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From 50582c5be1a613ee1d212855a8945b4c8ef8950f Mon Sep 17 00:00:00 2001
From: Kamil Dudka <kdudka@redhat.com>
Date: Mon, 10 Apr 2017 17:05:05 +0200
Subject: [PATCH 1/2] nss: factorize out nss_{un,}load_module to separate fncs

No change of behavior is intended by this commit.

Upstream-commit: fab3d1ec650e17fd15cf8b6d4ffa5bfd523501dc
Signed-off-by: Kamil Dudka <kdudka@redhat.com>
---
 lib/vtls/nss.c | 83 +++++++++++++++++++++++++++++++++++++++-------------------
 1 file changed, 56 insertions(+), 27 deletions(-)

diff --git a/lib/vtls/nss.c b/lib/vtls/nss.c
index 099f364..6b8f8c0 100644
--- a/lib/vtls/nss.c
+++ b/lib/vtls/nss.c
@@ -201,7 +201,7 @@ static const cipher_s cipherlist[] = {
 };
 
 static const char *pem_library = "libnsspem.so";
-static SECMODModule *mod = NULL;
+static SECMODModule *pem_module = NULL;
 
 /* NSPR I/O layer we use to detect blocking direction during SSL handshake */
 static PRDescIdentity nspr_io_identity = PR_INVALID_IO_LAYER;
@@ -600,7 +600,7 @@ static CURLcode nss_load_key(struct connectdata *conn, int sockindex,
     return CURLE_SSL_CERTPROBLEM;
 
   /* This will force the token to be seen as re-inserted */
-  tmp = SECMOD_WaitForAnyTokenEvent(mod, 0, 0);
+  tmp = SECMOD_WaitForAnyTokenEvent(pem_module, 0, 0);
   if(tmp)
     PK11_FreeSlot(tmp);
   PK11_IsPresent(slot);
@@ -1180,6 +1180,50 @@ static PRStatus nspr_io_close(PRFileDesc *fd)
   return close_fn(fd);
 }
 
+/* load a PKCS #11 module */
+static CURLcode nss_load_module(SECMODModule **pmod, const char *library,
+                                const char *name)
+{
+  char *config_string;
+  SECMODModule *module = *pmod;
+  if(module)
+    /* already loaded */
+    return CURLE_OK;
+
+  config_string = aprintf("library=%s name=%s", library, name);
+  if(!config_string)
+    return CURLE_OUT_OF_MEMORY;
+
+  module = SECMOD_LoadUserModule(config_string, NULL, PR_FALSE);
+  free(config_string);
+
+  if(module && module->loaded) {
+    /* loaded successfully */
+    *pmod = module;
+    return CURLE_OK;
+  }
+
+  if(module)
+    SECMOD_DestroyModule(module);
+  return CURLE_FAILED_INIT;
+}
+
+/* unload a PKCS #11 module */
+static void nss_unload_module(SECMODModule **pmod)
+{
+  SECMODModule *module = *pmod;
+  if(!module)
+    /* not loaded */
+    return;
+
+  if(SECMOD_UnloadUserModule(module) != SECSuccess)
+    /* unload failed */
+    return;
+
+  SECMOD_DestroyModule(module);
+  *pmod = NULL;
+}
+
 /* data might be NULL */
 static CURLcode nss_init_core(struct Curl_easy *data, const char *cert_dir)
 {
@@ -1327,10 +1371,7 @@ void Curl_nss_cleanup(void)
      * the certificates. */
     SSL_ClearSessionCache();
 
-    if(mod && SECSuccess == SECMOD_UnloadUserModule(mod)) {
-      SECMOD_DestroyModule(mod);
-      mod = NULL;
-    }
+    nss_unload_module(&pem_module);
     NSS_ShutdownContext(nss_context);
     nss_context = NULL;
   }
@@ -1685,29 +1726,17 @@ static CURLcode nss_setup_connect(struct connectdata *conn, int sockindex)
     goto error;
   }
 
-  result = CURLE_SSL_CONNECT_ERROR;
-
-  if(!mod) {
-    char *configstring = aprintf("library=%s name=PEM", pem_library);
-    if(!configstring) {
-      PR_Unlock(nss_initlock);
-      goto error;
-    }
-    mod = SECMOD_LoadUserModule(configstring, NULL, PR_FALSE);
-    free(configstring);
-
-    if(!mod || !mod->loaded) {
-      if(mod) {
-        SECMOD_DestroyModule(mod);
-        mod = NULL;
-      }
-      infof(data, "WARNING: failed to load NSS PEM library %s. Using "
-                  "OpenSSL PEM certificates will not work.\n", pem_library);
-    }
-  }
-
   PK11_SetPasswordFunc(nss_get_password);
+
+  result = nss_load_module(&pem_module, pem_library, "PEM");
   PR_Unlock(nss_initlock);
+  if(result == CURLE_FAILED_INIT)
+    infof(data, "WARNING: failed to load NSS PEM library %s. Using "
+                "OpenSSL PEM certificates will not work.\n", pem_library);
+  else if(result)
+    goto error;
+
+  result = CURLE_SSL_CONNECT_ERROR;
 
   model = PR_NewTCPSocket();
   if(!model)
-- 
2.9.3


From cf6f9017f0e144ad510fd5913b44b22a2146dd4b Mon Sep 17 00:00:00 2001
From: Kamil Dudka <kdudka@redhat.com>
Date: Mon, 10 Apr 2017 17:40:30 +0200
Subject: [PATCH 2/2] nss: load libnssckbi.so if no other trust is specified

The module contains a more comprehensive set of trust information than
supported by nss-pem, because libnssckbi.so also includes information
about distrusted certificates.

Reviewed-by: Kai Engert
Closes #1414

Upstream-commit: e3e8d0204b72509cfd63d97a159d1ac3fdea703b
Signed-off-by: Kamil Dudka <kdudka@redhat.com>
---
 docs/libcurl/opts/CURLOPT_CAINFO.3 |  5 ++++
 lib/vtls/nss.c                     | 51 ++++++++++++++++++++++++++++++++------
 2 files changed, 48 insertions(+), 8 deletions(-)

diff --git a/docs/libcurl/opts/CURLOPT_CAINFO.3 b/docs/libcurl/opts/CURLOPT_CAINFO.3
index 91b7e23..85436c3 100644
--- a/docs/libcurl/opts/CURLOPT_CAINFO.3
+++ b/docs/libcurl/opts/CURLOPT_CAINFO.3
@@ -41,6 +41,11 @@ is assumed to be stored, as established at build time.
 
 If curl is built against the NSS SSL library, the NSS PEM PKCS#11 module
 (libnsspem.so) needs to be available for this option to work properly.
+Starting with curl-7.55.0, if both \fICURLOPT_CAINFO(3)\fP and
+\fICURLOPT_CAPATH(3)\fP are unset, NSS-linked libcurl tries to load
+libnssckbi.so, which contains a more comprehensive set of trust information
+than supported by nss-pem, because libnssckbi.so also includes information
+about distrusted certificates.
 
 (iOS and macOS only) If curl is built against Secure Transport, then this
 option is supported for backward compatibility with other SSL engines, but it
diff --git a/lib/vtls/nss.c b/lib/vtls/nss.c
index 6b8f8c0..62665e7 100644
--- a/lib/vtls/nss.c
+++ b/lib/vtls/nss.c
@@ -81,6 +81,7 @@
 static PRLock *nss_initlock = NULL;
 static PRLock *nss_crllock = NULL;
 static PRLock *nss_findslot_lock = NULL;
+static PRLock *nss_trustload_lock = NULL;
 static struct curl_llist nss_crl_list;
 static NSSInitContext *nss_context = NULL;
 static volatile int initialized = 0;
@@ -203,6 +204,9 @@ static const cipher_s cipherlist[] = {
 static const char *pem_library = "libnsspem.so";
 static SECMODModule *pem_module = NULL;
 
+static const char *trust_library = "libnssckbi.so";
+static SECMODModule *trust_module = NULL;
+
 /* NSPR I/O layer we use to detect blocking direction during SSL handshake */
 static PRDescIdentity nspr_io_identity = PR_INVALID_IO_LAYER;
 static PRIOMethods nspr_io_methods;
@@ -1333,6 +1337,7 @@ int Curl_nss_init(void)
     nss_initlock = PR_NewLock();
     nss_crllock = PR_NewLock();
     nss_findslot_lock = PR_NewLock();
+    nss_trustload_lock = PR_NewLock();
   }
 
   /* We will actually initialize NSS later */
@@ -1372,6 +1377,7 @@ void Curl_nss_cleanup(void)
     SSL_ClearSessionCache();
 
     nss_unload_module(&pem_module);
+    nss_unload_module(&trust_module);
     NSS_ShutdownContext(nss_context);
     nss_context = NULL;
   }
@@ -1384,6 +1390,7 @@ void Curl_nss_cleanup(void)
   PR_DestroyLock(nss_initlock);
   PR_DestroyLock(nss_crllock);
   PR_DestroyLock(nss_findslot_lock);
+  PR_DestroyLock(nss_trustload_lock);
   nss_initlock = NULL;
 
   initialized = 0;
@@ -1505,12 +1512,44 @@ static CURLcode nss_load_ca_certificates(struct connectdata *conn,
   struct Curl_easy *data = conn->data;
   const char *cafile = SSL_CONN_CONFIG(CAfile);
   const char *capath = SSL_CONN_CONFIG(CApath);
+  bool use_trust_module;
+  CURLcode result = CURLE_OK;
 
-  if(cafile) {
-    CURLcode result = nss_load_cert(&conn->ssl[sockindex], cafile, PR_TRUE);
-    if(result)
-      return result;
+  /* treat empty string as unset */
+  if(cafile && !cafile[0])
+    cafile = NULL;
+  if(capath && !capath[0])
+    capath = NULL;
+
+  infof(data, "  CAfile: %s\n  CApath: %s\n",
+      cafile ? cafile : "none",
+      capath ? capath : "none");
+
+  /* load libnssckbi.so if no other trust roots were specified */
+  use_trust_module = !cafile && !capath;
+
+  PR_Lock(nss_trustload_lock);
+  if(use_trust_module && !trust_module) {
+    /* libnssckbi.so needed but not yet loaded --> load it! */
+    result = nss_load_module(&trust_module, trust_library, "trust");
+    infof(data, "%s %s\n", (result) ? "failed to load" : "loaded",
+          trust_library);
+    if(result == CURLE_FAILED_INIT)
+      /* make the error non-fatal if we are not going to verify peer */
+      result = CURLE_SSL_CACERT_BADFILE;
   }
+  else if(!use_trust_module && trust_module) {
+    /* libnssckbi.so not needed but already loaded --> unload it! */
+    infof(data, "unloading %s\n", trust_library);
+    nss_unload_module(&trust_module);
+  }
+  PR_Unlock(nss_trustload_lock);
+
+  if(cafile)
+    result = nss_load_cert(&conn->ssl[sockindex], cafile, PR_TRUE);
+
+  if(result)
+    return result;
 
   if(capath) {
     struct_stat st;
@@ -1544,10 +1583,6 @@ static CURLcode nss_load_ca_certificates(struct connectdata *conn,
       infof(data, "warning: CURLOPT_CAPATH not a directory (%s)\n", capath);
   }
 
-  infof(data, "  CAfile: %s\n  CApath: %s\n",
-      cafile ? cafile : "none",
-      capath ? capath : "none");
-
   return CURLE_OK;
 }
 
-- 
2.9.3