readPemFromFile() improved to select one of possible many PEM headers

1 files changed, 15 insertions, 5 deletions

diff --git a/pyasn1_modules/pem.py b/pyasn1_modules/pem.py
index 5009c01..e71fb14 100644
--- a/pyasn1_modules/pem.py
+++ b/pyasn1_modules/pem.py
@@ -2,7 +2,14 @@ import base64, sys
 
 stSpam, stHam, stDump = 0, 1, 2
 
-def readPemFromFile(fileObj, startMarker, endMarker):
+# The markers parameters is in form ('start1', 'stop1'), ('start2', 'stop2')...
+# Return is (marker-index, substrate)
+def readPemFromFile(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()
@@ -10,20 +17,23 @@ def readPemFromFile(fileObj, startMarker, endMarker):
             break
         certLine = certLine.strip()
         if state == stSpam:
-            if certLine == startMarker or certLine in startMarker:
+            if certLine in startMarkers:
                 certLines = []
+                idx = startMarkers[certLine]
                 state = stHam
                 continue
         if state == stHam:
-            if certLine == endMarker or certLine in endMarker:
+            if certLine in stopMarkers and stopMarkers[certLine] == idx:
                 state = stDump
             else:
                 certLines.append(certLine)
         if state == stDump:
             if sys.version_info[0] <= 2:
-                return ''.join([ base64.decodestring(x) for x in certLines ])
+                substrate = ''.join([ base64.decodestring(x) for x in certLines ])
             else:
-                return ''.encode().join([ base64.decodebytes(x.encode()) for x in certLines ])
+                substrate = ''.encode().join([ base64.decodebytes(x.encode()) for x in certLines ])
+            break
+    return idx, substrate
 
 def readBase64FromFile(fileObj):
     if sys.version_info[0] <= 2: