Issue #21356: Make ssl.RAND_egd() optional to support LibreSSL. The

vstinner · vstinner · commit 7c90667f7416 · 2015-01-06T13:53:37.000+01:00
availability of the function is checked during the compilation. Patch written
by Bernard Spil.
diff --git a/Doc/library/ssl.rst b/Doc/library/ssl.rst
@@ -299,6 +299,8 @@ Random generation
    See http://egd.sourceforge.net/ or http://prngd.sourceforge.net/ for sources
    of entropy-gathering daemons.
 
+   Availability: not available with LibreSSL.
+
 .. function:: RAND_add(bytes, entropy)
 
    Mixes the given *bytes* into the SSL pseudo-random number generator.  The
diff --git a/Lib/socket.py b/Lib/socket.py
@@ -67,7 +67,6 @@ def ssl(sock, keyfile=None, certfile=None):
     from _ssl import SSLError as sslerror
     from _ssl import \
          RAND_add, \
-         RAND_egd, \
          RAND_status, \
          SSL_ERROR_ZERO_RETURN, \
          SSL_ERROR_WANT_READ, \
@@ -78,6 +77,11 @@ def ssl(sock, keyfile=None, certfile=None):
          SSL_ERROR_WANT_CONNECT, \
          SSL_ERROR_EOF, \
          SSL_ERROR_INVALID_ERROR_CODE
+    try:
+        from _ssl import RAND_egd
+    except ImportError:
+        # LibreSSL does not provide RAND_egd
+        pass
 
 import os, sys, warnings
 
diff --git a/Lib/ssl.py b/Lib/ssl.py
@@ -106,7 +106,12 @@
 from _ssl import (VERIFY_DEFAULT, VERIFY_CRL_CHECK_LEAF, VERIFY_CRL_CHECK_CHAIN,
     VERIFY_X509_STRICT)
 from _ssl import txt2obj as _txt2obj, nid2obj as _nid2obj
-from _ssl import RAND_status, RAND_egd, RAND_add
+from _ssl import RAND_status, RAND_add
+try:
+    from _ssl import RAND_egd
+except ImportError:
+    # LibreSSL does not provide RAND_egd
+    pass
 
 def _import_symbols(prefix):
     for n in dir(_ssl):
diff --git a/Lib/test/test_ssl.py b/Lib/test/test_ssl.py
@@ -169,8 +169,9 @@ def test_random(self):
             sys.stdout.write("\n RAND_status is %d (%s)\n"
                              % (v, (v and "sufficient randomness") or
                                 "insufficient randomness"))
-        self.assertRaises(TypeError, ssl.RAND_egd, 1)
-        self.assertRaises(TypeError, ssl.RAND_egd, 'foo', 1)
+        if hasattr(ssl, 'RAND_egd'):
+            self.assertRaises(TypeError, ssl.RAND_egd, 1)
+            self.assertRaises(TypeError, ssl.RAND_egd, 'foo', 1)
         ssl.RAND_add("this is a random string", 75.0)
 
     def test_parse_cert(self):
diff --git a/Misc/NEWS b/Misc/NEWS
@@ -15,6 +15,10 @@ Core and Builtins
 Library
 -------
 
+- Issue #21356: Make ssl.RAND_egd() optional to support LibreSSL. The
+  availability of the function is checked during the compilation. Patch written
+  by Bernard Spil.
+
 - Backport the context argument to ftplib.FTP_TLS.
 
 - Issue #23111: Maximize compatibility in protocol versions of ftplib.FTP_TLS.
diff --git a/Modules/_ssl.c b/Modules/_ssl.c
@@ -3301,6 +3301,11 @@ Returns 1 if the OpenSSL PRNG has been seeded with enough data and 0 if not.\n\
 It is necessary to seed the PRNG with RAND_add() on some platforms before\n\
 using the ssl() function.");
 
+#endif /* HAVE_OPENSSL_RAND */
+
+
+#ifdef HAVE_RAND_EGD
+
 static PyObject *
 PySSL_RAND_egd(PyObject *self, PyObject *arg)
 {
@@ -3327,7 +3332,7 @@ Queries the entropy gather daemon (EGD) on the socket named by 'path'.\n\
 Returns number of bytes read.  Raises SSLError if connection to EGD\n\
 fails or if it does not provide enough data to seed PRNG.");
 
-#endif /* HAVE_OPENSSL_RAND */
+#endif /* HAVE_RAND_EGD */
 
 
 PyDoc_STRVAR(PySSL_get_default_verify_paths_doc,
@@ -3720,10 +3725,12 @@ static PyMethodDef PySSL_methods[] = {
 #ifdef HAVE_OPENSSL_RAND
     {"RAND_add",            PySSL_RAND_add, METH_VARARGS,
      PySSL_RAND_add_doc},
-    {"RAND_egd",            PySSL_RAND_egd, METH_VARARGS,
-     PySSL_RAND_egd_doc},
     {"RAND_status",         (PyCFunction)PySSL_RAND_status, METH_NOARGS,
      PySSL_RAND_status_doc},
+#endif
+#ifdef HAVE_RAND_EGD
+    {"RAND_egd",            PySSL_RAND_egd, METH_VARARGS,
+     PySSL_RAND_egd_doc},
 #endif
     {"get_default_verify_paths", (PyCFunction)PySSL_get_default_verify_paths,
      METH_NOARGS, PySSL_get_default_verify_paths_doc},
diff --git a/configure b/configure
@@ -8551,6 +8551,48 @@ _ACEOF
 
 fi
 	# Dynamic linking for HP-UX
+{ $as_echo "$as_me:${as_lineno-$LINENO}: checking for RAND_egd in -lcrypto" >&5
+$as_echo_n "checking for RAND_egd in -lcrypto... " >&6; }
+if ${ac_cv_lib_crypto_RAND_egd+:} false; then :
+  $as_echo_n "(cached) " >&6
+else
+  ac_check_lib_save_LIBS=$LIBS
+LIBS="-lcrypto  $LIBS"
+cat confdefs.h - <<_ACEOF >conftest.$ac_ext
+/* end confdefs.h.  */
+
+/* Override any GCC internal prototype to avoid an error.
+   Use char because int might match the return type of a GCC
+   builtin and then its argument prototype would still apply.  */
+#ifdef __cplusplus
+extern "C"
+#endif
+char RAND_egd ();
+int
+main ()
+{
+return RAND_egd ();
+  ;
+  return 0;
+}
+_ACEOF
+if ac_fn_c_try_link "$LINENO"; then :
+  ac_cv_lib_crypto_RAND_egd=yes
+else
+  ac_cv_lib_crypto_RAND_egd=no
+fi
+rm -f core conftest.err conftest.$ac_objext \
+    conftest$ac_exeext conftest.$ac_ext
+LIBS=$ac_check_lib_save_LIBS
+fi
+{ $as_echo "$as_me:${as_lineno-$LINENO}: result: $ac_cv_lib_crypto_RAND_egd" >&5
+$as_echo "$ac_cv_lib_crypto_RAND_egd" >&6; }
+if test "x$ac_cv_lib_crypto_RAND_egd" = xyes; then :
+
+$as_echo "#define HAVE_RAND_EGD 1" >>confdefs.h
+
+fi
+
 
 # only check for sem_init if thread support is requested
 if test "$with_threads" = "yes" -o -z "$with_threads"; then
diff --git a/configure.ac b/configure.ac
@@ -2221,6 +2221,9 @@ AC_MSG_RESULT($SHLIBS)
 # checks for libraries
 AC_CHECK_LIB(dl, dlopen)	# Dynamic linking for SunOS/Solaris and SYSV
 AC_CHECK_LIB(dld, shl_load)	# Dynamic linking for HP-UX
+AC_CHECK_LIB(crypto, RAND_egd,
+             AC_DEFINE(HAVE_RAND_EGD, 1,
+             [Define if the libcrypto has RAND_egd]))
 
 # only check for sem_init if thread support is requested
 if test "$with_threads" = "yes" -o -z "$with_threads"; then
diff --git a/pyconfig.h.in b/pyconfig.h.in
@@ -547,6 +547,9 @@
 /* Define to 1 if you have the `putenv' function. */
 #undef HAVE_PUTENV
 
+/* Define if the libcrypto has RAND_egd */
+#undef HAVE_RAND_EGD
+
 /* Define to 1 if you have the `readlink' function. */
 #undef HAVE_READLINK
 
