1 files changed, 51 insertions, 0 deletions
diff --git a/python/pyasn1-modules/pyasn1_modules/pem.py b/python/pyasn1-modules/pyasn1_modules/pem.py
new file mode 100644
index 000000000..d8d815873
--- /dev/null
+++ b/python/pyasn1-modules/pyasn1_modules/pem.py
@@ -0,0 +1,51 @@
+import base64, sys
+
+stSpam, stHam, stDump = 0, 1, 2
+
+# The markers parameters is in form ('start1', 'stop1'), ('start2', 'stop2')...
+# Return is (marker-index, substrate)
+def readPemBlocksFromFile(fileObj, *markers):
+    startMarkers = dict(map(lambda x: (x[1],x[0]),
+                            enumerate(map(lambda x: x[0], markers))))
+    stopMarkers = dict(map(lambda x: (x[1],x[0]),
+                           enumerate(map(lambda x: x[1], markers))))
+    idx = -1; substrate = ''
+    state = stSpam
+    while 1:
+        certLine = fileObj.readline()
+        if not certLine:
+            break
+        certLine = certLine.strip()
+        if state == stSpam:
+            if certLine in startMarkers:
+                certLines = []
+                idx = startMarkers[certLine]
+                state = stHam
+                continue
+        if state == stHam:
+            if certLine in stopMarkers and stopMarkers[certLine] == idx:
+                state = stDump
+            else:
+                certLines.append(certLine)
+        if state == stDump:
+            if sys.version_info[0] <= 2:
+                substrate = ''.join([ base64.b64decode(x) for x in certLines ])
+            else:
+                substrate = ''.encode().join([ base64.b64decode(x.encode()) for x in certLines ])
+            break
+    return idx, substrate
+
+# Backward compatibility routine
+def readPemFromFile(fileObj, 
+                    startMarker='-----BEGIN CERTIFICATE-----',
+                    endMarker='-----END CERTIFICATE-----'):
+    idx, substrate = readPemBlocksFromFile(fileObj, (startMarker, endMarker))
+    return substrate
+
+def readBase64FromFile(fileObj):
+    if sys.version_info[0] <= 2:
+        return ''.join([ base64.b64decode(x) for x in fileObj.readlines() ])
+    else:
+        return ''.encode().join(
+            [ base64.b64decode(x.encode()) for x in fileObj.readlines() ]
+        )