add md5 checksum support to Install.py for LATTE

lib/latte/Install.py

@@ -4,7 +4,7 @@
 # used to automate the steps described in the README file in this dir
 
 from __future__ import print_function
-import sys,os,re,subprocess
+import sys,os,re,subprocess,hashlib
 
 # help message
 
@@ -24,7 +24,7 @@ specify one or more options, order does not matter
   -b = download and build the LATTE library
   -p = specify folder of existing LATTE installation
   -m = copy Makefile.lammps.suffix to Makefile.lammps
-  -v = set version of LATTE library to download and set up (default = 1.1.1)
+  -v = set version of LATTE library to download and set up (default = 1.2.1)
 
 Example:
 
@@ -36,6 +36,13 @@ make lib-latte args="-p $HOME/latte"   # use existing LATTE installation
 
 version = '1.2.1'
 
+# known checksums for different LATTE versions. used to validate the download.
+checksums = { \
+        '1.1.0' : '533635721ee222d0ed2925a18fb5b294', \
+        '1.2.0' : '68bf0db879da5e068a71281020239ae7', \
+        '1.2.1' : 'bed76e7e76c545c36dd848a8f1fd35eb' \
+        }
+
 # print error message or help
 
 def error(str=None):
@@ -91,6 +98,17 @@ def geturl(url,fname):
     error("Failed to download source code with 'curl' or 'wget'")
   return
 
+def checkmd5sum(md5sum,fname):
+    with open(fname,'rb') as fh:
+        m = hashlib.md5()
+        while True:
+            data = fh.read(81920)
+            if not data:
+                break
+            m.update(data)
+    fh.close()
+    return m.hexdigest() == md5sum
+
 # parse args
 
 args = sys.argv[1:]
@@ -144,6 +162,11 @@ if buildflag:
   print("Downloading LATTE ...")
   geturl(url,"LATTE.tar.gz")
 
+  # verify downloaded archive integrity via md5 checksum, if known.
+  if version in checksums:
+    if not checkmd5sum(checksums[version],'LATTE.tar.gz'):
+      error("Checksum for LATTE library does not match")
+
   print("Unpacking LATTE ...")
   if os.path.exists(lattedir):
     cmd = 'rm -rf "%s"' % lattedir
@@ -162,7 +185,7 @@ if buildflag:
 
 # create 3 links in lib/latte to LATTE dirs
 # do this -b or -p is set
-  
+
 if buildflag or pathflag:
   print("Creating links to LATTE files")
   if os.path.isfile("includelink") or os.path.islink("includelink"):