xref: /curl/lib/vtls/x509asn1.c (revision fbf5d507)
1 /***************************************************************************
2  *                                  _   _ ____  _
3  *  Project                     ___| | | |  _ \| |
4  *                             / __| | | | |_) | |
5  *                            | (__| |_| |  _ <| |___
6  *                             \___|\___/|_| \_\_____|
7  *
8  * Copyright (C) Daniel Stenberg, <daniel@haxx.se>, et al.
9  *
10  * This software is licensed as described in the file COPYING, which
11  * you should have received as part of this distribution. The terms
12  * are also available at https://curl.se/docs/copyright.html.
13  *
14  * You may opt to use, copy, modify, merge, publish, distribute and/or sell
15  * copies of the Software, and permit persons to whom the Software is
16  * furnished to do so, under the terms of the COPYING file.
17  *
18  * This software is distributed on an "AS IS" basis, WITHOUT WARRANTY OF ANY
19  * KIND, either express or implied.
20  *
21  * SPDX-License-Identifier: curl
22  *
23  ***************************************************************************/
24 
25 #include "curl_setup.h"
26 
27 #if defined(USE_GNUTLS) || defined(USE_WOLFSSL) ||      \
28   defined(USE_SCHANNEL) || defined(USE_SECTRANSP) ||    \
29   defined(USE_MBEDTLS)
30 
31 #if defined(USE_WOLFSSL) || defined(USE_SCHANNEL)
32 #define WANT_PARSEX509 /* uses Curl_parseX509() */
33 #endif
34 
35 #if defined(USE_GNUTLS) || defined(USE_SCHANNEL) || defined(USE_SECTRANSP) || \
36   defined(USE_MBEDTLS)
37 #define WANT_EXTRACT_CERTINFO /* uses Curl_extract_certinfo() */
38 #define WANT_PARSEX509 /* ... uses Curl_parseX509() */
39 #endif
40 
41 #include <curl/curl.h>
42 #include "urldata.h"
43 #include "strcase.h"
44 #include "curl_ctype.h"
45 #include "hostcheck.h"
46 #include "vtls/vtls.h"
47 #include "vtls/vtls_int.h"
48 #include "sendf.h"
49 #include "inet_pton.h"
50 #include "curl_base64.h"
51 #include "x509asn1.h"
52 #include "dynbuf.h"
53 
54 /* The last 3 #include files should be in this order */
55 #include "curl_printf.h"
56 #include "curl_memory.h"
57 #include "memdebug.h"
58 
59 /*
60  * Constants.
61  */
62 
63 /* Largest supported ASN.1 structure. */
64 #define CURL_ASN1_MAX                   ((size_t) 0x40000)      /* 256K */
65 
66 /* ASN.1 classes. */
67 #define CURL_ASN1_UNIVERSAL             0
68 #define CURL_ASN1_APPLICATION           1
69 #define CURL_ASN1_CONTEXT_SPECIFIC      2
70 #define CURL_ASN1_PRIVATE               3
71 
72 /* ASN.1 types. */
73 #define CURL_ASN1_BOOLEAN               1
74 #define CURL_ASN1_INTEGER               2
75 #define CURL_ASN1_BIT_STRING            3
76 #define CURL_ASN1_OCTET_STRING          4
77 #define CURL_ASN1_NULL                  5
78 #define CURL_ASN1_OBJECT_IDENTIFIER     6
79 #define CURL_ASN1_OBJECT_DESCRIPTOR     7
80 #define CURL_ASN1_INSTANCE_OF           8
81 #define CURL_ASN1_REAL                  9
82 #define CURL_ASN1_ENUMERATED            10
83 #define CURL_ASN1_EMBEDDED              11
84 #define CURL_ASN1_UTF8_STRING           12
85 #define CURL_ASN1_RELATIVE_OID          13
86 #define CURL_ASN1_SEQUENCE              16
87 #define CURL_ASN1_SET                   17
88 #define CURL_ASN1_NUMERIC_STRING        18
89 #define CURL_ASN1_PRINTABLE_STRING      19
90 #define CURL_ASN1_TELETEX_STRING        20
91 #define CURL_ASN1_VIDEOTEX_STRING       21
92 #define CURL_ASN1_IA5_STRING            22
93 #define CURL_ASN1_UTC_TIME              23
94 #define CURL_ASN1_GENERALIZED_TIME      24
95 #define CURL_ASN1_GRAPHIC_STRING        25
96 #define CURL_ASN1_VISIBLE_STRING        26
97 #define CURL_ASN1_GENERAL_STRING        27
98 #define CURL_ASN1_UNIVERSAL_STRING      28
99 #define CURL_ASN1_CHARACTER_STRING      29
100 #define CURL_ASN1_BMP_STRING            30
101 
102 
103 #ifdef WANT_EXTRACT_CERTINFO
104 /* ASN.1 OID table entry. */
105 struct Curl_OID {
106   const char *numoid;  /* Dotted-numeric OID. */
107   const char *textoid; /* OID name. */
108 };
109 
110 /* ASN.1 OIDs. */
111 static const struct Curl_OID OIDtable[] = {
112   { "1.2.840.10040.4.1",        "dsa" },
113   { "1.2.840.10040.4.3",        "dsa-with-sha1" },
114   { "1.2.840.10045.2.1",        "ecPublicKey" },
115   { "1.2.840.10045.3.0.1",      "c2pnb163v1" },
116   { "1.2.840.10045.4.1",        "ecdsa-with-SHA1" },
117   { "1.2.840.10045.4.3.1",      "ecdsa-with-SHA224" },
118   { "1.2.840.10045.4.3.2",      "ecdsa-with-SHA256" },
119   { "1.2.840.10045.4.3.3",      "ecdsa-with-SHA384" },
120   { "1.2.840.10045.4.3.4",      "ecdsa-with-SHA512" },
121   { "1.2.840.10046.2.1",        "dhpublicnumber" },
122   { "1.2.840.113549.1.1.1",     "rsaEncryption" },
123   { "1.2.840.113549.1.1.2",     "md2WithRSAEncryption" },
124   { "1.2.840.113549.1.1.4",     "md5WithRSAEncryption" },
125   { "1.2.840.113549.1.1.5",     "sha1WithRSAEncryption" },
126   { "1.2.840.113549.1.1.10",    "RSASSA-PSS" },
127   { "1.2.840.113549.1.1.14",    "sha224WithRSAEncryption" },
128   { "1.2.840.113549.1.1.11",    "sha256WithRSAEncryption" },
129   { "1.2.840.113549.1.1.12",    "sha384WithRSAEncryption" },
130   { "1.2.840.113549.1.1.13",    "sha512WithRSAEncryption" },
131   { "1.2.840.113549.2.2",       "md2" },
132   { "1.2.840.113549.2.5",       "md5" },
133   { "1.3.14.3.2.26",            "sha1" },
134   { "2.5.4.3",                  "CN" },
135   { "2.5.4.4",                  "SN" },
136   { "2.5.4.5",                  "serialNumber" },
137   { "2.5.4.6",                  "C" },
138   { "2.5.4.7",                  "L" },
139   { "2.5.4.8",                  "ST" },
140   { "2.5.4.9",                  "streetAddress" },
141   { "2.5.4.10",                 "O" },
142   { "2.5.4.11",                 "OU" },
143   { "2.5.4.12",                 "title" },
144   { "2.5.4.13",                 "description" },
145   { "2.5.4.17",                 "postalCode" },
146   { "2.5.4.41",                 "name" },
147   { "2.5.4.42",                 "givenName" },
148   { "2.5.4.43",                 "initials" },
149   { "2.5.4.44",                 "generationQualifier" },
150   { "2.5.4.45",                 "X500UniqueIdentifier" },
151   { "2.5.4.46",                 "dnQualifier" },
152   { "2.5.4.65",                 "pseudonym" },
153   { "1.2.840.113549.1.9.1",     "emailAddress" },
154   { "2.5.4.72",                 "role" },
155   { "2.5.29.17",                "subjectAltName" },
156   { "2.5.29.18",                "issuerAltName" },
157   { "2.5.29.19",                "basicConstraints" },
158   { "2.16.840.1.101.3.4.2.4",   "sha224" },
159   { "2.16.840.1.101.3.4.2.1",   "sha256" },
160   { "2.16.840.1.101.3.4.2.2",   "sha384" },
161   { "2.16.840.1.101.3.4.2.3",   "sha512" },
162   { "1.2.840.113549.1.9.2",     "unstructuredName" },
163   { (const char *) NULL,        (const char *) NULL }
164 };
165 
166 #endif /* WANT_EXTRACT_CERTINFO */
167 
168 /*
169  * Lightweight ASN.1 parser.
170  * In particular, it does not check for syntactic/lexical errors.
171  * It is intended to support certificate information gathering for SSL backends
172  * that offer a mean to get certificates as a whole, but do not supply
173  * entry points to get particular certificate sub-fields.
174  * Please note there is no pretension here to rewrite a full SSL library.
175  */
176 
177 static const char *getASN1Element(struct Curl_asn1Element *elem,
178                                   const char *beg, const char *end)
179   WARN_UNUSED_RESULT;
180 
getASN1Element(struct Curl_asn1Element * elem,const char * beg,const char * end)181 static const char *getASN1Element(struct Curl_asn1Element *elem,
182                                   const char *beg, const char *end)
183 {
184   unsigned char b;
185   size_t len;
186   struct Curl_asn1Element lelem;
187 
188   /* Get a single ASN.1 element into `elem', parse ASN.1 string at `beg'
189      ending at `end'.
190      Returns a pointer in source string after the parsed element, or NULL
191      if an error occurs. */
192   if(!beg || !end || beg >= end || !*beg ||
193      (size_t)(end - beg) > CURL_ASN1_MAX)
194     return NULL;
195 
196   /* Process header byte. */
197   elem->header = beg;
198   b = (unsigned char) *beg++;
199   elem->constructed = (b & 0x20) != 0;
200   elem->class = (b >> 6) & 3;
201   b &= 0x1F;
202   if(b == 0x1F)
203     return NULL; /* Long tag values not supported here. */
204   elem->tag = b;
205 
206   /* Process length. */
207   if(beg >= end)
208     return NULL;
209   b = (unsigned char) *beg++;
210   if(!(b & 0x80))
211     len = b;
212   else if(!(b &= 0x7F)) {
213     /* Unspecified length. Since we have all the data, we can determine the
214        effective length by skipping element until an end element is found. */
215     if(!elem->constructed)
216       return NULL;
217     elem->beg = beg;
218     while(beg < end && *beg) {
219       beg = getASN1Element(&lelem, beg, end);
220       if(!beg)
221         return NULL;
222     }
223     if(beg >= end)
224       return NULL;
225     elem->end = beg;
226     return beg + 1;
227   }
228   else if((unsigned)b > (size_t)(end - beg))
229     return NULL; /* Does not fit in source. */
230   else {
231     /* Get long length. */
232     len = 0;
233     do {
234       if(len & 0xFF000000L)
235         return NULL;  /* Lengths > 32 bits are not supported. */
236       len = (len << 8) | (unsigned char) *beg++;
237     } while(--b);
238   }
239   if(len > (size_t)(end - beg))
240     return NULL;  /* Element data does not fit in source. */
241   elem->beg = beg;
242   elem->end = beg + len;
243   return elem->end;
244 }
245 
246 #ifdef WANT_EXTRACT_CERTINFO
247 
248 /*
249  * Search the null terminated OID or OID identifier in local table.
250  * Return the table entry pointer or NULL if not found.
251  */
searchOID(const char * oid)252 static const struct Curl_OID *searchOID(const char *oid)
253 {
254   const struct Curl_OID *op;
255   for(op = OIDtable; op->numoid; op++)
256     if(!strcmp(op->numoid, oid) || strcasecompare(op->textoid, oid))
257       return op;
258 
259   return NULL;
260 }
261 
262 /*
263  * Convert an ASN.1 Boolean value into its string representation.
264  *
265  * Return error code.
266  */
267 
bool2str(struct dynbuf * store,const char * beg,const char * end)268 static CURLcode bool2str(struct dynbuf *store,
269                          const char *beg, const char *end)
270 {
271   if(end - beg != 1)
272     return CURLE_BAD_FUNCTION_ARGUMENT;
273   return Curl_dyn_add(store, *beg ? "TRUE": "FALSE");
274 }
275 
276 /*
277  * Convert an ASN.1 octet string to a printable string.
278  *
279  * Return error code.
280  */
octet2str(struct dynbuf * store,const char * beg,const char * end)281 static CURLcode octet2str(struct dynbuf *store,
282                           const char *beg, const char *end)
283 {
284   CURLcode result = CURLE_OK;
285 
286   while(!result && beg < end)
287     result = Curl_dyn_addf(store, "%02x:", (unsigned char) *beg++);
288 
289   return result;
290 }
291 
bit2str(struct dynbuf * store,const char * beg,const char * end)292 static CURLcode bit2str(struct dynbuf *store,
293                         const char *beg, const char *end)
294 {
295   /* Convert an ASN.1 bit string to a printable string. */
296 
297   if(++beg > end)
298     return CURLE_BAD_FUNCTION_ARGUMENT;
299   return octet2str(store, beg, end);
300 }
301 
302 /*
303  * Convert an ASN.1 integer value into its string representation.
304  *
305  * Returns error.
306  */
int2str(struct dynbuf * store,const char * beg,const char * end)307 static CURLcode int2str(struct dynbuf *store,
308                         const char *beg, const char *end)
309 {
310   unsigned int val = 0;
311   size_t n = end - beg;
312 
313   if(!n)
314     return CURLE_BAD_FUNCTION_ARGUMENT;
315 
316   if(n > 4)
317     return octet2str(store, beg, end);
318 
319   /* Represent integers <= 32-bit as a single value. */
320   if(*beg & 0x80)
321     val = ~val;
322 
323   do
324     val = (val << 8) | *(const unsigned char *) beg++;
325   while(beg < end);
326   return Curl_dyn_addf(store, "%s%x", val >= 10 ? "0x" : "", val);
327 }
328 
329 /*
330  * Convert from an ASN.1 typed string to UTF8.
331  *
332  * The result is stored in a dynbuf that is inited by the user of this
333  * function.
334  *
335  * Returns error.
336  */
337 static CURLcode
utf8asn1str(struct dynbuf * to,int type,const char * from,const char * end)338 utf8asn1str(struct dynbuf *to, int type, const char *from, const char *end)
339 {
340   size_t inlength = end - from;
341   int size = 1;
342   CURLcode result = CURLE_OK;
343 
344   switch(type) {
345   case CURL_ASN1_BMP_STRING:
346     size = 2;
347     break;
348   case CURL_ASN1_UNIVERSAL_STRING:
349     size = 4;
350     break;
351   case CURL_ASN1_NUMERIC_STRING:
352   case CURL_ASN1_PRINTABLE_STRING:
353   case CURL_ASN1_TELETEX_STRING:
354   case CURL_ASN1_IA5_STRING:
355   case CURL_ASN1_VISIBLE_STRING:
356   case CURL_ASN1_UTF8_STRING:
357     break;
358   default:
359     return CURLE_BAD_FUNCTION_ARGUMENT;  /* Conversion not supported. */
360   }
361 
362   if(inlength % size)
363     /* Length inconsistent with character size. */
364     return CURLE_BAD_FUNCTION_ARGUMENT;
365 
366   if(type == CURL_ASN1_UTF8_STRING) {
367     /* Just copy. */
368     if(inlength)
369       result = Curl_dyn_addn(to, from, inlength);
370   }
371   else {
372     while(!result && (from < end)) {
373       char buf[4]; /* decode buffer */
374       size_t charsize = 1;
375       unsigned int wc = 0;
376 
377       switch(size) {
378       case 4:
379         wc = (wc << 8) | *(const unsigned char *) from++;
380         wc = (wc << 8) | *(const unsigned char *) from++;
381         FALLTHROUGH();
382       case 2:
383         wc = (wc << 8) | *(const unsigned char *) from++;
384         FALLTHROUGH();
385       default: /* case 1: */
386         wc = (wc << 8) | *(const unsigned char *) from++;
387       }
388       if(wc >= 0x00000080) {
389         if(wc >= 0x00000800) {
390           if(wc >= 0x00010000) {
391             if(wc >= 0x00200000) {
392               /* Invalid char. size for target encoding. */
393               return CURLE_WEIRD_SERVER_REPLY;
394             }
395             buf[3] = (char) (0x80 | (wc & 0x3F));
396             wc = (wc >> 6) | 0x00010000;
397             charsize++;
398           }
399           buf[2] = (char) (0x80 | (wc & 0x3F));
400           wc = (wc >> 6) | 0x00000800;
401           charsize++;
402         }
403         buf[1] = (char) (0x80 | (wc & 0x3F));
404         wc = (wc >> 6) | 0x000000C0;
405         charsize++;
406       }
407       buf[0] = (char) wc;
408       result = Curl_dyn_addn(to, buf, charsize);
409     }
410   }
411   return result;
412 }
413 
414 /*
415  * Convert an ASN.1 OID into its dotted string representation.
416  *
417  * Return error code.
418  */
encodeOID(struct dynbuf * store,const char * beg,const char * end)419 static CURLcode encodeOID(struct dynbuf *store,
420                           const char *beg, const char *end)
421 {
422   unsigned int x;
423   unsigned int y;
424   CURLcode result = CURLE_OK;
425 
426   /* Process the first two numbers. */
427   y = *(const unsigned char *) beg++;
428   x = y / 40;
429   y -= x * 40;
430 
431   result = Curl_dyn_addf(store, "%u.%u", x, y);
432   if(result)
433     return result;
434 
435   /* Process the trailing numbers. */
436   while(beg < end) {
437     x = 0;
438     do {
439       if(x & 0xFF000000)
440         return 0;
441       y = *(const unsigned char *) beg++;
442       x = (x << 7) | (y & 0x7F);
443     } while(y & 0x80);
444     result = Curl_dyn_addf(store, ".%u", x);
445   }
446   return result;
447 }
448 
449 /*
450  * Convert an ASN.1 OID into its dotted or symbolic string representation.
451  *
452  * Return error code.
453  */
454 
OID2str(struct dynbuf * store,const char * beg,const char * end,bool symbolic)455 static CURLcode OID2str(struct dynbuf *store,
456                         const char *beg, const char *end, bool symbolic)
457 {
458   CURLcode result = CURLE_OK;
459   if(beg < end) {
460     if(symbolic) {
461       struct dynbuf buf;
462       Curl_dyn_init(&buf, CURL_X509_STR_MAX);
463       result = encodeOID(&buf, beg, end);
464 
465       if(!result) {
466         const struct Curl_OID *op = searchOID(Curl_dyn_ptr(&buf));
467         if(op)
468           result = Curl_dyn_add(store, op->textoid);
469         else
470           result = Curl_dyn_add(store, Curl_dyn_ptr(&buf));
471         Curl_dyn_free(&buf);
472       }
473     }
474     else
475       result = encodeOID(store, beg, end);
476   }
477   return result;
478 }
479 
GTime2str(struct dynbuf * store,const char * beg,const char * end)480 static CURLcode GTime2str(struct dynbuf *store,
481                           const char *beg, const char *end)
482 {
483   const char *tzp;
484   const char *fracp;
485   char sec1, sec2;
486   size_t fracl;
487   size_t tzl;
488   const char *sep = "";
489 
490   /* Convert an ASN.1 Generalized time to a printable string.
491      Return the dynamically allocated string, or NULL if an error occurs. */
492 
493   for(fracp = beg; fracp < end && ISDIGIT(*fracp); fracp++)
494     ;
495 
496   /* Get seconds digits. */
497   sec1 = '0';
498   switch(fracp - beg - 12) {
499   case 0:
500     sec2 = '0';
501     break;
502   case 2:
503     sec1 = fracp[-2];
504     FALLTHROUGH();
505   case 1:
506     sec2 = fracp[-1];
507     break;
508   default:
509     return CURLE_BAD_FUNCTION_ARGUMENT;
510   }
511 
512   /* timezone follows optional fractional seconds. */
513   tzp = fracp;
514   fracl = 0; /* no fractional seconds detected so far */
515   if(fracp < end && (*fracp == '.' || *fracp == ',')) {
516     /* Have fractional seconds, e.g. "[.,]\d+". How many? */
517     fracp++; /* should be a digit char or BAD ARGUMENT */
518     tzp = fracp;
519     while(tzp < end && ISDIGIT(*tzp))
520       tzp++;
521     if(tzp == fracp) /* never looped, no digit after [.,] */
522       return CURLE_BAD_FUNCTION_ARGUMENT;
523     fracl = tzp - fracp; /* number of fractional sec digits */
524     DEBUGASSERT(fracl > 0);
525     /* Strip trailing zeroes in fractional seconds.
526      * May reduce fracl to 0 if only '0's are present. */
527     while(fracl && fracp[fracl - 1] == '0')
528       fracl--;
529   }
530 
531   /* Process timezone. */
532   if(tzp >= end) {
533     tzp = "";
534     tzl = 0;
535   }
536   else if(*tzp == 'Z') {
537     sep = " ";
538     tzp = "GMT";
539     tzl = 3;
540   }
541   else if((*tzp == '+') || (*tzp == '-')) {
542     sep = " UTC";
543     tzl = end - tzp;
544   }
545   else {
546     sep = " ";
547     tzl = end - tzp;
548   }
549 
550   return Curl_dyn_addf(store,
551                        "%.4s-%.2s-%.2s %.2s:%.2s:%c%c%s%.*s%s%.*s",
552                        beg, beg + 4, beg + 6,
553                        beg + 8, beg + 10, sec1, sec2,
554                        fracl ? ".": "", (int)fracl, fracp,
555                        sep, (int)tzl, tzp);
556 }
557 
558 #ifdef UNITTESTS
559 /* used by unit1656.c */
Curl_x509_GTime2str(struct dynbuf * store,const char * beg,const char * end)560 CURLcode Curl_x509_GTime2str(struct dynbuf *store,
561                              const char *beg, const char *end)
562 {
563   return GTime2str(store, beg, end);
564 }
565 #endif
566 
567 /*
568  * Convert an ASN.1 UTC time to a printable string.
569  *
570  * Return error code.
571  */
UTime2str(struct dynbuf * store,const char * beg,const char * end)572 static CURLcode UTime2str(struct dynbuf *store,
573                              const char *beg, const char *end)
574 {
575   const char *tzp;
576   size_t tzl;
577   const char *sec;
578 
579   for(tzp = beg; tzp < end && *tzp >= '0' && *tzp <= '9'; tzp++)
580     ;
581   /* Get the seconds. */
582   sec = beg + 10;
583   switch(tzp - sec) {
584   case 0:
585     sec = "00";
586     FALLTHROUGH();
587   case 2:
588     break;
589   default:
590     return CURLE_BAD_FUNCTION_ARGUMENT;
591   }
592 
593   /* Process timezone. */
594   if(tzp >= end)
595     return CURLE_BAD_FUNCTION_ARGUMENT;
596   if(*tzp == 'Z') {
597     tzp = "GMT";
598     end = tzp + 3;
599   }
600   else
601     tzp++;
602 
603   tzl = end - tzp;
604   return Curl_dyn_addf(store, "%u%.2s-%.2s-%.2s %.2s:%.2s:%.2s %.*s",
605                        20 - (*beg >= '5'), beg, beg + 2, beg + 4,
606                        beg + 6, beg + 8, sec,
607                        (int)tzl, tzp);
608 }
609 
610 /*
611  * Convert an ASN.1 element to a printable string.
612  *
613  * Return error
614  */
ASN1tostr(struct dynbuf * store,struct Curl_asn1Element * elem,int type)615 static CURLcode ASN1tostr(struct dynbuf *store,
616                           struct Curl_asn1Element *elem, int type)
617 {
618   CURLcode result = CURLE_BAD_FUNCTION_ARGUMENT;
619   if(elem->constructed)
620     return result; /* No conversion of structured elements. */
621 
622   if(!type)
623     type = elem->tag;   /* Type not forced: use element tag as type. */
624 
625   switch(type) {
626   case CURL_ASN1_BOOLEAN:
627     result = bool2str(store, elem->beg, elem->end);
628     break;
629   case CURL_ASN1_INTEGER:
630   case CURL_ASN1_ENUMERATED:
631     result = int2str(store, elem->beg, elem->end);
632     break;
633   case CURL_ASN1_BIT_STRING:
634     result = bit2str(store, elem->beg, elem->end);
635     break;
636   case CURL_ASN1_OCTET_STRING:
637     result = octet2str(store, elem->beg, elem->end);
638     break;
639   case CURL_ASN1_NULL:
640     result = Curl_dyn_addn(store, "", 1);
641     break;
642   case CURL_ASN1_OBJECT_IDENTIFIER:
643     result = OID2str(store, elem->beg, elem->end, TRUE);
644     break;
645   case CURL_ASN1_UTC_TIME:
646     result = UTime2str(store, elem->beg, elem->end);
647     break;
648   case CURL_ASN1_GENERALIZED_TIME:
649     result = GTime2str(store, elem->beg, elem->end);
650     break;
651   case CURL_ASN1_UTF8_STRING:
652   case CURL_ASN1_NUMERIC_STRING:
653   case CURL_ASN1_PRINTABLE_STRING:
654   case CURL_ASN1_TELETEX_STRING:
655   case CURL_ASN1_IA5_STRING:
656   case CURL_ASN1_VISIBLE_STRING:
657   case CURL_ASN1_UNIVERSAL_STRING:
658   case CURL_ASN1_BMP_STRING:
659     result = utf8asn1str(store, type, elem->beg, elem->end);
660     break;
661   }
662 
663   return result;
664 }
665 
666 /*
667  * ASCII encode distinguished name at `dn' into the store dynbuf.
668  *
669  * Returns error.
670  */
encodeDN(struct dynbuf * store,struct Curl_asn1Element * dn)671 static CURLcode encodeDN(struct dynbuf *store, struct Curl_asn1Element *dn)
672 {
673   struct Curl_asn1Element rdn;
674   struct Curl_asn1Element atv;
675   struct Curl_asn1Element oid;
676   struct Curl_asn1Element value;
677   const char *p1;
678   const char *p2;
679   const char *p3;
680   const char *str;
681   CURLcode result = CURLE_OK;
682   bool added = FALSE;
683   struct dynbuf temp;
684   Curl_dyn_init(&temp, CURL_X509_STR_MAX);
685 
686   for(p1 = dn->beg; p1 < dn->end;) {
687     p1 = getASN1Element(&rdn, p1, dn->end);
688     if(!p1) {
689       result = CURLE_BAD_FUNCTION_ARGUMENT;
690       goto error;
691     }
692     for(p2 = rdn.beg; p2 < rdn.end;) {
693       p2 = getASN1Element(&atv, p2, rdn.end);
694       if(!p2) {
695         result = CURLE_BAD_FUNCTION_ARGUMENT;
696         goto error;
697       }
698       p3 = getASN1Element(&oid, atv.beg, atv.end);
699       if(!p3) {
700         result = CURLE_BAD_FUNCTION_ARGUMENT;
701         goto error;
702       }
703       if(!getASN1Element(&value, p3, atv.end)) {
704         result = CURLE_BAD_FUNCTION_ARGUMENT;
705         goto error;
706       }
707       Curl_dyn_reset(&temp);
708       result = ASN1tostr(&temp, &oid, 0);
709       if(result)
710         goto error;
711 
712       str = Curl_dyn_ptr(&temp);
713 
714       if(!str) {
715         result = CURLE_BAD_FUNCTION_ARGUMENT;
716         goto error;
717       }
718 
719       /* Encode delimiter.
720          If attribute has a short uppercase name, delimiter is ", ". */
721       for(p3 = str; ISUPPER(*p3); p3++)
722         ;
723       if(added) {
724         if(p3 - str > 2)
725           result = Curl_dyn_addn(store, "/", 1);
726         else
727           result = Curl_dyn_addn(store, ", ", 2);
728         if(result)
729           goto error;
730       }
731 
732       /* Encode attribute name. */
733       result = Curl_dyn_add(store, str);
734       if(result)
735         goto error;
736 
737       /* Generate equal sign. */
738       result = Curl_dyn_addn(store, "=", 1);
739       if(result)
740         goto error;
741 
742       /* Generate value. */
743       result = ASN1tostr(store, &value, 0);
744       if(result)
745         goto error;
746       Curl_dyn_reset(&temp);
747       added = TRUE; /* use separator for next */
748     }
749   }
750 error:
751   Curl_dyn_free(&temp);
752 
753   return result;
754 }
755 
756 #endif /* WANT_EXTRACT_CERTINFO */
757 
758 #ifdef WANT_PARSEX509
759 /*
760  * ASN.1 parse an X509 certificate into structure subfields.
761  * Syntax is assumed to have already been checked by the SSL backend.
762  * See RFC 5280.
763  */
Curl_parseX509(struct Curl_X509certificate * cert,const char * beg,const char * end)764 int Curl_parseX509(struct Curl_X509certificate *cert,
765                    const char *beg, const char *end)
766 {
767   struct Curl_asn1Element elem;
768   struct Curl_asn1Element tbsCertificate;
769   const char *ccp;
770   static const char defaultVersion = 0;  /* v1. */
771 
772   cert->certificate.header = NULL;
773   cert->certificate.beg = beg;
774   cert->certificate.end = end;
775 
776   /* Get the sequence content. */
777   if(!getASN1Element(&elem, beg, end))
778     return -1;  /* Invalid bounds/size. */
779   beg = elem.beg;
780   end = elem.end;
781 
782   /* Get tbsCertificate. */
783   beg = getASN1Element(&tbsCertificate, beg, end);
784   if(!beg)
785     return -1;
786   /* Skip the signatureAlgorithm. */
787   beg = getASN1Element(&cert->signatureAlgorithm, beg, end);
788   if(!beg)
789     return -1;
790   /* Get the signatureValue. */
791   if(!getASN1Element(&cert->signature, beg, end))
792     return -1;
793 
794   /* Parse TBSCertificate. */
795   beg = tbsCertificate.beg;
796   end = tbsCertificate.end;
797   /* Get optional version, get serialNumber. */
798   cert->version.header = NULL;
799   cert->version.beg = &defaultVersion;
800   cert->version.end = &defaultVersion + sizeof(defaultVersion);
801   beg = getASN1Element(&elem, beg, end);
802   if(!beg)
803     return -1;
804   if(elem.tag == 0) {
805     if(!getASN1Element(&cert->version, elem.beg, elem.end))
806       return -1;
807     beg = getASN1Element(&elem, beg, end);
808     if(!beg)
809       return -1;
810   }
811   cert->serialNumber = elem;
812   /* Get signature algorithm. */
813   beg = getASN1Element(&cert->signatureAlgorithm, beg, end);
814   /* Get issuer. */
815   beg = getASN1Element(&cert->issuer, beg, end);
816   if(!beg)
817     return -1;
818   /* Get notBefore and notAfter. */
819   beg = getASN1Element(&elem, beg, end);
820   if(!beg)
821     return -1;
822   ccp = getASN1Element(&cert->notBefore, elem.beg, elem.end);
823   if(!ccp)
824     return -1;
825   if(!getASN1Element(&cert->notAfter, ccp, elem.end))
826     return -1;
827   /* Get subject. */
828   beg = getASN1Element(&cert->subject, beg, end);
829   if(!beg)
830     return -1;
831   /* Get subjectPublicKeyAlgorithm and subjectPublicKey. */
832   beg = getASN1Element(&cert->subjectPublicKeyInfo, beg, end);
833   if(!beg)
834     return -1;
835   ccp = getASN1Element(&cert->subjectPublicKeyAlgorithm,
836                        cert->subjectPublicKeyInfo.beg,
837                        cert->subjectPublicKeyInfo.end);
838   if(!ccp)
839     return -1;
840   if(!getASN1Element(&cert->subjectPublicKey, ccp,
841                      cert->subjectPublicKeyInfo.end))
842     return -1;
843   /* Get optional issuerUiqueID, subjectUniqueID and extensions. */
844   cert->issuerUniqueID.tag = cert->subjectUniqueID.tag = 0;
845   cert->extensions.tag = elem.tag = 0;
846   cert->issuerUniqueID.header = cert->subjectUniqueID.header = NULL;
847   cert->issuerUniqueID.beg = cert->issuerUniqueID.end = "";
848   cert->subjectUniqueID.beg = cert->subjectUniqueID.end = "";
849   cert->extensions.header = NULL;
850   cert->extensions.beg = cert->extensions.end = "";
851   if(beg < end) {
852     beg = getASN1Element(&elem, beg, end);
853     if(!beg)
854       return -1;
855   }
856   if(elem.tag == 1) {
857     cert->issuerUniqueID = elem;
858     if(beg < end) {
859       beg = getASN1Element(&elem, beg, end);
860       if(!beg)
861         return -1;
862     }
863   }
864   if(elem.tag == 2) {
865     cert->subjectUniqueID = elem;
866     if(beg < end) {
867       beg = getASN1Element(&elem, beg, end);
868       if(!beg)
869         return -1;
870     }
871   }
872   if(elem.tag == 3)
873     if(!getASN1Element(&cert->extensions, elem.beg, elem.end))
874       return -1;
875   return 0;
876 }
877 
878 #endif /* WANT_PARSEX509 */
879 
880 #ifdef WANT_EXTRACT_CERTINFO
881 
dumpAlgo(struct dynbuf * store,struct Curl_asn1Element * param,const char * beg,const char * end)882 static CURLcode dumpAlgo(struct dynbuf *store,
883                          struct Curl_asn1Element *param,
884                          const char *beg, const char *end)
885 {
886   struct Curl_asn1Element oid;
887 
888   /* Get algorithm parameters and return algorithm name. */
889 
890   beg = getASN1Element(&oid, beg, end);
891   if(!beg)
892     return CURLE_BAD_FUNCTION_ARGUMENT;
893   param->header = NULL;
894   param->tag = 0;
895   param->beg = param->end = end;
896   if(beg < end) {
897     const char *p = getASN1Element(param, beg, end);
898     if(!p)
899       return CURLE_BAD_FUNCTION_ARGUMENT;
900   }
901   return OID2str(store, oid.beg, oid.end, TRUE);
902 }
903 
904 /*
905  * This is a convenience function for push_certinfo_len that takes a zero
906  * terminated value.
907  */
ssl_push_certinfo(struct Curl_easy * data,int certnum,const char * label,const char * value)908 static CURLcode ssl_push_certinfo(struct Curl_easy *data,
909                                   int certnum,
910                                   const char *label,
911                                   const char *value)
912 {
913   size_t valuelen = strlen(value);
914 
915   return Curl_ssl_push_certinfo_len(data, certnum, label, value, valuelen);
916 }
917 
918 /*
919  * This is a convenience function for push_certinfo_len that takes a
920  * dynbuf value.
921  *
922  * It also does the verbose output if !certnum.
923  */
ssl_push_certinfo_dyn(struct Curl_easy * data,int certnum,const char * label,struct dynbuf * ptr)924 static CURLcode ssl_push_certinfo_dyn(struct Curl_easy *data,
925                                       int certnum,
926                                       const char *label,
927                                       struct dynbuf *ptr)
928 {
929   size_t valuelen = Curl_dyn_len(ptr);
930   char *value = Curl_dyn_ptr(ptr);
931 
932   CURLcode result = Curl_ssl_push_certinfo_len(data, certnum, label,
933                                                value, valuelen);
934 
935   if(!certnum && !result)
936     infof(data, "   %s: %s", label, value);
937 
938   return result;
939 }
940 
do_pubkey_field(struct Curl_easy * data,int certnum,const char * label,struct Curl_asn1Element * elem)941 static CURLcode do_pubkey_field(struct Curl_easy *data, int certnum,
942                                 const char *label,
943                                 struct Curl_asn1Element *elem)
944 {
945   CURLcode result;
946   struct dynbuf out;
947 
948   Curl_dyn_init(&out, CURL_X509_STR_MAX);
949 
950   /* Generate a certificate information record for the public key. */
951 
952   result = ASN1tostr(&out, elem, 0);
953   if(!result) {
954     if(data->set.ssl.certinfo)
955       result = ssl_push_certinfo_dyn(data, certnum, label, &out);
956     Curl_dyn_free(&out);
957   }
958   return result;
959 }
960 
961 /* return 0 on success, 1 on error */
do_pubkey(struct Curl_easy * data,int certnum,const char * algo,struct Curl_asn1Element * param,struct Curl_asn1Element * pubkey)962 static int do_pubkey(struct Curl_easy *data, int certnum,
963                      const char *algo, struct Curl_asn1Element *param,
964                      struct Curl_asn1Element *pubkey)
965 {
966   struct Curl_asn1Element elem;
967   struct Curl_asn1Element pk;
968   const char *p;
969 
970   /* Generate all information records for the public key. */
971 
972   if(strcasecompare(algo, "ecPublicKey")) {
973     /*
974      * ECC public key is all the data, a value of type BIT STRING mapped to
975      * OCTET STRING and should not be parsed as an ASN.1 value.
976      */
977     const size_t len = ((pubkey->end - pubkey->beg - 2) * 4);
978     if(!certnum)
979       infof(data, "   ECC Public Key (%zu bits)", len);
980     if(data->set.ssl.certinfo) {
981       char q[sizeof(len) * 8 / 3 + 1];
982       (void)msnprintf(q, sizeof(q), "%zu", len);
983       if(ssl_push_certinfo(data, certnum, "ECC Public Key", q))
984         return 1;
985     }
986     return do_pubkey_field(data, certnum, "ecPublicKey", pubkey) == CURLE_OK
987       ? 0 : 1;
988   }
989 
990   /* Get the public key (single element). */
991   if(!getASN1Element(&pk, pubkey->beg + 1, pubkey->end))
992     return 1;
993 
994   if(strcasecompare(algo, "rsaEncryption")) {
995     const char *q;
996     size_t len;
997 
998     p = getASN1Element(&elem, pk.beg, pk.end);
999     if(!p)
1000       return 1;
1001 
1002     /* Compute key length. */
1003     for(q = elem.beg; !*q && q < elem.end; q++)
1004       ;
1005     len = ((elem.end - q) * 8);
1006     if(len) {
1007       unsigned int i;
1008       for(i = *(unsigned char *) q; !(i & 0x80); i <<= 1)
1009         len--;
1010     }
1011     if(len > 32)
1012       elem.beg = q;     /* Strip leading zero bytes. */
1013     if(!certnum)
1014       infof(data, "   RSA Public Key (%zu bits)", len);
1015     if(data->set.ssl.certinfo) {
1016       char r[sizeof(len) * 8 / 3 + 1];
1017       msnprintf(r, sizeof(r), "%zu", len);
1018       if(ssl_push_certinfo(data, certnum, "RSA Public Key", r))
1019         return 1;
1020     }
1021     /* Generate coefficients. */
1022     if(do_pubkey_field(data, certnum, "rsa(n)", &elem))
1023       return 1;
1024     if(!getASN1Element(&elem, p, pk.end))
1025       return 1;
1026     if(do_pubkey_field(data, certnum, "rsa(e)", &elem))
1027       return 1;
1028   }
1029   else if(strcasecompare(algo, "dsa")) {
1030     p = getASN1Element(&elem, param->beg, param->end);
1031     if(p) {
1032       if(do_pubkey_field(data, certnum, "dsa(p)", &elem))
1033         return 1;
1034       p = getASN1Element(&elem, p, param->end);
1035       if(p) {
1036         if(do_pubkey_field(data, certnum, "dsa(q)", &elem))
1037           return 1;
1038         if(getASN1Element(&elem, p, param->end)) {
1039           if(do_pubkey_field(data, certnum, "dsa(g)", &elem))
1040             return 1;
1041           if(do_pubkey_field(data, certnum, "dsa(pub_key)", &pk))
1042             return 1;
1043         }
1044       }
1045     }
1046   }
1047   else if(strcasecompare(algo, "dhpublicnumber")) {
1048     p = getASN1Element(&elem, param->beg, param->end);
1049     if(p) {
1050       if(do_pubkey_field(data, certnum, "dh(p)", &elem))
1051         return 1;
1052       if(getASN1Element(&elem, param->beg, param->end)) {
1053         if(do_pubkey_field(data, certnum, "dh(g)", &elem))
1054           return 1;
1055         if(do_pubkey_field(data, certnum, "dh(pub_key)", &pk))
1056           return 1;
1057       }
1058     }
1059   }
1060   return 0;
1061 }
1062 
1063 /*
1064  * Convert an ASN.1 distinguished name into a printable string.
1065  * Return error.
1066  */
DNtostr(struct dynbuf * store,struct Curl_asn1Element * dn)1067 static CURLcode DNtostr(struct dynbuf *store,
1068                         struct Curl_asn1Element *dn)
1069 {
1070   return encodeDN(store, dn);
1071 }
1072 
Curl_extract_certinfo(struct Curl_easy * data,int certnum,const char * beg,const char * end)1073 CURLcode Curl_extract_certinfo(struct Curl_easy *data,
1074                                int certnum,
1075                                const char *beg,
1076                                const char *end)
1077 {
1078   struct Curl_X509certificate cert;
1079   struct Curl_asn1Element param;
1080   char *certptr;
1081   size_t clen;
1082   struct dynbuf out;
1083   CURLcode result = CURLE_OK;
1084   unsigned int version;
1085   const char *ptr;
1086   int rc;
1087 
1088   if(!data->set.ssl.certinfo)
1089     if(certnum)
1090       return CURLE_OK;
1091 
1092   Curl_dyn_init(&out, CURL_X509_STR_MAX);
1093   /* Prepare the certificate information for curl_easy_getinfo(). */
1094 
1095   /* Extract the certificate ASN.1 elements. */
1096   if(Curl_parseX509(&cert, beg, end))
1097     return CURLE_PEER_FAILED_VERIFICATION;
1098 
1099   /* Subject. */
1100   result = DNtostr(&out, &cert.subject);
1101   if(result)
1102     goto done;
1103   if(data->set.ssl.certinfo) {
1104     result = ssl_push_certinfo_dyn(data, certnum, "Subject", &out);
1105     if(result)
1106       goto done;
1107   }
1108   Curl_dyn_reset(&out);
1109 
1110   /* Issuer. */
1111   result = DNtostr(&out, &cert.issuer);
1112   if(result)
1113     goto done;
1114   if(data->set.ssl.certinfo) {
1115     result = ssl_push_certinfo_dyn(data, certnum, "Issuer", &out);
1116     if(result)
1117       goto done;
1118   }
1119   Curl_dyn_reset(&out);
1120 
1121   /* Version (always fits in less than 32 bits). */
1122   version = 0;
1123   for(ptr = cert.version.beg; ptr < cert.version.end; ptr++)
1124     version = (version << 8) | *(const unsigned char *) ptr;
1125   if(data->set.ssl.certinfo) {
1126     result = Curl_dyn_addf(&out, "%x", version);
1127     if(result)
1128       goto done;
1129     result = ssl_push_certinfo_dyn(data, certnum, "Version", &out);
1130     if(result)
1131       goto done;
1132     Curl_dyn_reset(&out);
1133   }
1134 
1135   /* Serial number. */
1136   result = ASN1tostr(&out, &cert.serialNumber, 0);
1137   if(result)
1138     goto done;
1139   if(data->set.ssl.certinfo) {
1140     result = ssl_push_certinfo_dyn(data, certnum, "Serial Number", &out);
1141     if(result)
1142       goto done;
1143   }
1144   Curl_dyn_reset(&out);
1145 
1146   /* Signature algorithm .*/
1147   result = dumpAlgo(&out, &param, cert.signatureAlgorithm.beg,
1148                     cert.signatureAlgorithm.end);
1149   if(result)
1150     goto done;
1151   if(data->set.ssl.certinfo) {
1152     result = ssl_push_certinfo_dyn(data, certnum, "Signature Algorithm",
1153                                    &out);
1154     if(result)
1155       goto done;
1156   }
1157   Curl_dyn_reset(&out);
1158 
1159   /* Start Date. */
1160   result = ASN1tostr(&out, &cert.notBefore, 0);
1161   if(result)
1162     goto done;
1163   if(data->set.ssl.certinfo) {
1164     result = ssl_push_certinfo_dyn(data, certnum, "Start Date", &out);
1165     if(result)
1166       goto done;
1167   }
1168   Curl_dyn_reset(&out);
1169 
1170   /* Expire Date. */
1171   result = ASN1tostr(&out, &cert.notAfter, 0);
1172   if(result)
1173     goto done;
1174   if(data->set.ssl.certinfo) {
1175     result = ssl_push_certinfo_dyn(data, certnum, "Expire Date", &out);
1176     if(result)
1177       goto done;
1178   }
1179   Curl_dyn_reset(&out);
1180 
1181   /* Public Key Algorithm. */
1182   result = dumpAlgo(&out, &param, cert.subjectPublicKeyAlgorithm.beg,
1183                     cert.subjectPublicKeyAlgorithm.end);
1184   if(result)
1185     goto done;
1186   if(data->set.ssl.certinfo) {
1187     result = ssl_push_certinfo_dyn(data, certnum, "Public Key Algorithm",
1188                                    &out);
1189     if(result)
1190       goto done;
1191   }
1192 
1193   rc = do_pubkey(data, certnum, Curl_dyn_ptr(&out),
1194                  &param, &cert.subjectPublicKey);
1195   if(rc) {
1196     result = CURLE_OUT_OF_MEMORY; /* the most likely error */
1197     goto done;
1198   }
1199   Curl_dyn_reset(&out);
1200 
1201   /* Signature. */
1202   result = ASN1tostr(&out, &cert.signature, 0);
1203   if(result)
1204     goto done;
1205   if(data->set.ssl.certinfo) {
1206     result = ssl_push_certinfo_dyn(data, certnum, "Signature", &out);
1207     if(result)
1208       goto done;
1209   }
1210   Curl_dyn_reset(&out);
1211 
1212   /* Generate PEM certificate. */
1213   result = Curl_base64_encode(cert.certificate.beg,
1214                               cert.certificate.end - cert.certificate.beg,
1215                               &certptr, &clen);
1216   if(result)
1217     goto done;
1218 
1219   /* Generate the final output certificate string. Format is:
1220      -----BEGIN CERTIFICATE-----\n
1221      <max 64 base64 characters>\n
1222      .
1223      .
1224      .
1225      -----END CERTIFICATE-----\n
1226    */
1227 
1228   Curl_dyn_reset(&out);
1229 
1230   /* Build the certificate string. */
1231   result = Curl_dyn_add(&out, "-----BEGIN CERTIFICATE-----\n");
1232   if(!result) {
1233     size_t j = 0;
1234 
1235     while(!result && (j < clen)) {
1236       size_t chunksize = (clen - j) > 64 ? 64 : (clen - j);
1237       result = Curl_dyn_addn(&out, &certptr[j], chunksize);
1238       if(!result)
1239         result = Curl_dyn_addn(&out, "\n", 1);
1240       j += chunksize;
1241     }
1242     if(!result)
1243       result = Curl_dyn_add(&out, "-----END CERTIFICATE-----\n");
1244   }
1245   free(certptr);
1246   if(!result)
1247     if(data->set.ssl.certinfo)
1248       result = ssl_push_certinfo_dyn(data, certnum, "Cert", &out);
1249 
1250 done:
1251   if(result)
1252     failf(data, "Failed extracting certificate chain");
1253   Curl_dyn_free(&out);
1254   return result;
1255 }
1256 
1257 #endif /* WANT_EXTRACT_CERTINFO */
1258 
1259 #endif /* USE_GNUTLS or USE_WOLFSSL or USE_SCHANNEL or USE_SECTRANSP */
1260