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