X-Git-Url: https://git.exim.org/exim.git/blobdiff_plain/25ba25448b55c2fd5ea9b1aeed82e02d59816a07..a85c067ba6c6940512cf57ec213277a370d87e70:/src/src/tlscert-openssl.c

diff --git a/src/src/tlscert-openssl.c b/src/src/tlscert-openssl.c
index 29095782a..a4c3d19fa 100644
--- a/src/src/tlscert-openssl.c
+++ b/src/src/tlscert-openssl.c
@@ -2,7 +2,9 @@
 *     Exim - an Internet mail transport agent    *
 *************************************************/
 
-/* Copyright (c) Jeremy Harris 2014 */
+/* Copyright (c) The Exim Maintainers 2022 */
+/* Copyright (c) Jeremy Harris 2014 - 2019 */
+/* SPDX-License-Identifier: GPL-2.0-only */
 
 /* This module provides TLS (aka SSL) support for Exim using the OpenSSL
 library. It is #included into the tls.c file when that library is used.
@@ -17,15 +19,30 @@ library. It is #included into the tls.c file when that library is used.
 #include <openssl/rand.h>
 #include <openssl/x509v3.h>
 
+#ifdef LIBRESSL_VERSION_NUMBER	/* LibreSSL */
+# if LIBRESSL_VERSION_NUMBER >= 0x2090000fL
+#  define EXIM_HAVE_ASN1_MACROS
+# endif
+#else				/* OpenSSL */
+# if OPENSSL_VERSION_NUMBER >= 0x10100000L
+#  define EXIM_HAVE_ASN1_MACROS
+# endif
+#endif
+
+#if OPENSSL_VERSION_NUMBER < 0x10100000L || defined(LIBRESSL_VERSION_NUMBER)
+# define ASN1_STRING_get0_data ASN1_STRING_data
+#endif
 
 /*****************************************************
 *  Export/import a certificate, binary/printable
-*****************************************************/
-int
+******************************************************
+Return booolean success
+*/
+BOOL
 tls_export_cert(uschar * buf, size_t buflen, void * cert)
 {
 BIO * bp = BIO_new(BIO_s_mem());
-int fail;
+BOOL fail;
 
 if ((fail = PEM_write_bio_X509(bp, (X509 *)cert) ? 0 : 1))
   log_write(0, LOG_MAIN, "TLS error in certificate export: %s",
@@ -46,82 +63,151 @@ else
   }
 
 BIO_free(bp);
-return fail;
+return !fail;
 }
 
-int
+/* On error, NULL out the destination */
+BOOL
 tls_import_cert(const uschar * buf, void ** cert)
 {
-void * reset_point = store_get(0);
+rmark reset_point = store_mark();
 const uschar * cp = string_unprinting(US buf);
 BIO * bp;
-X509 * x;
+X509 * x = *(X509 **)cert;
+
+if (x) X509_free(x);
 
 bp = BIO_new_mem_buf(US cp, -1);
-x = PEM_read_bio_X509(bp, NULL, 0, NULL);
-int fail = 0;
-if (!x)
-  fail = 1;
-else
-  *cert = (void *)x;
+if (!(x = PEM_read_bio_X509(bp, NULL, 0, NULL)))
+  log_write(0, LOG_MAIN, "TLS error in certificate import: %s",
+    ERR_error_string(ERR_get_error(), NULL));
+
+*cert = (void *)x;
 BIO_free(bp);
 store_reset(reset_point);
-return fail;
+return !!x;
 }
 
 void
-tls_free_cert(void * cert)
+tls_free_cert(void ** cert)
 {
-X509_free((X509 *)cert);
+X509 * x = *(X509 **)cert;
+if (x)
+  {
+  X509_free(x);
+  *cert = NULL;
+  }
 }
 
+
 /*****************************************************
 *  Certificate field extraction routines
 *****************************************************/
+
+/* First, some internal service functions */
+
 static uschar *
-bio_string_copy(BIO * bp, int len)
+badalloc(void)
 {
-uschar * cp = US"";
-len = len > 0 ? (int) BIO_get_mem_data(bp, &cp) : 0;
-cp = string_copyn(cp, len);
-BIO_free(bp);
-return cp;
+expand_string_message = US"allocation failure";
+return NULL;
 }
 
 static uschar *
-bio_string_time_to_int(BIO * bp, int len)
+bio_string_copy(BIO * bp, int len)
 {
 uschar * cp = US"";
-struct tm t;
 len = len > 0 ? (int) BIO_get_mem_data(bp, &cp) : 0;
-/*XXX %Z might be glibc-specific? */
-(void) strptime(CS cp, "%b%t%e%t%T%t%Y%t%Z", &t);
+cp = string_copyn(cp, len);
 BIO_free(bp);
-/*XXX timegm might not be portable? */
-return string_sprintf("%u", (unsigned) timegm(&t));
+return cp;
 }
 
 static uschar *
-asn1_time_copy(const ASN1_TIME * time, uschar * mod)
+asn1_time_copy(const ASN1_TIME * asntime, uschar * mod)
 {
+uschar * s = NULL;
 BIO * bp = BIO_new(BIO_s_mem());
-int len = ASN1_TIME_print(bp, time);
-return mod &&  Ustrcmp(mod, "int") == 0
-  ? bio_string_time_to_int(bp, len)
-  : bio_string_copy(bp, len);
+int len;
+
+if (!bp)
+  return badalloc();
+len = ASN1_TIME_print(bp, asntime);
+len = len > 0 ? (int) BIO_get_mem_data(bp, CSS &s) : 0;
+
+if (mod && Ustrcmp(mod, "raw") == 0)		/* native ASN */
+  s = string_copyn(s, len);
+else
+  {
+  struct tm tm;
+  struct tm * tm_p = &tm;
+  BOOL mod_tz = TRUE;
+  uschar * tz = to_tz(US"GMT0");    /* need to call strptime with baseline TZ */
+
+  /* Parse OpenSSL ASN1_TIME_print output.  A shame there seems to
+  be no other interface for the times.
+  */
+
+  /*XXX %Z might be glibc-specific?  Solaris has it, at least*/
+  /*XXX should we switch to POSIX locale for this? */
+  tm.tm_isdst = 0;
+  if (!len || !strptime(CCS s, "%b %e %T %Y %Z", &tm))
+    expand_string_message = US"failed time conversion";
+
+  else
+    {
+    time_t t = mktime(&tm);	/* make the tm self-consistent */
+
+    if (mod && Ustrcmp(mod, "int") == 0)	/* seconds since epoch */
+      s = string_sprintf(TIME_T_FMT, t);
+
+    else
+      {
+      if (!f.timestamps_utc)	/* decoded string in local TZ */
+	{				/* shift to local TZ */
+	restore_tz(tz);
+	mod_tz = FALSE;
+	tm_p = localtime(&t);
+	}
+      /* "utc" is default, and rfc5280 says cert times should be Zulu */
+
+      /* convert to string in our format */
+      len = 32;
+      s = store_get(len, GET_UNTAINTED);
+      strftime(CS s, (size_t)len, "%b %e %T %Y %z", tm_p);
+      }
+    }
+
+  if (mod_tz)
+    restore_tz(tz);
+  }
+BIO_free(bp);
+return s;
 }
 
 static uschar *
 x509_name_copy(X509_NAME * name)
 {
 BIO * bp = BIO_new(BIO_s_mem());
-int len_good =
+int len_good;
+
+if (!bp) return badalloc();
+
+len_good =
   X509_NAME_print_ex(bp, name, 0, XN_FLAG_RFC2253) >= 0
   ? 1 : 0;
 return bio_string_copy(bp, len_good);
 }
 
 /**/
+/* Now the extractors, called from expand.c
+Arguments:
+  cert		The certificate
+  mod		Optional modifiers for the operator
+
+Return:
+  Allocated string with extracted value
+*/
 
 uschar *
 tls_cert_issuer(void * cert, uschar * mod)
@@ -147,8 +233,11 @@ tls_cert_serial_number(void * cert, uschar * mod)
 {
 uschar txt[256];
 BIO * bp = BIO_new(BIO_s_mem());
-int len = i2a_ASN1_INTEGER(bp, X509_get_serialNumber((X509 *)cert));
+int len;
 
+if (!bp) return badalloc();
+
+len = i2a_ASN1_INTEGER(bp, X509_get_serialNumber((X509 *)cert));
 if (len < sizeof(txt))
   BIO_read(bp, txt, len);
 else
@@ -160,18 +249,32 @@ return string_copynlc(txt, len);	/* lowercase */
 uschar *
 tls_cert_signature(void * cert, uschar * mod)
 {
-BIO * bp = BIO_new(BIO_s_mem());
 uschar * cp = NULL;
+BIO * bp = BIO_new(BIO_s_mem());
+
+if (!bp) return badalloc();
 
 if (X509_print_ex(bp, (X509 *)cert, 0,
-  X509_FLAG_NO_HEADER | X509_FLAG_NO_VERSION | X509_FLAG_NO_SERIAL | 
-  X509_FLAG_NO_SIGNAME | X509_FLAG_NO_ISSUER | X509_FLAG_NO_VALIDITY | 
-  X509_FLAG_NO_SUBJECT | X509_FLAG_NO_PUBKEY | X509_FLAG_NO_EXTENSIONS | 
+  X509_FLAG_NO_HEADER | X509_FLAG_NO_VERSION | X509_FLAG_NO_SERIAL |
+  X509_FLAG_NO_SIGNAME | X509_FLAG_NO_ISSUER | X509_FLAG_NO_VALIDITY |
+  X509_FLAG_NO_SUBJECT | X509_FLAG_NO_PUBKEY | X509_FLAG_NO_EXTENSIONS |
   /* X509_FLAG_NO_SIGDUMP is the missing one */
   X509_FLAG_NO_AUX) == 1)
   {
   long len = BIO_get_mem_data(bp, &cp);
-  cp = string_copyn(cp, len);
+  gstring * g = NULL;
+
+  /* Strip leading "Signature Algorithm" line */
+  while (*cp && *cp != '\n') { cp++; len--; }
+  if (*cp) { cp++; len--; }
+
+  /* Strip possible leading "    Signature Value:\n" (seen with OpenSSL 3.0.5) */
+  if (Ustrncmp(cp, "    Signature Value:\n", 21) == 0) { cp += 21; len -= 21; }
+
+  /* Copy only hexchars and colon (different OpenSSL versions do different spacing) */
+  for ( ; len-- && *cp; cp++)
+    if (Ustrchr("0123456789abcdef:", *cp)) g = string_catn(g, cp, 1);
+  cp = string_from_gstring(g);
   }
 BIO_free(bp);
 return cp;
@@ -180,7 +283,29 @@ return cp;
 uschar *
 tls_cert_signature_algorithm(void * cert, uschar * mod)
 {
-return string_copy(US OBJ_nid2ln(X509_get_signature_type((X509 *)cert)));
+uschar * cp = NULL;
+BIO * bp = BIO_new(BIO_s_mem());
+
+if (!bp) return badalloc();
+
+if (X509_print_ex(bp, (X509 *)cert, 0,
+  X509_FLAG_NO_HEADER | X509_FLAG_NO_VERSION | X509_FLAG_NO_SERIAL |
+  /* X509_FLAG_NO_SIGNAME is the missing one */
+  X509_FLAG_NO_ISSUER | X509_FLAG_NO_VALIDITY |
+  X509_FLAG_NO_SUBJECT | X509_FLAG_NO_PUBKEY | X509_FLAG_NO_EXTENSIONS |
+  X509_FLAG_NO_SIGDUMP | X509_FLAG_NO_AUX) == 1)
+  {
+  long len = BIO_get_mem_data(bp, &cp);
+
+  /* Strip leading "    Signature Algorithm: " and trailing newline */
+  while (*cp && *cp != ':') { cp++; len--; }
+  do { cp++; len--; } while (*cp && *cp == ' ');
+  if (cp[len-1] == '\n') len--;
+
+  cp = string_copyn(cp, len);
+  }
+BIO_free(bp);
+return cp;
 }
 
 uschar *
@@ -193,7 +318,7 @@ return mod ? tls_field_from_dn(cp, mod) : cp;
 uschar *
 tls_cert_version(void * cert, uschar * mod)
 {
-return string_sprintf("%d", X509_get_version((X509 *)cert));
+return string_sprintf("%ld", X509_get_version((X509 *)cert));
 }
 
 uschar *
@@ -209,17 +334,22 @@ uschar * cp1;
 uschar * cp2;
 uschar * cp3;
 
+if (!bp) return badalloc();
+
+#ifdef EXIM_HAVE_ASN1_MACROS
+ASN1_STRING_print(bp, adata);
+#else
 M_ASN1_OCTET_STRING_print(bp, adata);
-/* binary data, DER encoded */
+#endif
 
+/* binary data, DER encoded */
 /* just dump for now */
 len = BIO_get_mem_data(bp, &cp1);
-cp3 = cp2 = store_get(len*3+1);
+cp3 = cp2 = store_get(len*3+1, GET_TAINTED);
 
 while(len)
   {
-  sprintf(CS cp2, "%.2x ", *cp1++);
-  cp2 += 3;
+  cp2 += sprintf(CS cp2, "%.2x ", *cp1++);
   len--;
   }
 cp2[-1] = '\0';
@@ -230,26 +360,26 @@ return cp3;
 uschar *
 tls_cert_subject_altname(void * cert, uschar * mod)
 {
-uschar * list = NULL;
+gstring * list = NULL;
 STACK_OF(GENERAL_NAME) * san = (STACK_OF(GENERAL_NAME) *)
   X509_get_ext_d2i((X509 *)cert, NID_subject_alt_name, NULL, NULL);
-uschar sep = '\n';
+uschar osep = '\n';
 uschar * tag = US"";
 uschar * ele;
 int match = -1;
+int len;
 
 if (!san) return NULL;
 
-while (mod)
+while (mod && *mod)
   {
-  if (*mod == '>' && *++mod) sep = *mod++;
-  else if (Ustrcmp(mod, "dns")==0) { match = GEN_DNS; mod += 3; }
-  else if (Ustrcmp(mod, "uri")==0) { match = GEN_URI; mod += 3; }
-  else if (Ustrcmp(mod, "mail")==0) { match = GEN_EMAIL; mod += 4; }
-  else continue;
+  if (*mod == '>' && *++mod) osep = *mod++;
+  else if (Ustrncmp(mod,"dns",3)==0) { match = GEN_DNS; mod += 3; }
+  else if (Ustrncmp(mod,"uri",3)==0) { match = GEN_URI; mod += 3; }
+  else if (Ustrncmp(mod,"mail",4)==0) { match = GEN_EMAIL; mod += 4; }
+  else mod++;
 
-  if (*mod++ != ',')
-    break;
+  if (*mod == ',') mod++;
   }
 
 while (sk_GENERAL_NAME_num(san) > 0)
@@ -261,25 +391,32 @@ while (sk_GENERAL_NAME_num(san) > 0)
     {
     case GEN_DNS:
       tag = US"DNS";
-      ele = ASN1_STRING_data(namePart->d.dNSName);
+      ele = US ASN1_STRING_get0_data(namePart->d.dNSName);
+      len = ASN1_STRING_length(namePart->d.dNSName);
       break;
     case GEN_URI:
       tag = US"URI";
-      ele = ASN1_STRING_data(namePart->d.uniformResourceIdentifier);
+      ele = US ASN1_STRING_get0_data(namePart->d.uniformResourceIdentifier);
+      len = ASN1_STRING_length(namePart->d.uniformResourceIdentifier);
       break;
     case GEN_EMAIL:
       tag = US"MAIL";
-      ele = ASN1_STRING_data(namePart->d.rfc822Name);
+      ele = US ASN1_STRING_get0_data(namePart->d.rfc822Name);
+      len = ASN1_STRING_length(namePart->d.rfc822Name);
       break;
     default:
       continue;	/* ignore unrecognised types */
     }
-  list = string_append_listele(list, sep,
+  if (ele[len])	/* not nul-terminated */
+    ele = string_copyn(ele, len);
+
+  if (Ustrlen(ele) == len)	/* ignore any with embedded nul */
+    list = string_append_listele(list, osep,
 	  match == -1 ? string_sprintf("%s=%s", tag, ele) : ele);
   }
 
 sk_GENERAL_NAME_free(san);
-return list;
+return string_from_gstring(list);
 }
 
 uschar *
@@ -288,22 +425,23 @@ tls_cert_ocsp_uri(void * cert, uschar * mod)
 STACK_OF(ACCESS_DESCRIPTION) * ads = (STACK_OF(ACCESS_DESCRIPTION) *)
   X509_get_ext_d2i((X509 *)cert, NID_info_access, NULL, NULL);
 int adsnum = sk_ACCESS_DESCRIPTION_num(ads);
-int i;
 uschar sep = '\n';
-uschar * list = NULL;
+gstring * list = NULL;
 
 if (mod)
   if (*mod == '>' && *++mod) sep = *mod++;
 
-for (i = 0; i < adsnum; i++)
+for (int i = 0; i < adsnum; i++)
   {
   ACCESS_DESCRIPTION * ad = sk_ACCESS_DESCRIPTION_value(ads, i);
 
   if (ad && OBJ_obj2nid(ad->method) == NID_ad_OCSP)
-    list = string_append_listele(list, sep,
-	      ASN1_STRING_data(ad->location->d.ia5));
+    list = string_append_listele_n(list, sep,
+      US ASN1_STRING_get0_data(ad->location->d.ia5),
+      ASN1_STRING_length(ad->location->d.ia5));
   }
-return list;
+sk_ACCESS_DESCRIPTION_free(ads);
+return string_from_gstring(list);
 }
 
 uschar *
@@ -313,30 +451,28 @@ STACK_OF(DIST_POINT) * dps = (STACK_OF(DIST_POINT) *)
   X509_get_ext_d2i((X509 *)cert,  NID_crl_distribution_points,
     NULL, NULL);
 DIST_POINT * dp;
-int dpsnum = sk_DIST_POINT_num(dps);
-int i;
 uschar sep = '\n';
-uschar * list = NULL;
+gstring * list = NULL;
 
 if (mod)
   if (*mod == '>' && *++mod) sep = *mod++;
 
-if (dps) for (i = 0; i < dpsnum; i++)
+if (dps) for (int i = 0, dpsnum = sk_DIST_POINT_num(dps); i < dpsnum; i++)
   if ((dp = sk_DIST_POINT_value(dps, i)))
     {
     STACK_OF(GENERAL_NAME) * names = dp->distpoint->name.fullname;
     GENERAL_NAME * np;
-    int nnum = sk_GENERAL_NAME_num(names);
-    int j;
 
-    for (j = 0; j < nnum; j++)
+    for (int j = 0, nnum = sk_GENERAL_NAME_num(names); j < nnum; j++)
       if (  (np = sk_GENERAL_NAME_value(names, j))
 	 && np->type == GEN_URI
 	 )
-	list = string_append_listele(list, sep,
-		ASN1_STRING_data(np->d.uniformResourceIdentifier));
+	list = string_append_listele_n(list, sep,
+	  US ASN1_STRING_get0_data(np->d.uniformResourceIdentifier),
+	  ASN1_STRING_length(np->d.uniformResourceIdentifier));
     }
-return list;
+sk_DIST_POINT_free(dps);
+return string_from_gstring(list);
 }
 
 
@@ -344,10 +480,29 @@ return list;
 /*****************************************************
 *  Certificate operator routines
 *****************************************************/
+uschar *
+tls_cert_der_b64(void * cert)
+{
+BIO * bp = BIO_new(BIO_s_mem());
+uschar * cp = NULL;
+
+if (!i2d_X509_bio(bp, (X509 *)cert))
+  log_write(0, LOG_MAIN, "TLS error in certificate export: %s",
+    ERR_error_string(ERR_get_error(), NULL));
+else
+  {
+  long len = BIO_get_mem_data(bp, &cp);
+  cp = b64encode(CUS cp, (int)len);
+  }
+
+BIO_free(bp);
+return cp;
+}
+
+
 static uschar *
 fingerprint(X509 * cert, const EVP_MD * fdig)
 {
-int j;
 unsigned int n;
 uschar md[EVP_MAX_MD_SIZE];
 uschar * cp;
@@ -357,24 +512,24 @@ if (!X509_digest(cert,fdig,md,&n))
   expand_string_message = US"tls_cert_fprt: out of mem\n";
   return NULL;
   }
-cp = store_get(n*2+1);
-for (j = 0; j < (int)n; j++) sprintf(CS cp+2*j, "%02X", md[j]);
+cp = store_get(n*2+1, GET_TAINTED);
+for (int j = 0; j < (int)n; j++) sprintf(CS cp+2*j, "%02X", md[j]);
 return(cp);
 }
 
-uschar * 
+uschar *
 tls_cert_fprt_md5(void * cert)
 {
 return fingerprint((X509 *)cert, EVP_md5());
 }
 
-uschar * 
+uschar *
 tls_cert_fprt_sha1(void * cert)
 {
 return fingerprint((X509 *)cert, EVP_sha1());
 }
 
-uschar * 
+uschar *
 tls_cert_fprt_sha256(void * cert)
 {
 return fingerprint((X509 *)cert, EVP_sha256());