diff --git a/contrib/linearize/README.md b/contrib/linearize/README.md
--- a/contrib/linearize/README.md
+++ b/contrib/linearize/README.md
@@ -7,7 +7,8 @@
     $ ./linearize-hashes.py linearize.cfg > hashlist.txt
 
 Required configuration file settings for linearize-hashes:
-* RPC: `rpcuser`, `rpcpassword`
+* RPC: `datadir` (Required if `rpcuser` and `rpcpassword` are not specified)
+* RPC: `rpcuser`, `rpcpassword` (Required if `datadir` is not specified)
 
 Optional config file setting for linearize-hashes:
 * RPC: `host`  (Default: `127.0.0.1`)
diff --git a/contrib/linearize/example-linearize.cfg b/contrib/linearize/example-linearize.cfg
--- a/contrib/linearize/example-linearize.cfg
+++ b/contrib/linearize/example-linearize.cfg
@@ -1,6 +1,7 @@
 # bitcoind RPC settings (linearize-hashes)
 rpcuser=someuser
 rpcpassword=somepassword
+#datadir=~/.bitcoin
 host=127.0.0.1
 port=8332
 #port=18332
diff --git a/contrib/linearize/linearize-hashes.py b/contrib/linearize/linearize-hashes.py
--- a/contrib/linearize/linearize-hashes.py
+++ b/contrib/linearize/linearize-hashes.py
@@ -16,6 +16,8 @@
 import re
 import base64
 import sys
+import os
+import os.path
 
 settings = {}
 
@@ -100,6 +102,15 @@
         height += num_blocks
 
 
+def get_rpc_cookie():
+    # Open the cookie file
+    with open(os.path.join(os.path.expanduser(settings['datadir']), '.cookie'), 'r') as f:
+        combined = f.readline()
+        combined_split = combined.split(":")
+        settings['rpcuser'] = combined_split[0]
+        settings['rpcpassword'] = combined_split[1]
+
+
 if __name__ == '__main__':
     if len(sys.argv) != 2:
         print("Usage: linearize-hashes.py CONFIG-FILE")
@@ -129,8 +140,15 @@
         settings['max_height'] = 313000
     if 'rev_hash_bytes' not in settings:
         settings['rev_hash_bytes'] = 'false'
+
+    use_userpass = True
+    use_datadir = False
     if 'rpcuser' not in settings or 'rpcpassword' not in settings:
-        print("Missing username and/or password in cfg file", file=sys.stderr)
+        use_userpass = False
+    if 'datadir' in settings and not use_userpass:
+        use_datadir = True
+    if not use_userpass and not use_datadir:
+        print("Missing datadir or username and/or password in cfg file", file=sys.stderr)
         sys.exit(1)
 
     settings['port'] = int(settings['port'])
@@ -140,4 +158,8 @@
     # Force hash byte format setting to be lowercase to make comparisons easier.
     settings['rev_hash_bytes'] = settings['rev_hash_bytes'].lower()
 
+    # Get the rpc user and pass from the cookie if the datadir is set
+    if use_datadir:
+        get_rpc_cookie()
+
     get_block_hashes(settings)