]> git.ipfire.org Git - thirdparty/cups.git/blobdiff - cups/tls-gnutls.c
Support AddressSanitizer in builds.
[thirdparty/cups.git] / cups / tls-gnutls.c
index 13c260ba599218d8dda1c61a3f33d88ef65a009e..05ec8ec7f1a7942930cc847b0a79218a3f371be4 100644 (file)
@@ -1,20 +1,14 @@
 /*
- * "$Id$"
- *
  * TLS support code for CUPS using GNU TLS.
  *
- * Copyright 2007-2014 by Apple Inc.
- * Copyright 1997-2007 by Easy Software Products, all rights reserved.
- *
- * These coded instructions, statements, and computer programs are the
- * property of Apple Inc. and are protected by Federal copyright
- * law.  Distribution and use rights are outlined in the file "LICENSE.txt"
- * which should have been included with this file.  If this file is
- * file is missing or damaged, see the license at "http://www.cups.org/".
+ * Copyright © 2007-2018 by Apple Inc.
+ * Copyright © 1997-2007 by Easy Software Products, all rights reserved.
  *
- * This file is subject to the Apple OS-Developed Software exception.
+ * Licensed under Apache License v2.0.  See the file "LICENSE" for more
+ * information.
  */
 
+/**** This file is included from tls.c ****/
 
 /*
  * Include necessary headers...
@@ -31,17 +25,24 @@ static int          tls_auto_create = 0;
                                        /* Auto-create self-signed certs? */
 static char            *tls_common_name = NULL;
                                        /* Default common name */
+static gnutls_x509_crl_t tls_crl = NULL;/* Certificate revocation list */
 static char            *tls_keypath = NULL;
                                        /* Server cert keychain path */
 static _cups_mutex_t   tls_mutex = _CUPS_MUTEX_INITIALIZER;
                                        /* Mutex for keychain/certs */
+static int             tls_options = -1,/* Options for TLS connections */
+                       tls_min_version = _HTTP_TLS_1_0,
+                       tls_max_version = _HTTP_TLS_MAX;
 
 
 /*
  * Local functions...
  */
 
+static gnutls_x509_crt_t http_gnutls_create_credential(http_credential_t *credential);
 static const char      *http_gnutls_default_path(char *buffer, size_t bufsize);
+static void            http_gnutls_load_crl(void);
+static const char      *http_gnutls_make_path(char *buffer, size_t bufsize, const char *dirname, const char *filename, const char *ext);
 static ssize_t         http_gnutls_read(gnutls_transport_ptr_t ptr, void *data, size_t length);
 static ssize_t         http_gnutls_write(gnutls_transport_ptr_t ptr, const void *data, size_t length);
 
@@ -49,7 +50,7 @@ static ssize_t                http_gnutls_write(gnutls_transport_ptr_t ptr, const void *data,
 /*
  * 'cupsMakeServerCredentials()' - Make a self-signed certificate and private key pair.
  *
- * @since CUPS 2.0@
+ * @since CUPS 2.0/OS 10.10@
  */
 
 int                                    /* O - 1 on success, 0 on failure */
@@ -88,9 +89,9 @@ cupsMakeServerCredentials(
     _cupsSetError(IPP_STATUS_ERROR_INTERNAL, strerror(EINVAL), 0);
     return (0);
   }
-    
-  snprintf(crtfile, sizeof(crtfile), "%s/%s.crt", path, common_name);
-  snprintf(keyfile, sizeof(keyfile), "%s/%s.key", path, common_name);
+
+  http_gnutls_make_path(crtfile, sizeof(crtfile), path, common_name, "crt");
+  http_gnutls_make_path(keyfile, sizeof(keyfile), path, common_name, "key");
 
  /*
   * Create the encryption key...
@@ -226,7 +227,7 @@ cupsMakeServerCredentials(
  * Note: The server credentials are used by all threads in the running process.
  * This function is threadsafe.
  *
- * @since CUPS 2.0@
+ * @since CUPS 2.0/OS 10.10@
  */
 
 int                                    /* O - 1 on success, 0 on failure */
@@ -287,7 +288,7 @@ cupsSetServerCredentials(
  * 'httpCopyCredentials()' - Copy the credentials associated with the peer in
  *                           an encrypted connection.
  *
- * @since CUPS 1.5/OS X 10.7@
+ * @since CUPS 1.5/macOS 10.7@
  */
 
 int                                    /* O - Status of call (0 = success) */
@@ -295,12 +296,33 @@ httpCopyCredentials(
     http_t      *http,                 /* I - Connection to server */
     cups_array_t **credentials)                /* O - Array of credentials */
 {
+  unsigned             count;          /* Number of certificates */
+  const gnutls_datum_t *certs;         /* Certificates */
+
+
+  DEBUG_printf(("httpCopyCredentials(http=%p, credentials=%p)", http, credentials));
+
   if (credentials)
     *credentials = NULL;
 
   if (!http || !http->tls || !credentials)
     return (-1);
 
+  *credentials = cupsArrayNew(NULL, NULL);
+  certs        = gnutls_certificate_get_peers(http->tls, &count);
+
+  DEBUG_printf(("1httpCopyCredentials: certs=%p, count=%u", certs, count));
+
+  if (certs && count)
+  {
+    while (count > 0)
+    {
+      httpAddCredential(*credentials, certs->data, certs->size);
+      certs ++;
+      count --;
+    }
+  }
+
   return (0);
 }
 
@@ -334,7 +356,7 @@ _httpFreeCredentials(
 /*
  * 'httpCredentialsAreValidForName()' - Return whether the credentials are valid for the given name.
  *
- * @since CUPS 2.0@
+ * @since CUPS 2.0/OS 10.10@
  */
 
 int                                    /* O - 1 if valid, 0 otherwise */
@@ -342,63 +364,58 @@ httpCredentialsAreValidForName(
     cups_array_t *credentials,         /* I - Credentials */
     const char   *common_name)         /* I - Name to check */
 {
-#if 0
-  char                 cert_name[256]; /* Certificate's common name (C string) */
-  int                  valid = 1;      /* Valid name? */
-
-
-  if ((secCert = http_cdsa_create_credential((http_credential_t *)cupsArrayFirst(credentials))) == NULL)
-    return (0);
+  gnutls_x509_crt_t    cert;           /* Certificate */
+  int                  result = 0;     /* Result */
 
- /*
-  * Compare the common names...
-  */
 
-  if ((cfcert_name = SecCertificateCopySubjectSummary(secCert)) == NULL)
+  cert = http_gnutls_create_credential((http_credential_t *)cupsArrayFirst(credentials));
+  if (cert)
   {
-   /*
-    * Can't get common name, cannot be valid...
-    */
+    result = gnutls_x509_crt_check_hostname(cert, common_name) != 0;
 
-    valid = 0;
-  }
-  else if (CFStringGetCString(cfcert_name, cert_name, sizeof(cert_name), kCFStringEncodingUTF8) &&
-           _cups_strcasecmp(common_name, cert_name))
-  {
-   /*
-    * Not an exact match for the common name, check for wildcard certs...
-    */
+    if (result)
+    {
+      int              i,              /* Looping var */
+                       count;          /* Number of revoked certificates */
+      unsigned char    cserial[1024],  /* Certificate serial number */
+                       rserial[1024];  /* Revoked serial number */
+      size_t           cserial_size,   /* Size of cert serial number */
+                       rserial_size;   /* Size of revoked serial number */
 
-    const char *domain = strchr(common_name, '.');
-                                       /* Domain in common name */
+      _cupsMutexLock(&tls_mutex);
 
-    if (strncmp(cert_name, "*.", 2) || !domain || _cups_strcasecmp(domain, cert_name + 1))
-    {
-     /*
-      * Not a wildcard match.
-      */
+      count = gnutls_x509_crl_get_crt_count(tls_crl);
 
-      /* TODO: Check subject alternate names */
-      valid = 0;
-    }
-  }
+      if (count > 0)
+      {
+        cserial_size = sizeof(cserial);
+        gnutls_x509_crt_get_serial(cert, cserial, &cserial_size);
+
+        for (i = 0; i < count; i ++)
+       {
+         rserial_size = sizeof(rserial);
+          if (!gnutls_x509_crl_get_crt_serial(tls_crl, (unsigned)i, rserial, &rserial_size, NULL) && cserial_size == rserial_size && !memcmp(cserial, rserial, rserial_size))
+         {
+           result = 0;
+           break;
+         }
+       }
+      }
 
-  if (cfcert_name)
-    CFRelease(cfcert_name);
+      _cupsMutexUnlock(&tls_mutex);
+    }
 
-  CFRelease(secCert);
+    gnutls_x509_crt_deinit(cert);
+  }
 
-  return (valid);
-#else
-  return (1);
-#endif /* 0 */
+  return (result);
 }
 
 
 /*
  * 'httpCredentialsGetTrust()' - Return the trust of credentials.
  *
- * @since CUPS 2.0@
+ * @since CUPS 2.0/OS 10.10@
  */
 
 http_trust_t                           /* O - Level of trust */
@@ -408,20 +425,29 @@ httpCredentialsGetTrust(
 {
   http_trust_t         trust = HTTP_TRUST_OK;
                                        /* Trusted? */
-
-#if 0
+  gnutls_x509_crt_t    cert;           /* Certificate */
   cups_array_t         *tcreds = NULL; /* Trusted credentials */
   _cups_globals_t      *cg = _cupsGlobals();
                                        /* Per-thread globals */
-#endif /* 0 */
 
 
   if (!common_name)
+  {
+    _cupsSetError(IPP_STATUS_ERROR_INTERNAL, _("No common name specified."), 1);
     return (HTTP_TRUST_UNKNOWN);
+  }
 
-#if 0
-  if ((secCert = http_cdsa_create_credential((http_credential_t *)cupsArrayFirst(credentials))) == NULL)
+  if ((cert = http_gnutls_create_credential((http_credential_t *)cupsArrayFirst(credentials))) == NULL)
+  {
+    _cupsSetError(IPP_STATUS_ERROR_INTERNAL, _("Unable to create credentials from array."), 1);
     return (HTTP_TRUST_UNKNOWN);
+  }
+
+  if (cg->any_root < 0)
+  {
+    _cupsSetDefaults();
+    http_gnutls_load_crl();
+  }
 
  /*
   * Look this common name up in the default keychains...
@@ -444,14 +470,34 @@ httpCredentialsGetTrust(
       * credentials and allow if the new ones have a later expiration...
       */
 
-      if (httpCredentialsGetExpiration(credentials) <= httpCredentialsGetExpiration(tcreds) ||
-          !httpCredentialsAreValidForName(credentials, common_name))
+      if (!cg->trust_first)
+      {
+       /*
+        * Do not trust certificates on first use...
+       */
+
+        _cupsSetError(IPP_STATUS_ERROR_INTERNAL, _("Trust on first use is disabled."), 1);
+
+        trust = HTTP_TRUST_INVALID;
+      }
+      else if (httpCredentialsGetExpiration(credentials) <= httpCredentialsGetExpiration(tcreds))
+      {
+       /*
+        * The new credentials are not newly issued...
+       */
+
+        _cupsSetError(IPP_STATUS_ERROR_INTERNAL, _("New credentials are older than stored credentials."), 1);
+
+        trust = HTTP_TRUST_INVALID;
+      }
+      else if (!httpCredentialsAreValidForName(credentials, common_name))
       {
        /*
-        * Either the new credentials are not newly issued, or the common name
-       * does not match the issued certificate...
+        * The common name does not match the issued certificate...
        */
 
+        _cupsSetError(IPP_STATUS_ERROR_INTERNAL, _("New credentials are not valid for name."), 1);
+
         trust = HTTP_TRUST_INVALID;
       }
       else if (httpCredentialsGetExpiration(tcreds) < time(NULL))
@@ -469,15 +515,74 @@ httpCredentialsGetTrust(
     httpFreeCredentials(tcreds);
   }
   else if (cg->validate_certs && !httpCredentialsAreValidForName(credentials, common_name))
+  {
+    _cupsSetError(IPP_STATUS_ERROR_INTERNAL, _("No stored credentials, not valid for name."), 1);
     trust = HTTP_TRUST_INVALID;
+  }
+  else if (!cg->trust_first)
+  {
+   /*
+    * See if we have a site CA certificate we can compare...
+    */
+
+    if (!httpLoadCredentials(NULL, &tcreds, "site"))
+    {
+      if (cupsArrayCount(credentials) != (cupsArrayCount(tcreds) + 1))
+      {
+       /*
+        * Certificate isn't directly generated from the CA cert...
+       */
+
+        trust = HTTP_TRUST_INVALID;
+      }
+      else
+      {
+       /*
+        * Do a tail comparison of the two certificates...
+       */
+
+        http_credential_t      *a, *b;         /* Certificates */
+
+        for (a = (http_credential_t *)cupsArrayFirst(tcreds), b = (http_credential_t *)cupsArrayIndex(credentials, 1);
+            a && b;
+            a = (http_credential_t *)cupsArrayNext(tcreds), b = (http_credential_t *)cupsArrayNext(credentials))
+         if (a->datalen != b->datalen || memcmp(a->data, b->data, a->datalen))
+           break;
 
-  if (!cg->expired_certs && !SecCertificateIsValid(secCert, CFAbsoluteTimeGetCurrent()))
-    trust = HTTP_TRUST_EXPIRED;
-  else if (!cg->any_root && cupsArrayCount(credentials) == 1)
+        if (a || b)
+         trust = HTTP_TRUST_INVALID;
+      }
+
+      if (trust != HTTP_TRUST_OK)
+       _cupsSetError(IPP_STATUS_ERROR_INTERNAL, _("Credentials do not validate against site CA certificate."), 1);
+    }
+    else
+    {
+      _cupsSetError(IPP_STATUS_ERROR_INTERNAL, _("Trust on first use is disabled."), 1);
+      trust = HTTP_TRUST_INVALID;
+    }
+  }
+
+  if (trust == HTTP_TRUST_OK && !cg->expired_certs)
+  {
+    time_t     curtime;                /* Current date/time */
+
+    time(&curtime);
+    if (curtime < gnutls_x509_crt_get_activation_time(cert) ||
+        curtime > gnutls_x509_crt_get_expiration_time(cert))
+    {
+      _cupsSetError(IPP_STATUS_ERROR_INTERNAL, _("Credentials have expired."), 1);
+      trust = HTTP_TRUST_EXPIRED;
+    }
+  }
+
+  if (trust == HTTP_TRUST_OK && !cg->any_root && cupsArrayCount(credentials) == 1)
+  {
+    _cupsSetError(IPP_STATUS_ERROR_INTERNAL, _("Self-signed credentials are blocked."), 1);
     trust = HTTP_TRUST_INVALID;
+  }
 
-  CFRelease(secCert);
-#endif /* 0 */
+  gnutls_x509_crt_deinit(cert);
 
   return (trust);
 }
@@ -486,27 +591,32 @@ httpCredentialsGetTrust(
 /*
  * 'httpCredentialsGetExpiration()' - Return the expiration date of the credentials.
  *
- * @since CUPS 2.0@
+ * @since CUPS 2.0/OS 10.10@
  */
 
 time_t                                 /* O - Expiration date of credentials */
 httpCredentialsGetExpiration(
     cups_array_t *credentials)         /* I - Credentials */
 {
-#if 0
-  expiration = (time_t)(SecCertificateNotValidAfter(secCert) + kCFAbsoluteTimeIntervalSince1970);
+  gnutls_x509_crt_t    cert;           /* Certificate */
+  time_t               result = 0;     /* Result */
 
-  return (expiration);
-#else
-  return (INT_MAX);
-#endif /* 0 */
+
+  cert = http_gnutls_create_credential((http_credential_t *)cupsArrayFirst(credentials));
+  if (cert)
+  {
+    result = gnutls_x509_crt_get_expiration_time(cert);
+    gnutls_x509_crt_deinit(cert);
+  }
+
+  return (result);
 }
 
 
 /*
  * 'httpCredentialsString()' - Return a string representing the credentials.
  *
- * @since CUPS 2.0@
+ * @since CUPS 2.0/OS 10.10@
  */
 
 size_t                                 /* O - Total size of credentials string */
@@ -515,6 +625,10 @@ httpCredentialsString(
     char         *buffer,              /* I - Buffer or @code NULL@ */
     size_t       bufsize)              /* I - Size of buffer */
 {
+  http_credential_t    *first;         /* First certificate */
+  gnutls_x509_crt_t    cert;           /* Certificate */
+
+
   DEBUG_printf(("httpCredentialsString(credentials=%p, buffer=%p, bufsize=" CUPS_LLFMT ")", credentials, buffer, CUPS_LLCAST bufsize));
 
   if (!buffer)
@@ -523,35 +637,37 @@ httpCredentialsString(
   if (buffer && bufsize > 0)
     *buffer = '\0';
 
-#if 0
   if ((first = (http_credential_t *)cupsArrayFirst(credentials)) != NULL &&
-      (secCert = http_cdsa_create_credential(first)) != NULL)
+      (cert = http_gnutls_create_credential(first)) != NULL)
   {
-    CFStringRef                cf_name;        /* CF common name string */
-    char               name[256];      /* Common name associated with cert */
+    char               name[256],      /* Common name associated with cert */
+                       issuer[256];    /* Issuer associated with cert */
+    size_t             len;            /* Length of string */
     time_t             expiration;     /* Expiration date of cert */
-    _cups_md5_state_t  md5_state;      /* MD5 state */
+    int                sigalg;         /* Signature algorithm */
     unsigned char      md5_digest[16]; /* MD5 result */
 
-    if ((cf_name = SecCertificateCopySubjectSummary(secCert)) != NULL)
-    {
-      CFStringGetCString(cf_name, name, (CFIndex)sizeof(name), kCFStringEncodingUTF8);
-      CFRelease(cf_name);
-    }
+    len = sizeof(name) - 1;
+    if (gnutls_x509_crt_get_dn_by_oid(cert, GNUTLS_OID_X520_COMMON_NAME, 0, 0, name, &len) >= 0)
+      name[len] = '\0';
     else
       strlcpy(name, "unknown", sizeof(name));
 
-    expiration = (time_t)(SecCertificateNotValidAfter(secCert) + kCFAbsoluteTimeIntervalSince1970);
+    len = sizeof(issuer) - 1;
+    if (gnutls_x509_crt_get_issuer_dn_by_oid(cert, GNUTLS_OID_X520_ORGANIZATION_NAME, 0, 0, issuer, &len) >= 0)
+      issuer[len] = '\0';
+    else
+      strlcpy(issuer, "unknown", sizeof(issuer));
+
+    expiration = gnutls_x509_crt_get_expiration_time(cert);
+    sigalg     = gnutls_x509_crt_get_signature_algorithm(cert);
 
-    _cupsMD5Init(&md5_state);
-    _cupsMD5Append(&md5_state, first->data, (int)first->datalen);
-    _cupsMD5Finish(&md5_state, md5_digest);
+    cupsHashData("md5", first->data, first->datalen, md5_digest, sizeof(md5_digest));
 
-    snprintf(buffer, bufsize, "%s / %s / %02X%02X%02X%02X%02X%02X%02X%02X%02X%02X%02X%02X%02X%02X%02X%02X", name, httpGetDateString(expiration), md5_digest[0], md5_digest[1], md5_digest[2], md5_digest[3], md5_digest[4], md5_digest[5], md5_digest[6], md5_digest[7], md5_digest[8], md5_digest[9], md5_digest[10], md5_digest[11], md5_digest[12], md5_digest[13], md5_digest[14], md5_digest[15]);
+    snprintf(buffer, bufsize, "%s (issued by %s) / %s / %s / %02X%02X%02X%02X%02X%02X%02X%02X%02X%02X%02X%02X%02X%02X%02X%02X", name, issuer, httpGetDateString(expiration), gnutls_sign_get_name(sigalg), md5_digest[0], md5_digest[1], md5_digest[2], md5_digest[3], md5_digest[4], md5_digest[5], md5_digest[6], md5_digest[7], md5_digest[8], md5_digest[9], md5_digest[10], md5_digest[11], md5_digest[12], md5_digest[13], md5_digest[14], md5_digest[15]);
 
-    CFRelease(secCert);
+    gnutls_x509_crt_deinit(cert);
   }
-#endif // 0
 
   DEBUG_printf(("1httpCredentialsString: Returning \"%s\".", buffer));
 
@@ -562,7 +678,7 @@ httpCredentialsString(
 /*
  * 'httpLoadCredentials()' - Load X.509 credentials from a keychain file.
  *
- * @since CUPS 2.0@
+ * @since CUPS 2.0/OS 10.10@
  */
 
 int                                    /* O - 0 on success, -1 on error */
@@ -571,18 +687,129 @@ httpLoadCredentials(
     cups_array_t **credentials,                /* IO - Credentials */
     const char   *common_name)         /* I  - Common name for credentials */
 {
-  (void)path;
-  (void)credentials;
-  (void)common_name;
+  cups_file_t          *fp;            /* Certificate file */
+  char                 filename[1024], /* filename.crt */
+                       temp[1024],     /* Temporary string */
+                       line[256];      /* Base64-encoded line */
+  unsigned char                *data = NULL;   /* Buffer for cert data */
+  size_t               alloc_data = 0, /* Bytes allocated */
+                       num_data = 0;   /* Bytes used */
+  int                  decoded;        /* Bytes decoded */
+  int                  in_certificate = 0;
+                                       /* In a certificate? */
+
+
+  if (!credentials || !common_name)
+    return (-1);
+
+  if (!path)
+    path = http_gnutls_default_path(temp, sizeof(temp));
+  if (!path)
+    return (-1);
+
+  http_gnutls_make_path(filename, sizeof(filename), path, common_name, "crt");
+
+  if ((fp = cupsFileOpen(filename, "r")) == NULL)
+    return (-1);
+
+  while (cupsFileGets(fp, line, sizeof(line)))
+  {
+    if (!strcmp(line, "-----BEGIN CERTIFICATE-----"))
+    {
+      if (in_certificate)
+      {
+       /*
+       * Missing END CERTIFICATE...
+       */
+
+        httpFreeCredentials(*credentials);
+       *credentials = NULL;
+        break;
+      }
+
+      in_certificate = 1;
+    }
+    else if (!strcmp(line, "-----END CERTIFICATE-----"))
+    {
+      if (!in_certificate || !num_data)
+      {
+       /*
+       * Missing data...
+       */
+
+        httpFreeCredentials(*credentials);
+       *credentials = NULL;
+        break;
+      }
+
+      if (!*credentials)
+        *credentials = cupsArrayNew(NULL, NULL);
 
-  return (-1);
+      if (httpAddCredential(*credentials, data, num_data))
+      {
+        httpFreeCredentials(*credentials);
+       *credentials = NULL;
+        break;
+      }
+
+      num_data       = 0;
+      in_certificate = 0;
+    }
+    else if (in_certificate)
+    {
+      if (alloc_data == 0)
+      {
+        data       = malloc(2048);
+       alloc_data = 2048;
+
+        if (!data)
+         break;
+      }
+      else if ((num_data + strlen(line)) >= alloc_data)
+      {
+        unsigned char *tdata = realloc(data, alloc_data + 1024);
+                                       /* Expanded buffer */
+
+       if (!tdata)
+       {
+         httpFreeCredentials(*credentials);
+         *credentials = NULL;
+         break;
+       }
+
+       data       = tdata;
+        alloc_data += 1024;
+      }
+
+      decoded = alloc_data - num_data;
+      httpDecode64_2((char *)data + num_data, &decoded, line);
+      num_data += (size_t)decoded;
+    }
+  }
+
+  cupsFileClose(fp);
+
+  if (in_certificate)
+  {
+   /*
+    * Missing END CERTIFICATE...
+    */
+
+    httpFreeCredentials(*credentials);
+    *credentials = NULL;
+  }
+
+  if (data)
+    free(data);
+
+  return (*credentials ? 0 : -1);
 }
 
 
 /*
  * 'httpSaveCredentials()' - Save X.509 credentials to a keychain file.
  *
- * @since CUPS 2.0@
+ * @since CUPS 2.0/OS 10.10@
  */
 
 int                                    /* O - -1 on error, 0 on success */
@@ -591,11 +818,87 @@ httpSaveCredentials(
     cups_array_t *credentials,         /* I - Credentials */
     const char   *common_name)         /* I - Common name for credentials */
 {
-  (void)path;
-  (void)credentials;
-  (void)common_name;
+  cups_file_t          *fp;            /* Certificate file */
+  char                 filename[1024], /* filename.crt */
+                       nfilename[1024],/* filename.crt.N */
+                       temp[1024],     /* Temporary string */
+                       line[256];      /* Base64-encoded line */
+  const unsigned char  *ptr;           /* Pointer into certificate */
+  ssize_t              remaining;      /* Bytes left */
+  http_credential_t    *cred;          /* Current credential */
+
+
+  if (!credentials || !common_name)
+    return (-1);
+
+  if (!path)
+    path = http_gnutls_default_path(temp, sizeof(temp));
+  if (!path)
+    return (-1);
+
+  http_gnutls_make_path(filename, sizeof(filename), path, common_name, "crt");
+  snprintf(nfilename, sizeof(nfilename), "%s.N", filename);
+
+  if ((fp = cupsFileOpen(nfilename, "w")) == NULL)
+    return (-1);
+
+  fchmod(cupsFileNumber(fp), 0600);
+
+  for (cred = (http_credential_t *)cupsArrayFirst(credentials);
+       cred;
+       cred = (http_credential_t *)cupsArrayNext(credentials))
+  {
+    cupsFilePuts(fp, "-----BEGIN CERTIFICATE-----\n");
+    for (ptr = cred->data, remaining = (ssize_t)cred->datalen; remaining > 0; remaining -= 45, ptr += 45)
+    {
+      httpEncode64_2(line, sizeof(line), (char *)ptr, remaining > 45 ? 45 : remaining);
+      cupsFilePrintf(fp, "%s\n", line);
+    }
+    cupsFilePuts(fp, "-----END CERTIFICATE-----\n");
+  }
+
+  cupsFileClose(fp);
+
+  return (rename(nfilename, filename));
+}
+
+
+/*
+ * 'http_gnutls_create_credential()' - Create a single credential in the internal format.
+ */
+
+static gnutls_x509_crt_t                       /* O - Certificate */
+http_gnutls_create_credential(
+    http_credential_t *credential)             /* I - Credential */
+{
+  int                  result;                 /* Result from GNU TLS */
+  gnutls_x509_crt_t    cert;                   /* Certificate */
+  gnutls_datum_t       datum;                  /* Data record */
+
+
+  DEBUG_printf(("3http_gnutls_create_credential(credential=%p)", credential));
+
+  if (!credential)
+    return (NULL);
+
+  if ((result = gnutls_x509_crt_init(&cert)) < 0)
+  {
+    DEBUG_printf(("4http_gnutls_create_credential: init error: %s", gnutls_strerror(result)));
+    return (NULL);
+  }
+
+  datum.data = credential->data;
+  datum.size = credential->datalen;
+
+  if ((result = gnutls_x509_crt_import(cert, &datum, GNUTLS_X509_FMT_DER)) < 0)
+  {
+    DEBUG_printf(("4http_gnutls_create_credential: import error: %s", gnutls_strerror(result)));
 
-  return (-1);
+    gnutls_x509_crt_deinit(cert);
+    return (NULL);
+  }
+
+  return (cert);
 }
 
 
@@ -643,6 +946,139 @@ http_gnutls_default_path(char   *buffer,/* I - Path buffer */
 }
 
 
+/*
+ * 'http_gnutls_load_crl()' - Load the certificate revocation list, if any.
+ */
+
+static void
+http_gnutls_load_crl(void)
+{
+  _cupsMutexLock(&tls_mutex);
+
+  if (!gnutls_x509_crl_init(&tls_crl))
+  {
+    cups_file_t                *fp;            /* CRL file */
+    char               filename[1024], /* site.crl */
+                       line[256];      /* Base64-encoded line */
+    unsigned char      *data = NULL;   /* Buffer for cert data */
+    size_t             alloc_data = 0, /* Bytes allocated */
+                       num_data = 0;   /* Bytes used */
+    int                        decoded;        /* Bytes decoded */
+    gnutls_datum_t     datum;          /* Data record */
+
+
+    http_gnutls_make_path(filename, sizeof(filename), CUPS_SERVERROOT, "site", "crl");
+
+    if ((fp = cupsFileOpen(filename, "r")) != NULL)
+    {
+      while (cupsFileGets(fp, line, sizeof(line)))
+      {
+       if (!strcmp(line, "-----BEGIN X509 CRL-----"))
+       {
+         if (num_data)
+         {
+          /*
+           * Missing END X509 CRL...
+           */
+
+           break;
+         }
+       }
+       else if (!strcmp(line, "-----END X509 CRL-----"))
+       {
+         if (!num_data)
+         {
+          /*
+           * Missing data...
+           */
+
+           break;
+         }
+
+          datum.data = data;
+         datum.size = num_data;
+
+         gnutls_x509_crl_import(tls_crl, &datum, GNUTLS_X509_FMT_PEM);
+
+         num_data = 0;
+       }
+       else
+       {
+         if (alloc_data == 0)
+         {
+           data       = malloc(2048);
+           alloc_data = 2048;
+
+           if (!data)
+             break;
+         }
+         else if ((num_data + strlen(line)) >= alloc_data)
+         {
+           unsigned char *tdata = realloc(data, alloc_data + 1024);
+                                           /* Expanded buffer */
+
+           if (!tdata)
+             break;
+
+           data       = tdata;
+           alloc_data += 1024;
+         }
+
+         decoded = alloc_data - num_data;
+         httpDecode64_2((char *)data + num_data, &decoded, line);
+         num_data += (size_t)decoded;
+       }
+      }
+
+      cupsFileClose(fp);
+
+      if (data)
+       free(data);
+    }
+  }
+
+  _cupsMutexUnlock(&tls_mutex);
+}
+
+
+/*
+ * 'http_gnutls_make_path()' - Format a filename for a certificate or key file.
+ */
+
+static const char *                    /* O - Filename */
+http_gnutls_make_path(
+    char       *buffer,                        /* I - Filename buffer */
+    size_t     bufsize,                        /* I - Size of buffer */
+    const char *dirname,               /* I - Directory */
+    const char *filename,              /* I - Filename (usually hostname) */
+    const char *ext)                   /* I - Extension */
+{
+  char *bufptr,                        /* Pointer into buffer */
+       *bufend = buffer + bufsize - 1; /* End of buffer */
+
+
+  snprintf(buffer, bufsize, "%s/", dirname);
+  bufptr = buffer + strlen(buffer);
+
+  while (*filename && bufptr < bufend)
+  {
+    if (_cups_isalnum(*filename) || *filename == '-' || *filename == '.')
+      *bufptr++ = *filename;
+    else
+      *bufptr++ = '_';
+
+    filename ++;
+  }
+
+  if (bufptr < bufend)
+    *bufptr++ = '.';
+
+  strlcpy(bufptr, ext, (size_t)(bufend - bufptr + 1));
+
+  return (buffer);
+}
+
+
 /*
  * 'http_gnutls_read()' - Read function for the GNU TLS library.
  */
@@ -661,7 +1097,7 @@ http_gnutls_read(
 
   http = (http_t *)ptr;
 
-  if (!http->blocking)
+  if (!http->blocking || http->timeout_value > 0.0)
   {
    /*
     * Make sure we have data before we read...
@@ -774,15 +1210,20 @@ _httpTLSRead(http_t *http,               /* I - Connection to server */
 
 
 /*
- * '_httpTLSSetCredentials()' - Set the TLS credentials.
+ * '_httpTLSSetOptions()' - Set TLS protocol and cipher suite options.
  */
 
-int                                    /* O - Status of connection */
-_httpTLSSetCredentials(http_t *http)   /* I - Connection to server */
+void
+_httpTLSSetOptions(int options,                /* I - Options */
+                   int min_version,    /* I - Minimum TLS version */
+                   int max_version)    /* I - Maximum TLS version */
 {
-  (void)http;
-
-  return (0);
+  if (!(options & _HTTP_TLS_SET_DEFAULT) || tls_options < 0)
+  {
+    tls_options     = options;
+    tls_min_version = min_version;
+    tls_max_version = max_version;
+  }
 }
 
 
@@ -798,9 +1239,31 @@ _httpTLSStart(http_t *http)               /* I - Connection to server */
   int                  status;         /* Status of handshake */
   gnutls_certificate_credentials_t *credentials;
                                        /* TLS credentials */
+  char                 priority_string[2048];
+                                       /* Priority string */
+  int                  version;        /* Current version */
+  double               old_timeout;    /* Old timeout value */
+  http_timeout_cb_t    old_cb;         /* Old timeout callback */
+  void                 *old_data;      /* Old timeout data */
+  static const char * const versions[] =/* SSL/TLS versions */
+  {
+    "VERS-SSL3.0",
+    "VERS-TLS1.0",
+    "VERS-TLS1.1",
+    "VERS-TLS1.2",
+    "VERS-TLS1.3",
+    "VERS-TLS-ALL"
+  };
+
 
+  DEBUG_printf(("3_httpTLSStart(http=%p)", http));
 
-  DEBUG_printf(("7_httpTLSStart(http=%p)", http));
+  if (tls_options < 0)
+  {
+    DEBUG_puts("4_httpTLSStart: Setting defaults.");
+    _cupsSetDefaults();
+    DEBUG_printf(("4_httpTLSStart: tls_options=%x", tls_options));
+  }
 
   if (http->mode == _HTTP_MODE_SERVER && !tls_keypath)
   {
@@ -880,8 +1343,7 @@ _httpTLSStart(http_t *http)                /* I - Connection to server */
                keyfile[1024];          /* Private key file */
     int                have_creds = 0;         /* Have credentials? */
 
-
-    if (http->fields[HTTP_FIELD_HOST][0])
+    if (http->fields[HTTP_FIELD_HOST])
     {
      /*
       * Use hostname for TLS upgrade...
@@ -918,17 +1380,97 @@ _httpTLSStart(http_t *http)              /* I - Connection to server */
 
     if (hostname[0])
     {
-      snprintf(crtfile, sizeof(crtfile), "%s/%s.crt", tls_keypath, hostname);
-      snprintf(keyfile, sizeof(keyfile), "%s/%s.key", tls_keypath, hostname);
+     /*
+      * First look in the CUPS keystore...
+      */
+
+      http_gnutls_make_path(crtfile, sizeof(crtfile), tls_keypath, hostname, "crt");
+      http_gnutls_make_path(keyfile, sizeof(keyfile), tls_keypath, hostname, "key");
+
+      if (access(crtfile, R_OK) || access(keyfile, R_OK))
+      {
+       /*
+        * No CUPS-managed certs, look for CA certs...
+        */
+
+        char cacrtfile[1024], cakeyfile[1024]; /* CA cert files */
+
+        snprintf(cacrtfile, sizeof(cacrtfile), "/etc/letsencrypt/live/%s/fullchain.pem", hostname);
+        snprintf(cakeyfile, sizeof(cakeyfile), "/etc/letsencrypt/live/%s/privkey.pem", hostname);
+
+        if ((access(cacrtfile, R_OK) || access(cakeyfile, R_OK)) && (hostptr = strchr(hostname, '.')) != NULL)
+        {
+         /*
+          * Try just domain name...
+          */
+
+          hostptr ++;
+          if (strchr(hostptr, '.'))
+          {
+            snprintf(cacrtfile, sizeof(cacrtfile), "/etc/letsencrypt/live/%s/fullchain.pem", hostptr);
+            snprintf(cakeyfile, sizeof(cakeyfile), "/etc/letsencrypt/live/%s/privkey.pem", hostptr);
+          }
+        }
+
+        if (!access(cacrtfile, R_OK) && !access(cakeyfile, R_OK))
+        {
+         /*
+          * Use the CA certs...
+          */
+
+          strlcpy(crtfile, cacrtfile, sizeof(crtfile));
+          strlcpy(keyfile, cakeyfile, sizeof(keyfile));
+        }
+      }
 
-      have_creds = !access(crtfile, 0) && !access(keyfile, 0);
+      have_creds = !access(crtfile, R_OK) && !access(keyfile, R_OK);
     }
     else if (tls_common_name)
     {
-      snprintf(crtfile, sizeof(crtfile), "%s/%s.crt", tls_keypath, tls_common_name);
-      snprintf(keyfile, sizeof(keyfile), "%s/%s.key", tls_keypath, tls_common_name);
+     /*
+      * First look in the CUPS keystore...
+      */
+
+      http_gnutls_make_path(crtfile, sizeof(crtfile), tls_keypath, tls_common_name, "crt");
+      http_gnutls_make_path(keyfile, sizeof(keyfile), tls_keypath, tls_common_name, "key");
+
+      if (access(crtfile, R_OK) || access(keyfile, R_OK))
+      {
+       /*
+        * No CUPS-managed certs, look for CA certs...
+        */
+
+        char cacrtfile[1024], cakeyfile[1024]; /* CA cert files */
+
+        snprintf(cacrtfile, sizeof(cacrtfile), "/etc/letsencrypt/live/%s/fullchain.pem", tls_common_name);
+        snprintf(cakeyfile, sizeof(cakeyfile), "/etc/letsencrypt/live/%s/privkey.pem", tls_common_name);
+
+        if ((access(cacrtfile, R_OK) || access(cakeyfile, R_OK)) && (hostptr = strchr(tls_common_name, '.')) != NULL)
+        {
+         /*
+          * Try just domain name...
+          */
+
+          hostptr ++;
+          if (strchr(hostptr, '.'))
+          {
+            snprintf(cacrtfile, sizeof(cacrtfile), "/etc/letsencrypt/live/%s/fullchain.pem", hostptr);
+            snprintf(cakeyfile, sizeof(cakeyfile), "/etc/letsencrypt/live/%s/privkey.pem", hostptr);
+          }
+        }
+
+        if (!access(cacrtfile, R_OK) && !access(cakeyfile, R_OK))
+        {
+         /*
+          * Use the CA certs...
+          */
+
+          strlcpy(crtfile, cacrtfile, sizeof(crtfile));
+          strlcpy(keyfile, cakeyfile, sizeof(keyfile));
+        }
+      }
 
-      have_creds = !access(crtfile, 0) && !access(keyfile, 0);
+      have_creds = !access(crtfile, R_OK) && !access(keyfile, R_OK);
     }
 
     if (!have_creds && tls_auto_create && (hostname[0] || tls_common_name))
@@ -948,7 +1490,8 @@ _httpTLSStart(http_t *http)                /* I - Connection to server */
 
     DEBUG_printf(("4_httpTLSStart: Using certificate \"%s\" and private key \"%s\".", crtfile, keyfile));
 
-    status = gnutls_certificate_set_x509_key_file(*credentials, crtfile, keyfile, GNUTLS_X509_FMT_PEM);
+    if (!status)
+      status = gnutls_certificate_set_x509_key_file(*credentials, crtfile, keyfile, GNUTLS_X509_FMT_PEM);
   }
 
   if (!status)
@@ -970,11 +1513,89 @@ _httpTLSStart(http_t *http)              /* I - Connection to server */
     return (-1);
   }
 
+  strlcpy(priority_string, "NORMAL", sizeof(priority_string));
+
+  if (tls_max_version < _HTTP_TLS_MAX)
+  {
+   /*
+    * Require specific TLS versions...
+    */
+
+    strlcat(priority_string, ":-VERS-TLS-ALL", sizeof(priority_string));
+    for (version = tls_min_version; version <= tls_max_version; version ++)
+    {
+      strlcat(priority_string, ":+", sizeof(priority_string));
+      strlcat(priority_string, versions[version], sizeof(priority_string));
+    }
+  }
+  else if (tls_min_version == _HTTP_TLS_SSL3)
+  {
+   /*
+    * Allow all versions of TLS and SSL/3.0...
+    */
+
+    strlcat(priority_string, ":+VERS-TLS-ALL:+VERS-SSL3.0", sizeof(priority_string));
+  }
+  else
+  {
+   /*
+    * Require a minimum version...
+    */
+
+    strlcat(priority_string, ":+VERS-TLS-ALL", sizeof(priority_string));
+    for (version = 0; version < tls_min_version; version ++)
+    {
+      strlcat(priority_string, ":-", sizeof(priority_string));
+      strlcat(priority_string, versions[version], sizeof(priority_string));
+    }
+  }
+
+  if (tls_options & _HTTP_TLS_ALLOW_RC4)
+    strlcat(priority_string, ":+ARCFOUR-128", sizeof(priority_string));
+  else
+    strlcat(priority_string, ":!ARCFOUR-128", sizeof(priority_string));
+
+  strlcat(priority_string, ":!ANON-DH", sizeof(priority_string));
+
+  if (tls_options & _HTTP_TLS_DENY_CBC)
+    strlcat(priority_string, ":!AES-128-CBC:!AES-256-CBC:!CAMELLIA-128-CBC:!CAMELLIA-256-CBC:!3DES-CBC", sizeof(priority_string));
+
+#ifdef HAVE_GNUTLS_PRIORITY_SET_DIRECT
+  gnutls_priority_set_direct(http->tls, priority_string, NULL);
+
+#else
+  gnutls_priority_t priority;          /* Priority */
+
+  gnutls_priority_init(&priority, priority_string, NULL);
+  gnutls_priority_set(http->tls, priority);
+  gnutls_priority_deinit(priority);
+#endif /* HAVE_GNUTLS_PRIORITY_SET_DIRECT */
+
   gnutls_transport_set_ptr(http->tls, (gnutls_transport_ptr_t)http);
   gnutls_transport_set_pull_function(http->tls, http_gnutls_read);
+#ifdef HAVE_GNUTLS_TRANSPORT_SET_PULL_TIMEOUT_FUNCTION
   gnutls_transport_set_pull_timeout_function(http->tls, (gnutls_pull_timeout_func)httpWait);
+#endif /* HAVE_GNUTLS_TRANSPORT_SET_PULL_TIMEOUT_FUNCTION */
   gnutls_transport_set_push_function(http->tls, http_gnutls_write);
 
+ /*
+  * Enforce a minimum timeout of 10 seconds for the TLS handshake...
+  */
+
+  old_timeout  = http->timeout_value;
+  old_cb       = http->timeout_cb;
+  old_data     = http->timeout_data;
+
+  if (!old_cb || old_timeout < 10.0)
+  {
+    DEBUG_puts("4_httpTLSStart: Setting timeout to 10 seconds.");
+    httpSetTimeout(http, 10.0, NULL, NULL);
+  }
+
+ /*
+  * Do the TLS handshake...
+  */
+
   while ((status = gnutls_handshake(http->tls)) != GNUTLS_E_SUCCESS)
   {
     DEBUG_printf(("5_httpStartTLS: gnutls_handshake returned %d (%s)",
@@ -992,14 +1613,19 @@ _httpTLSStart(http_t *http)              /* I - Connection to server */
       free(credentials);
       http->tls = NULL;
 
+      httpSetTimeout(http, old_timeout, old_cb, old_data);
+
       return (-1);
     }
   }
 
-  http->tls_credentials = credentials;
+ /*
+  * Restore the previous timeout settings...
+  */
 
-  // TODO: Put this in the right place; no-op for now, this to get things to compile
-//  http_tls_set_credentials(http);
+  httpSetTimeout(http, old_timeout, old_cb, old_data);
+
+  http->tls_credentials = credentials;
 
   return (0);
 }
@@ -1075,8 +1701,3 @@ _httpTLSWrite(http_t     *http,           /* I - Connection to server */
 
   return ((int)result);
 }
-
-
-/*
- * End of "$Id$".
- */