Adding upstream version 4.92.upstream/4.92upstream

Signed-off-by: Daniel Baumann <daniel.baumann@progress-linux.org>

1 files changed, 485 insertions, 0 deletions

diff --git a/src/tlscert-gnu.c b/src/tlscert-gnu.c
new file mode 100644
index 0000000..9fe8c49
--- /dev/null
+++ b/src/tlscert-gnu.c
@@ -0,0 +1,485 @@
+/*************************************************
+*     Exim - an Internet mail transport agent    *
+*************************************************/
+
+/* Copyright (c) Jeremy Harris 2014 - 2018 */
+
+/* This file provides TLS/SSL support for Exim using the GnuTLS library,
+one of the available supported implementations.  This file is #included into
+tls.c when USE_GNUTLS has been set.
+*/
+
+#include <gnutls/gnutls.h>
+/* needed for cert checks in verification and DN extraction: */
+#include <gnutls/x509.h>
+/* needed to disable PKCS11 autoload unless requested */
+#if GNUTLS_VERSION_NUMBER >= 0x020c00
+# include <gnutls/pkcs11.h>
+#endif
+
+
+/*****************************************************
+*  Export/import a certificate, binary/printable
+*****************************************************/
+int
+tls_export_cert(uschar * buf, size_t buflen, void * cert)
+{
+size_t sz = buflen;
+void * reset_point = store_get(0);
+int fail;
+const uschar * cp;
+
+if ((fail = gnutls_x509_crt_export((gnutls_x509_crt_t)cert,
+    GNUTLS_X509_FMT_PEM, buf, &sz)))
+  {
+  log_write(0, LOG_MAIN, "TLS error in certificate export: %s",
+    gnutls_strerror(fail));
+  return 1;
+  }
+if ((cp = string_printing(buf)) != buf)
+  {
+  Ustrncpy(buf, cp, buflen);
+  if (buf[buflen-1])
+    fail = 1;
+  }
+store_reset(reset_point);
+return fail;
+}
+
+int
+tls_import_cert(const uschar * buf, void ** cert)
+{
+void * reset_point = store_get(0);
+gnutls_datum_t datum;
+gnutls_x509_crt_t crt = *(gnutls_x509_crt_t *)cert;
+int fail = 0;
+
+if (crt)
+  gnutls_x509_crt_deinit(crt);
+else
+  gnutls_global_init();
+
+gnutls_x509_crt_init(&crt);
+
+datum.data = string_unprinting(US buf);
+datum.size = Ustrlen(datum.data);
+if ((fail = gnutls_x509_crt_import(crt, &datum, GNUTLS_X509_FMT_PEM)))
+  {
+  log_write(0, LOG_MAIN, "TLS error in certificate import: %s",
+    gnutls_strerror(fail));
+  fail = 1;
+  }
+else
+  *cert = (void *)crt;
+
+store_reset(reset_point);
+return fail;
+}
+
+void
+tls_free_cert(void ** cert)
+{
+gnutls_x509_crt_t crt = *(gnutls_x509_crt_t *)cert;
+if (crt)
+  {
+  gnutls_x509_crt_deinit(crt);
+  gnutls_global_deinit();
+  *cert = NULL;
+  }
+}
+
+/*****************************************************
+*  Certificate field extraction routines
+*****************************************************/
+
+/* First, some internal service functions */
+
+static uschar *
+g_err(const char * tag, const char * from, int gnutls_err)
+{
+expand_string_message = string_sprintf("%s: %s fail: %s\n",
+  from, tag, gnutls_strerror(gnutls_err));
+return NULL;
+}
+
+
+static uschar *
+time_copy(time_t t, uschar * mod)
+{
+uschar * cp;
+size_t len = 32;
+
+if (mod && Ustrcmp(mod, "int") == 0)
+  return string_sprintf("%u", (unsigned)t);
+
+cp = store_get(len);
+if (f.timestamps_utc)
+  {
+  uschar * tz = to_tz(US"GMT0");
+  len = strftime(CS cp, len, "%b %e %T %Y %Z", gmtime(&t));
+  restore_tz(tz);
+  }
+else
+  len = strftime(CS cp, len, "%b %e %T %Y %Z", localtime(&t));
+return len > 0 ? cp : NULL;
+}
+
+
+/**/
+/* 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)
+{
+uschar * cp = NULL;
+int ret;
+size_t siz = 0;
+
+if ((ret = gnutls_x509_crt_get_issuer_dn(cert, CS cp, &siz))
+    != GNUTLS_E_SHORT_MEMORY_BUFFER)
+  return g_err("gi0", __FUNCTION__, ret);
+
+cp = store_get(siz);
+if ((ret = gnutls_x509_crt_get_issuer_dn(cert, CS cp, &siz)) < 0)
+  return g_err("gi1", __FUNCTION__, ret);
+
+return mod ? tls_field_from_dn(cp, mod) : cp;
+}
+
+uschar *
+tls_cert_not_after(void * cert, uschar * mod)
+{
+return time_copy(
+  gnutls_x509_crt_get_expiration_time((gnutls_x509_crt_t)cert),
+  mod);
+}
+
+uschar *
+tls_cert_not_before(void * cert, uschar * mod)
+{
+return time_copy(
+  gnutls_x509_crt_get_activation_time((gnutls_x509_crt_t)cert),
+  mod);
+}
+
+uschar *
+tls_cert_serial_number(void * cert, uschar * mod)
+{
+uschar bin[50], txt[150];
+size_t sz = sizeof(bin);
+uschar * sp;
+uschar * dp;
+int ret;
+
+if ((ret = gnutls_x509_crt_get_serial((gnutls_x509_crt_t)cert,
+    bin, &sz)))
+  return g_err("gs0", __FUNCTION__, ret);
+
+for(dp = txt, sp = bin; sz; sz--)
+  dp += sprintf(CS dp, "%.2x", *sp++);
+for(sp = txt; sp[0]=='0' && sp[1]; ) sp++;	/* leading zeroes */
+return string_copy(sp);
+}
+
+uschar *
+tls_cert_signature(void * cert, uschar * mod)
+{
+uschar * cp1 = NULL;
+uschar * cp2;
+uschar * cp3;
+size_t len = 0;
+int ret;
+
+if ((ret = gnutls_x509_crt_get_signature((gnutls_x509_crt_t)cert, CS cp1, &len))
+    != GNUTLS_E_SHORT_MEMORY_BUFFER)
+  return g_err("gs0", __FUNCTION__, ret);
+
+cp1 = store_get(len*4+1);
+if (gnutls_x509_crt_get_signature((gnutls_x509_crt_t)cert, CS cp1, &len) != 0)
+  return g_err("gs1", __FUNCTION__, ret);
+
+for(cp3 = cp2 = cp1+len; cp1 < cp2; cp1++)
+  cp3 += sprintf(CS cp3, "%.2x ", *cp1);
+cp3[-1]= '\0';
+
+return cp2;
+}
+
+uschar *
+tls_cert_signature_algorithm(void * cert, uschar * mod)
+{
+gnutls_sign_algorithm_t algo =
+  gnutls_x509_crt_get_signature_algorithm((gnutls_x509_crt_t)cert);
+return algo < 0 ? NULL : string_copy(US gnutls_sign_get_name(algo));
+}
+
+uschar *
+tls_cert_subject(void * cert, uschar * mod)
+{
+uschar * cp = NULL;
+int ret;
+size_t siz = 0;
+
+if ((ret = gnutls_x509_crt_get_dn(cert, CS cp, &siz))
+    != GNUTLS_E_SHORT_MEMORY_BUFFER)
+  return g_err("gs0", __FUNCTION__, ret);
+
+cp = store_get(siz);
+if ((ret = gnutls_x509_crt_get_dn(cert, CS cp, &siz)) < 0)
+  return g_err("gs1", __FUNCTION__, ret);
+
+return mod ? tls_field_from_dn(cp, mod) : cp;
+}
+
+uschar *
+tls_cert_version(void * cert, uschar * mod)
+{
+return string_sprintf("%d", gnutls_x509_crt_get_version(cert));
+}
+
+uschar *
+tls_cert_ext_by_oid(void * cert, uschar * oid, int idx)
+{
+uschar * cp1 = NULL;
+uschar * cp2;
+uschar * cp3;
+size_t siz = 0;
+unsigned int crit;
+int ret;
+
+ret = gnutls_x509_crt_get_extension_by_oid ((gnutls_x509_crt_t)cert,
+  CS oid, idx, CS cp1, &siz, &crit);
+if (ret != GNUTLS_E_SHORT_MEMORY_BUFFER)
+  return g_err("ge0", __FUNCTION__, ret);
+
+cp1 = store_get(siz*4 + 1);
+
+ret = gnutls_x509_crt_get_extension_by_oid ((gnutls_x509_crt_t)cert,
+  CS oid, idx, CS cp1, &siz, &crit);
+if (ret < 0)
+  return g_err("ge1", __FUNCTION__, ret);
+
+/* binary data, DER encoded */
+
+/* just dump for now */
+for(cp3 = cp2 = cp1+siz; cp1 < cp2; cp1++)
+  cp3 += sprintf(CS cp3, "%.2x ", *cp1);
+cp3[-1]= '\0';
+
+return cp2;
+}
+
+uschar *
+tls_cert_subject_altname(void * cert, uschar * mod)
+{
+gstring * list = NULL;
+int index;
+size_t siz;
+int ret;
+uschar sep = '\n';
+uschar * tag = US"";
+uschar * ele;
+int match = -1;
+
+while (mod)
+  {
+  if (*mod == '>' && *++mod) sep = *mod++;
+  else if (Ustrcmp(mod, "dns")==0) { match = GNUTLS_SAN_DNSNAME; mod += 3; }
+  else if (Ustrcmp(mod, "uri")==0) { match = GNUTLS_SAN_URI; mod += 3; }
+  else if (Ustrcmp(mod, "mail")==0) { match = GNUTLS_SAN_RFC822NAME; mod += 4; }
+  else continue;
+
+  if (*mod++ != ',')
+    break;
+  }
+
+for(index = 0;; index++)
+  {
+  siz = 0;
+  switch(ret = gnutls_x509_crt_get_subject_alt_name(
+      (gnutls_x509_crt_t)cert, index, NULL, &siz, NULL))
+    {
+    case GNUTLS_E_REQUESTED_DATA_NOT_AVAILABLE:
+      return string_from_gstring(list);	/* no more elements; normal exit */
+
+    case GNUTLS_E_SHORT_MEMORY_BUFFER:
+      break;
+
+    default:
+      return g_err("gs0", __FUNCTION__, ret);
+    }
+
+  ele = store_get(siz+1);
+  if ((ret = gnutls_x509_crt_get_subject_alt_name(
+    (gnutls_x509_crt_t)cert, index, ele, &siz, NULL)) < 0)
+    return g_err("gs1", __FUNCTION__, ret);
+  ele[siz] = '\0';
+
+  if (  match != -1 && match != ret	/* wrong type of SAN */
+     || Ustrlen(ele) != siz)		/* contains a NUL */
+    continue;
+  switch (ret)
+    {
+    case GNUTLS_SAN_DNSNAME:    tag = US"DNS";  break;
+    case GNUTLS_SAN_URI:        tag = US"URI";  break;
+    case GNUTLS_SAN_RFC822NAME: tag = US"MAIL"; break;
+    default: continue;        /* ignore unrecognised types */
+    }
+  list = string_append_listele(list, sep,
+          match == -1 ? string_sprintf("%s=%s", tag, ele) : ele);
+  }
+/*NOTREACHED*/
+}
+
+uschar *
+tls_cert_ocsp_uri(void * cert, uschar * mod)
+{
+#if GNUTLS_VERSION_NUMBER >= 0x030000
+gnutls_datum_t uri;
+int ret;
+uschar sep = '\n';
+int index;
+gstring * list = NULL;
+
+if (mod)
+  if (*mod == '>' && *++mod) sep = *mod++;
+
+for(index = 0;; index++)
+  {
+  ret = gnutls_x509_crt_get_authority_info_access((gnutls_x509_crt_t)cert,
+	  index, GNUTLS_IA_OCSP_URI, &uri, NULL);
+
+  if (ret == GNUTLS_E_REQUESTED_DATA_NOT_AVAILABLE)
+    return string_from_gstring(list);
+  if (ret < 0)
+    return g_err("gai", __FUNCTION__, ret);
+
+  list = string_append_listele_n(list, sep, uri.data, uri.size);
+  }
+/*NOTREACHED*/
+
+#else
+
+expand_string_message =
+  string_sprintf("%s: OCSP support with GnuTLS requires version 3.0.0\n",
+    __FUNCTION__);
+return NULL;
+
+#endif
+}
+
+uschar *
+tls_cert_crl_uri(void * cert, uschar * mod)
+{
+int ret;
+size_t siz;
+uschar sep = '\n';
+int index;
+gstring * list = NULL;
+uschar * ele;
+
+if (mod)
+  if (*mod == '>' && *++mod) sep = *mod++;
+
+for(index = 0;; index++)
+  {
+  siz = 0;
+  switch(ret = gnutls_x509_crt_get_crl_dist_points(
+    (gnutls_x509_crt_t)cert, index, NULL, &siz, NULL, NULL))
+    {
+    case GNUTLS_E_REQUESTED_DATA_NOT_AVAILABLE:
+      return string_from_gstring(list);
+    case GNUTLS_E_SHORT_MEMORY_BUFFER:
+      break;
+    default:
+      return g_err("gc0", __FUNCTION__, ret);
+    }
+
+  ele = store_get(siz);
+  if ((ret = gnutls_x509_crt_get_crl_dist_points(
+      (gnutls_x509_crt_t)cert, index, ele, &siz, NULL, NULL)) < 0)
+    return g_err("gc1", __FUNCTION__, ret);
+
+  list = string_append_listele_n(list, sep, ele, siz);
+  }
+/*NOTREACHED*/
+}
+
+
+/*****************************************************
+*  Certificate operator routines
+*****************************************************/
+uschar *
+tls_cert_der_b64(void * cert)
+{
+size_t len = 0;
+uschar * cp = NULL;
+int fail;
+
+if (  (fail = gnutls_x509_crt_export((gnutls_x509_crt_t)cert,
+	GNUTLS_X509_FMT_DER, cp, &len)) != GNUTLS_E_SHORT_MEMORY_BUFFER
+   || !(cp = store_get((int)len))
+   || (fail = gnutls_x509_crt_export((gnutls_x509_crt_t)cert,
+        GNUTLS_X509_FMT_DER, cp, &len))
+   )
+  {
+  log_write(0, LOG_MAIN, "TLS error in certificate export: %s",
+    gnutls_strerror(fail));
+  return NULL;
+  }
+return b64encode(cp, (int)len);
+}
+
+
+static uschar *
+fingerprint(gnutls_x509_crt_t cert, gnutls_digest_algorithm_t algo)
+{
+int ret;
+size_t siz = 0;
+uschar * cp;
+uschar * cp2;
+uschar * cp3;
+
+if ((ret = gnutls_x509_crt_get_fingerprint(cert, algo, NULL, &siz))
+    != GNUTLS_E_SHORT_MEMORY_BUFFER)
+  return g_err("gf0", __FUNCTION__, ret);
+
+cp = store_get(siz*3+1);
+if ((ret = gnutls_x509_crt_get_fingerprint(cert, algo, cp, &siz)) < 0)
+  return g_err("gf1", __FUNCTION__, ret);
+
+for (cp3 = cp2 = cp+siz; cp < cp2; cp++)
+  cp3 += sprintf(CS cp3, "%02X", *cp);
+return cp2;
+}
+
+
+uschar *
+tls_cert_fprt_md5(void * cert)
+{
+return fingerprint((gnutls_x509_crt_t)cert, GNUTLS_DIG_MD5);
+}
+
+uschar *
+tls_cert_fprt_sha1(void * cert)
+{
+return fingerprint((gnutls_x509_crt_t)cert, GNUTLS_DIG_SHA1);
+}
+
+uschar *
+tls_cert_fprt_sha256(void * cert)
+{
+return fingerprint((gnutls_x509_crt_t)cert, GNUTLS_DIG_SHA256);
+}
+
+
+/* vi: aw ai sw=2
+*/
+/* End of tlscert-gnu.c */