src/src/tlscert-openssl.c

   1 /*************************************************
   2 *     Exim - an Internet mail transport agent    *
   3 *************************************************/
   4
   5 /* Copyright (c) Jeremy Harris 2014 */
   6
   7 /* This module provides TLS (aka SSL) support for Exim using the OpenSSL
   8 library. It is #included into the tls.c file when that library is used.
   9 */
  10
  11
  12 /* Heading stuff */
  13
  14 #include <openssl/lhash.h>
  15 #include <openssl/ssl.h>
  16 #include <openssl/err.h>
  17 #include <openssl/rand.h>
  18 #include <openssl/x509v3.h>
  19
  20
  21 /*****************************************************
  22 *  Export/import a certificate, binary/printable
  23 *****************************************************/
  24 int
  25 tls_export_cert(uschar * buf, size_t buflen, void * cert)
  26 {
  27 BIO * bp = BIO_new(BIO_s_mem());
  28 int fail;
  29
  30 if ((fail = PEM_write_bio_X509(bp, (X509 *)cert) ? 0 : 1))
  31   log_write(0, LOG_MAIN, "TLS error in certificate export: %s",
  32     ERR_error_string(ERR_get_error(), NULL));
  33 else
  34   {
  35   char * cp = CS buf;
  36   int n;
  37   buflen -= 2;
  38   for(;;)
  39     {
  40     if ((n = BIO_gets(bp, cp, (int)buflen)) <= 0) break;
  41     cp += n+1;
  42     buflen -= n+1;
  43     cp[-2] = '\\'; cp[-1] = 'n'; /* newline->"\n" */
  44     }                            /* compat with string_printing() */
  45   *cp = '\0';
  46   }
  47
  48 BIO_free(bp);
  49 return fail;
  50 }
  51
  52 int
  53 tls_import_cert(const uschar * buf, void ** cert)
  54 {
  55 void * reset_point = store_get(0);
  56 const uschar * cp = string_unprinting(US buf);
  57 BIO * bp;
  58 X509 * x;
  59
  60 bp = BIO_new_mem_buf(US cp, -1);
  61 x = PEM_read_bio_X509(bp, NULL, 0, NULL);
  62 int fail = 0;
  63 if (!x)
  64   fail = 1;
  65 else
  66   *cert = (void *)x;
  67 BIO_free(bp);
  68 store_reset(reset_point);
  69 return fail;
  70 }
  71
  72 void
  73 tls_free_cert(void * cert)
  74 {
  75 X509_free((X509 *)cert);
  76 }
  77
  78 /*****************************************************
  79 *  Certificate field extraction routines
  80 *****************************************************/
  81 static uschar *
  82 bio_string_copy(BIO * bp, int len)
  83 {
  84 uschar * cp = "";
  85 len = len > 0 ? (int) BIO_get_mem_data(bp, &cp) : 0;
  86 cp = string_copyn(cp, len);
  87 BIO_free(bp);
  88 return cp;
  89 }
  90
  91 static uschar *
  92 asn1_time_copy(const ASN1_TIME * time)
  93 {
  94 BIO * bp = BIO_new(BIO_s_mem());
  95 int len = ASN1_TIME_print(bp, time);
  96 return bio_string_copy(bp, len);
  97 }
  98
  99 static uschar *
 100 x509_name_copy(X509_NAME * name)
 101 {
 102 BIO * bp = BIO_new(BIO_s_mem());
 103 int len_good =
 104   X509_NAME_print_ex(bp, name, 0, XN_FLAG_RFC2253) >= 0
 105   ? 1 : 0;
 106 return bio_string_copy(bp, len_good);
 107 }
 108
 109 /**/
 110
 111 uschar *
 112 tls_cert_issuer(void * cert, uschar * mod)
 113 {
 114 return x509_name_copy(X509_get_issuer_name((X509 *)cert));
 115 }
 116
 117 uschar *
 118 tls_cert_not_before(void * cert, uschar * mod)
 119 {
 120 return asn1_time_copy(X509_get_notBefore((X509 *)cert));
 121 }
 122
 123 uschar *
 124 tls_cert_not_after(void * cert, uschar * mod)
 125 {
 126 return asn1_time_copy(X509_get_notAfter((X509 *)cert));
 127 }
 128
 129 uschar *
 130 tls_cert_serial_number(void * cert, uschar * mod)
 131 {
 132 uschar txt[256];
 133 BIO * bp = BIO_new(BIO_s_mem());
 134 int len = i2a_ASN1_INTEGER(bp, X509_get_serialNumber((X509 *)cert));
 135
 136 if (len < sizeof(txt))
 137   BIO_read(bp, txt, len);
 138 else
 139   len = 0;
 140 BIO_free(bp);
 141 return string_copynlc(txt, len);        /* lowercase */
 142 }
 143
 144 uschar *
 145 tls_cert_signature(void * cert, uschar * mod)
 146 {
 147 BIO * bp = BIO_new(BIO_s_mem());
 148 uschar * cp = NULL;
 149
 150 if (X509_print_ex(bp, (X509 *)cert, 0,
 151   X509_FLAG_NO_HEADER | X509_FLAG_NO_VERSION | X509_FLAG_NO_SERIAL |
 152   X509_FLAG_NO_SIGNAME | X509_FLAG_NO_ISSUER | X509_FLAG_NO_VALIDITY |
 153   X509_FLAG_NO_SUBJECT | X509_FLAG_NO_PUBKEY | X509_FLAG_NO_EXTENSIONS |
 154   /* X509_FLAG_NO_SIGDUMP is the missing one */
 155   X509_FLAG_NO_AUX) == 1)
 156   {
 157   long len = BIO_get_mem_data(bp, &cp);
 158   cp = string_copyn(cp, len);
 159   }
 160 BIO_free(bp);
 161 return cp;
 162 }
 163
 164 uschar *
 165 tls_cert_signature_algorithm(void * cert, uschar * mod)
 166 {
 167 return string_copy(OBJ_nid2ln(X509_get_signature_type((X509 *)cert)));
 168 }
 169
 170 uschar *
 171 tls_cert_subject(void * cert, uschar * mod)
 172 {
 173 return x509_name_copy(X509_get_subject_name((X509 *)cert));
 174 }
 175
 176 uschar *
 177 tls_cert_version(void * cert, uschar * mod)
 178 {
 179 return string_sprintf("%d", X509_get_version((X509 *)cert));
 180 }
 181
 182 uschar *
 183 tls_cert_ext_by_oid(void * cert, uschar * oid, int idx)
 184 {
 185 int nid = OBJ_create(oid, "", "");
 186 int nidx = X509_get_ext_by_NID((X509 *)cert, nid, idx);
 187 X509_EXTENSION * ex = X509_get_ext((X509 *)cert, nidx);
 188 ASN1_OCTET_STRING * adata = X509_EXTENSION_get_data(ex);
 189 BIO * bp = BIO_new(BIO_s_mem());
 190 long len;
 191 uschar * cp1;
 192 uschar * cp2;
 193 uschar * cp3;
 194
 195 M_ASN1_OCTET_STRING_print(bp, adata);
 196 /* binary data, DER encoded */
 197
 198 /* just dump for now */
 199 len = BIO_get_mem_data(bp, &cp1);
 200 cp3 = cp2 = store_get(len*3+1);
 201
 202 while(len)
 203   {
 204   sprintf(cp2, "%.2x ", *cp1++);
 205   cp2 += 3;
 206   len--;
 207   }
 208 cp2[-1] = '\0';
 209
 210 return cp3;
 211 }
 212
 213 uschar *
 214 tls_cert_subject_altname(void * cert, uschar * mod)
 215 {
 216 uschar * list = NULL;
 217 STACK_OF(GENERAL_NAME) * san = (STACK_OF(GENERAL_NAME) *)
 218   X509_get_ext_d2i((X509 *)cert, NID_subject_alt_name, NULL, NULL);
 219 uschar sep = '\n';
 220 uschar * tag = US"";
 221 uschar * ele;
 222 int match = -1;
 223
 224 if (!san) return NULL;
 225
 226 while (mod)
 227   {
 228   if (*mod == '>' && *++mod) sep = *mod++;
 229   else if (Ustrcmp(mod, "dns")==0) { match = GEN_DNS; mod += 3; }
 230   else if (Ustrcmp(mod, "uri")==0) { match = GEN_URI; mod += 3; }
 231   else if (Ustrcmp(mod, "mail")==0) { match = GEN_EMAIL; mod += 4; }
 232   else continue;
 233
 234   if (*mod++ != ',')
 235     break;
 236   }
 237
 238 while (sk_GENERAL_NAME_num(san) > 0)
 239   {
 240   GENERAL_NAME * namePart = sk_GENERAL_NAME_pop(san);
 241   if (match != -1 && match != namePart->type)
 242     continue;
 243   switch (namePart->type)
 244     {
 245     case GEN_DNS:
 246       tag = US"DNS";
 247       ele = ASN1_STRING_data(namePart->d.dNSName);
 248       break;
 249     case GEN_URI:
 250       tag = US"URI";
 251       ele = ASN1_STRING_data(namePart->d.uniformResourceIdentifier);
 252       break;
 253     case GEN_EMAIL:
 254       tag = US"MAIL";
 255       ele = ASN1_STRING_data(namePart->d.rfc822Name);
 256       break;
 257     default:
 258       continue; /* ignore unrecognised types */
 259     }
 260   list = string_append_listele(list, sep,
 261           match == -1 ? string_sprintf("%s=%s", tag, ele) : ele);
 262   }
 263
 264 sk_GENERAL_NAME_free(san);
 265 return list;
 266 }
 267
 268 uschar *
 269 tls_cert_ocsp_uri(void * cert, uschar * mod)
 270 {
 271 STACK_OF(ACCESS_DESCRIPTION) * ads = (STACK_OF(ACCESS_DESCRIPTION) *)
 272   X509_get_ext_d2i((X509 *)cert, NID_info_access, NULL, NULL);
 273 int adsnum = sk_ACCESS_DESCRIPTION_num(ads);
 274 int i;
 275 uschar sep = '\n';
 276 uschar * list = NULL;
 277
 278 if (mod)
 279   if (*mod == '>' && *++mod) sep = *mod++;
 280
 281 for (i = 0; i < adsnum; i++)
 282   {
 283   ACCESS_DESCRIPTION * ad = sk_ACCESS_DESCRIPTION_value(ads, i);
 284
 285   if (ad && OBJ_obj2nid(ad->method) == NID_ad_OCSP)
 286     list = string_append_listele(list, sep,
 287               ASN1_STRING_data(ad->location->d.ia5));
 288   }
 289 return list;
 290 }
 291
 292 uschar *
 293 tls_cert_crl_uri(void * cert, uschar * mod)
 294 {
 295 STACK_OF(DIST_POINT) * dps = (STACK_OF(DIST_POINT) *)
 296   X509_get_ext_d2i((X509 *)cert,  NID_crl_distribution_points,
 297     NULL, NULL);
 298 DIST_POINT * dp;
 299 int dpsnum = sk_DIST_POINT_num(dps);
 300 int i;
 301 uschar sep = '\n';
 302 uschar * list = NULL;
 303
 304 if (mod)
 305   if (*mod == '>' && *++mod) sep = *mod++;
 306
 307 if (dps) for (i = 0; i < dpsnum; i++)
 308   if ((dp = sk_DIST_POINT_value(dps, i)))
 309     {
 310     STACK_OF(GENERAL_NAME) * names = dp->distpoint->name.fullname;
 311     GENERAL_NAME * np;
 312     int nnum = sk_GENERAL_NAME_num(names);
 313     int j;
 314
 315     for (j = 0; j < nnum; j++)
 316       if (  (np = sk_GENERAL_NAME_value(names, j))
 317          && np->type == GEN_URI
 318          )
 319         list = string_append_listele(list, sep,
 320                 ASN1_STRING_data(np->d.uniformResourceIdentifier));
 321     }
 322 return list;
 323 }
 324
 325 /* vi: aw ai sw=2
 326 */
 327 /* End of tlscert-openssl.c */