1 /*        $NetBSD: ks_keychain.c,v 1.2 2017/01/28 21:31:48 christos Exp $       */
2 
3 /*
4  * Copyright (c) 2007 Kungliga Tekniska Högskolan
5  * (Royal Institute of Technology, Stockholm, Sweden).
6  * All rights reserved.
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  * 1. Redistributions of source code must retain the above copyright
13  *    notice, this list of conditions and the following disclaimer.
14  *
15  * 2. Redistributions in binary form must reproduce the above copyright
16  *    notice, this list of conditions and the following disclaimer in the
17  *    documentation and/or other materials provided with the distribution.
18  *
19  * 3. Neither the name of the Institute nor the names of its contributors
20  *    may be used to endorse or promote products derived from this software
21  *    without specific prior written permission.
22  *
23  * THIS SOFTWARE IS PROVIDED BY THE INSTITUTE AND CONTRIBUTORS ``AS IS'' AND
24  * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
25  * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
26  * ARE DISCLAIMED.  IN NO EVENT SHALL THE INSTITUTE OR CONTRIBUTORS BE LIABLE
27  * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
28  * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
29  * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
30  * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
31  * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
32  * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
33  * SUCH DAMAGE.
34  */
35 
36 #include "hx_locl.h"
37 
38 #ifdef HAVE_FRAMEWORK_SECURITY
39 
40 #pragma clang diagnostic push
41 #pragma clang diagnostic ignored "-Wdeprecated-declarations"
42 
43 #include <Security/Security.h>
44 
45 /* Missing function decls in pre Leopard */
46 #ifdef NEED_SECKEYGETCSPHANDLE_PROTO
47 OSStatus SecKeyGetCSPHandle(SecKeyRef, CSSM_CSP_HANDLE *);
48 OSStatus SecKeyGetCredentials(SecKeyRef, CSSM_ACL_AUTHORIZATION_TAG,
49                                     int, const CSSM_ACCESS_CREDENTIALS **);
50 #define kSecCredentialTypeDefault 0
51 #define CSSM_SIZE uint32_t
52 #endif
53 
54 
55 static int
getAttribute(SecKeychainItemRef itemRef,SecItemAttr item,SecKeychainAttributeList ** attrs)56 getAttribute(SecKeychainItemRef itemRef, SecItemAttr item,
57                SecKeychainAttributeList **attrs)
58 {
59     SecKeychainAttributeInfo attrInfo;
60     UInt32 attrFormat = 0;
61     OSStatus ret;
62 
63     *attrs = NULL;
64 
65     attrInfo.count = 1;
66     attrInfo.tag = &item;
67     attrInfo.format = &attrFormat;
68 
69     ret = SecKeychainItemCopyAttributesAndData(itemRef, &attrInfo, NULL,
70                                                          attrs, NULL, NULL);
71     if (ret)
72           return EINVAL;
73     return 0;
74 }
75 
76 
77 /*
78  *
79  */
80 
81 struct kc_rsa {
82     SecKeychainItemRef item;
83     size_t keysize;
84 };
85 
86 
87 static int
kc_rsa_public_encrypt(int flen,const unsigned char * from,unsigned char * to,RSA * rsa,int padding)88 kc_rsa_public_encrypt(int flen,
89                           const unsigned char *from,
90                           unsigned char *to,
91                           RSA *rsa,
92                           int padding)
93 {
94     return -1;
95 }
96 
97 static int
kc_rsa_public_decrypt(int flen,const unsigned char * from,unsigned char * to,RSA * rsa,int padding)98 kc_rsa_public_decrypt(int flen,
99                           const unsigned char *from,
100                           unsigned char *to,
101                           RSA *rsa,
102                           int padding)
103 {
104     return -1;
105 }
106 
107 
108 static int
kc_rsa_private_encrypt(int flen,const unsigned char * from,unsigned char * to,RSA * rsa,int padding)109 kc_rsa_private_encrypt(int flen,
110                            const unsigned char *from,
111                            unsigned char *to,
112                            RSA *rsa,
113                            int padding)
114 {
115     struct kc_rsa *kc = RSA_get_app_data(rsa);
116 
117     CSSM_RETURN cret;
118     OSStatus ret;
119     const CSSM_ACCESS_CREDENTIALS *creds;
120     SecKeyRef privKeyRef = (SecKeyRef)kc->item;
121     CSSM_CSP_HANDLE cspHandle;
122     const CSSM_KEY *cssmKey;
123     CSSM_CC_HANDLE sigHandle = 0;
124     CSSM_DATA sig, in;
125     int fret = 0;
126 
127     if (padding != RSA_PKCS1_PADDING)
128           return -1;
129 
130     cret = SecKeyGetCSSMKey(privKeyRef, &cssmKey);
131     if(cret) abort();
132 
133     cret = SecKeyGetCSPHandle(privKeyRef, &cspHandle);
134     if(cret) abort();
135 
136     ret = SecKeyGetCredentials(privKeyRef, CSSM_ACL_AUTHORIZATION_SIGN,
137                                      kSecCredentialTypeDefault, &creds);
138     if(ret) abort();
139 
140     ret = CSSM_CSP_CreateSignatureContext(cspHandle, CSSM_ALGID_RSA,
141                                                     creds, cssmKey, &sigHandle);
142     if(ret) abort();
143 
144     in.Data = (uint8 *)from;
145     in.Length = flen;
146 
147     sig.Data = (uint8 *)to;
148     sig.Length = kc->keysize;
149 
150     cret = CSSM_SignData(sigHandle, &in, 1, CSSM_ALGID_NONE, &sig);
151     if(cret) {
152           /* cssmErrorString(cret); */
153           fret = -1;
154     } else
155           fret = sig.Length;
156 
157     if(sigHandle)
158           CSSM_DeleteContext(sigHandle);
159 
160     return fret;
161 }
162 
163 static int
kc_rsa_private_decrypt(int flen,const unsigned char * from,unsigned char * to,RSA * rsa,int padding)164 kc_rsa_private_decrypt(int flen, const unsigned char *from, unsigned char *to,
165                            RSA * rsa, int padding)
166 {
167     struct kc_rsa *kc = RSA_get_app_data(rsa);
168 
169     CSSM_RETURN cret;
170     OSStatus ret;
171     const CSSM_ACCESS_CREDENTIALS *creds;
172     SecKeyRef privKeyRef = (SecKeyRef)kc->item;
173     CSSM_CSP_HANDLE cspHandle;
174     const CSSM_KEY *cssmKey;
175     CSSM_CC_HANDLE handle = 0;
176     CSSM_DATA out, in, rem;
177     int fret = 0;
178     CSSM_SIZE outlen = 0;
179     char remdata[1024];
180 
181     if (padding != RSA_PKCS1_PADDING)
182           return -1;
183 
184     cret = SecKeyGetCSSMKey(privKeyRef, &cssmKey);
185     if(cret) abort();
186 
187     cret = SecKeyGetCSPHandle(privKeyRef, &cspHandle);
188     if(cret) abort();
189 
190     ret = SecKeyGetCredentials(privKeyRef, CSSM_ACL_AUTHORIZATION_DECRYPT,
191                                      kSecCredentialTypeDefault, &creds);
192     if(ret) abort();
193 
194 
195     ret = CSSM_CSP_CreateAsymmetricContext (cspHandle,
196                                                       CSSM_ALGID_RSA,
197                                                       creds,
198                                                       cssmKey,
199                                                       CSSM_PADDING_PKCS1,
200                                                       &handle);
201     if(ret) abort();
202 
203     in.Data = (uint8 *)from;
204     in.Length = flen;
205 
206     out.Data = (uint8 *)to;
207     out.Length = kc->keysize;
208 
209     rem.Data = (uint8 *)remdata;
210     rem.Length = sizeof(remdata);
211 
212     cret = CSSM_DecryptData(handle, &in, 1, &out, 1, &outlen, &rem);
213     if(cret) {
214           /* cssmErrorString(cret); */
215           fret = -1;
216     } else
217           fret = out.Length;
218 
219     if(handle)
220           CSSM_DeleteContext(handle);
221 
222     return fret;
223 }
224 
225 static int
kc_rsa_init(RSA * rsa)226 kc_rsa_init(RSA *rsa)
227 {
228     return 1;
229 }
230 
231 static int
kc_rsa_finish(RSA * rsa)232 kc_rsa_finish(RSA *rsa)
233 {
234     struct kc_rsa *kc_rsa = RSA_get_app_data(rsa);
235     CFRelease(kc_rsa->item);
236     memset(kc_rsa, 0, sizeof(*kc_rsa));
237     free(kc_rsa);
238     return 1;
239 }
240 
241 static const RSA_METHOD kc_rsa_pkcs1_method = {
242     "hx509 Keychain PKCS#1 RSA",
243     kc_rsa_public_encrypt,
244     kc_rsa_public_decrypt,
245     kc_rsa_private_encrypt,
246     kc_rsa_private_decrypt,
247     NULL,
248     NULL,
249     kc_rsa_init,
250     kc_rsa_finish,
251     0,
252     NULL,
253     NULL,
254     NULL,
255     NULL
256 };
257 
258 static int
set_private_key(hx509_context context,SecKeychainItemRef itemRef,hx509_cert cert)259 set_private_key(hx509_context context,
260                     SecKeychainItemRef itemRef,
261                     hx509_cert cert)
262 {
263     struct kc_rsa *kc;
264     hx509_private_key key;
265     RSA *rsa;
266     int ret;
267 
268     ret = hx509_private_key_init(&key, NULL, NULL);
269     if (ret)
270           return ret;
271 
272     kc = calloc(1, sizeof(*kc));
273     if (kc == NULL)
274           _hx509_abort("out of memory");
275 
276     kc->item = itemRef;
277 
278     rsa = RSA_new();
279     if (rsa == NULL)
280           _hx509_abort("out of memory");
281 
282     /* Argh, fake modulus since OpenSSL API is on crack */
283     {
284           SecKeychainAttributeList *attrs = NULL;
285           uint32_t size;
286           void *data;
287 
288           rsa->n = BN_new();
289           if (rsa->n == NULL) abort();
290 
291           ret = getAttribute(itemRef, kSecKeyKeySizeInBits, &attrs);
292           if (ret) abort();
293 
294           size = *(uint32_t *)attrs->attr[0].data;
295           SecKeychainItemFreeAttributesAndData(attrs, NULL);
296 
297           kc->keysize = (size + 7) / 8;
298 
299           data = malloc(kc->keysize);
300           memset(data, 0xe0, kc->keysize);
301           BN_bin2bn(data, kc->keysize, rsa->n);
302           free(data);
303     }
304     rsa->e = NULL;
305 
306     RSA_set_method(rsa, &kc_rsa_pkcs1_method);
307     ret = RSA_set_app_data(rsa, kc);
308     if (ret != 1)
309           _hx509_abort("RSA_set_app_data");
310 
311     hx509_private_key_assign_rsa(key, rsa);
312     _hx509_cert_assign_key(cert, key);
313 
314     return 0;
315 }
316 
317 /*
318  *
319  */
320 
321 struct ks_keychain {
322     int anchors;
323     SecKeychainRef keychain;
324 };
325 
326 static int
keychain_init(hx509_context context,hx509_certs certs,void ** data,int flags,const char * residue,hx509_lock lock)327 keychain_init(hx509_context context,
328                 hx509_certs certs, void **data, int flags,
329                 const char *residue, hx509_lock lock)
330 {
331     struct ks_keychain *ctx;
332 
333     ctx = calloc(1, sizeof(*ctx));
334     if (ctx == NULL) {
335           hx509_clear_error_string(context);
336           return ENOMEM;
337     }
338 
339     if (residue) {
340           if (strcasecmp(residue, "system-anchors") == 0) {
341               ctx->anchors = 1;
342           } else if (strncasecmp(residue, "FILE:", 5) == 0) {
343               OSStatus ret;
344 
345               ret = SecKeychainOpen(residue + 5, &ctx->keychain);
346               if (ret != noErr) {
347                     hx509_set_error_string(context, 0, ENOENT,
348                                                "Failed to open %s", residue);
349                     free(ctx);
350                     return ENOENT;
351               }
352           } else {
353               hx509_set_error_string(context, 0, ENOENT,
354                                            "Unknown subtype %s", residue);
355               free(ctx);
356               return ENOENT;
357           }
358     }
359 
360     *data = ctx;
361     return 0;
362 }
363 
364 /*
365  *
366  */
367 
368 static int
keychain_free(hx509_certs certs,void * data)369 keychain_free(hx509_certs certs, void *data)
370 {
371     struct ks_keychain *ctx = data;
372     if (ctx->keychain)
373           CFRelease(ctx->keychain);
374     memset(ctx, 0, sizeof(*ctx));
375     free(ctx);
376     return 0;
377 }
378 
379 /*
380  *
381  */
382 
383 struct iter {
384     hx509_certs certs;
385     void *cursor;
386     SecKeychainSearchRef searchRef;
387 };
388 
389 static int
keychain_iter_start(hx509_context context,hx509_certs certs,void * data,void ** cursor)390 keychain_iter_start(hx509_context context,
391                         hx509_certs certs, void *data, void **cursor)
392 {
393     struct ks_keychain *ctx = data;
394     struct iter *iter;
395 
396     iter = calloc(1, sizeof(*iter));
397     if (iter == NULL) {
398           hx509_set_error_string(context, 0, ENOMEM, "out of memory");
399           return ENOMEM;
400     }
401 
402     if (ctx->anchors) {
403         CFArrayRef anchors;
404           int ret;
405           int i;
406 
407           ret = hx509_certs_init(context, "MEMORY:ks-file-create",
408                                      0, NULL, &iter->certs);
409           if (ret) {
410               free(iter);
411               return ret;
412           }
413 
414           ret = SecTrustCopyAnchorCertificates(&anchors);
415           if (ret != 0) {
416               hx509_certs_free(&iter->certs);
417               free(iter);
418               hx509_set_error_string(context, 0, ENOMEM,
419                                            "Can't get trust anchors from Keychain");
420               return ENOMEM;
421           }
422           for (i = 0; i < CFArrayGetCount(anchors); i++) {
423               SecCertificateRef cr;
424               hx509_cert cert;
425               CSSM_DATA cssm;
426 
427               cr = (SecCertificateRef)CFArrayGetValueAtIndex(anchors, i);
428 
429               SecCertificateGetData(cr, &cssm);
430 
431               cert = hx509_cert_init_data(context, cssm.Data, cssm.Length, NULL);
432               if (cert == NULL)
433                     continue;
434 
435               ret = hx509_certs_add(context, iter->certs, cert);
436               hx509_cert_free(cert);
437           }
438           CFRelease(anchors);
439     }
440 
441     if (iter->certs) {
442           int ret;
443           ret = hx509_certs_start_seq(context, iter->certs, &iter->cursor);
444           if (ret) {
445               hx509_certs_free(&iter->certs);
446               free(iter);
447               return ret;
448           }
449     } else {
450           OSStatus ret;
451 
452           ret = SecKeychainSearchCreateFromAttributes(ctx->keychain,
453                                                                 kSecCertificateItemClass,
454                                                                 NULL,
455                                                                 &iter->searchRef);
456           if (ret) {
457               free(iter);
458               hx509_set_error_string(context, 0, ret,
459                                            "Failed to start search for attributes");
460               return ENOMEM;
461           }
462     }
463 
464     *cursor = iter;
465     return 0;
466 }
467 
468 /*
469  *
470  */
471 
472 static int
keychain_iter(hx509_context context,hx509_certs certs,void * data,void * cursor,hx509_cert * cert)473 keychain_iter(hx509_context context,
474                 hx509_certs certs, void *data, void *cursor, hx509_cert *cert)
475 {
476     SecKeychainAttributeList *attrs = NULL;
477     SecKeychainAttributeInfo attrInfo;
478     UInt32 attrFormat[1] = { 0 };
479     SecKeychainItemRef itemRef;
480     SecItemAttr item[1];
481     heim_error_t error = NULL;
482     struct iter *iter = cursor;
483     OSStatus ret;
484     UInt32 len;
485     void *ptr = NULL;
486 
487     if (iter->certs)
488           return hx509_certs_next_cert(context, iter->certs, iter->cursor, cert);
489 
490     *cert = NULL;
491 
492     ret = SecKeychainSearchCopyNext(iter->searchRef, &itemRef);
493     if (ret == errSecItemNotFound)
494           return 0;
495     else if (ret != 0)
496           return EINVAL;
497 
498     /*
499      * Pick out certificate and matching "keyid"
500      */
501 
502     item[0] = kSecPublicKeyHashItemAttr;
503 
504     attrInfo.count = 1;
505     attrInfo.tag = item;
506     attrInfo.format = attrFormat;
507 
508     ret = SecKeychainItemCopyAttributesAndData(itemRef, &attrInfo, NULL,
509                                                          &attrs, &len, &ptr);
510     if (ret)
511           return EINVAL;
512 
513     *cert = hx509_cert_init_data(context, ptr, len, &error);
514     if (*cert == NULL) {
515           ret = heim_error_get_code(error);
516           heim_release(error);
517           goto out;
518     }
519 
520     /*
521      * Find related private key if there is one by looking at
522      * kSecPublicKeyHashItemAttr == kSecKeyLabel
523      */
524     {
525           SecKeychainSearchRef search;
526           SecKeychainAttribute attrKeyid;
527           SecKeychainAttributeList attrList;
528 
529           attrKeyid.tag = kSecKeyLabel;
530           attrKeyid.length = attrs->attr[0].length;
531           attrKeyid.data = attrs->attr[0].data;
532 
533           attrList.count = 1;
534           attrList.attr = &attrKeyid;
535 
536           ret = SecKeychainSearchCreateFromAttributes(NULL,
537                                                                 CSSM_DL_DB_RECORD_PRIVATE_KEY,
538                                                                 &attrList,
539                                                                 &search);
540           if (ret) {
541               ret = 0;
542               goto out;
543           }
544 
545           ret = SecKeychainSearchCopyNext(search, &itemRef);
546           CFRelease(search);
547           if (ret == errSecItemNotFound) {
548               ret = 0;
549               goto out;
550           } else if (ret) {
551               ret = EINVAL;
552               goto out;
553           }
554           set_private_key(context, itemRef, *cert);
555     }
556 
557 out:
558     SecKeychainItemFreeAttributesAndData(attrs, ptr);
559 
560     return ret;
561 }
562 
563 /*
564  *
565  */
566 
567 static int
keychain_iter_end(hx509_context context,hx509_certs certs,void * data,void * cursor)568 keychain_iter_end(hx509_context context,
569                       hx509_certs certs,
570                       void *data,
571                       void *cursor)
572 {
573     struct iter *iter = cursor;
574 
575     if (iter->certs) {
576           hx509_certs_end_seq(context, iter->certs, iter->cursor);
577           hx509_certs_free(&iter->certs);
578     } else {
579           CFRelease(iter->searchRef);
580     }
581 
582     memset(iter, 0, sizeof(*iter));
583     free(iter);
584     return 0;
585 }
586 
587 /*
588  *
589  */
590 
591 struct hx509_keyset_ops keyset_keychain = {
592     "KEYCHAIN",
593     0,
594     keychain_init,
595     NULL,
596     keychain_free,
597     NULL,
598     NULL,
599     keychain_iter_start,
600     keychain_iter,
601     keychain_iter_end,
602     NULL,
603     NULL,
604     NULL
605 };
606 
607 #pragma clang diagnostic pop
608 
609 #endif /* HAVE_FRAMEWORK_SECURITY */
610 
611 /*
612  *
613  */
614 
615 void
_hx509_ks_keychain_register(hx509_context context)616 _hx509_ks_keychain_register(hx509_context context)
617 {
618 #ifdef HAVE_FRAMEWORK_SECURITY
619     _hx509_ks_register(context, &keyset_keychain);
620 #endif
621 }
622