From: INADA Naoki <methane@users.noreply.github.com>
Date: Mon, 2 Oct 2017 07:33:42 +0000 (+0900)
Subject: bpo-31659: Use simple slicing to format PEM cert (GH-3849)
X-Git-Tag: v3.7.0a2~78
X-Git-Url: https://granicus.if.org/sourcecode?a=commitdiff_plain;h=b75a228af8c0553aef44e4e03763af90fbc8737f;p=python

bpo-31659: Use simple slicing to format PEM cert (GH-3849)

DER_cert_to_PEM_cert() used textwrap.fill() to format PEM.
But it's library to wrap lines on word boundary, while PEM is
base64 encoded string.

Additionally, importing textwrap is little slow.
---

diff --git a/Lib/ssl.py b/Lib/ssl.py
index 24f24b17bf..75caae0c44 100644
--- a/Lib/ssl.py
+++ b/Lib/ssl.py
@@ -91,7 +91,6 @@ ALERT_DESCRIPTION_UNKNOWN_PSK_IDENTITY
 """
 
 import ipaddress
-import textwrap
 import re
 import sys
 import os
@@ -1201,9 +1200,10 @@ def DER_cert_to_PEM_cert(der_cert_bytes):
     PEM version of it as a string."""
 
     f = str(base64.standard_b64encode(der_cert_bytes), 'ASCII', 'strict')
-    return (PEM_HEADER + '\n' +
-            textwrap.fill(f, 64) + '\n' +
-            PEM_FOOTER + '\n')
+    ss = [PEM_HEADER]
+    ss += [f[i:i+64] for i in range(0, len(f), 64)]
+    ss.append(PEM_FOOTER + '\n')
+    return '\n'.join(ss)
 
 def PEM_cert_to_DER_cert(pem_cert_string):
     """Takes a certificate in ASCII PEM format and returns the