xref: /freebsd/crypto/openssl/crypto/asn1/a_strex.c (revision a7148ab39c03abd4d1a84997c70bf96f15dd2a09)
1 /*
2  * Copyright 2000-2024 The OpenSSL Project Authors. All Rights Reserved.
3  *
4  * Licensed under the Apache License 2.0 (the "License").  You may not use
5  * this file except in compliance with the License.  You can obtain a copy
6  * in the file LICENSE in the source distribution or at
7  * https://www.openssl.org/source/license.html
8  */
9 
10 #include <stdio.h>
11 #include <string.h>
12 #include "internal/cryptlib.h"
13 #include "internal/sizes.h"
14 #include "crypto/asn1.h"
15 #include <openssl/crypto.h>
16 #include <openssl/x509.h>
17 #include <openssl/asn1.h>
18 
19 #include "charmap.h"
20 
21 /*
22  * ASN1_STRING_print_ex() and X509_NAME_print_ex(). Enhanced string and name
23  * printing routines handling multibyte characters, RFC2253 and a host of
24  * other options.
25  */
26 
27 #define CHARTYPE_BS_ESC         (ASN1_STRFLGS_ESC_2253 | CHARTYPE_FIRST_ESC_2253 | CHARTYPE_LAST_ESC_2253)
28 
29 #define ESC_FLAGS (ASN1_STRFLGS_ESC_2253 | \
30                   ASN1_STRFLGS_ESC_2254 | \
31                   ASN1_STRFLGS_ESC_QUOTE | \
32                   ASN1_STRFLGS_ESC_CTRL | \
33                   ASN1_STRFLGS_ESC_MSB)
34 
35 /*
36  * Three IO functions for sending data to memory, a BIO and a FILE
37  * pointer.
38  */
send_bio_chars(void * arg,const void * buf,int len)39 static int send_bio_chars(void *arg, const void *buf, int len)
40 {
41     if (!arg)
42         return 1;
43     if (BIO_write(arg, buf, len) != len)
44         return 0;
45     return 1;
46 }
47 
48 #ifndef OPENSSL_NO_STDIO
send_fp_chars(void * arg,const void * buf,int len)49 static int send_fp_chars(void *arg, const void *buf, int len)
50 {
51     if (!arg)
52         return 1;
53     if (fwrite(buf, 1, len, arg) != (unsigned int)len)
54         return 0;
55     return 1;
56 }
57 #endif
58 
59 typedef int char_io (void *arg, const void *buf, int len);
60 
61 /*
62  * This function handles display of strings, one character at a time. It is
63  * passed an unsigned long for each character because it could come from 2 or
64  * even 4 byte forms.
65  */
66 
do_esc_char(unsigned long c,unsigned short flags,char * do_quotes,char_io * io_ch,void * arg)67 static int do_esc_char(unsigned long c, unsigned short flags, char *do_quotes,
68                        char_io *io_ch, void *arg)
69 {
70     unsigned short chflgs;
71     unsigned char chtmp;
72     char tmphex[HEX_SIZE(long) + 3];
73 
74     if (c > 0xffffffffL)
75         return -1;
76     if (c > 0xffff) {
77         BIO_snprintf(tmphex, sizeof(tmphex), "\\W%08lX", c);
78         if (!io_ch(arg, tmphex, 10))
79             return -1;
80         return 10;
81     }
82     if (c > 0xff) {
83         BIO_snprintf(tmphex, sizeof(tmphex), "\\U%04lX", c);
84         if (!io_ch(arg, tmphex, 6))
85             return -1;
86         return 6;
87     }
88     chtmp = (unsigned char)c;
89     if (chtmp > 0x7f)
90         chflgs = flags & ASN1_STRFLGS_ESC_MSB;
91     else
92         chflgs = char_type[chtmp] & flags;
93     if (chflgs & CHARTYPE_BS_ESC) {
94         /* If we don't escape with quotes, signal we need quotes */
95         if (chflgs & ASN1_STRFLGS_ESC_QUOTE) {
96             if (do_quotes)
97                 *do_quotes = 1;
98             if (!io_ch(arg, &chtmp, 1))
99                 return -1;
100             return 1;
101         }
102         if (!io_ch(arg, "\\", 1))
103             return -1;
104         if (!io_ch(arg, &chtmp, 1))
105             return -1;
106         return 2;
107     }
108     if (chflgs & (ASN1_STRFLGS_ESC_CTRL
109                   | ASN1_STRFLGS_ESC_MSB
110                   | ASN1_STRFLGS_ESC_2254)) {
111         BIO_snprintf(tmphex, 11, "\\%02X", chtmp);
112         if (!io_ch(arg, tmphex, 3))
113             return -1;
114         return 3;
115     }
116     /*
117      * If we get this far and do any escaping at all must escape the escape
118      * character itself: backslash.
119      */
120     if (chtmp == '\\' && (flags & ESC_FLAGS)) {
121         if (!io_ch(arg, "\\\\", 2))
122             return -1;
123         return 2;
124     }
125     if (!io_ch(arg, &chtmp, 1))
126         return -1;
127     return 1;
128 }
129 
130 #define BUF_TYPE_WIDTH_MASK     0x7
131 #define BUF_TYPE_CONVUTF8       0x8
132 
133 /*
134  * This function sends each character in a buffer to do_esc_char(). It
135  * interprets the content formats and converts to or from UTF8 as
136  * appropriate.
137  */
138 
do_buf(unsigned char * buf,int buflen,int type,unsigned short flags,char * quotes,char_io * io_ch,void * arg)139 static int do_buf(unsigned char *buf, int buflen,
140                   int type, unsigned short flags, char *quotes, char_io *io_ch,
141                   void *arg)
142 {
143     int i, outlen, len, charwidth;
144     unsigned short orflags;
145     unsigned char *p, *q;
146     unsigned long c;
147 
148     p = buf;
149     q = buf + buflen;
150     outlen = 0;
151     charwidth = type & BUF_TYPE_WIDTH_MASK;
152 
153     switch (charwidth) {
154     case 4:
155         if (buflen & 3) {
156             ERR_raise(ERR_LIB_ASN1, ASN1_R_INVALID_UNIVERSALSTRING_LENGTH);
157             return -1;
158         }
159         break;
160     case 2:
161         if (buflen & 1) {
162             ERR_raise(ERR_LIB_ASN1, ASN1_R_INVALID_BMPSTRING_LENGTH);
163             return -1;
164         }
165         break;
166     default:
167         break;
168     }
169 
170     while (p != q) {
171         if (p == buf && flags & ASN1_STRFLGS_ESC_2253)
172             orflags = CHARTYPE_FIRST_ESC_2253;
173         else
174             orflags = 0;
175 
176         switch (charwidth) {
177         case 4:
178             c = ((unsigned long)*p++) << 24;
179             c |= ((unsigned long)*p++) << 16;
180             c |= ((unsigned long)*p++) << 8;
181             c |= *p++;
182             break;
183 
184         case 2:
185             c = ((unsigned long)*p++) << 8;
186             c |= *p++;
187             break;
188 
189         case 1:
190             c = *p++;
191             break;
192 
193         case 0:
194             i = UTF8_getc(p, buflen, &c);
195             if (i < 0)
196                 return -1;      /* Invalid UTF8String */
197             buflen -= i;
198             p += i;
199             break;
200         default:
201             return -1;          /* invalid width */
202         }
203         if (p == q && flags & ASN1_STRFLGS_ESC_2253)
204             orflags = CHARTYPE_LAST_ESC_2253;
205         if (type & BUF_TYPE_CONVUTF8) {
206             unsigned char utfbuf[6];
207             int utflen;
208             utflen = UTF8_putc(utfbuf, sizeof(utfbuf), c);
209             for (i = 0; i < utflen; i++) {
210                 /*
211                  * We don't need to worry about setting orflags correctly
212                  * because if utflen==1 its value will be correct anyway
213                  * otherwise each character will be > 0x7f and so the
214                  * character will never be escaped on first and last.
215                  */
216                 len = do_esc_char(utfbuf[i], flags | orflags, quotes,
217                                   io_ch, arg);
218                 if (len < 0)
219                     return -1;
220                 outlen += len;
221             }
222         } else {
223             len = do_esc_char(c, flags | orflags, quotes,
224                               io_ch, arg);
225             if (len < 0)
226                 return -1;
227             outlen += len;
228         }
229     }
230     return outlen;
231 }
232 
233 /* This function hex dumps a buffer of characters */
234 
do_hex_dump(char_io * io_ch,void * arg,unsigned char * buf,int buflen)235 static int do_hex_dump(char_io *io_ch, void *arg, unsigned char *buf,
236                        int buflen)
237 {
238     static const char hexdig[] = "0123456789ABCDEF";
239     unsigned char *p, *q;
240     char hextmp[2];
241     if (arg) {
242         p = buf;
243         q = buf + buflen;
244         while (p != q) {
245             hextmp[0] = hexdig[*p >> 4];
246             hextmp[1] = hexdig[*p & 0xf];
247             if (!io_ch(arg, hextmp, 2))
248                 return -1;
249             p++;
250         }
251     }
252     return buflen << 1;
253 }
254 
255 /*
256  * "dump" a string. This is done when the type is unknown, or the flags
257  * request it. We can either dump the content octets or the entire DER
258  * encoding. This uses the RFC2253 #01234 format.
259  */
260 
do_dump(unsigned long lflags,char_io * io_ch,void * arg,const ASN1_STRING * str)261 static int do_dump(unsigned long lflags, char_io *io_ch, void *arg,
262                    const ASN1_STRING *str)
263 {
264     /*
265      * Placing the ASN1_STRING in a temp ASN1_TYPE allows the DER encoding to
266      * readily obtained
267      */
268     ASN1_TYPE t;
269     unsigned char *der_buf, *p;
270     int outlen, der_len;
271 
272     if (!io_ch(arg, "#", 1))
273         return -1;
274     /* If we don't dump DER encoding just dump content octets */
275     if (!(lflags & ASN1_STRFLGS_DUMP_DER)) {
276         outlen = do_hex_dump(io_ch, arg, str->data, str->length);
277         if (outlen < 0)
278             return -1;
279         return outlen + 1;
280     }
281     t.type = str->type;
282     t.value.ptr = (char *)str;
283     der_len = i2d_ASN1_TYPE(&t, NULL);
284     if (der_len <= 0)
285         return -1;
286     if ((der_buf = OPENSSL_malloc(der_len)) == NULL) {
287         ERR_raise(ERR_LIB_ASN1, ERR_R_MALLOC_FAILURE);
288         return -1;
289     }
290     p = der_buf;
291     i2d_ASN1_TYPE(&t, &p);
292     outlen = do_hex_dump(io_ch, arg, der_buf, der_len);
293     OPENSSL_free(der_buf);
294     if (outlen < 0)
295         return -1;
296     return outlen + 1;
297 }
298 
299 /*
300  * Lookup table to convert tags to character widths, 0 = UTF8 encoded, -1 is
301  * used for non string types otherwise it is the number of bytes per
302  * character
303  */
304 
305 static const signed char tag2nbyte[] = {
306     -1, -1, -1, -1, -1,         /* 0-4 */
307     -1, -1, -1, -1, -1,         /* 5-9 */
308     -1, -1,                     /* 10-11 */
309      0,                         /* 12 V_ASN1_UTF8STRING */
310     -1, -1, -1, -1, -1,         /* 13-17 */
311      1,                         /* 18 V_ASN1_NUMERICSTRING */
312      1,                         /* 19 V_ASN1_PRINTABLESTRING */
313      1,                         /* 20 V_ASN1_T61STRING */
314     -1,                         /* 21 */
315      1,                         /* 22 V_ASN1_IA5STRING */
316      1,                         /* 23 V_ASN1_UTCTIME */
317      1,                         /* 24 V_ASN1_GENERALIZEDTIME */
318     -1,                         /* 25 */
319      1,                         /* 26 V_ASN1_ISO64STRING */
320     -1,                         /* 27 */
321      4,                         /* 28 V_ASN1_UNIVERSALSTRING */
322     -1,                         /* 29 */
323      2                          /* 30 V_ASN1_BMPSTRING */
324 };
325 
326 /*
327  * This is the main function, print out an ASN1_STRING taking note of various
328  * escape and display options. Returns number of characters written or -1 if
329  * an error occurred.
330  */
331 
do_print_ex(char_io * io_ch,void * arg,unsigned long lflags,const ASN1_STRING * str)332 static int do_print_ex(char_io *io_ch, void *arg, unsigned long lflags,
333                        const ASN1_STRING *str)
334 {
335     int outlen, len;
336     int type;
337     char quotes;
338     unsigned short flags;
339     quotes = 0;
340     /* Keep a copy of escape flags */
341     flags = (unsigned short)(lflags & ESC_FLAGS);
342 
343     type = str->type;
344 
345     outlen = 0;
346 
347     if (lflags & ASN1_STRFLGS_SHOW_TYPE) {
348         const char *tagname;
349 
350         tagname = ASN1_tag2str(type);
351         /* We can directly cast here as tagname will never be too large. */
352         outlen += (int)strlen(tagname);
353         if (!io_ch(arg, tagname, outlen) || !io_ch(arg, ":", 1))
354             return -1;
355         outlen++;
356     }
357 
358     /* Decide what to do with type, either dump content or display it */
359 
360     /* Dump everything */
361     if (lflags & ASN1_STRFLGS_DUMP_ALL)
362         type = -1;
363     /* Ignore the string type */
364     else if (lflags & ASN1_STRFLGS_IGNORE_TYPE)
365         type = 1;
366     else {
367         /* Else determine width based on type */
368         if ((type > 0) && (type < 31))
369             type = tag2nbyte[type];
370         else
371             type = -1;
372         if ((type == -1) && !(lflags & ASN1_STRFLGS_DUMP_UNKNOWN))
373             type = 1;
374     }
375 
376     if (type == -1) {
377         len = do_dump(lflags, io_ch, arg, str);
378         if (len < 0 || len > INT_MAX - outlen)
379             return -1;
380         outlen += len;
381         return outlen;
382     }
383 
384     if (lflags & ASN1_STRFLGS_UTF8_CONVERT) {
385         /*
386          * Note: if string is UTF8 and we want to convert to UTF8 then we
387          * just interpret it as 1 byte per character to avoid converting
388          * twice.
389          */
390         if (!type)
391             type = 1;
392         else
393             type |= BUF_TYPE_CONVUTF8;
394     }
395 
396     len = do_buf(str->data, str->length, type, flags, &quotes, io_ch, NULL);
397     if (len < 0 || len > INT_MAX - 2 - outlen)
398         return -1;
399     outlen += len;
400     if (quotes)
401         outlen += 2;
402     if (!arg)
403         return outlen;
404     if (quotes && !io_ch(arg, "\"", 1))
405         return -1;
406     if (do_buf(str->data, str->length, type, flags, NULL, io_ch, arg) < 0)
407         return -1;
408     if (quotes && !io_ch(arg, "\"", 1))
409         return -1;
410     return outlen;
411 }
412 
413 /* Used for line indenting: print 'indent' spaces */
414 
do_indent(char_io * io_ch,void * arg,int indent)415 static int do_indent(char_io *io_ch, void *arg, int indent)
416 {
417     int i;
418     for (i = 0; i < indent; i++)
419         if (!io_ch(arg, " ", 1))
420             return 0;
421     return 1;
422 }
423 
424 #define FN_WIDTH_LN     25
425 #define FN_WIDTH_SN     10
426 
do_name_ex(char_io * io_ch,void * arg,const X509_NAME * n,int indent,unsigned long flags)427 static int do_name_ex(char_io *io_ch, void *arg, const X509_NAME *n,
428                       int indent, unsigned long flags)
429 {
430     int i, prev = -1, orflags, cnt;
431     int fn_opt, fn_nid;
432     ASN1_OBJECT *fn;
433     const ASN1_STRING *val;
434     const X509_NAME_ENTRY *ent;
435     char objtmp[80];
436     const char *objbuf;
437     int outlen, len;
438     char *sep_dn, *sep_mv, *sep_eq;
439     int sep_dn_len, sep_mv_len, sep_eq_len;
440     if (indent < 0)
441         indent = 0;
442     outlen = indent;
443     if (!do_indent(io_ch, arg, indent))
444         return -1;
445     switch (flags & XN_FLAG_SEP_MASK) {
446     case XN_FLAG_SEP_MULTILINE:
447         sep_dn = "\n";
448         sep_dn_len = 1;
449         sep_mv = " + ";
450         sep_mv_len = 3;
451         break;
452 
453     case XN_FLAG_SEP_COMMA_PLUS:
454         sep_dn = ",";
455         sep_dn_len = 1;
456         sep_mv = "+";
457         sep_mv_len = 1;
458         indent = 0;
459         break;
460 
461     case XN_FLAG_SEP_CPLUS_SPC:
462         sep_dn = ", ";
463         sep_dn_len = 2;
464         sep_mv = " + ";
465         sep_mv_len = 3;
466         indent = 0;
467         break;
468 
469     case XN_FLAG_SEP_SPLUS_SPC:
470         sep_dn = "; ";
471         sep_dn_len = 2;
472         sep_mv = " + ";
473         sep_mv_len = 3;
474         indent = 0;
475         break;
476 
477     default:
478         return -1;
479     }
480 
481     if (flags & XN_FLAG_SPC_EQ) {
482         sep_eq = " = ";
483         sep_eq_len = 3;
484     } else {
485         sep_eq = "=";
486         sep_eq_len = 1;
487     }
488 
489     fn_opt = flags & XN_FLAG_FN_MASK;
490 
491     cnt = X509_NAME_entry_count(n);
492     for (i = 0; i < cnt; i++) {
493         if (flags & XN_FLAG_DN_REV)
494             ent = X509_NAME_get_entry(n, cnt - i - 1);
495         else
496             ent = X509_NAME_get_entry(n, i);
497         if (prev != -1) {
498             if (prev == X509_NAME_ENTRY_set(ent)) {
499                 if (!io_ch(arg, sep_mv, sep_mv_len))
500                     return -1;
501                 outlen += sep_mv_len;
502             } else {
503                 if (!io_ch(arg, sep_dn, sep_dn_len))
504                     return -1;
505                 outlen += sep_dn_len;
506                 if (!do_indent(io_ch, arg, indent))
507                     return -1;
508                 outlen += indent;
509             }
510         }
511         prev = X509_NAME_ENTRY_set(ent);
512         fn = X509_NAME_ENTRY_get_object(ent);
513         val = X509_NAME_ENTRY_get_data(ent);
514         fn_nid = OBJ_obj2nid(fn);
515         if (fn_opt != XN_FLAG_FN_NONE) {
516             int objlen, fld_len;
517             if ((fn_opt == XN_FLAG_FN_OID) || (fn_nid == NID_undef)) {
518                 OBJ_obj2txt(objtmp, sizeof(objtmp), fn, 1);
519                 fld_len = 0;    /* XXX: what should this be? */
520                 objbuf = objtmp;
521             } else {
522                 if (fn_opt == XN_FLAG_FN_SN) {
523                     fld_len = FN_WIDTH_SN;
524                     objbuf = OBJ_nid2sn(fn_nid);
525                 } else if (fn_opt == XN_FLAG_FN_LN) {
526                     fld_len = FN_WIDTH_LN;
527                     objbuf = OBJ_nid2ln(fn_nid);
528                 } else {
529                     fld_len = 0; /* XXX: what should this be? */
530                     objbuf = "";
531                 }
532             }
533             objlen = strlen(objbuf);
534             if (!io_ch(arg, objbuf, objlen))
535                 return -1;
536             if ((objlen < fld_len) && (flags & XN_FLAG_FN_ALIGN)) {
537                 if (!do_indent(io_ch, arg, fld_len - objlen))
538                     return -1;
539                 outlen += fld_len - objlen;
540             }
541             if (!io_ch(arg, sep_eq, sep_eq_len))
542                 return -1;
543             outlen += objlen + sep_eq_len;
544         }
545         /*
546          * If the field name is unknown then fix up the DER dump flag. We
547          * might want to limit this further so it will DER dump on anything
548          * other than a few 'standard' fields.
549          */
550         if ((fn_nid == NID_undef) && (flags & XN_FLAG_DUMP_UNKNOWN_FIELDS))
551             orflags = ASN1_STRFLGS_DUMP_ALL;
552         else
553             orflags = 0;
554 
555         len = do_print_ex(io_ch, arg, flags | orflags, val);
556         if (len < 0)
557             return -1;
558         outlen += len;
559     }
560     return outlen;
561 }
562 
563 /* Wrappers round the main functions */
564 
X509_NAME_print_ex(BIO * out,const X509_NAME * nm,int indent,unsigned long flags)565 int X509_NAME_print_ex(BIO *out, const X509_NAME *nm, int indent,
566                        unsigned long flags)
567 {
568     if (flags == XN_FLAG_COMPAT)
569         return X509_NAME_print(out, nm, indent);
570     return do_name_ex(send_bio_chars, out, nm, indent, flags);
571 }
572 
573 #ifndef OPENSSL_NO_STDIO
X509_NAME_print_ex_fp(FILE * fp,const X509_NAME * nm,int indent,unsigned long flags)574 int X509_NAME_print_ex_fp(FILE *fp, const X509_NAME *nm, int indent,
575                           unsigned long flags)
576 {
577     if (flags == XN_FLAG_COMPAT) {
578         BIO *btmp;
579         int ret;
580         btmp = BIO_new_fp(fp, BIO_NOCLOSE);
581         if (!btmp)
582             return -1;
583         ret = X509_NAME_print(btmp, nm, indent);
584         BIO_free(btmp);
585         return ret;
586     }
587     return do_name_ex(send_fp_chars, fp, nm, indent, flags);
588 }
589 #endif
590 
ASN1_STRING_print_ex(BIO * out,const ASN1_STRING * str,unsigned long flags)591 int ASN1_STRING_print_ex(BIO *out, const ASN1_STRING *str, unsigned long flags)
592 {
593     return do_print_ex(send_bio_chars, out, flags, str);
594 }
595 
596 #ifndef OPENSSL_NO_STDIO
ASN1_STRING_print_ex_fp(FILE * fp,const ASN1_STRING * str,unsigned long flags)597 int ASN1_STRING_print_ex_fp(FILE *fp, const ASN1_STRING *str, unsigned long flags)
598 {
599     return do_print_ex(send_fp_chars, fp, flags, str);
600 }
601 #endif
602 
603 /*
604  * Utility function: convert any string type to UTF8, returns number of bytes
605  * in output string or a negative error code
606  */
607 
ASN1_STRING_to_UTF8(unsigned char ** out,const ASN1_STRING * in)608 int ASN1_STRING_to_UTF8(unsigned char **out, const ASN1_STRING *in)
609 {
610     ASN1_STRING stmp, *str = &stmp;
611     int mbflag, type, ret;
612     if (!in)
613         return -1;
614     type = in->type;
615     if ((type < 0) || (type > 30))
616         return -1;
617     mbflag = tag2nbyte[type];
618     if (mbflag == -1)
619         return -1;
620     mbflag |= MBSTRING_FLAG;
621     stmp.data = NULL;
622     stmp.length = 0;
623     stmp.flags = 0;
624     ret =
625         ASN1_mbstring_copy(&str, in->data, in->length, mbflag,
626                            B_ASN1_UTF8STRING);
627     if (ret < 0)
628         return ret;
629     *out = stmp.data;
630     return stmp.length;
631 }
632