diff --git a/poky/bitbake/lib/bb/fetch2/__init__.py b/poky/bitbake/lib/bb/fetch2/__init__.py
index ad89868..914fa5c 100644
--- a/poky/bitbake/lib/bb/fetch2/__init__.py
+++ b/poky/bitbake/lib/bb/fetch2/__init__.py
@@ -808,6 +808,29 @@
     fetcher = bb.fetch2.Fetch([url], d)
     return fetcher.localpath(url)
 
+# Need to export PATH as binary could be in metadata paths
+# rather than host provided
+# Also include some other variables.
+FETCH_EXPORT_VARS = ['HOME', 'PATH',
+                     'HTTP_PROXY', 'http_proxy',
+                     'HTTPS_PROXY', 'https_proxy',
+                     'FTP_PROXY', 'ftp_proxy',
+                     'FTPS_PROXY', 'ftps_proxy',
+                     'NO_PROXY', 'no_proxy',
+                     'ALL_PROXY', 'all_proxy',
+                     'GIT_PROXY_COMMAND',
+                     'GIT_SSH',
+                     'GIT_SSL_CAINFO',
+                     'GIT_SMART_HTTP',
+                     'SSH_AUTH_SOCK', 'SSH_AGENT_PID',
+                     'SOCKS5_USER', 'SOCKS5_PASSWD',
+                     'DBUS_SESSION_BUS_ADDRESS',
+                     'P4CONFIG',
+                     'SSL_CERT_FILE',
+                     'AWS_ACCESS_KEY_ID',
+                     'AWS_SECRET_ACCESS_KEY',
+                     'AWS_DEFAULT_REGION']
+
 def runfetchcmd(cmd, d, quiet=False, cleanup=None, log=None, workdir=None):
     """
     Run cmd returning the command output
@@ -816,28 +839,7 @@
     Optionally remove the files/directories listed in cleanup upon failure
     """
 
-    # Need to export PATH as binary could be in metadata paths
-    # rather than host provided
-    # Also include some other variables.
-    # FIXME: Should really include all export varaiables?
-    exportvars = ['HOME', 'PATH',
-                  'HTTP_PROXY', 'http_proxy',
-                  'HTTPS_PROXY', 'https_proxy',
-                  'FTP_PROXY', 'ftp_proxy',
-                  'FTPS_PROXY', 'ftps_proxy',
-                  'NO_PROXY', 'no_proxy',
-                  'ALL_PROXY', 'all_proxy',
-                  'GIT_PROXY_COMMAND',
-                  'GIT_SSH',
-                  'GIT_SSL_CAINFO',
-                  'GIT_SMART_HTTP',
-                  'SSH_AUTH_SOCK', 'SSH_AGENT_PID',
-                  'SOCKS5_USER', 'SOCKS5_PASSWD',
-                  'DBUS_SESSION_BUS_ADDRESS',
-                  'P4CONFIG',
-                  'AWS_ACCESS_KEY_ID',
-                  'AWS_SECRET_ACCESS_KEY',
-                  'AWS_DEFAULT_REGION']
+    exportvars = FETCH_EXPORT_VARS
 
     if not cleanup:
         cleanup = []
diff --git a/poky/bitbake/lib/bb/fetch2/wget.py b/poky/bitbake/lib/bb/fetch2/wget.py
index 784df70..29fcfbb 100644
--- a/poky/bitbake/lib/bb/fetch2/wget.py
+++ b/poky/bitbake/lib/bb/fetch2/wget.py
@@ -52,13 +52,19 @@
 
 
 class Wget(FetchMethod):
+    """Class to fetch urls via 'wget'"""
 
     # CDNs like CloudFlare may do a 'browser integrity test' which can fail
     # with the standard wget/urllib User-Agent, so pretend to be a modern
     # browser.
     user_agent = "Mozilla/5.0 (X11; Ubuntu; Linux x86_64; rv:84.0) Gecko/20100101 Firefox/84.0"
 
-    """Class to fetch urls via 'wget'"""
+    def check_certs(self, d):
+        """
+        Should certificates be checked?
+        """
+        return (d.getVar("BB_CHECK_SSL_CERTS") or "1") != "0"
+
     def supports(self, ud, d):
         """
         Check to see if a given url can be fetched with wget.
@@ -82,7 +88,10 @@
         if not ud.localfile:
             ud.localfile = d.expand(urllib.parse.unquote(ud.host + ud.path).replace("/", "."))
 
-        self.basecmd = d.getVar("FETCHCMD_wget") or "/usr/bin/env wget -t 2 -T 30 --passive-ftp --no-check-certificate"
+        self.basecmd = d.getVar("FETCHCMD_wget") or "/usr/bin/env wget -t 2 -T 30 --passive-ftp"
+
+        if not self.check_certs(d):
+            self.basecmd += " --no-check-certificate"
 
     def _runwget(self, ud, d, command, quiet, workdir=None):
 
@@ -282,19 +291,44 @@
                 newreq = urllib.request.HTTPRedirectHandler.redirect_request(self, req, fp, code, msg, headers, newurl)
                 newreq.get_method = req.get_method
                 return newreq
-        exported_proxies = export_proxies(d)
 
-        handlers = [FixedHTTPRedirectHandler, HTTPMethodFallback]
-        if exported_proxies:
-            handlers.append(urllib.request.ProxyHandler())
-        handlers.append(CacheHTTPHandler())
-        # Since Python 2.7.9 ssl cert validation is enabled by default
-        # see PEP-0476, this causes verification errors on some https servers
-        # so disable by default.
-        import ssl
-        if hasattr(ssl, '_create_unverified_context'):
-            handlers.append(urllib.request.HTTPSHandler(context=ssl._create_unverified_context()))
-        opener = urllib.request.build_opener(*handlers)
+        # We need to update the environment here as both the proxy and HTTPS
+        # handlers need variables set. The proxy needs http_proxy and friends to
+        # be set, and HTTPSHandler ends up calling into openssl to load the
+        # certificates. In buildtools configurations this will be looking at the
+        # wrong place for certificates by default: we set SSL_CERT_FILE to the
+        # right location in the buildtools environment script but as BitBake
+        # prunes prunes the environment this is lost. When binaries are executed
+        # runfetchcmd ensures these values are in the environment, but this is
+        # pure Python so we need to update the environment.
+        #
+        # Avoid tramping the environment too much by using bb.utils.environment
+        # to scope the changes to the build_opener request, which is when the
+        # environment lookups happen.
+        newenv = {}
+        for name in bb.fetch2.FETCH_EXPORT_VARS:
+            value = d.getVar(name)
+            if not value:
+                origenv = d.getVar("BB_ORIGENV")
+                if origenv:
+                    value = origenv.getVar(name)
+            if value:
+                newenv[name] = value
+
+        with bb.utils.environment(**newenv):
+            import ssl
+
+            if self.check_certs(d):
+                context = ssl.create_default_context()
+            else:
+                context = ssl._create_unverified_context()
+
+            handlers = [FixedHTTPRedirectHandler,
+                        HTTPMethodFallback,
+                        urllib.request.ProxyHandler(),
+                        CacheHTTPHandler(),
+                        urllib.request.HTTPSHandler(context=context)]
+            opener = urllib.request.build_opener(*handlers)
 
         try:
             uri = ud.url.split(";")[0]
diff --git a/poky/bitbake/lib/bb/tests/utils.py b/poky/bitbake/lib/bb/tests/utils.py
index a7ff33d..4d5e21b 100644
--- a/poky/bitbake/lib/bb/tests/utils.py
+++ b/poky/bitbake/lib/bb/tests/utils.py
@@ -666,3 +666,21 @@
 
         layers = [{"SRC_URI"}, {"QT_GIT", "QT_MODULE", "QT_MODULE_BRANCH_PARAM", "QT_GIT_PROTOCOL"}, {"QT_GIT_PROJECT", "QT_MODULE_BRANCH", "BPN"}, {"PN", "SPECIAL_PKGSUFFIX"}]
         self.check_referenced("${SRC_URI}", layers)
+
+
+class EnvironmentTests(unittest.TestCase):
+    def test_environment(self):
+        os.environ["A"] = "this is A"
+        self.assertIn("A", os.environ)
+        self.assertEqual(os.environ["A"], "this is A")
+        self.assertNotIn("B", os.environ)
+
+        with bb.utils.environment(B="this is B"):
+            self.assertIn("A", os.environ)
+            self.assertEqual(os.environ["A"], "this is A")
+            self.assertIn("B", os.environ)
+            self.assertEqual(os.environ["B"], "this is B")
+
+        self.assertIn("A", os.environ)
+        self.assertEqual(os.environ["A"], "this is A")
+        self.assertNotIn("B", os.environ)
diff --git a/poky/bitbake/lib/bb/utils.py b/poky/bitbake/lib/bb/utils.py
index e6e82d1..7063491 100644
--- a/poky/bitbake/lib/bb/utils.py
+++ b/poky/bitbake/lib/bb/utils.py
@@ -1681,3 +1681,19 @@
             shutil.move(src, dst)
         else:
             raise err
+
+@contextmanager
+def environment(**envvars):
+    """
+    Context manager to selectively update the environment with the specified mapping.
+    """
+    backup = dict(os.environ)
+    try:
+        os.environ.update(envvars)
+        yield
+    finally:
+        for var in envvars:
+            if var in backup:
+                os.environ[var] = backup[var]
+            else:
+                del os.environ[var]