diff --git a/gallery_dl/util.py b/gallery_dl/util.py
index c2ce507d..dbfa800d 100644
--- a/gallery_dl/util.py
+++ b/gallery_dl/util.py
@@ -14,6 +14,7 @@ import sys
 import json
 import time
 import random
+import hashlib
 import sqlite3
 import binascii
 import datetime
@@ -112,6 +113,24 @@ def noop():
     """Does nothing"""
 
 
+def md5(s):
+    """Generate MD5 hexdigest of 's'"""
+    if not s:
+        s = b""
+    elif isinstance(s, str):
+        s = s.encode()
+    return hashlib.md5(s).hexdigest()
+
+
+def sha1(s):
+    """Generate SHA1 hexdigest of 's'"""
+    if not s:
+        s = b""
+    elif isinstance(s, str):
+        s = s.encode()
+    return hashlib.sha1(s).hexdigest()
+
+
 def generate_token(size=16):
     """Generate a random token with hexadecimal digits"""
     data = random.getrandbits(size * 8).to_bytes(size, "big")
@@ -593,6 +612,8 @@ GLOBALS = {
     "abort"    : raises(exception.StopExtraction),
     "terminate": raises(exception.TerminateExtraction),
     "restart"  : raises(exception.RestartExtraction),
+    "hash_sha1": sha1,
+    "hash_md5" : md5,
     "re"       : re,
 }
 
diff --git a/test/test_util.py b/test/test_util.py
index 67fdf601..e837fab8 100644
--- a/test/test_util.py
+++ b/test/test_util.py
@@ -394,6 +394,46 @@ class TestOther(unittest.TestCase):
     def test_noop(self):
         self.assertEqual(util.noop(), None)
 
+    def test_md5(self):
+        self.assertEqual(util.md5(b""),
+                         "d41d8cd98f00b204e9800998ecf8427e")
+        self.assertEqual(util.md5(b"hello"),
+                         "5d41402abc4b2a76b9719d911017c592")
+
+        self.assertEqual(util.md5(""),
+                         "d41d8cd98f00b204e9800998ecf8427e")
+        self.assertEqual(util.md5("hello"),
+                         "5d41402abc4b2a76b9719d911017c592")
+        self.assertEqual(util.md5("ワルド"),
+                         "051f29cd6c942cf110a0ccc5729871d2")
+
+        self.assertEqual(util.md5(0),
+                         "d41d8cd98f00b204e9800998ecf8427e")
+        self.assertEqual(util.md5(()),
+                         "d41d8cd98f00b204e9800998ecf8427e")
+        self.assertEqual(util.md5(None),
+                         "d41d8cd98f00b204e9800998ecf8427e")
+
+    def test_sha1(self):
+        self.assertEqual(util.sha1(b""),
+                         "da39a3ee5e6b4b0d3255bfef95601890afd80709")
+        self.assertEqual(util.sha1(b"hello"),
+                         "aaf4c61ddcc5e8a2dabede0f3b482cd9aea9434d")
+
+        self.assertEqual(util.sha1(""),
+                         "da39a3ee5e6b4b0d3255bfef95601890afd80709")
+        self.assertEqual(util.sha1("hello"),
+                         "aaf4c61ddcc5e8a2dabede0f3b482cd9aea9434d")
+        self.assertEqual(util.sha1("ワルド"),
+                         "0cbe319081aa0e9298448ec2bb16df8c494aa04e")
+
+        self.assertEqual(util.sha1(0),
+                         "da39a3ee5e6b4b0d3255bfef95601890afd80709")
+        self.assertEqual(util.sha1(()),
+                         "da39a3ee5e6b4b0d3255bfef95601890afd80709")
+        self.assertEqual(util.sha1(None),
+                         "da39a3ee5e6b4b0d3255bfef95601890afd80709")
+
     def test_compile_expression(self):
         expr = util.compile_expression("1 + 2 * 3")
         self.assertEqual(expr(), 7)