsig part and the
629  *	canonicalized rrset.
630  * @param algo: DNSKEY algorithm.
631  * @param sigblock: signature rdata field from RRSIG
632  * @param sigblock_len: length of sigblock data.
633  * @param key: public key data from DNSKEY RR.
634  * @param keylen: length of keydata.
635  * @param reason: bogus reason in more detail.
636  * @return secure if verification succeeded, bogus on crypto failure,
637  *	unchecked on format errors and alloc failures.
638  */
639 enum sec_status
640 verify_canonrrset(sldns_buffer* buf, int algo, unsigned char* sigblock,
641 	unsigned int sigblock_len, unsigned char* key, unsigned int keylen,
642 	char** reason)
643 {
644 	const EVP_MD *digest_type;
645 	EVP_MD_CTX* ctx;
646 	int res, dofree = 0, docrypto_free = 0;
647 	EVP_PKEY *evp_key = NULL;
648 
649 #ifndef USE_DSA
650 	if((algo == LDNS_DSA || algo == LDNS_DSA_NSEC3) &&(fake_dsa||fake_sha1))
651 		return sec_status_secure;
652 #endif
653 #ifndef USE_SHA1
654 	if(fake_sha1 && (algo == LDNS_DSA || algo == LDNS_DSA_NSEC3 || algo == LDNS_RSASHA1 || algo == LDNS_RSASHA1_NSEC3))
655 		return sec_status_secure;
656 #endif
657 
658 	if(!setup_key_digest(algo, &evp_key, &digest_type, key, keylen)) {
659 		verbose(VERB_QUERY, "verify: failed to setup key");
660 		*reason = "use of key for crypto failed";
661 		EVP_PKEY_free(evp_key);
662 		return sec_status_bogus;
663 	}
664 #ifdef USE_DSA
665 	/* if it is a DSA signature in bind format, convert to DER format */
666 	if((algo == LDNS_DSA || algo == LDNS_DSA_NSEC3) &&
667 		sigblock_len == 1+2*SHA_DIGEST_LENGTH) {
668 		if(!setup_dsa_sig(&sigblock, &sigblock_len)) {
669 			verbose(VERB_QUERY, "verify: failed to setup DSA sig");
670 			*reason = "use of key for DSA crypto failed";
671 			EVP_PKEY_free(evp_key);
672 			return sec_status_bogus;
673 		}
674 		docrypto_free = 1;
675 	}
676 #endif
677 #if defined(USE_ECDSA) && defined(USE_DSA)
678 	else
679 #endif
680 #ifdef USE_ECDSA
681 	if(algo == LDNS_ECDSAP256SHA256 || algo == LDNS_ECDSAP384SHA384) {
682 		/* EVP uses ASN prefix on sig, which is not in the wire data */
683 		if(!setup_ecdsa_sig(&sigblock, &sigblock_len)) {
684 			verbose(VERB_QUERY, "verify: failed to setup ECDSA sig");
685 			*reason = "use of signature for ECDSA crypto failed";
686 			EVP_PKEY_free(evp_key);
687 			return sec_status_bogus;
688 		}
689 		dofree = 1;
690 	}
691 #endif /* USE_ECDSA */
692 
693 	/* do the signature cryptography work */
694 #ifdef HAVE_EVP_MD_CTX_NEW
695 	ctx = EVP_MD_CTX_new();
696 #else
697 	ctx = (EVP_MD_CTX*)malloc(sizeof(*ctx));
698 	if(ctx) EVP_MD_CTX_init(ctx);
699 #endif
700 	if(!ctx) {
701 		log_err("EVP_MD_CTX_new: malloc failure");
702 		EVP_PKEY_free(evp_key);
703 		if(dofree) free(sigblock);
704 		else if(docrypto_free) OPENSSL_free(sigblock);
705 		return sec_status_unchecked;
706 	}
707 #ifndef HAVE_EVP_DIGESTVERIFY
708 	if(EVP_DigestInit(ctx, digest_type) == 0) {
709 		verbose(VERB_QUERY, "verify: EVP_DigestInit failed");
710 #ifdef HAVE_EVP_MD_CTX_NEW
711 		EVP_MD_CTX_destroy(ctx);
712 #else
713 		EVP_MD_CTX_cleanup(ctx);
714 		free(ctx);
715 #endif
716 		EVP_PKEY_free(evp_key);
717 		if(dofree) free(sigblock);
718 		else if(docrypto_free) OPENSSL_free(sigblock);
719 		return sec_status_unchecked;
720 	}
721 	if(EVP_DigestUpdate(ctx, (unsigned char*)sldns_buffer_begin(buf),
722 		(unsigned int)sldns_buffer_limit(buf)) == 0) {
723 		verbose(VERB_QUERY, "verify: EVP_DigestUpdate failed");
724 #ifdef HAVE_EVP_MD_CTX_NEW
725 		EVP_MD_CTX_destroy(ctx);
726 #else
727 		EVP_MD_CTX_cleanup(ctx);
728 		free(ctx);
729 #endif
730 		EVP_PKEY_free(evp_key);
731 		if(dofree) free(sigblock);
732 		else if(docrypto_free) OPENSSL_free(sigblock);
733 		return sec_status_unchecked;
734 	}
735 
736 	res = EVP_VerifyFinal(ctx, sigblock, sigblock_len, evp_key);
737 #else /* HAVE_EVP_DIGESTVERIFY */
738 	if(EVP_DigestVerifyInit(ctx, NULL, digest_type, NULL, evp_key) == 0) {
739 		verbose(VERB_QUERY, "verify: EVP_DigestVerifyInit failed");
740 #ifdef HAVE_EVP_MD_CTX_NEW
741 		EVP_MD_CTX_destroy(ctx);
742 #else
743 		EVP_MD_CTX_cleanup(ctx);
744 		free(ctx);
745 #endif
746 		EVP_PKEY_free(evp_key);
747 		if(dofree) free(sigblock);
748 		else if(docrypto_free) OPENSSL_free(sigblock);
749 		return sec_status_unchecked;
750 	}
751 	res = EVP_DigestVerify(ctx, sigblock, sigblock_len,
752 		(unsigned char*)sldns_buffer_begin(buf),
753 		sldns_buffer_limit(buf));
754 #endif
755 #ifdef HAVE_EVP_MD_CTX_NEW
756 	EVP_MD_CTX_destroy(ctx);
757 #else
758 	EVP_MD_CTX_cleanup(ctx);
759 	free(ctx);
760 #endif
761 	EVP_PKEY_free(evp_key);
762 
763 	if(dofree) free(sigblock);
764 	else if(docrypto_free) OPENSSL_free(sigblock);
765 
766 	if(res == 1) {
767 		return sec_status_secure;
768 	} else if(res == 0) {
769 		verbose(VERB_QUERY, "verify: signature mismatch");
770 		*reason = "signature crypto failed";
771 		return sec_status_bogus;
772 	}
773 
774 	log_crypto_error("verify:", ERR_get_error());
775 	return sec_status_unchecked;
776 }
777 
778 /**************************************************/
779 #elif defined(HAVE_NSS)
780 /* libnss implementation */
781 /* nss3 */
782 #include "sechash.h"
783 #include "pk11pub.h"
784 #include "keyhi.h"
785 #include "secerr.h"
786 #include "cryptohi.h"
787 /* nspr4 */
788 #include "prerror.h"
789 
790 /* return size of digest if supported, or 0 otherwise */
791 size_t
792 nsec3_hash_algo_size_supported(int id)
793 {
794 	switch(id) {
795 	case NSEC3_HASH_SHA1:
796 		return SHA1_LENGTH;
797 	default:
798 		return 0;
799 	}
800 }
801 
802 /* perform nsec3 hash. return false on failure */
803 int
804 secalgo_nsec3_hash(int algo, unsigned char* buf, size_t len,
805         unsigned char* res)
806 {
807 	switch(algo) {
808 	case NSEC3_HASH_SHA1:
809 		(void)HASH_HashBuf(HASH_AlgSHA1, res, buf, (unsigned long)len);
810 		return 1;
811 	default:
812 		return 0;
813 	}
814 }
815 
816 void
817 secalgo_hash_sha256(unsigned char* buf, size_t len, unsigned char* res)
818 {
819 	(void)HASH_HashBuf(HASH_AlgSHA256, res, buf, (unsigned long)len);
820 }
821 
822 size_t
823 ds_digest_size_supported(int algo)
824 {
825 	/* uses libNSS */
826 	switch(algo) {
827 #ifdef USE_SHA1
828 		case LDNS_SHA1:
829 			return SHA1_LENGTH;
830 #endif
831 #ifdef USE_SHA2
832 		case LDNS_SHA256:
833 			return SHA256_LENGTH;
834 #endif
835 #ifdef USE_ECDSA
836 		case LDNS_SHA384:
837 			return SHA384_LENGTH;
838 #endif
839 		/* GOST not supported in NSS */
840 		case LDNS_HASH_GOST:
841 		default: break;
842 	}
843 	return 0;
844 }
845 
846 int
847 secalgo_ds_digest(int algo, unsigned char* buf, size_t len,
848 	unsigned char* res)
849 {
850 	/* uses libNSS */
851 	switch(algo) {
852 #ifdef USE_SHA1
853 		case LDNS_SHA1:
854 			return HASH_HashBuf(HASH_AlgSHA1, res, buf, len)
855 				== SECSuccess;
856 #endif
857 #if defined(USE_SHA2)
858 		case LDNS_SHA256:
859 			return HASH_HashBuf(HASH_AlgSHA256, res, buf, len)
860 				== SECSuccess;
861 #endif
862 #ifdef USE_ECDSA
863 		case LDNS_SHA384:
864 			return HASH_HashBuf(HASH_AlgSHA384, res, buf, len)
865 				== SECSuccess;
866 #endif
867 		case LDNS_HASH_GOST:
868 		default:
869 			verbose(VERB_QUERY, "unknown DS digest algorithm %d",
870 				algo);
871 			break;
872 	}
873 	return 0;
874 }
875 
876 int
877 dnskey_algo_id_is_supported(int id)
878 {
879 	/* uses libNSS */
880 	switch(id) {
881 	case LDNS_RSAMD5:
882 		/* RFC 6725 deprecates RSAMD5 */
883 		return 0;
884 #if defined(USE_SHA1) || defined(USE_SHA2)
885 #if defined(USE_DSA) && defined(USE_SHA1)
886 	case LDNS_DSA:
887 	case LDNS_DSA_NSEC3:
888 #endif
889 #ifdef USE_SHA1
890 	case LDNS_RSASHA1:
891 	case LDNS_RSASHA1_NSEC3:
892 #endif
893 #ifdef USE_SHA2
894 	case LDNS_RSASHA256:
895 #endif
896 #ifdef USE_SHA2
897 	case LDNS_RSASHA512:
898 #endif
899 		return 1;
900 #endif /* SHA1 or SHA2 */
901 
902 #ifdef USE_ECDSA
903 	case LDNS_ECDSAP256SHA256:
904 	case LDNS_ECDSAP384SHA384:
905 		return PK11_TokenExists(CKM_ECDSA);
906 #endif
907 	case LDNS_ECC_GOST:
908 	default:
909 		return 0;
910 	}
911 }
912 
913 /* return a new public key for NSS */
914 static SECKEYPublicKey* nss_key_create(KeyType ktype)
915 {
916 	SECKEYPublicKey* key;
917 	PLArenaPool* arena = PORT_NewArena(DER_DEFAULT_CHUNKSIZE);
918 	if(!arena) {
919 		log_err("out of memory, PORT_NewArena failed");
920 		return NULL;
921 	}
922 	key = PORT_ArenaZNew(arena, SECKEYPublicKey);
923 	if(!key) {
924 		log_err("out of memory, PORT_ArenaZNew failed");
925 		PORT_FreeArena(arena, PR_FALSE);
926 		return NULL;
927 	}
928 	key->arena = arena;
929 	key->keyType = ktype;
930 	key->pkcs11Slot = NULL;
931 	key->pkcs11ID = CK_INVALID_HANDLE;
932 	return key;
933 }
934 
935 static SECKEYPublicKey* nss_buf2ecdsa(unsigned char* key, size_t len, int algo)
936 {
937 	SECKEYPublicKey* pk;
938 	SECItem pub = {siBuffer, NULL, 0};
939 	SECItem params = {siBuffer, NULL, 0};
940 	static unsigned char param256[] = {
941 		/* OBJECTIDENTIFIER 1.2.840.10045.3.1.7 (P-256)
942 		 * {iso(1) member-body(2) us(840) ansi-x962(10045) curves(3) prime(1) prime256v1(7)} */
943 		0x06, 0x08, 0x2a, 0x86, 0x48, 0xce, 0x3d, 0x03, 0x01, 0x07
944 	};
945 	static unsigned char param384[] = {
946 		/* OBJECTIDENTIFIER 1.3.132.0.34 (P-384)
947 		 * {iso(1) identified-organization(3) certicom(132) curve(0) ansip384r1(34)} */
948 		0x06, 0x05, 0x2b, 0x81, 0x04, 0x00, 0x22
949 	};
950 	unsigned char buf[256+2]; /* sufficient for 2*384/8+1 */
951 
952 	/* check length, which uncompressed must be 2 bignums */
953 	if(algo == LDNS_ECDSAP256SHA256) {
954 		if(len != 2*256/8) return NULL;
955 		/* ECCurve_X9_62_PRIME_256V1 */
956 	} else if(algo == LDNS_ECDSAP384SHA384) {
957 		if(len != 2*384/8) return NULL;
958 		/* ECCurve_X9_62_PRIME_384R1 */
959 	} else    return NULL;
960 
961 	buf[0] = 0x04; /* POINT_FORM_UNCOMPRESSED */
962 	memmove(buf+1, key, len);
963 	pub.data = buf;
964 	pub.len = len+1;
965 	if(algo == LDNS_ECDSAP256SHA256) {
966 		params.data = param256;
967 		params.len = sizeof(param256);
968 	} else {
969 		params.data = param384;
970 		params.len = sizeof(param384);
971 	}
972 
973 	pk = nss_key_create(ecKey);
974 	if(!pk)
975 		return NULL;
976 	pk->u.ec.size = (len/2)*8;
977 	if(SECITEM_CopyItem(pk->arena, &pk->u.ec.publicValue, &pub)) {
978 		SECKEY_DestroyPublicKey(pk);
979 		return NULL;
980 	}
981 	if(SECITEM_CopyItem(pk->arena, &pk->u.ec.DEREncodedParams, &params)) {
982 		SECKEY_DestroyPublicKey(pk);
983 		return NULL;
984 	}
985 
986 	return pk;
987 }
988 
989 static SECKEYPublicKey* nss_buf2dsa(unsigned char* key, size_t len)
990 {
991 	SECKEYPublicKey* pk;
992 	uint8_t T;
993 	uint16_t length;
994 	uint16_t offset;
995 	SECItem Q = {siBuffer, NULL, 0};
996 	SECItem P = {siBuffer, NULL, 0};
997 	SECItem G = {siBuffer, NULL, 0};
998 	SECItem Y = {siBuffer, NULL, 0};
999 
1000 	if(len == 0)
1001 		return NULL;
1002 	T = (uint8_t)key[0];
1003 	length = (64 + T * 8);
1004 	offset = 1;
1005 
1006 	if (T > 8) {
1007 		return NULL;
1008 	}
1009 	if(len < (size_t)1 + SHA1_LENGTH + 3*length)
1010 		return NULL;
1011 
1012 	Q.data = key+offset;
1013 	Q.len = SHA1_LENGTH;
1014 	offset += SHA1_LENGTH;
1015 
1016 	P.data = key+offset;
1017 	P.len = length;
1018 	offset += length;
1019 
1020 	G.data = key+offset;
1021 	G.len = length;
1022 	offset += length;
1023 
1024 	Y.data = key+offset;
1025 	Y.len = length;
1026 	offset += length;
1027 
1028 	pk = nss_key_create(dsaKey);
1029 	if(!pk)
1030 		return NULL;
1031 	if(SECITEM_CopyItem(pk->arena, &pk->u.dsa.params.prime, &P)) {
1032 		SECKEY_DestroyPublicKey(pk);
1033 		return NULL;
1034 	}
1035 	if(SECITEM_CopyItem(pk->arena, &pk->u.dsa.params.subPrime, &Q)) {
1036 		SECKEY_DestroyPublicKey(pk);
1037 		return NULL;
1038 	}
1039 	if(SECITEM_CopyItem(pk->arena, &pk->u.dsa.params.base, &G)) {
1040 		SECKEY_DestroyPublicKey(pk);
1041 		return NULL;
1042 	}
1043 	if(SECITEM_CopyItem(pk->arena, &pk->u.dsa.publicValue, &Y)) {
1044 		SECKEY_DestroyPublicKey(pk);
1045 		return NULL;
1046 	}
1047 	return pk;
1048 }
1049 
1050 static SECKEYPublicKey* nss_buf2rsa(unsigned char* key, size_t len)
1051 {
1052 	SECKEYPublicKey* pk;
1053 	uint16_t exp;
1054 	uint16_t offset;
1055 	uint16_t int16;
1056 	SECItem modulus = {siBuffer, NULL, 0};
1057 	SECItem exponent = {siBuffer, NULL, 0};
1058 	if(len == 0)
1059 		return NULL;
1060 	if(key[0] == 0) {
1061 		if(len < 3)
1062 			return NULL;
1063 		/* the exponent is too large so it's places further */
1064 		memmove(&int16, key+1, 2);
1065 		exp = ntohs(int16);
1066 		offset = 3;
1067 	} else {
1068 		exp = key[0];
1069 		offset = 1;
1070 	}
1071 
1072 	/* key length at least one */
1073 	if(len < (size_t)offset + exp + 1)
1074 		return NULL;
1075 
1076 	exponent.data = key+offset;
1077 	exponent.len = exp;
1078 	offset += exp;
1079 	modulus.data = key+offset;
1080 	modulus.len = (len - offset);
1081 
1082 	pk = nss_key_create(rsaKey);
1083 	if(!pk)
1084 		return NULL;
1085 	if(SECITEM_CopyItem(pk->arena, &pk->u.rsa.modulus, &modulus)) {
1086 		SECKEY_DestroyPublicKey(pk);
1087 		return NULL;
1088 	}
1089 	if(SECITEM_CopyItem(pk->arena, &pk->u.rsa.publicExponent, &exponent)) {
1090 		SECKEY_DestroyPublicKey(pk);
1091 		return NULL;
1092 	}
1093 	return pk;
1094 }
1095 
1096 /**
1097  * Setup key and digest for verification. Adjust sig if necessary.
1098  *
1099  * @param algo: key algorithm
1100  * @param evp_key: EVP PKEY public key to create.
1101  * @param digest_type: digest type to use
1102  * @param key: key to setup for.
1103  * @param keylen: length of key.
1104  * @param prefix: if returned, the ASN prefix for the hashblob.
1105  * @param prefixlen: length of the prefix.
1106  * @return false on failure.
1107  */
1108 static int
1109 nss_setup_key_digest(int algo, SECKEYPublicKey** pubkey, HASH_HashType* htype,
1110 	unsigned char* key, size_t keylen, unsigned char** prefix,
1111 	size_t* prefixlen)
1112 {
1113 	/* uses libNSS */
1114 
1115 	/* hash prefix for md5, RFC2537 */
1116 	static unsigned char p_md5[] = {0x30, 0x20, 0x30, 0x0c, 0x06, 0x08, 0x2a,
1117 	0x86, 0x48, 0x86, 0xf7, 0x0d, 0x02, 0x05, 0x05, 0x00, 0x04, 0x10};
1118 	/* hash prefix to prepend to hash output, from RFC3110 */
1119 	static unsigned char p_sha1[] = {0x30, 0x21, 0x30, 0x09, 0x06, 0x05, 0x2B,
1120 		0x0E, 0x03, 0x02, 0x1A, 0x05, 0x00, 0x04, 0x14};
1121 	/* from RFC5702 */
1122 	static unsigned char p_sha256[] = {0x30, 0x31, 0x30, 0x0d, 0x06, 0x09, 0x60,
1123 	0x86, 0x48, 0x01, 0x65, 0x03, 0x04, 0x02, 0x01, 0x05, 0x00, 0x04, 0x20};
1124 	static unsigned char p_sha512[] = {0x30, 0x51, 0x30, 0x0d, 0x06, 0x09, 0x60,
1125 	0x86, 0x48, 0x01, 0x65, 0x03, 0x04, 0x02, 0x03, 0x05, 0x00, 0x04, 0x40};
1126 	/* from RFC6234 */
1127 	/* for future RSASHA384 ..
1128 	static unsigned char p_sha384[] = {0x30, 0x51, 0x30, 0x0d, 0x06, 0x09, 0x60,
1129 	0x86, 0x48, 0x01, 0x65, 0x03, 0x04, 0x02, 0x02, 0x05, 0x00, 0x04, 0x30};
1130 	*/
1131 
1132 	switch(algo) {
1133 
1134 #if defined(USE_SHA1) || defined(USE_SHA2)
1135 #if defined(USE_DSA) && defined(USE_SHA1)
1136 		case LDNS_DSA:
1137 		case LDNS_DSA_NSEC3:
1138 			*pubkey = nss_buf2dsa(key, keylen);
1139 			if(!*pubkey) {
1140 				log_err("verify: malloc failure in crypto");
1141 				return 0;
1142 			}
1143 			*htype = HASH_AlgSHA1;
1144 			/* no prefix for DSA verification */
1145 			break;
1146 #endif
1147 #ifdef USE_SHA1
1148 		case LDNS_RSASHA1:
1149 		case LDNS_RSASHA1_NSEC3:
1150 #endif
1151 #ifdef USE_SHA2
1152 		case LDNS_RSASHA256:
1153 #endif
1154 #ifdef USE_SHA2
1155 		case LDNS_RSASHA512:
1156 #endif
1157 			*pubkey = nss_buf2rsa(key, keylen);
1158 			if(!*pubkey) {
1159 				log_err("verify: malloc failure in crypto");
1160 				return 0;
1161 			}
1162 			/* select SHA version */
1163 #ifdef USE_SHA2
1164 			if(algo == LDNS_RSASHA256) {
1165 				*htype = HASH_AlgSHA256;
1166 				*prefix = p_sha256;
1167 				*prefixlen = sizeof(p_sha256);
1168 			} else
1169 #endif
1170 #ifdef USE_SHA2
1171 				if(algo == LDNS_RSASHA512) {
1172 				*htype = HASH_AlgSHA512;
1173 				*prefix = p_sha512;
1174 				*prefixlen = sizeof(p_sha512);
1175 			} else
1176 #endif
1177 #ifdef USE_SHA1
1178 			{
1179 				*htype = HASH_AlgSHA1;
1180 				*prefix = p_sha1;
1181 				*prefixlen = sizeof(p_sha1);
1182 			}
1183 #else
1184 			{
1185 				verbose(VERB_QUERY, "verify: no digest algo");
1186 				return 0;
1187 			}
1188 #endif
1189 
1190 			break;
1191 #endif /* SHA1 or SHA2 */
1192 
1193 		case LDNS_RSAMD5:
1194 			*pubkey = nss_buf2rsa(key, keylen);
1195 			if(!*pubkey) {
1196 				log_err("verify: malloc failure in crypto");
1197 				return 0;
1198 			}
1199 			*htype = HASH_AlgMD5;
1200 			*prefix = p_md5;
1201 			*prefixlen = sizeof(p_md5);
1202 
1203 			break;
1204 #ifdef USE_ECDSA
1205 		case LDNS_ECDSAP256SHA256:
1206 			*pubkey = nss_buf2ecdsa(key, keylen,
1207 				LDNS_ECDSAP256SHA256);
1208 			if(!*pubkey) {
1209 				log_err("verify: malloc failure in crypto");
1210 				return 0;
1211 			}
1212 			*htype = HASH_AlgSHA256;
1213 			/* no prefix for DSA verification */
1214 			break;
1215 		case LDNS_ECDSAP384SHA384:
1216 			*pubkey = nss_buf2ecdsa(key, keylen,
1217 				LDNS_ECDSAP384SHA384);
1218 			if(!*pubkey) {
1219 				log_err("verify: malloc failure in crypto");
1220 				return 0;
1221 			}
1222 			*htype = HASH_AlgSHA384;
1223 			/* no prefix for DSA verification */
1224 			break;
1225 #endif /* USE_ECDSA */
1226 		case LDNS_ECC_GOST:
1227 		default:
1228 			verbose(VERB_QUERY, "verify: unknown algorithm %d",
1229 				algo);
1230 			return 0;
1231 	}
1232 	return 1;
1233 }
1234 
1235 /**
1236  * Check a canonical sig+rrset and signature against a dnskey
1237  * @param buf: buffer with data to verify, the first rrsig part and the
1238  *	canonicalized rrset.
1239  * @param algo: DNSKEY algorithm.
1240  * @param sigblock: signature rdata field from RRSIG
1241  * @param sigblock_len: length of sigblock data.
1242  * @param key: public key data from DNSKEY RR.
1243  * @param keylen: length of keydata.
1244  * @param reason: bogus reason in more detail.
1245  * @return secure if verification succeeded, bogus on crypto failure,
1246  *	unchecked on format errors and alloc failures.
1247  */
1248 enum sec_status
1249 verify_canonrrset(sldns_buffer* buf, int algo, unsigned char* sigblock,
1250 	unsigned int sigblock_len, unsigned char* key, unsigned int keylen,
1251 	char** reason)
1252 {
1253 	/* uses libNSS */
1254 	/* large enough for the different hashes */
1255 	unsigned char hash[HASH_LENGTH_MAX];
1256 	unsigned char hash2[HASH_LENGTH_MAX*2];
1257 	HASH_HashType htype = 0;
1258 	SECKEYPublicKey* pubkey = NULL;
1259 	SECItem secsig = {siBuffer, sigblock, sigblock_len};
1260 	SECItem sechash = {siBuffer, hash, 0};
1261 	SECStatus res;
1262 	unsigned char* prefix = NULL; /* prefix for hash, RFC3110, RFC5702 */
1263 	size_t prefixlen = 0;
1264 	int err;
1265 
1266 	if(!nss_setup_key_digest(algo, &pubkey, &htype, key, keylen,
1267 		&prefix, &prefixlen)) {
1268 		verbose(VERB_QUERY, "verify: failed to setup key");
1269 		*reason = "use of key for crypto failed";
1270 		SECKEY_DestroyPublicKey(pubkey);
1271 		return sec_status_bogus;
1272 	}
1273 
1274 #if defined(USE_DSA) && defined(USE_SHA1)
1275 	/* need to convert DSA, ECDSA signatures? */
1276 	if((algo == LDNS_DSA || algo == LDNS_DSA_NSEC3)) {
1277 		if(sigblock_len == 1+2*SHA1_LENGTH) {
1278 			secsig.data ++;
1279 			secsig.len --;
1280 		} else {
1281 			SECItem* p = DSAU_DecodeDerSig(&secsig);
1282 			if(!p) {
1283 				verbose(VERB_QUERY, "verify: failed DER decode");
1284 				*reason = "signature DER decode failed";
1285 				SECKEY_DestroyPublicKey(pubkey);
1286 				return sec_status_bogus;
1287 			}
1288 			if(SECITEM_CopyItem(pubkey->arena, &secsig, p)) {
1289 				log_err("alloc failure in DER decode");
1290 				SECKEY_DestroyPublicKey(pubkey);
1291 				SECITEM_FreeItem(p, PR_TRUE);
1292 				return sec_status_unchecked;
1293 			}
1294 			SECITEM_FreeItem(p, PR_TRUE);
1295 		}
1296 	}
1297 #endif /* USE_DSA */
1298 
1299 	/* do the signature cryptography work */
1300 	/* hash the data */
1301 	sechash.len = HASH_ResultLen(htype);
1302 	if(sechash.len > sizeof(hash)) {
1303 		verbose(VERB_QUERY, "verify: hash too large for buffer");
1304 		SECKEY_DestroyPublicKey(pubkey);
1305 		return sec_status_unchecked;
1306 	}
1307 	if(HASH_HashBuf(htype, hash, (unsigned char*)sldns_buffer_begin(buf),
1308 		(unsigned int)sldns_buffer_limit(buf)) != SECSuccess) {
1309 		verbose(VERB_QUERY, "verify: HASH_HashBuf failed");
1310 		SECKEY_DestroyPublicKey(pubkey);
1311 		return sec_status_unchecked;
1312 	}
1313 	if(prefix) {
1314 		int hashlen = sechash.len;
1315 		if(prefixlen+hashlen > sizeof(hash2)) {
1316 			verbose(VERB_QUERY, "verify: hashprefix too large");
1317 			SECKEY_DestroyPublicKey(pubkey);
1318 			return sec_status_unchecked;
1319 		}
1320 		sechash.data = hash2;
1321 		sechash.len = prefixlen+hashlen;
1322 		memcpy(sechash.data, prefix, prefixlen);
1323 		memmove(sechash.data+prefixlen, hash, hashlen);
1324 	}
1325 
1326 	/* verify the signature */
1327 	res = PK11_Verify(pubkey, &secsig, &sechash, NULL /*wincx*/);
1328 	SECKEY_DestroyPublicKey(pubkey);
1329 
1330 	if(res == SECSuccess) {
1331 		return sec_status_secure;
1332 	}
1333 	err = PORT_GetError();
1334 	if(err != SEC_ERROR_BAD_SIGNATURE) {
1335 		/* failed to verify */
1336 		verbose(VERB_QUERY, "verify: PK11_Verify failed: %s",
1337 			PORT_ErrorToString(err));
1338 		/* if it is not supported, like ECC is removed, we get,
1339 		 * SEC_ERROR_NO_MODULE */
1340 		if(err == SEC_ERROR_NO_MODULE)
1341 			return sec_status_unchecked;
1342 		/* but other errors are commonly returned
1343 		 * for a bad signature from NSS.  Thus we return bogus,
1344 		 * not unchecked */
1345 		*reason = "signature crypto failed";
1346 		return sec_status_bogus;
1347 	}
1348 	verbose(VERB_QUERY, "verify: signature mismatch: %s",
1349 		PORT_ErrorToString(err));
1350 	*reason = "signature crypto failed";
1351 	return sec_status_bogus;
1352 }
1353 
1354 #elif defined(HAVE_NETTLE)
1355 
1356 #include "sha.h"
1357 #include "bignum.h"
1358 #include "macros.h"
1359 #include "rsa.h"
1360 #include "dsa.h"
1361 #ifdef HAVE_NETTLE_DSA_COMPAT_H
1362 #include "dsa-compat.h"
1363 #endif
1364 #include "asn1.h"
1365 #ifdef USE_ECDSA
1366 #include "ecdsa.h"
1367 #include "ecc-curve.h"
1368 #endif
1369 #ifdef HAVE_NETTLE_EDDSA_H
1370 #include "eddsa.h"
1371 #endif
1372 
1373 static int
1374 _digest_nettle(int algo, uint8_t* buf, size_t len,
1375 	unsigned char* res)
1376 {
1377 	switch(algo) {
1378 		case SHA1_DIGEST_SIZE:
1379 		{
1380 			struct sha1_ctx ctx;
1381 			sha1_init(&ctx);
1382 			sha1_update(&ctx, len, buf);
1383 			sha1_digest(&ctx, SHA1_DIGEST_SIZE, res);
1384 			return 1;
1385 		}
1386 		case SHA256_DIGEST_SIZE:
1387 		{
1388 			struct sha256_ctx ctx;
1389 			sha256_init(&ctx);
1390 			sha256_update(&ctx, len, buf);
1391 			sha256_digest(&ctx, SHA256_DIGEST_SIZE, res);
1392 			return 1;
1393 		}
1394 		case SHA384_DIGEST_SIZE:
1395 		{
1396 			struct sha384_ctx ctx;
1397 			sha384_init(&ctx);
1398 			sha384_update(&ctx, len, buf);
1399 			sha384_digest(&ctx, SHA384_DIGEST_SIZE, res);
1400 			return 1;
1401 		}
1402 		case SHA512_DIGEST_SIZE:
1403 		{
1404 			struct sha512_ctx ctx;
1405 			sha512_init(&ctx);
1406 			sha512_update(&ctx, len, buf);
1407 			sha512_digest(&ctx, SHA512_DIGEST_SIZE, res);
1408 			return 1;
1409 		}
1410 		default:
1411 			break;
1412 	}
1413 	return 0;
1414 }
1415 
1416 /* return size of digest if supported, or 0 otherwise */
1417 size_t
1418 nsec3_hash_algo_size_supported(int id)
1419 {
1420 	switch(id) {
1421 	case NSEC3_HASH_SHA1:
1422 		return SHA1_DIGEST_SIZE;
1423 	default:
1424 		return 0;
1425 	}
1426 }
1427 
1428 /* perform nsec3 hash. return false on failure */
1429 int
1430 secalgo_nsec3_hash(int algo, unsigned char* buf, size_t len,
1431         unsigned char* res)
1432 {
1433 	switch(algo) {
1434 	case NSEC3_HASH_SHA1:
1435 		return _digest_nettle(SHA1_DIGEST_SIZE, (uint8_t*)buf, len,
1436 			res);
1437 	default:
1438 		return 0;
1439 	}
1440 }
1441 
1442 void
1443 secalgo_hash_sha256(unsigned char* buf, size_t len, unsigned char* res)
1444 {
1445 	_digest_nettle(SHA256_DIGEST_SIZE, (uint8_t*)buf, len, res);
1446 }
1447 
1448 /**
1449  * Return size of DS digest according to its hash algorithm.
1450  * @param algo: DS digest algo.
1451  * @return size in bytes of digest, or 0 if not supported.
1452  */
1453 size_t
1454 ds_digest_size_supported(int algo)
1455 {
1456 	switch(algo) {
1457 		case LDNS_SHA1:
1458 #ifdef USE_SHA1
1459 			return SHA1_DIGEST_SIZE;
1460 #else
1461 			if(fake_sha1) return 20;
1462 			return 0;
1463 #endif
1464 #ifdef USE_SHA2
1465 		case LDNS_SHA256:
1466 			return SHA256_DIGEST_SIZE;
1467 #endif
1468 #ifdef USE_ECDSA
1469 		case LDNS_SHA384:
1470 			return SHA384_DIGEST_SIZE;
1471 #endif
1472 		/* GOST not supported */
1473 		case LDNS_HASH_GOST:
1474 		default:
1475 			break;
1476 	}
1477 	return 0;
1478 }
1479 
1480 int
1481 secalgo_ds_digest(int algo, unsigned char* buf, size_t len,
1482 	unsigned char* res)
1483 {
1484 	switch(algo) {
1485 #ifdef USE_SHA1
1486 		case LDNS_SHA1:
1487 			return _digest_nettle(SHA1_DIGEST_SIZE, buf, len, res);
1488 #endif
1489 #if defined(USE_SHA2)
1490 		case LDNS_SHA256:
1491 			return _digest_nettle(SHA256_DIGEST_SIZE, buf, len, res);
1492 #endif
1493 #ifdef USE_ECDSA
1494 		case LDNS_SHA384:
1495 			return _digest_nettle(SHA384_DIGEST_SIZE, buf, len, res);
1496 
1497 #endif
1498 		case LDNS_HASH_GOST:
1499 		default:
1500 			verbose(VERB_QUERY, "unknown DS digest algorithm %d",
1501 				algo);
1502 			break;
1503 	}
1504 	return 0;
1505 }
1506 
1507 int
1508 dnskey_algo_id_is_supported(int id)
1509 {
1510 	/* uses libnettle */
1511 	switch(id) {
1512 #if defined(USE_DSA) && defined(USE_SHA1)
1513 	case LDNS_DSA:
1514 	case LDNS_DSA_NSEC3:
1515 #endif
1516 #ifdef USE_SHA1
1517 	case LDNS_RSASHA1:
1518 	case LDNS_RSASHA1_NSEC3:
1519 #endif
1520 #ifdef USE_SHA2
1521 	case LDNS_RSASHA256:
1522 	case LDNS_RSASHA512:
1523 #endif
1524 #ifdef USE_ECDSA
1525 	case LDNS_ECDSAP256SHA256:
1526 	case LDNS_ECDSAP384SHA384:
1527 #endif
1528 		return 1;
1529 #ifdef USE_ED25519
1530 	case LDNS_ED25519:
1531 		return 1;
1532 #endif
1533 	case LDNS_RSAMD5: /* RFC 6725 deprecates RSAMD5 */
1534 	case LDNS_ECC_GOST:
1535 	default:
1536 		return 0;
1537 	}
1538 }
1539 
1540 #if defined(USE_DSA) && defined(USE_SHA1)
1541 static char *
1542 _verify_nettle_dsa(sldns_buffer* buf, unsigned char* sigblock,
1543 	unsigned int sigblock_len, unsigned char* key, unsigned int keylen)
1544 {
1545 	uint8_t digest[SHA1_DIGEST_SIZE];
1546 	uint8_t key_t_value;
1547 	int res = 0;
1548 	size_t offset;
1549 	struct dsa_public_key pubkey;
1550 	struct dsa_signature signature;
1551 	unsigned int expected_len;
1552 
1553 	/* Extract DSA signature from the record */
1554 	nettle_dsa_signature_init(&signature);
1555 	/* Signature length: 41 bytes - RFC 2536 sec. 3 */
1556 	if(sigblock_len == 41) {
1557 		if(key[0] != sigblock[0])
1558 			return "invalid T value in DSA signature or pubkey";
1559 		nettle_mpz_set_str_256_u(signature.r, 20, sigblock+1);
1560 		nettle_mpz_set_str_256_u(signature.s, 20, sigblock+1+20);
1561 	} else {
1562 		/* DER encoded, decode the ASN1 notated R and S bignums */
1563 		/* SEQUENCE { r INTEGER, s INTEGER } */
1564 		struct asn1_der_iterator i, seq;
1565 		if(asn1_der_iterator_first(&i, sigblock_len,
1566 			(uint8_t*)sigblock) != ASN1_ITERATOR_CONSTRUCTED
1567 			|| i.type != ASN1_SEQUENCE)
1568 			return "malformed DER encoded DSA signature";
1569 		/* decode this element of i using the seq iterator */
1570 		if(asn1_der_decode_constructed(&i, &seq) !=
1571 			ASN1_ITERATOR_PRIMITIVE || seq.type != ASN1_INTEGER)
1572 			return "malformed DER encoded DSA signature";
1573 		if(!asn1_der_get_bignum(&seq, signature.r, 20*8))
1574 			return "malformed DER encoded DSA signature";
1575 		if(asn1_der_iterator_next(&seq) != ASN1_ITERATOR_PRIMITIVE
1576 			|| seq.type != ASN1_INTEGER)
1577 			return "malformed DER encoded DSA signature";
1578 		if(!asn1_der_get_bignum(&seq, signature.s, 20*8))
1579 			return "malformed DER encoded DSA signature";
1580 		if(asn1_der_iterator_next(&i) != ASN1_ITERATOR_END)
1581 			return "malformed DER encoded DSA signature";
1582 	}
1583 
1584 	/* Validate T values constraints - RFC 2536 sec. 2 & sec. 3 */
1585 	key_t_value = key[0];
1586 	if (key_t_value > 8) {
1587 		return "invalid T value in DSA pubkey";
1588 	}
1589 
1590 	/* Pubkey minimum length: 21 bytes - RFC 2536 sec. 2 */
1591 	if (keylen < 21) {
1592 		return "DSA pubkey too short";
1593 	}
1594 
1595 	expected_len =   1 +		/* T */
1596 		        20 +		/* Q */
1597 		       (64 + key_t_value*8) +	/* P */
1598 		       (64 + key_t_value*8) +	/* G */
1599 		       (64 + key_t_value*8);	/* Y */
1600 	if (keylen != expected_len ) {
1601 		return "invalid DSA pubkey length";
1602 	}
1603 
1604 	/* Extract DSA pubkey from the record */
1605 	nettle_dsa_public_key_init(&pubkey);
1606 	offset = 1;
1607 	nettle_mpz_set_str_256_u(pubkey.q, 20, key+offset);
1608 	offset += 20;
1609 	nettle_mpz_set_str_256_u(pubkey.p, (64 + key_t_value*8), key+offset);
1610 	offset += (64 + key_t_value*8);
1611 	nettle_mpz_set_str_256_u(pubkey.g, (64 + key_t_value*8), key+offset);
1612 	offset += (64 + key_t_value*8);
1613 	nettle_mpz_set_str_256_u(pubkey.y, (64 + key_t_value*8), key+offset);
1614 
1615 	/* Digest content of "buf" and verify its DSA signature in "sigblock"*/
1616 	res = _digest_nettle(SHA1_DIGEST_SIZE, (unsigned char*)sldns_buffer_begin(buf),
1617 						(unsigned int)sldns_buffer_limit(buf), (unsigned char*)digest);
1618 	res &= dsa_sha1_verify_digest(&pubkey, digest, &signature);
1619 
1620 	/* Clear and return */
1621 	nettle_dsa_signature_clear(&signature);
1622 	nettle_dsa_public_key_clear(&pubkey);
1623 	if (!res)
1624 		return "DSA signature verification failed";
1625 	else
1626 		return NULL;
1627 }
1628 #endif /* USE_DSA */
1629 
1630 static char *
1631 _verify_nettle_rsa(sldns_buffer* buf, unsigned int digest_size, char* sigblock,
1632 	unsigned int sigblock_len, uint8_t* key, unsigned int keylen)
1633 {
1634 	uint16_t exp_len = 0;
1635 	size_t exp_offset = 0, mod_offset = 0;
1636 	struct rsa_public_key pubkey;
1637 	mpz_t signature;
1638 	int res = 0;
1639 
1640 	/* RSA pubkey parsing as per RFC 3110 sec. 2 */
1641 	if( keylen <= 1) {
1642 		return "null RSA key";
1643 	}
1644 	if (key[0] != 0) {
1645 		/* 1-byte length */
1646 		exp_len = key[0];
1647 		exp_offset = 1;
1648 	} else {
1649 		/* 1-byte NUL + 2-bytes exponent length */
1650 		if (keylen < 3) {
1651 			return "incorrect RSA key length";
1652 		}
1653 		exp_len = READ_UINT16(key+1);
1654 		if (exp_len == 0)
1655 			return "null RSA exponent length";
1656 		exp_offset = 3;
1657 	}
1658 	/* Check that we are not over-running input length */
1659 	if (keylen < exp_offset + exp_len + 1) {
1660 		return "RSA key content shorter than expected";
1661 	}
1662 	mod_offset = exp_offset + exp_len;
1663 	nettle_rsa_public_key_init(&pubkey);
1664 	pubkey.size = keylen - mod_offset;
1665 	nettle_mpz_set_str_256_u(pubkey.e, exp_len, &key[exp_offset]);
1666 	nettle_mpz_set_str_256_u(pubkey.n, pubkey.size, &key[mod_offset]);
1667 
1668 	/* Digest content of "buf" and verify its RSA signature in "sigblock"*/
1669 	nettle_mpz_init_set_str_256_u(signature, sigblock_len, (uint8_t*)sigblock);
1670 	switch (digest_size) {
1671 		case SHA1_DIGEST_SIZE:
1672 		{
1673 			uint8_t digest[SHA1_DIGEST_SIZE];
1674 			res = _digest_nettle(SHA1_DIGEST_SIZE, (unsigned char*)sldns_buffer_begin(buf),
1675 						(unsigned int)sldns_buffer_limit(buf), (unsigned char*)digest);
1676 			res &= rsa_sha1_verify_digest(&pubkey, digest, signature);
1677 			break;
1678 		}
1679 		case SHA256_DIGEST_SIZE:
1680 		{
1681 			uint8_t digest[SHA256_DIGEST_SIZE];
1682 			res = _digest_nettle(SHA256_DIGEST_SIZE, (unsigned char*)sldns_buffer_begin(buf),
1683 						(unsigned int)sldns_buffer_limit(buf), (unsigned char*)digest);
1684 			res &= rsa_sha256_verify_digest(&pubkey, digest, signature);
1685 			break;
1686 		}
1687 		case SHA512_DIGEST_SIZE:
1688 		{
1689 			uint8_t digest[SHA512_DIGEST_SIZE];
1690 			res = _digest_nettle(SHA512_DIGEST_SIZE, (unsigned char*)sldns_buffer_begin(buf),
1691 						(unsigned int)sldns_buffer_limit(buf), (unsigned char*)digest);
1692 			res &= rsa_sha512_verify_digest(&pubkey, digest, signature);
1693 			break;
1694 		}
1695 		default:
1696 			break;
1697 	}
1698 
1699 	/* Clear and return */
1700 	nettle_rsa_public_key_clear(&pubkey);
1701 	mpz_clear(signature);
1702 	if (!res) {
1703 		return "RSA signature verification failed";
1704 	} else {
1705 		return NULL;
1706 	}
1707 }
1708 
1709 #ifdef USE_ECDSA
1710 static char *
1711 _verify_nettle_ecdsa(sldns_buffer* buf, unsigned int digest_size, unsigned char* sigblock,
1712 	unsigned int sigblock_len, unsigned char* key, unsigned int keylen)
1713 {
1714 	int res = 0;
1715 	struct ecc_point pubkey;
1716 	struct dsa_signature signature;
1717 
1718 	/* Always matched strength, as per RFC 6605 sec. 1 */
1719 	if (sigblock_len != 2*digest_size || keylen != 2*digest_size) {
1720 		return "wrong ECDSA signature length";
1721 	}
1722 
1723 	/* Parse ECDSA signature as per RFC 6605 sec. 4 */
1724 	nettle_dsa_signature_init(&signature);
1725 	switch (digest_size) {
1726 		case SHA256_DIGEST_SIZE:
1727 		{
1728 			uint8_t digest[SHA256_DIGEST_SIZE];
1729 			mpz_t x, y;
1730 			nettle_ecc_point_init(&pubkey, nettle_get_secp_256r1());
1731 			nettle_mpz_init_set_str_256_u(x, SHA256_DIGEST_SIZE, key);
1732 			nettle_mpz_init_set_str_256_u(y, SHA256_DIGEST_SIZE, key+SHA256_DIGEST_SIZE);
1733 			nettle_mpz_set_str_256_u(signature.r, SHA256_DIGEST_SIZE, sigblock);
1734 			nettle_mpz_set_str_256_u(signature.s, SHA256_DIGEST_SIZE, sigblock+SHA256_DIGEST_SIZE);
1735 			res = _digest_nettle(SHA256_DIGEST_SIZE, (unsigned char*)sldns_buffer_begin(buf),
1736 						(unsigned int)sldns_buffer_limit(buf), (unsigned char*)digest);
1737 			res &= nettle_ecc_point_set(&pubkey, x, y);
1738 			res &= nettle_ecdsa_verify (&pubkey, SHA256_DIGEST_SIZE, digest, &signature);
1739 			mpz_clear(x);
1740 			mpz_clear(y);
1741 			break;
1742 		}
1743 		case SHA384_DIGEST_SIZE:
1744 		{
1745 			uint8_t digest[SHA384_DIGEST_SIZE];
1746 			mpz_t x, y;
1747 			nettle_ecc_point_init(&pubkey, nettle_get_secp_384r1());
1748 			nettle_mpz_init_set_str_256_u(x, SHA384_DIGEST_SIZE, key);
1749 			nettle_mpz_init_set_str_256_u(y, SHA384_DIGEST_SIZE, key+SHA384_DIGEST_SIZE);
1750 			nettle_mpz_set_str_256_u(signature.r, SHA384_DIGEST_SIZE, sigblock);
1751 			nettle_mpz_set_str_256_u(signature.s, SHA384_DIGEST_SIZE, sigblock+SHA384_DIGEST_SIZE);
1752 			res = _digest_nettle(SHA384_DIGEST_SIZE, (unsigned char*)sldns_buffer_begin(buf),
1753 						(unsigned int)sldns_buffer_limit(buf), (unsigned char*)digest);
1754 			res &= nettle_ecc_point_set(&pubkey, x, y);
1755 			res &= nettle_ecdsa_verify (&pubkey, SHA384_DIGEST_SIZE, digest, &signature);
1756 			mpz_clear(x);
1757 			mpz_clear(y);
1758 			nettle_ecc_point_clear(&pubkey);
1759 			break;
1760 		}
1761 		default:
1762 			return "unknown ECDSA algorithm";
1763 	}
1764 
1765 	/* Clear and return */
1766 	nettle_dsa_signature_clear(&signature);
1767 	if (!res)
1768 		return "ECDSA signature verification failed";
1769 	else
1770 		return NULL;
1771 }
1772 #endif
1773 
1774 #ifdef USE_ED25519
1775 static char *
1776 _verify_nettle_ed25519(sldns_buffer* buf, unsigned char* sigblock,
1777 	unsigned int sigblock_len, unsigned char* key, unsigned int keylen)
1778 {
1779 	int res = 0;
1780 
1781 	if(sigblock_len != ED25519_SIGNATURE_SIZE) {
1782 		return "wrong ED25519 signature length";
1783 	}
1784 	if(keylen != ED25519_KEY_SIZE) {
1785 		return "wrong ED25519 key length";
1786 	}
1787 
1788 	res = ed25519_sha512_verify((uint8_t*)key, sldns_buffer_limit(buf),
1789 		sldns_buffer_begin(buf), (uint8_t*)sigblock);
1790 
1791 	if (!res)
1792 		return "ED25519 signature verification failed";
1793 	else
1794 		return NULL;
1795 }
1796 #endif
1797 
1798 /**
1799  * Check a canonical sig+rrset and signature against a dnskey
1800  * @param buf: buffer with data to verify, the first rrsig part and the
1801  *	canonicalized rrset.
1802  * @param algo: DNSKEY algorithm.
1803  * @param sigblock: signature rdata field from RRSIG
1804  * @param sigblock_len: length of sigblock data.
1805  * @param key: public key data from DNSKEY RR.
1806  * @param keylen: length of keydata.
1807  * @param reason: bogus reason in more detail.
1808  * @return secure if verification succeeded, bogus on crypto failure,
1809  *	unchecked on format errors and alloc failures.
1810  */
1811 enum sec_status
1812 verify_canonrrset(sldns_buffer* buf, int algo, unsigned char* sigblock,
1813 	unsigned int sigblock_len, unsigned char* key, unsigned int keylen,
1814 	char** reason)
1815 {
1816 	unsigned int digest_size = 0;
1817 
1818 	if (sigblock_len == 0 || keylen == 0) {
1819 		*reason = "null signature";
1820 		return sec_status_bogus;
1821 	}
1822 
1823 	switch(algo) {
1824 #if defined(USE_DSA) && defined(USE_SHA1)
1825 	case LDNS_DSA:
1826 	case LDNS_DSA_NSEC3:
1827 		*reason = _verify_nettle_dsa(buf, sigblock, sigblock_len, key, keylen);
1828 		if (*reason != NULL)
1829 			return sec_status_bogus;
1830 		else
1831 			return sec_status_secure;
1832 #endif /* USE_DSA */
1833 
1834 #ifdef USE_SHA1
1835 	case LDNS_RSASHA1:
1836 	case LDNS_RSASHA1_NSEC3:
1837 		digest_size = (digest_size ? digest_size : SHA1_DIGEST_SIZE);
1838 #endif
1839 		/* double fallthrough annotation to please gcc parser */
1840 		/* fallthrough */
1841 #ifdef USE_SHA2
1842 		/* fallthrough */
1843 	case LDNS_RSASHA256:
1844 		digest_size = (digest_size ? digest_size : SHA256_DIGEST_SIZE);
1845 		/* fallthrough */
1846 	case LDNS_RSASHA512:
1847 		digest_size = (digest_size ? digest_size : SHA512_DIGEST_SIZE);
1848 
1849 #endif
1850 		*reason = _verify_nettle_rsa(buf, digest_size, (char*)sigblock,
1851 						sigblock_len, key, keylen);
1852 		if (*reason != NULL)
1853 			return sec_status_bogus;
1854 		else
1855 			return sec_status_secure;
1856 
1857 #ifdef USE_ECDSA
1858 	case LDNS_ECDSAP256SHA256:
1859 		digest_size = (digest_size ? digest_size : SHA256_DIGEST_SIZE);
1860 		/* fallthrough */
1861 	case LDNS_ECDSAP384SHA384:
1862 		digest_size = (digest_size ? digest_size : SHA384_DIGEST_SIZE);
1863 		*reason = _verify_nettle_ecdsa(buf, digest_size, sigblock,
1864 						sigblock_len, key, keylen);
1865 		if (*reason != NULL)
1866 			return sec_status_bogus;
1867 		else
1868 			return sec_status_secure;
1869 #endif
1870 #ifdef USE_ED25519
1871 	case LDNS_ED25519:
1872 		*reason = _verify_nettle_ed25519(buf, sigblock, sigblock_len,
1873 			key, keylen);
1874 		if (*reason != NULL)
1875 			return sec_status_bogus;
1876 		else
1877 			return sec_status_secure;
1878 #endif
1879 	case LDNS_RSAMD5:
1880 	case LDNS_ECC_GOST:
1881 	default:
1882 		*reason = "unable to verify signature, unknown algorithm";
1883 		return sec_status_bogus;
1884 	}
1885 }
1886 
1887 #endif /* HAVE_SSL or HAVE_NSS or HAVE_NETTLE */
1888