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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 
30 #if defined(USE_WOLFSSL) || defined(USE_SCHANNEL)
31 #define WANT_PARSEX509 /* uses Curl_parseX509() */
32 #endif
33 
34 #if defined(USE_GNUTLS) || defined(USE_SCHANNEL) || defined(USE_SECTRANSP)
35 #define WANT_EXTRACT_CERTINFO /* uses Curl_extract_certinfo() */
36 #define WANT_PARSEX509 /* ... uses Curl_parseX509() */
37 #endif
38 
39 #include <curl/curl.h>
40 #include "urldata.h"
41 #include "strcase.h"
42 #include "curl_ctype.h"
43 #include "hostcheck.h"
44 #include "vtls/vtls.h"
45 #include "vtls/vtls_int.h"
46 #include "sendf.h"
47 #include "inet_pton.h"
48 #include "curl_base64.h"
49 #include "x509asn1.h"
50 #include "dynbuf.h"
51 
52 /* The last 3 #include files should be in this order */
53 #include "curl_printf.h"
54 #include "curl_memory.h"
55 #include "memdebug.h"
56 
57 /*
58  * Constants.
59  */
60 
61 /* Largest supported ASN.1 structure. */
62 #define CURL_ASN1_MAX                   ((size_t) 0x40000)      /* 256K */
63 
64 /* ASN.1 classes. */
65 #define CURL_ASN1_UNIVERSAL             0
66 #define CURL_ASN1_APPLICATION           1
67 #define CURL_ASN1_CONTEXT_SPECIFIC      2
68 #define CURL_ASN1_PRIVATE               3
69 
70 /* ASN.1 types. */
71 #define CURL_ASN1_BOOLEAN               1
72 #define CURL_ASN1_INTEGER               2
73 #define CURL_ASN1_BIT_STRING            3
74 #define CURL_ASN1_OCTET_STRING          4
75 #define CURL_ASN1_NULL                  5
76 #define CURL_ASN1_OBJECT_IDENTIFIER     6
77 #define CURL_ASN1_OBJECT_DESCRIPTOR     7
78 #define CURL_ASN1_INSTANCE_OF           8
79 #define CURL_ASN1_REAL                  9
80 #define CURL_ASN1_ENUMERATED            10
81 #define CURL_ASN1_EMBEDDED              11
82 #define CURL_ASN1_UTF8_STRING           12
83 #define CURL_ASN1_RELATIVE_OID          13
84 #define CURL_ASN1_SEQUENCE              16
85 #define CURL_ASN1_SET                   17
86 #define CURL_ASN1_NUMERIC_STRING        18
87 #define CURL_ASN1_PRINTABLE_STRING      19
88 #define CURL_ASN1_TELETEX_STRING        20
89 #define CURL_ASN1_VIDEOTEX_STRING       21
90 #define CURL_ASN1_IA5_STRING            22
91 #define CURL_ASN1_UTC_TIME              23
92 #define CURL_ASN1_GENERALIZED_TIME      24
93 #define CURL_ASN1_GRAPHIC_STRING        25
94 #define CURL_ASN1_VISIBLE_STRING        26
95 #define CURL_ASN1_GENERAL_STRING        27
96 #define CURL_ASN1_UNIVERSAL_STRING      28
97 #define CURL_ASN1_CHARACTER_STRING      29
98 #define CURL_ASN1_BMP_STRING            30
99 
100 /* Max sixes */
101 
102 #define MAX_X509_STR  10000
103 #define MAX_X509_CERT 100000
104 
105 #ifdef WANT_EXTRACT_CERTINFO
106 /* ASN.1 OID table entry. */
107 struct Curl_OID {
108   const char *numoid;  /* Dotted-numeric OID. */
109   const char *textoid; /* OID name. */
110 };
111 
112 /* ASN.1 OIDs. */
113 static const char       cnOID[] = "2.5.4.3";    /* Common name. */
114 static const char       sanOID[] = "2.5.29.17"; /* Subject alternative name. */
115 
116 static const struct Curl_OID OIDtable[] = {
117   { "1.2.840.10040.4.1",        "dsa" },
118   { "1.2.840.10040.4.3",        "dsa-with-sha1" },
119   { "1.2.840.10045.2.1",        "ecPublicKey" },
120   { "1.2.840.10045.3.0.1",      "c2pnb163v1" },
121   { "1.2.840.10045.4.1",        "ecdsa-with-SHA1" },
122   { "1.2.840.10046.2.1",        "dhpublicnumber" },
123   { "1.2.840.113549.1.1.1",     "rsaEncryption" },
124   { "1.2.840.113549.1.1.2",     "md2WithRSAEncryption" },
125   { "1.2.840.113549.1.1.4",     "md5WithRSAEncryption" },
126   { "1.2.840.113549.1.1.5",     "sha1WithRSAEncryption" },
127   { "1.2.840.113549.1.1.10",    "RSASSA-PSS" },
128   { "1.2.840.113549.1.1.14",    "sha224WithRSAEncryption" },
129   { "1.2.840.113549.1.1.11",    "sha256WithRSAEncryption" },
130   { "1.2.840.113549.1.1.12",    "sha384WithRSAEncryption" },
131   { "1.2.840.113549.1.1.13",    "sha512WithRSAEncryption" },
132   { "1.2.840.113549.2.2",       "md2" },
133   { "1.2.840.113549.2.5",       "md5" },
134   { "1.3.14.3.2.26",            "sha1" },
135   { cnOID,                      "CN" },
136   { "2.5.4.4",                  "SN" },
137   { "2.5.4.5",                  "serialNumber" },
138   { "2.5.4.6",                  "C" },
139   { "2.5.4.7",                  "L" },
140   { "2.5.4.8",                  "ST" },
141   { "2.5.4.9",                  "streetAddress" },
142   { "2.5.4.10",                 "O" },
143   { "2.5.4.11",                 "OU" },
144   { "2.5.4.12",                 "title" },
145   { "2.5.4.13",                 "description" },
146   { "2.5.4.17",                 "postalCode" },
147   { "2.5.4.41",                 "name" },
148   { "2.5.4.42",                 "givenName" },
149   { "2.5.4.43",                 "initials" },
150   { "2.5.4.44",                 "generationQualifier" },
151   { "2.5.4.45",                 "X500UniqueIdentifier" },
152   { "2.5.4.46",                 "dnQualifier" },
153   { "2.5.4.65",                 "pseudonym" },
154   { "1.2.840.113549.1.9.1",     "emailAddress" },
155   { "2.5.4.72",                 "role" },
156   { sanOID,                     "subjectAltName" },
157   { "2.5.29.18",                "issuerAltName" },
158   { "2.5.29.19",                "basicConstraints" },
159   { "2.16.840.1.101.3.4.2.4",   "sha224" },
160   { "2.16.840.1.101.3.4.2.1",   "sha256" },
161   { "2.16.840.1.101.3.4.2.2",   "sha384" },
162   { "2.16.840.1.101.3.4.2.3",   "sha512" },
163   { "1.2.840.113549.1.9.2",     "unstructuredName" },
164   { (const char *) NULL,        (const char *) NULL }
165 };
166 
167 #endif /* WANT_EXTRACT_CERTINFO */
168 
169 /*
170  * Lightweight ASN.1 parser.
171  * In particular, it does not check for syntactic/lexical errors.
172  * It is intended to support certificate information gathering for SSL backends
173  * that offer a mean to get certificates as a whole, but do not supply
174  * entry points to get particular certificate sub-fields.
175  * Please note there is no pretension here to rewrite a full SSL library.
176  */
177 
178 static const char *getASN1Element(struct Curl_asn1Element *elem,
179                                   const char *beg, const char *end)
180   WARN_UNUSED_RESULT;
181 
getASN1Element(struct Curl_asn1Element * elem,const char * beg,const char * end)182 static const char *getASN1Element(struct Curl_asn1Element *elem,
183                                   const char *beg, const char *end)
184 {
185   unsigned char b;
186   size_t len;
187   struct Curl_asn1Element lelem;
188 
189   /* Get a single ASN.1 element into `elem', parse ASN.1 string at `beg'
190      ending at `end'.
191      Returns a pointer in source string after the parsed element, or NULL
192      if an error occurs. */
193   if(!beg || !end || beg >= end || !*beg ||
194      (size_t)(end - beg) > CURL_ASN1_MAX)
195     return NULL;
196 
197   /* Process header byte. */
198   elem->header = beg;
199   b = (unsigned char) *beg++;
200   elem->constructed = (b & 0x20) != 0;
201   elem->class = (b >> 6) & 3;
202   b &= 0x1F;
203   if(b == 0x1F)
204     return NULL; /* Long tag values not supported here. */
205   elem->tag = b;
206 
207   /* Process length. */
208   if(beg >= end)
209     return NULL;
210   b = (unsigned char) *beg++;
211   if(!(b & 0x80))
212     len = b;
213   else if(!(b &= 0x7F)) {
214     /* Unspecified length. Since we have all the data, we can determine the
215        effective length by skipping element until an end element is found. */
216     if(!elem->constructed)
217       return NULL;
218     elem->beg = beg;
219     while(beg < end && *beg) {
220       beg = getASN1Element(&lelem, beg, end);
221       if(!beg)
222         return NULL;
223     }
224     if(beg >= end)
225       return NULL;
226     elem->end = beg;
227     return beg + 1;
228   }
229   else if((unsigned)b > (size_t)(end - beg))
230     return NULL; /* Does not fit in source. */
231   else {
232     /* Get long length. */
233     len = 0;
234     do {
235       if(len & 0xFF000000L)
236         return NULL;  /* Lengths > 32 bits are not supported. */
237       len = (len << 8) | (unsigned char) *beg++;
238     } while(--b);
239   }
240   if(len > (size_t)(end - beg))
241     return NULL;  /* Element data does not fit in source. */
242   elem->beg = beg;
243   elem->end = beg + len;
244   return elem->end;
245 }
246 
247 #ifdef WANT_EXTRACT_CERTINFO
248 
249 /*
250  * Search the null terminated OID or OID identifier in local table.
251  * Return the table entry pointer or NULL if not found.
252  */
searchOID(const char * oid)253 static const struct Curl_OID *searchOID(const char *oid)
254 {
255   const struct Curl_OID *op;
256   for(op = OIDtable; op->numoid; op++)
257     if(!strcmp(op->numoid, oid) || strcasecompare(op->textoid, oid))
258       return op;
259 
260   return NULL;
261 }
262 
263 /*
264  * Convert an ASN.1 Boolean value into its string representation.
265  *
266  * Return error code.
267  */
268 
bool2str(struct dynbuf * store,const char * beg,const char * end)269 static CURLcode bool2str(struct dynbuf *store,
270                          const char *beg, const char *end)
271 {
272   if(end - beg != 1)
273     return CURLE_BAD_FUNCTION_ARGUMENT;
274   return Curl_dyn_add(store, *beg? "TRUE": "FALSE");
275 }
276 
277 /*
278  * Convert an ASN.1 octet string to a printable string.
279  *
280  * Return error code.
281  */
octet2str(struct dynbuf * store,const char * beg,const char * end)282 static CURLcode octet2str(struct dynbuf *store,
283                           const char *beg, const char *end)
284 {
285   CURLcode result = CURLE_OK;
286 
287   while(!result && beg < end)
288     result = Curl_dyn_addf(store, "%02x:", (unsigned char) *beg++);
289 
290   return result;
291 }
292 
bit2str(struct dynbuf * store,const char * beg,const char * end)293 static CURLcode bit2str(struct dynbuf *store,
294                         const char *beg, const char *end)
295 {
296   /* Convert an ASN.1 bit string to a printable string. */
297 
298   if(++beg > end)
299     return CURLE_BAD_FUNCTION_ARGUMENT;
300   return octet2str(store, beg, end);
301 }
302 
303 /*
304  * Convert an ASN.1 integer value into its string representation.
305  *
306  * Returns error.
307  */
int2str(struct dynbuf * store,const char * beg,const char * end)308 static CURLcode int2str(struct dynbuf *store,
309                         const char *beg, const char *end)
310 {
311   unsigned int val = 0;
312   size_t n = end - beg;
313 
314   if(!n)
315     return CURLE_BAD_FUNCTION_ARGUMENT;
316 
317   if(n > 4)
318     return octet2str(store, beg, end);
319 
320   /* Represent integers <= 32-bit as a single value. */
321   if(*beg & 0x80)
322     val = ~val;
323 
324   do
325     val = (val << 8) | *(const unsigned char *) beg++;
326   while(beg < end);
327   return Curl_dyn_addf(store, "%s%x", val >= 10? "0x": "", val);
328 }
329 
330 /*
331  * Convert from an ASN.1 typed string to UTF8.
332  *
333  * The result is stored in a dynbuf that is inited by the user of this
334  * function.
335  *
336  * Returns error.
337  */
338 static CURLcode
utf8asn1str(struct dynbuf * to,int type,const char * from,const char * end)339 utf8asn1str(struct dynbuf *to, int type, const char *from, const char *end)
340 {
341   size_t inlength = end - from;
342   int size = 1;
343   CURLcode result = CURLE_OK;
344 
345   switch(type) {
346   case CURL_ASN1_BMP_STRING:
347     size = 2;
348     break;
349   case CURL_ASN1_UNIVERSAL_STRING:
350     size = 4;
351     break;
352   case CURL_ASN1_NUMERIC_STRING:
353   case CURL_ASN1_PRINTABLE_STRING:
354   case CURL_ASN1_TELETEX_STRING:
355   case CURL_ASN1_IA5_STRING:
356   case CURL_ASN1_VISIBLE_STRING:
357   case CURL_ASN1_UTF8_STRING:
358     break;
359   default:
360     return CURLE_BAD_FUNCTION_ARGUMENT;  /* Conversion not supported. */
361   }
362 
363   if(inlength % size)
364     /* Length inconsistent with character size. */
365     return CURLE_BAD_FUNCTION_ARGUMENT;
366 
367   if(type == CURL_ASN1_UTF8_STRING) {
368     /* Just copy. */
369     if(inlength)
370       result = Curl_dyn_addn(to, from, inlength);
371   }
372   else {
373     while(!result && (from < end)) {
374       char buf[4]; /* decode buffer */
375       int charsize = 1;
376       unsigned int wc = 0;
377 
378       switch(size) {
379       case 4:
380         wc = (wc << 8) | *(const unsigned char *) from++;
381         wc = (wc << 8) | *(const unsigned char *) from++;
382         FALLTHROUGH();
383       case 2:
384         wc = (wc << 8) | *(const unsigned char *) from++;
385         FALLTHROUGH();
386       default: /* case 1: */
387         wc = (wc << 8) | *(const unsigned char *) from++;
388       }
389       if(wc >= 0x00000080) {
390         if(wc >= 0x00000800) {
391           if(wc >= 0x00010000) {
392             if(wc >= 0x00200000) {
393               free(buf);
394               /* Invalid char. size for target encoding. */
395               return CURLE_WEIRD_SERVER_REPLY;
396             }
397             buf[3] = (char) (0x80 | (wc & 0x3F));
398             wc = (wc >> 6) | 0x00010000;
399             charsize++;
400           }
401           buf[2] = (char) (0x80 | (wc & 0x3F));
402           wc = (wc >> 6) | 0x00000800;
403           charsize++;
404         }
405         buf[1] = (char) (0x80 | (wc & 0x3F));
406         wc = (wc >> 6) | 0x000000C0;
407         charsize++;
408       }
409       buf[0] = (char) wc;
410       result = Curl_dyn_addn(to, buf, charsize);
411     }
412   }
413   return result;
414 }
415 
416 /*
417  * Convert an ASN.1 OID into its dotted string representation.
418  *
419  * Return error code.
420  */
encodeOID(struct dynbuf * store,const char * beg,const char * end)421 static CURLcode encodeOID(struct dynbuf *store,
422                           const char *beg, const char *end)
423 {
424   unsigned int x;
425   unsigned int y;
426   CURLcode result = CURLE_OK;
427 
428   /* Process the first two numbers. */
429   y = *(const unsigned char *) beg++;
430   x = y / 40;
431   y -= x * 40;
432 
433   result = Curl_dyn_addf(store, "%u.%u", x, y);
434   if(result)
435     return result;
436 
437   /* Process the trailing numbers. */
438   while(beg < end) {
439     x = 0;
440     do {
441       if(x & 0xFF000000)
442         return 0;
443       y = *(const unsigned char *) beg++;
444       x = (x << 7) | (y & 0x7F);
445     } while(y & 0x80);
446     result = Curl_dyn_addf(store, ".%u", x);
447   }
448   return result;
449 }
450 
451 /*
452  * Convert an ASN.1 OID into its dotted or symbolic string representation.
453  *
454  * Return error code.
455  */
456 
OID2str(struct dynbuf * store,const char * beg,const char * end,bool symbolic)457 static CURLcode OID2str(struct dynbuf *store,
458                         const char *beg, const char *end, bool symbolic)
459 {
460   CURLcode result = CURLE_OK;
461   if(beg < end) {
462     if(symbolic) {
463       struct dynbuf buf;
464       Curl_dyn_init(&buf, MAX_X509_STR);
465       result = encodeOID(&buf, beg, end);
466 
467       if(!result) {
468         const struct Curl_OID *op = searchOID(Curl_dyn_ptr(&buf));
469         if(op)
470           result = Curl_dyn_add(store, op->textoid);
471         else
472           result = CURLE_BAD_FUNCTION_ARGUMENT;
473         Curl_dyn_free(&buf);
474       }
475     }
476     else
477       result = encodeOID(store, beg, end);
478   }
479   return result;
480 }
481 
GTime2str(struct dynbuf * store,const char * beg,const char * end)482 static CURLcode GTime2str(struct dynbuf *store,
483                           const char *beg, const char *end)
484 {
485   const char *tzp;
486   const char *fracp;
487   char sec1, sec2;
488   size_t fracl;
489   size_t tzl;
490   const char *sep = "";
491 
492   /* Convert an ASN.1 Generalized time to a printable string.
493      Return the dynamically allocated string, or NULL if an error occurs. */
494 
495   for(fracp = beg; fracp < end && *fracp >= '0' && *fracp <= '9'; fracp++)
496     ;
497 
498   /* Get seconds digits. */
499   sec1 = '0';
500   switch(fracp - beg - 12) {
501   case 0:
502     sec2 = '0';
503     break;
504   case 2:
505     sec1 = fracp[-2];
506     FALLTHROUGH();
507   case 1:
508     sec2 = fracp[-1];
509     break;
510   default:
511     return CURLE_BAD_FUNCTION_ARGUMENT;
512   }
513 
514   /* Scan for timezone, measure fractional seconds. */
515   tzp = fracp;
516   fracl = 0;
517   if(fracp < end && (*fracp == '.' || *fracp == ',')) {
518     fracp++;
519     do
520       tzp++;
521     while(tzp < end && *tzp >= '0' && *tzp <= '9');
522     /* Strip leading zeroes in fractional seconds. */
523     for(fracl = tzp - fracp - 1; fracl && fracp[fracl - 1] == '0'; fracl--)
524       ;
525   }
526 
527   /* Process timezone. */
528   if(tzp >= end)
529     ;           /* Nothing to do. */
530   else if(*tzp == 'Z') {
531     tzp = " GMT";
532     end = tzp + 4;
533   }
534   else {
535     sep = " ";
536     tzp++;
537   }
538 
539   tzl = end - tzp;
540   return Curl_dyn_addf(store,
541                        "%.4s-%.2s-%.2s %.2s:%.2s:%c%c%s%.*s%s%.*s",
542                        beg, beg + 4, beg + 6,
543                        beg + 8, beg + 10, sec1, sec2,
544                        fracl? ".": "", (int)fracl, fracp,
545                        sep, (int)tzl, tzp);
546 }
547 
548 /*
549  * Convert an ASN.1 UTC time to a printable string.
550  *
551  * Return error code.
552  */
UTime2str(struct dynbuf * store,const char * beg,const char * end)553 static CURLcode UTime2str(struct dynbuf *store,
554                              const char *beg, const char *end)
555 {
556   const char *tzp;
557   size_t tzl;
558   const char *sec;
559 
560   for(tzp = beg; tzp < end && *tzp >= '0' && *tzp <= '9'; tzp++)
561     ;
562   /* Get the seconds. */
563   sec = beg + 10;
564   switch(tzp - sec) {
565   case 0:
566     sec = "00";
567     FALLTHROUGH();
568   case 2:
569     break;
570   default:
571     return CURLE_BAD_FUNCTION_ARGUMENT;
572   }
573 
574   /* Process timezone. */
575   if(tzp >= end)
576     return CURLE_BAD_FUNCTION_ARGUMENT;
577   if(*tzp == 'Z') {
578     tzp = "GMT";
579     end = tzp + 3;
580   }
581   else
582     tzp++;
583 
584   tzl = end - tzp;
585   return Curl_dyn_addf(store, "%u%.2s-%.2s-%.2s %.2s:%.2s:%.2s %.*s",
586                        20 - (*beg >= '5'), beg, beg + 2, beg + 4,
587                        beg + 6, beg + 8, sec,
588                        (int)tzl, tzp);
589 }
590 
591 /*
592  * Convert an ASN.1 element to a printable string.
593  *
594  * Return error
595  */
ASN1tostr(struct dynbuf * store,struct Curl_asn1Element * elem,int type)596 static CURLcode ASN1tostr(struct dynbuf *store,
597                           struct Curl_asn1Element *elem, int type)
598 {
599   CURLcode result = CURLE_BAD_FUNCTION_ARGUMENT;
600   if(elem->constructed)
601     return CURLE_OK; /* No conversion of structured elements. */
602 
603   if(!type)
604     type = elem->tag;   /* Type not forced: use element tag as type. */
605 
606   switch(type) {
607   case CURL_ASN1_BOOLEAN:
608     result = bool2str(store, elem->beg, elem->end);
609     break;
610   case CURL_ASN1_INTEGER:
611   case CURL_ASN1_ENUMERATED:
612     result = int2str(store, elem->beg, elem->end);
613     break;
614   case CURL_ASN1_BIT_STRING:
615     result = bit2str(store, elem->beg, elem->end);
616     break;
617   case CURL_ASN1_OCTET_STRING:
618     result = octet2str(store, elem->beg, elem->end);
619     break;
620   case CURL_ASN1_NULL:
621     result = Curl_dyn_addn(store, "", 1);
622     break;
623   case CURL_ASN1_OBJECT_IDENTIFIER:
624     result = OID2str(store, elem->beg, elem->end, TRUE);
625     break;
626   case CURL_ASN1_UTC_TIME:
627     result = UTime2str(store, elem->beg, elem->end);
628     break;
629   case CURL_ASN1_GENERALIZED_TIME:
630     result = GTime2str(store, elem->beg, elem->end);
631     break;
632   case CURL_ASN1_UTF8_STRING:
633   case CURL_ASN1_NUMERIC_STRING:
634   case CURL_ASN1_PRINTABLE_STRING:
635   case CURL_ASN1_TELETEX_STRING:
636   case CURL_ASN1_IA5_STRING:
637   case CURL_ASN1_VISIBLE_STRING:
638   case CURL_ASN1_UNIVERSAL_STRING:
639   case CURL_ASN1_BMP_STRING:
640     result = utf8asn1str(store, type, elem->beg, elem->end);
641     break;
642   }
643 
644   return result;
645 }
646 
647 /*
648  * ASCII encode distinguished name at `dn' into the store dynbuf.
649  *
650  * Returns error.
651  */
encodeDN(struct dynbuf * store,struct Curl_asn1Element * dn)652 static CURLcode encodeDN(struct dynbuf *store, struct Curl_asn1Element *dn)
653 {
654   struct Curl_asn1Element rdn;
655   struct Curl_asn1Element atv;
656   struct Curl_asn1Element oid;
657   struct Curl_asn1Element value;
658   const char *p1;
659   const char *p2;
660   const char *p3;
661   const char *str;
662   CURLcode result = CURLE_OK;
663   bool added = FALSE;
664   struct dynbuf temp;
665   Curl_dyn_init(&temp, MAX_X509_STR);
666 
667   for(p1 = dn->beg; p1 < dn->end;) {
668     p1 = getASN1Element(&rdn, p1, dn->end);
669     if(!p1) {
670       result = CURLE_BAD_FUNCTION_ARGUMENT;
671       goto error;
672     }
673     for(p2 = rdn.beg; p2 < rdn.end;) {
674       p2 = getASN1Element(&atv, p2, rdn.end);
675       if(!p2) {
676         result = CURLE_BAD_FUNCTION_ARGUMENT;
677         goto error;
678       }
679       p3 = getASN1Element(&oid, atv.beg, atv.end);
680       if(!p3) {
681         result = CURLE_BAD_FUNCTION_ARGUMENT;
682         goto error;
683       }
684       if(!getASN1Element(&value, p3, atv.end)) {
685         result = CURLE_BAD_FUNCTION_ARGUMENT;
686         goto error;
687       }
688       Curl_dyn_reset(&temp);
689       result = ASN1tostr(&temp, &oid, 0);
690       if(result)
691         goto error;
692 
693       str = Curl_dyn_ptr(&temp);
694 
695       /* Encode delimiter.
696          If attribute has a short uppercase name, delimiter is ", ". */
697       for(p3 = str; ISUPPER(*p3); p3++)
698         ;
699       if(added) {
700         if(p3 - str > 2)
701           result = Curl_dyn_addn(store, "/", 1);
702         else
703           result = Curl_dyn_addn(store, ", ", 2);
704         if(result)
705           goto error;
706       }
707 
708       /* Encode attribute name. */
709       result = Curl_dyn_add(store, str);
710       if(result)
711         goto error;
712 
713       /* Generate equal sign. */
714       result = Curl_dyn_addn(store, "=", 1);
715       if(result)
716         goto error;
717 
718       /* Generate value. */
719       result = ASN1tostr(store, &value, 0);
720       if(result)
721         goto error;
722       Curl_dyn_reset(&temp);
723       added = TRUE; /* use separator for next */
724     }
725   }
726 error:
727   Curl_dyn_free(&temp);
728 
729   return result;
730 }
731 
732 #endif /* WANT_EXTRACT_CERTINFO */
733 
734 #ifdef WANT_PARSEX509
735 /*
736  * ASN.1 parse an X509 certificate into structure subfields.
737  * Syntax is assumed to have already been checked by the SSL backend.
738  * See RFC 5280.
739  */
Curl_parseX509(struct Curl_X509certificate * cert,const char * beg,const char * end)740 int Curl_parseX509(struct Curl_X509certificate *cert,
741                    const char *beg, const char *end)
742 {
743   struct Curl_asn1Element elem;
744   struct Curl_asn1Element tbsCertificate;
745   const char *ccp;
746   static const char defaultVersion = 0;  /* v1. */
747 
748   cert->certificate.header = NULL;
749   cert->certificate.beg = beg;
750   cert->certificate.end = end;
751 
752   /* Get the sequence content. */
753   if(!getASN1Element(&elem, beg, end))
754     return -1;  /* Invalid bounds/size. */
755   beg = elem.beg;
756   end = elem.end;
757 
758   /* Get tbsCertificate. */
759   beg = getASN1Element(&tbsCertificate, beg, end);
760   if(!beg)
761     return -1;
762   /* Skip the signatureAlgorithm. */
763   beg = getASN1Element(&cert->signatureAlgorithm, beg, end);
764   if(!beg)
765     return -1;
766   /* Get the signatureValue. */
767   if(!getASN1Element(&cert->signature, beg, end))
768     return -1;
769 
770   /* Parse TBSCertificate. */
771   beg = tbsCertificate.beg;
772   end = tbsCertificate.end;
773   /* Get optional version, get serialNumber. */
774   cert->version.header = NULL;
775   cert->version.beg = &defaultVersion;
776   cert->version.end = &defaultVersion + sizeof(defaultVersion);
777   beg = getASN1Element(&elem, beg, end);
778   if(!beg)
779     return -1;
780   if(elem.tag == 0) {
781     if(!getASN1Element(&cert->version, elem.beg, elem.end))
782       return -1;
783     beg = getASN1Element(&elem, beg, end);
784     if(!beg)
785       return -1;
786   }
787   cert->serialNumber = elem;
788   /* Get signature algorithm. */
789   beg = getASN1Element(&cert->signatureAlgorithm, beg, end);
790   /* Get issuer. */
791   beg = getASN1Element(&cert->issuer, beg, end);
792   if(!beg)
793     return -1;
794   /* Get notBefore and notAfter. */
795   beg = getASN1Element(&elem, beg, end);
796   if(!beg)
797     return -1;
798   ccp = getASN1Element(&cert->notBefore, elem.beg, elem.end);
799   if(!ccp)
800     return -1;
801   if(!getASN1Element(&cert->notAfter, ccp, elem.end))
802     return -1;
803   /* Get subject. */
804   beg = getASN1Element(&cert->subject, beg, end);
805   if(!beg)
806     return -1;
807   /* Get subjectPublicKeyAlgorithm and subjectPublicKey. */
808   beg = getASN1Element(&cert->subjectPublicKeyInfo, beg, end);
809   if(!beg)
810     return -1;
811   ccp = getASN1Element(&cert->subjectPublicKeyAlgorithm,
812                        cert->subjectPublicKeyInfo.beg,
813                        cert->subjectPublicKeyInfo.end);
814   if(!ccp)
815     return -1;
816   if(!getASN1Element(&cert->subjectPublicKey, ccp,
817                      cert->subjectPublicKeyInfo.end))
818     return -1;
819   /* Get optional issuerUiqueID, subjectUniqueID and extensions. */
820   cert->issuerUniqueID.tag = cert->subjectUniqueID.tag = 0;
821   cert->extensions.tag = elem.tag = 0;
822   cert->issuerUniqueID.header = cert->subjectUniqueID.header = NULL;
823   cert->issuerUniqueID.beg = cert->issuerUniqueID.end = "";
824   cert->subjectUniqueID.beg = cert->subjectUniqueID.end = "";
825   cert->extensions.header = NULL;
826   cert->extensions.beg = cert->extensions.end = "";
827   if(beg < end) {
828     beg = getASN1Element(&elem, beg, end);
829     if(!beg)
830       return -1;
831   }
832   if(elem.tag == 1) {
833     cert->issuerUniqueID = elem;
834     if(beg < end) {
835       beg = getASN1Element(&elem, beg, end);
836       if(!beg)
837         return -1;
838     }
839   }
840   if(elem.tag == 2) {
841     cert->subjectUniqueID = elem;
842     if(beg < end) {
843       beg = getASN1Element(&elem, beg, end);
844       if(!beg)
845         return -1;
846     }
847   }
848   if(elem.tag == 3)
849     if(!getASN1Element(&cert->extensions, elem.beg, elem.end))
850       return -1;
851   return 0;
852 }
853 
854 #endif /* WANT_PARSEX509 */
855 
856 #ifdef WANT_EXTRACT_CERTINFO
857 
dumpAlgo(struct dynbuf * store,struct Curl_asn1Element * param,const char * beg,const char * end)858 static CURLcode dumpAlgo(struct dynbuf *store,
859                          struct Curl_asn1Element *param,
860                          const char *beg, const char *end)
861 {
862   struct Curl_asn1Element oid;
863 
864   /* Get algorithm parameters and return algorithm name. */
865 
866   beg = getASN1Element(&oid, beg, end);
867   if(!beg)
868     return CURLE_BAD_FUNCTION_ARGUMENT;
869   param->header = NULL;
870   param->tag = 0;
871   param->beg = param->end = end;
872   if(beg < end) {
873     const char *p = getASN1Element(param, beg, end);
874     if(!p)
875       return CURLE_BAD_FUNCTION_ARGUMENT;
876   }
877   return OID2str(store, oid.beg, oid.end, TRUE);
878 }
879 
880 /*
881  * This is a convenience function for push_certinfo_len that takes a zero
882  * terminated value.
883  */
ssl_push_certinfo(struct Curl_easy * data,int certnum,const char * label,const char * value)884 static CURLcode ssl_push_certinfo(struct Curl_easy *data,
885                                   int certnum,
886                                   const char *label,
887                                   const char *value)
888 {
889   size_t valuelen = strlen(value);
890 
891   return Curl_ssl_push_certinfo_len(data, certnum, label, value, valuelen);
892 }
893 
894 /*
895  * This is a convenience function for push_certinfo_len that takes a
896  * dynbuf value.
897  *
898  * It also does the verbose output if !certnum.
899  */
ssl_push_certinfo_dyn(struct Curl_easy * data,int certnum,const char * label,struct dynbuf * ptr)900 static CURLcode ssl_push_certinfo_dyn(struct Curl_easy *data,
901                                       int certnum,
902                                       const char *label,
903                                       struct dynbuf *ptr)
904 {
905   size_t valuelen = Curl_dyn_len(ptr);
906   char *value = Curl_dyn_ptr(ptr);
907 
908   CURLcode result = Curl_ssl_push_certinfo_len(data, certnum, label,
909                                                value, valuelen);
910 
911   if(!certnum && !result)
912     infof(data, "   %s: %s", label, value);
913 
914   return result;
915 }
916 
do_pubkey_field(struct Curl_easy * data,int certnum,const char * label,struct Curl_asn1Element * elem)917 static CURLcode do_pubkey_field(struct Curl_easy *data, int certnum,
918                                 const char *label,
919                                 struct Curl_asn1Element *elem)
920 {
921   CURLcode result;
922   struct dynbuf out;
923 
924   Curl_dyn_init(&out, MAX_X509_STR);
925 
926   /* Generate a certificate information record for the public key. */
927 
928   result = ASN1tostr(&out, elem, 0);
929   if(!result) {
930     if(data->set.ssl.certinfo)
931       result = ssl_push_certinfo_dyn(data, certnum, label, &out);
932     Curl_dyn_free(&out);
933   }
934   return result;
935 }
936 
937 /* 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)938 static int do_pubkey(struct Curl_easy *data, int certnum,
939                      const char *algo, struct Curl_asn1Element *param,
940                      struct Curl_asn1Element *pubkey)
941 {
942   struct Curl_asn1Element elem;
943   struct Curl_asn1Element pk;
944   const char *p;
945 
946   /* Generate all information records for the public key. */
947 
948   if(strcasecompare(algo, "ecPublicKey")) {
949     /*
950      * ECC public key is all the data, a value of type BIT STRING mapped to
951      * OCTET STRING and should not be parsed as an ASN.1 value.
952      */
953     const size_t len = ((pubkey->end - pubkey->beg - 2) * 4);
954     if(!certnum)
955       infof(data, "   ECC Public Key (%zu bits)", len);
956     if(data->set.ssl.certinfo) {
957       char q[sizeof(len) * 8 / 3 + 1];
958       (void)msnprintf(q, sizeof(q), "%zu", len);
959       if(ssl_push_certinfo(data, certnum, "ECC Public Key", q))
960         return 1;
961     }
962     return do_pubkey_field(data, certnum, "ecPublicKey", pubkey);
963   }
964 
965   /* Get the public key (single element). */
966   if(!getASN1Element(&pk, pubkey->beg + 1, pubkey->end))
967     return 1;
968 
969   if(strcasecompare(algo, "rsaEncryption")) {
970     const char *q;
971     size_t len;
972 
973     p = getASN1Element(&elem, pk.beg, pk.end);
974     if(!p)
975       return 1;
976 
977     /* Compute key length. */
978     for(q = elem.beg; !*q && q < elem.end; q++)
979       ;
980     len = ((elem.end - q) * 8);
981     if(len) {
982       unsigned int i;
983       for(i = *(unsigned char *) q; !(i & 0x80); i <<= 1)
984         len--;
985     }
986     if(len > 32)
987       elem.beg = q;     /* Strip leading zero bytes. */
988     if(!certnum)
989       infof(data, "   RSA Public Key (%zu bits)", len);
990     if(data->set.ssl.certinfo) {
991       char r[sizeof(len) * 8 / 3 + 1];
992       msnprintf(r, sizeof(r), "%zu", len);
993       if(ssl_push_certinfo(data, certnum, "RSA Public Key", r))
994         return 1;
995     }
996     /* Generate coefficients. */
997     if(do_pubkey_field(data, certnum, "rsa(n)", &elem))
998       return 1;
999     if(!getASN1Element(&elem, p, pk.end))
1000       return 1;
1001     if(do_pubkey_field(data, certnum, "rsa(e)", &elem))
1002       return 1;
1003   }
1004   else if(strcasecompare(algo, "dsa")) {
1005     p = getASN1Element(&elem, param->beg, param->end);
1006     if(p) {
1007       if(do_pubkey_field(data, certnum, "dsa(p)", &elem))
1008         return 1;
1009       p = getASN1Element(&elem, p, param->end);
1010       if(p) {
1011         if(do_pubkey_field(data, certnum, "dsa(q)", &elem))
1012           return 1;
1013         if(getASN1Element(&elem, p, param->end)) {
1014           if(do_pubkey_field(data, certnum, "dsa(g)", &elem))
1015             return 1;
1016           if(do_pubkey_field(data, certnum, "dsa(pub_key)", &pk))
1017             return 1;
1018         }
1019       }
1020     }
1021   }
1022   else if(strcasecompare(algo, "dhpublicnumber")) {
1023     p = getASN1Element(&elem, param->beg, param->end);
1024     if(p) {
1025       if(do_pubkey_field(data, certnum, "dh(p)", &elem))
1026         return 1;
1027       if(getASN1Element(&elem, param->beg, param->end)) {
1028         if(do_pubkey_field(data, certnum, "dh(g)", &elem))
1029           return 1;
1030         if(do_pubkey_field(data, certnum, "dh(pub_key)", &pk))
1031           return 1;
1032       }
1033     }
1034   }
1035   return 0;
1036 }
1037 
1038 /*
1039  * Convert an ASN.1 distinguished name into a printable string.
1040  * Return error.
1041  */
DNtostr(struct dynbuf * store,struct Curl_asn1Element * dn)1042 static CURLcode DNtostr(struct dynbuf *store,
1043                         struct Curl_asn1Element *dn)
1044 {
1045   return encodeDN(store, dn);
1046 }
1047 
Curl_extract_certinfo(struct Curl_easy * data,int certnum,const char * beg,const char * end)1048 CURLcode Curl_extract_certinfo(struct Curl_easy *data,
1049                                int certnum,
1050                                const char *beg,
1051                                const char *end)
1052 {
1053   struct Curl_X509certificate cert;
1054   struct Curl_asn1Element param;
1055   char *certptr;
1056   size_t clen;
1057   struct dynbuf out;
1058   CURLcode result = CURLE_OK;
1059   unsigned int version;
1060   const char *ptr;
1061   int rc;
1062 
1063   if(!data->set.ssl.certinfo)
1064     if(certnum)
1065       return CURLE_OK;
1066 
1067   Curl_dyn_init(&out, MAX_X509_STR);
1068   /* Prepare the certificate information for curl_easy_getinfo(). */
1069 
1070   /* Extract the certificate ASN.1 elements. */
1071   if(Curl_parseX509(&cert, beg, end))
1072     return CURLE_PEER_FAILED_VERIFICATION;
1073 
1074   /* Subject. */
1075   result = DNtostr(&out, &cert.subject);
1076   if(result)
1077     goto done;
1078   if(data->set.ssl.certinfo) {
1079     result = ssl_push_certinfo_dyn(data, certnum, "Subject", &out);
1080     if(result)
1081       goto done;
1082   }
1083   Curl_dyn_reset(&out);
1084 
1085   /* Issuer. */
1086   result = DNtostr(&out, &cert.issuer);
1087   if(result)
1088     goto done;
1089   if(data->set.ssl.certinfo) {
1090     result = ssl_push_certinfo_dyn(data, certnum, "Issuer", &out);
1091     if(result)
1092       goto done;
1093   }
1094   Curl_dyn_reset(&out);
1095 
1096   /* Version (always fits in less than 32 bits). */
1097   version = 0;
1098   for(ptr = cert.version.beg; ptr < cert.version.end; ptr++)
1099     version = (version << 8) | *(const unsigned char *) ptr;
1100   if(data->set.ssl.certinfo) {
1101     result = Curl_dyn_addf(&out, "%x", version);
1102     if(result)
1103       goto done;
1104     result = ssl_push_certinfo_dyn(data, certnum, "Version", &out);
1105     if(result)
1106       goto done;
1107     Curl_dyn_reset(&out);
1108   }
1109 
1110   /* Serial number. */
1111   result = ASN1tostr(&out, &cert.serialNumber, 0);
1112   if(result)
1113     goto done;
1114   if(data->set.ssl.certinfo) {
1115     result = ssl_push_certinfo_dyn(data, certnum, "Serial Number", &out);
1116     if(result)
1117       goto done;
1118   }
1119   Curl_dyn_reset(&out);
1120 
1121   /* Signature algorithm .*/
1122   result = dumpAlgo(&out, &param, cert.signatureAlgorithm.beg,
1123                     cert.signatureAlgorithm.end);
1124   if(result)
1125     goto done;
1126   if(data->set.ssl.certinfo) {
1127     result = ssl_push_certinfo_dyn(data, certnum, "Signature Algorithm",
1128                                    &out);
1129     if(result)
1130       goto done;
1131   }
1132   Curl_dyn_reset(&out);
1133 
1134   /* Start Date. */
1135   result = ASN1tostr(&out, &cert.notBefore, 0);
1136   if(result)
1137     goto done;
1138   if(data->set.ssl.certinfo) {
1139     result = ssl_push_certinfo_dyn(data, certnum, "Start Date", &out);
1140     if(result)
1141       goto done;
1142   }
1143   Curl_dyn_reset(&out);
1144 
1145   /* Expire Date. */
1146   result = ASN1tostr(&out, &cert.notAfter, 0);
1147   if(result)
1148     goto done;
1149   if(data->set.ssl.certinfo) {
1150     result = ssl_push_certinfo_dyn(data, certnum, "Expire Date", &out);
1151     if(result)
1152       goto done;
1153   }
1154   Curl_dyn_reset(&out);
1155 
1156   /* Public Key Algorithm. */
1157   result = dumpAlgo(&out, &param, cert.subjectPublicKeyAlgorithm.beg,
1158                     cert.subjectPublicKeyAlgorithm.end);
1159   if(result)
1160     goto done;
1161   if(data->set.ssl.certinfo) {
1162     result = ssl_push_certinfo_dyn(data, certnum, "Public Key Algorithm",
1163                                    &out);
1164     if(result)
1165       goto done;
1166   }
1167 
1168   rc = do_pubkey(data, certnum, Curl_dyn_ptr(&out),
1169                  &param, &cert.subjectPublicKey);
1170   if(rc) {
1171     result = CURLE_OUT_OF_MEMORY; /* the most likely error */
1172     goto done;
1173   }
1174   Curl_dyn_reset(&out);
1175 
1176   /* Signature. */
1177   result = ASN1tostr(&out, &cert.signature, 0);
1178   if(result)
1179     goto done;
1180   if(data->set.ssl.certinfo) {
1181     result = ssl_push_certinfo_dyn(data, certnum, "Signature", &out);
1182     if(result)
1183       goto done;
1184   }
1185   Curl_dyn_reset(&out);
1186 
1187   /* Generate PEM certificate. */
1188   result = Curl_base64_encode(cert.certificate.beg,
1189                               cert.certificate.end - cert.certificate.beg,
1190                               &certptr, &clen);
1191   if(result)
1192     goto done;
1193 
1194   /* Generate the final output certificate string. Format is:
1195      -----BEGIN CERTIFICATE-----\n
1196      <max 64 base64 characters>\n
1197      .
1198      .
1199      .
1200      -----END CERTIFICATE-----\n
1201    */
1202 
1203   Curl_dyn_reset(&out);
1204 
1205   /* Build the certificate string. */
1206   result = Curl_dyn_add(&out, "-----BEGIN CERTIFICATE-----\n");
1207   if(!result) {
1208     size_t j = 0;
1209 
1210     while(!result && (j < clen)) {
1211       size_t chunksize = (clen - j) > 64 ? 64 : (clen - j);
1212       result = Curl_dyn_addn(&out, &certptr[j], chunksize);
1213       if(!result)
1214         result = Curl_dyn_addn(&out, "\n", 1);
1215       j += chunksize;
1216     }
1217     if(!result)
1218       result = Curl_dyn_add(&out, "-----END CERTIFICATE-----\n");
1219   }
1220   free(certptr);
1221   if(!result)
1222     if(data->set.ssl.certinfo)
1223       result = ssl_push_certinfo_dyn(data, certnum, "Cert", &out);
1224 
1225 done:
1226   Curl_dyn_free(&out);
1227   return result;
1228 }
1229 
1230 #endif /* WANT_EXTRACT_CERTINFO */
1231 
1232 #endif /* USE_GNUTLS or USE_WOLFSSL or USE_SCHANNEL or USE_SECTRANSP */
1233