Improve BLS Bin2Hex tool

Added sanity check and automatic detection

Signed-off-by: Lukas Kozak <luks.kozak@gmail.com>

scripts/bls_bintohex.py

@@ -1,31 +1,50 @@
 #!/usr/bin/env python3
 
-import argparse
-import binascii
-import sys
+import argparse, binascii
+import sys, glob, re, os
 
 parser = argparse.ArgumentParser(description='Tool to convert your BLS key from binary to the accepted hex format.')
-parser.add_argument('file')
-parser.add_argument('-o', '--output', type=str, metavar='output', help='name your keyfile')
+parser.add_argument('-i', '--input', type=str, metavar='input', help='path to BLS keyfile')
 args = parser.parse_args()
 
+## Finds first bls keyfile in the directory or takes file given by user
+if args.input:
+    inputName = args.input
+    print(inputName)
+else:
+    keylist = glob.glob('UTC*bls_*')
+    inputName = keylist[0]
+
+## Read
 try:
-    with open(args.file, 'rb') as inputFile:
+    with open(inputName, 'rb') as inputFile:
         binFormat = inputFile.read()
 except IOError:
     print('File couldn\'t be opened.')
     sys.exit(1)
 
+## Sanity check and conversion
+try:
+    binascii.unhexlify(binFormat)
+except binascii.Error:
     hexFormat = binascii.hexlify(binFormat)
+else:
+    print("Keyfile is already in text format, no conversion required!")
+    sys.exit(0)
+
+## Name output appropriately based on the public key
+matchObj = re.search('UTC.*bls_(.*)', inputName)
 
-if args.output is not None:
-    outputName = args.output
+if matchObj:
+    outputName = matchObj.group(1) + ".key"
 else:
-    outputName = 'PUB.key'
+    outputName = 'bls.key'
 
+## Write
 try:
-    with open(outputName, 'wt') as outputFile:
+    with open(outputName, 'w') as outputFile:
         outputFile.write(hexFormat.decode('ascii'))
+    print("Keyfile converted to: {}".format(outputName))
 except IOError:
     print('File couldn\'t be written.')
     sys.exit(1)