Integrate a modified version of Dave Cridland's Suelta SASL library.

sleekxmpp/thirdparty/suelta/saslprep.py

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+from __future__ import unicode_literals
+
+import sys
+import stringprep
+import unicodedata
+
+
+def saslprep(text, strict=True):
+    """
+    Return a processed version of the given string, using the SASLPrep
+    profile of stringprep.
+
+    :param text: The string to process, in UTF-8.
+    :param strict: If ``True``, prevent the use of unassigned code points.
+    """
+
+    if sys.version_info < (3, 0):
+        if type(text) == str:
+            text = text.decode('us-ascii')
+
+    # Mapping:
+    #
+    #  -  non-ASCII space characters [StringPrep, C.1.2] that can be
+    #     mapped to SPACE (U+0020), and
+    #
+    #  -  the 'commonly mapped to nothing' characters [StringPrep, B.1]
+    #     that can be mapped to nothing.
+    buffer = ''
+    for char in text:
+        if stringprep.in_table_c12(char):
+            buffer += ' '
+        elif not stringprep.in_table_b1(char):
+            buffer += char
+
+    # Normalization using form KC
+    text = unicodedata.normalize('NFKC', buffer)
+
+    # Check for bidirectional string
+    buffer = ''
+    first_is_randal = False
+    if text:
+        first_is_randal = stringprep.in_table_d1(text[0])
+        if first_is_randal and not stringprep.in_table_d1(text[-1]):
+            raise UnicodeError('Section 6.3 [end]')
+
+    # Check for prohibited characters
+    for x in range(len(text)):
+        if strict and stringprep.in_table_a1(text[x]):
+            raise UnicodeError('Unassigned Codepoint')
+        if stringprep.in_table_c12(text[x]):
+            raise UnicodeError('In table C.1.2')
+        if stringprep.in_table_c21(text[x]):
+            raise UnicodeError('In table C.2.1')
+        if stringprep.in_table_c22(text[x]):
+            raise UnicodeError('In table C.2.2')
+        if stringprep.in_table_c3(text[x]):
+            raise UnicodeError('In table C.3')
+        if stringprep.in_table_c4(text[x]):
+            raise UnicodeError('In table C.4')
+        if stringprep.in_table_c5(text[x]):
+            raise UnicodeError('In table C.5')
+        if stringprep.in_table_c6(text[x]):
+            raise UnicodeError('In table C.6')
+        if stringprep.in_table_c7(text[x]):
+            raise UnicodeError('In table C.7')
+        if stringprep.in_table_c8(text[x]):
+            raise UnicodeError('In table C.8')
+        if stringprep.in_table_c9(text[x]):
+            raise UnicodeError('In table C.9')
+        if x:
+            if first_is_randal and stringprep.in_table_d2(text[x]):
+                raise UnicodeError('Section 6.2')
+            if not first_is_randal and \
+               x != len(text) - 1 and \
+               stringprep.in_table_d1(text[x]):
+                raise UnicodeError('Section 6.3')
+
+    return text