@@ -233,9 +233,9 @@ def check_blocksize_name(self, name, block_size=0, digest_size=0):
             self.assertEqual(m.block_size, block_size)
             self.assertEqual(m.digest_size, digest_size)
             self.assertEqual(len(m.digest()), digest_size)
-            self.assertEqual(m.name.lower(), name.lower())
+            self.assertEqual(m.name, name)
             # split for sha3_512 / _sha3.sha3 object
-            self.assertIn(name.split("_")[0], repr(m).lower())
+            self.assertIn(name.split("_")[0], repr(m))
 
     def test_blocksize_name(self):
         self.check_blocksize_name('md5', 64, 16)
 
@@ -28,6 +28,9 @@ Core and Builtins
 Library
 -------
 
+- Issue #18532: Change the builtin hash algorithms' names to lower case names
+  as promised by hashlib's documentation.
+
 - Issue #18405: Improve the entropy of crypt.mksalt().
 
 - Issue #12015: The tempfile module now uses a suffix of 8 random characters
 
@@ -439,7 +439,7 @@ MD5_get_block_size(PyObject *self, void *closure)
 static PyObject *
 MD5_get_name(PyObject *self, void *closure)
 {
-    return PyUnicode_FromStringAndSize("MD5", 3);
+    return PyUnicode_FromStringAndSize("md5", 3);
 }
 
 static PyObject *
 
@@ -411,7 +411,7 @@ SHA1_get_block_size(PyObject *self, void *closure)
 static PyObject *
 SHA1_get_name(PyObject *self, void *closure)
 {
-    return PyUnicode_FromStringAndSize("SHA1", 4);
+    return PyUnicode_FromStringAndSize("sha1", 4);
 }
 
 static PyObject *
 
@@ -501,9 +501,9 @@ static PyObject *
 SHA256_get_name(PyObject *self, void *closure)
 {
     if (((SHAobject *)self)->digestsize == 32)
-        return PyUnicode_FromStringAndSize("SHA256", 6);
+        return PyUnicode_FromStringAndSize("sha256", 6);
     else
-        return PyUnicode_FromStringAndSize("SHA224", 6);
+        return PyUnicode_FromStringAndSize("sha224", 6);
 }
 
 static PyGetSetDef SHA_getseters[] = {
 
@@ -567,9 +567,9 @@ static PyObject *
 SHA512_get_name(PyObject *self, void *closure)
 {
     if (((SHAobject *)self)->digestsize == 64)
-        return PyUnicode_FromStringAndSize("SHA512", 6);
+        return PyUnicode_FromStringAndSize("sha512", 6);
     else
-        return PyUnicode_FromStringAndSize("SHA384", 6);
+        return PyUnicode_FromStringAndSize("sha384", 6);
 }
 
 static PyGetSetDef SHA_getseters[] = {
Original file line number	Diff line number	Diff line change
@@ -439,7 +439,7 @@ MD5_get_block_size(PyObject self, void closure)
439	439	static PyObject *
440	440	MD5_get_name(PyObject self, void closure)
441	441	{
442		- return PyUnicode_FromStringAndSize("MD5", 3);
	442	+ return PyUnicode_FromStringAndSize("md5", 3);
443	443	}
444	444
445	445	static PyObject *
Original file line number	Diff line number	Diff line change
@@ -411,7 +411,7 @@ SHA1_get_block_size(PyObject self, void closure)
411	411	static PyObject *
412	412	SHA1_get_name(PyObject self, void closure)
413	413	{
414		- return PyUnicode_FromStringAndSize("SHA1", 4);
	414	+ return PyUnicode_FromStringAndSize("sha1", 4);
415	415	}
416	416
417	417	static PyObject *
Original file line number	Diff line number	Diff line change
@@ -501,9 +501,9 @@ static PyObject *
501	501	SHA256_get_name(PyObject self, void closure)
502	502	{
503	503	if (((SHAobject *)self)->digestsize == 32)
504		- return PyUnicode_FromStringAndSize("SHA256", 6);
	504	+ return PyUnicode_FromStringAndSize("sha256", 6);
505	505	else
506		- return PyUnicode_FromStringAndSize("SHA224", 6);
	506	+ return PyUnicode_FromStringAndSize("sha224", 6);
507	507	}
508	508
509	509	static PyGetSetDef SHA_getseters[] = {
Original file line number	Diff line number	Diff line change
@@ -567,9 +567,9 @@ static PyObject *
567	567	SHA512_get_name(PyObject self, void closure)
568	568	{
569	569	if (((SHAobject *)self)->digestsize == 64)
570		- return PyUnicode_FromStringAndSize("SHA512", 6);
	570	+ return PyUnicode_FromStringAndSize("sha512", 6);
571	571	else
572		- return PyUnicode_FromStringAndSize("SHA384", 6);
	572	+ return PyUnicode_FromStringAndSize("sha384", 6);
573	573	}
574	574
575	575	static PyGetSetDef SHA_getseters[] = {