diff --git a/Lib/test/test_binascii.py b/Lib/test/test_binascii.py
index cd76dbb..3c6d88f 100755
--- a/Lib/test/test_binascii.py
+++ b/Lib/test/test_binascii.py
@@ -5,6 +5,14 @@
 import binascii
 import array
 
+# Note: "*_hex" functions are aliases for "(un)hexlify"
+b2a_functions = ['b2a_base64', 'b2a_hex', 'b2a_hqx', 'b2a_qp', 'b2a_uu',
+                 'hexlify', 'rlecode_hqx']
+a2b_functions = ['a2b_base64', 'a2b_hex', 'a2b_hqx', 'a2b_qp', 'a2b_uu',
+                 'unhexlify', 'rledecode_hqx']
+all_functions = a2b_functions + b2a_functions + ['crc32', 'crc_hqx']
+
+
 class BinASCIITest(unittest.TestCase):
 
     type2test = bytes
@@ -24,30 +32,45 @@
 
     def test_functions(self):
         # Check presence of all functions
-        funcs = []
-        for suffix in "base64", "hqx", "uu", "hex":
-            prefixes = ["a2b_", "b2a_"]
-            if suffix == "hqx":
-                prefixes.extend(["crc_", "rlecode_", "rledecode_"])
-            for prefix in prefixes:
-                name = prefix + suffix
-                self.assertTrue(hasattr(getattr(binascii, name), '__call__'))
-                self.assertRaises(TypeError, getattr(binascii, name))
-        for name in ("hexlify", "unhexlify"):
+        for name in all_functions:
             self.assertTrue(hasattr(getattr(binascii, name), '__call__'))
             self.assertRaises(TypeError, getattr(binascii, name))
 
+    def test_returned_value(self):
+        # Limit to the minimum of all limits (b2a_uu)
+        MAX_ALL = 45
+        raw = self.rawdata[:MAX_ALL]
+        for fa, fb in zip(a2b_functions, b2a_functions):
+            a2b = getattr(binascii, fa)
+            b2a = getattr(binascii, fb)
+            try:
+                a = b2a(self.type2test(raw))
+                res = a2b(self.type2test(a))
+            except Exception as err:
+                self.fail("{}/{} conversion raises {!r}".format(fb, fa, err))
+            if fb == 'b2a_hqx':
+                # b2a_hqx returns a tuple
+                res, _ = res
+            self.assertEqual(res, raw, "{}/{} conversion: "
+                             "{!r} != {!r}".format(fb, fa, res, raw))
+            self.assertIsInstance(res, bytes)
+            self.assertIsInstance(a, bytes)
+            self.assertLess(max(c for c in a), 128)
+        self.assertIsInstance(binascii.crc_hqx(raw, 0), int)
+        self.assertIsInstance(binascii.crc32(raw), int)
+
     def test_base64valid(self):
         # Test base64 with valid data
         MAX_BASE64 = 57
         lines = []
-        for i in range(0, len(self.data), MAX_BASE64):
-            b = self.data[i:i+MAX_BASE64]
+        for i in range(0, len(self.rawdata), MAX_BASE64):
+            b = self.type2test(self.rawdata[i:i+MAX_BASE64])
             a = binascii.b2a_base64(b)
             lines.append(a)
         res = bytes()
         for line in lines:
-            b = binascii.a2b_base64(line)
+            a = self.type2test(line)
+            b = binascii.a2b_base64(a)
             res += b
         self.assertEqual(res, self.rawdata)
 
@@ -57,7 +80,7 @@
         MAX_BASE64 = 57
         lines = []
         for i in range(0, len(self.data), MAX_BASE64):
-            b = self.data[i:i+MAX_BASE64]
+            b = self.type2test(self.rawdata[i:i+MAX_BASE64])
             a = binascii.b2a_base64(b)
             lines.append(a)
 
@@ -79,24 +102,26 @@
             return res + noise + line
         res = bytearray()
         for line in map(addnoise, lines):
-            b = binascii.a2b_base64(line)
+            a = self.type2test(line)
+            b = binascii.a2b_base64(a)
             res += b
         self.assertEqual(res, self.rawdata)
 
         # Test base64 with just invalid characters, which should return
         # empty strings. TBD: shouldn't it raise an exception instead ?
-        self.assertEqual(binascii.a2b_base64(fillers), b'')
+        self.assertEqual(binascii.a2b_base64(self.type2test(fillers)), b'')
 
     def test_uu(self):
         MAX_UU = 45
         lines = []
         for i in range(0, len(self.data), MAX_UU):
-            b = self.data[i:i+MAX_UU]
+            b = self.type2test(self.rawdata[i:i+MAX_UU])
             a = binascii.b2a_uu(b)
             lines.append(a)
         res = bytes()
         for line in lines:
-            b = binascii.a2b_uu(line)
+            a = self.type2test(line)
+            b = binascii.a2b_uu(a)
             res += b
         self.assertEqual(res, self.rawdata)
 
@@ -112,19 +137,27 @@
         self.assertEqual(binascii.b2a_uu(b'x'), b'!>   \n')
 
     def test_crc32(self):
-        crc = binascii.crc32(b"Test the CRC-32 of")
-        crc = binascii.crc32(b" this string.", crc)
+        crc = binascii.crc32(self.type2test(b"Test the CRC-32 of"))
+        crc = binascii.crc32(self.type2test(b" this string."), crc)
         self.assertEqual(crc, 1571220330)
 
         self.assertRaises(TypeError, binascii.crc32)
 
-    # The hqx test is in test_binhex.py
+    def test_hqx(self):
+        # Perform binhex4 style RLE-compression
+        # Then calculate the hexbin4 binary-to-ASCII translation
+        rle = binascii.rlecode_hqx(self.data)
+        a = binascii.b2a_hqx(self.type2test(rle))
+        b, _ = binascii.a2b_hqx(self.type2test(a))
+        res = binascii.rledecode_hqx(b)
+
+        self.assertEqual(res, self.rawdata)
 
     def test_hex(self):
         # test hexlification
         s = b'{s\005\000\000\000worldi\002\000\000\000s\005\000\000\000helloi\001\000\000\0000'
-        t = binascii.b2a_hex(s)
-        u = binascii.a2b_hex(t)
+        t = binascii.b2a_hex(self.type2test(s))
+        u = binascii.a2b_hex(self.type2test(t))
         self.assertEqual(s, u)
         self.assertRaises(binascii.Error, binascii.a2b_hex, t[:-1])
         self.assertRaises(binascii.Error, binascii.a2b_hex, t[:-1] + b'q')
@@ -165,16 +198,17 @@
 
     def test_empty_string(self):
         # A test for SF bug #1022953.  Make sure SystemError is not raised.
-        for n in ['b2a_qp', 'a2b_hex', 'b2a_base64', 'a2b_uu', 'a2b_qp',
-                  'b2a_hex', 'unhexlify', 'hexlify', 'crc32', 'b2a_hqx',
-                  'a2b_hqx', 'a2b_base64', 'rlecode_hqx', 'b2a_uu',
-                  'rledecode_hqx']:
-            f = getattr(binascii, n)
+        empty = self.type2test(b'')
+        for func in all_functions:
+            if func == 'crc_hqx':
+                # crc_hqx needs 2 arguments
+                binascii.crc_hqx(empty, 0)
+                continue
+            f = getattr(binascii, func)
             try:
-                f(b'')
-            except SystemError as err:
-                self.fail("%s(b'') raises SystemError: %s" % (n, err))
-        binascii.crc_hqx(b'', 0)
+                f(empty)
+            except Exception as err:
+                self.fail("{}({!r}) raises {!r}".format(func, empty, err))
 
     def test_no_binary_strings(self):
         # b2a_ must not accept strings
@@ -190,6 +224,10 @@
         return array.array('B', list(s))
 
 
+class BytearrayBinASCIITest(BinASCIITest):
+    type2test = bytearray
+
+
 class MemoryviewBinASCIITest(BinASCIITest):
     type2test = memoryview
 
@@ -197,6 +235,7 @@
 def test_main():
     support.run_unittest(BinASCIITest,
                          ArrayBinASCIITest,
+                         BytearrayBinASCIITest,
                          MemoryviewBinASCIITest)
 
 if __name__ == "__main__":
diff --git a/Misc/NEWS b/Misc/NEWS
index b220306..07b1503 100644
--- a/Misc/NEWS
+++ b/Misc/NEWS
@@ -213,6 +213,9 @@
 Library
 -------
 
+- Issue #7703: Add support for the new buffer API to `binascii.a2bhqx`.
+  Patch by Florent Xicluna, along with some additional tests.
+
 - Issue #7701: Fix crash in binascii.b2a_uu() in debug mode when given a
   1-byte argument.  Patch by Victor Stinner.
 
diff --git a/Modules/binascii.c b/Modules/binascii.c
index 833283f..289225b 100644
--- a/Modules/binascii.c
+++ b/Modules/binascii.c
@@ -537,6 +537,7 @@
 static PyObject *
 binascii_a2b_hqx(PyObject *self, PyObject *args)
 {
+	Py_buffer pascii;
 	unsigned char *ascii_data, *bin_data;
 	int leftbits = 0;
 	unsigned char this_ch;
@@ -545,19 +546,26 @@
 	Py_ssize_t len;
 	int done = 0;
 
-	if ( !PyArg_ParseTuple(args, "t#:a2b_hqx", &ascii_data, &len) )
+	if ( !PyArg_ParseTuple(args, "s*:a2b_hqx", &pascii) )
 		return NULL;
+	ascii_data = pascii.buf;
+	len = pascii.len;
 
 	assert(len >= 0);
 
-	if (len > PY_SSIZE_T_MAX - 2)
+	if (len > PY_SSIZE_T_MAX - 2) {
+		PyBuffer_Release(&pascii);
 		return PyErr_NoMemory();
+	}
 
 	/* Allocate a string that is too big (fixed later) 
 	   Add two to the initial length to prevent interning which
 	   would preclude subsequent resizing.  */
 	if ( (rv=PyBytes_FromStringAndSize(NULL, len+2)) == NULL )
+	if ( (rv=PyBytes_FromStringAndSize(NULL, len+2)) == NULL ) {
+		PyBuffer_Release(&pascii);
 		return NULL;
+	}
 	bin_data = (unsigned char *)PyBytes_AS_STRING(rv);
 
 	for( ; len > 0 ; len--, ascii_data++ ) {
@@ -567,6 +575,7 @@
 			continue;
 		if ( this_ch == FAIL ) {
 			PyErr_SetString(Error, "Illegal char");
+			PyBuffer_Release(&pascii);
 			Py_DECREF(rv);
 			return NULL;
 		}
@@ -589,6 +598,7 @@
 	if ( leftbits && !done ) {
 		PyErr_SetString(Incomplete,
 				"String has incomplete number of bytes");
+		PyBuffer_Release(&pascii);
 		Py_DECREF(rv);
 		return NULL;
 	}
@@ -600,10 +610,12 @@
 	}
 	if (rv) {
 		PyObject *rrv = Py_BuildValue("Oi", rv, done);
+		PyBuffer_Release(&pascii);
 		Py_DECREF(rv);
 		return rrv;
 	}
 
+	PyBuffer_Release(&pascii);
 	return NULL;
 }