This has been added to avoid the situation where some host ctype.h functions

return true for characters > 127.  I.e. they are allowing extended ASCII
characters through which then cause problems.  E.g. marking superscript '2' as
a number then causes the common (ch - '0') conversion to number to fail
miserably.  Likewise letters with diacritical marks can also cause problems.

If a non-ASCII character set is being used (currently only EBCDIC), it is
adjusted for.

The implementation uses a single table with a bit for each of the defined
classes.  These functions accept an int argument and fail for
values out of range or for characters outside of the ASCII set.  They will
work for both signed and unsigned character inputs.

Reviewed-by: Andy Polyakov <appro@openssl.org>
(Merged from https://github.com/openssl/openssl/pull/4102)

1 files changed, 80 insertions, 0 deletions

diff --git a/crypto/include/internal/ctype.h b/crypto/include/internal/ctype.h
new file mode 100644
index 0000000000..a35b12bfbf
--- /dev/null
+++ b/crypto/include/internal/ctype.h
@@ -0,0 +1,80 @@
+/*
+ * Copyright 2017 The OpenSSL Project Authors. All Rights Reserved.
+ *
+ * Licensed under the OpenSSL license (the "License").  You may not use
+ * this file except in compliance with the License.  You can obtain a copy
+ * in the file LICENSE in the source distribution or at
+ * https://www.openssl.org/source/license.html
+ */
+
+/*
+ * This version of ctype.h provides a standardised and platform
+ * independent implementation that supports seven bit ASCII characters.
+ * The specific intent is to not pass extended ASCII characters (> 127)
+ * even if the host operating system would.
+ *
+ * There is EBCDIC support included for machines which use this.  However,
+ * there are a number of concerns about how well EBCDIC is supported
+ * throughout the rest of the source code.  Refer to issue #4154 for
+ * details.
+ */
+#ifndef INTERNAL_CTYPE_H
+# define INTERNAL_CTYPE_H
+
+# define CTYPE_MASK_lower       0x1
+# define CTYPE_MASK_upper       0x2
+# define CTYPE_MASK_digit       0x4
+# define CTYPE_MASK_space       0x8
+# define CTYPE_MASK_xdigit      0x10
+# define CTYPE_MASK_blank       0x20
+# define CTYPE_MASK_cntrl       0x40
+# define CTYPE_MASK_graph       0x80
+# define CTYPE_MASK_print       0x100
+# define CTYPE_MASK_punct       0x200
+# define CTYPE_MASK_base64      0x400
+# define CTYPE_MASK_asn1print   0x800
+
+# define CTYPE_MASK_alpha   (CTYPE_MASK_lower | CTYPE_MASK_upper)
+# define CTYPE_MASK_alnum   (CTYPE_MASK_alpha | CTYPE_MASK_digit)
+
+/*
+ * The ascii mask assumes that any other classification implies that
+ * the character is ASCII and that there are no ASCII characters
+ * that aren't in any of the classifications.
+ *
+ * This assumption holds at the moment, but it might not in the future.
+ */
+# define CTYPE_MASK_ascii   (~0)
+
+# ifdef CHARSET_EBCDIC
+int ossl_toascii(int c);
+int ossl_fromascii(int c);
+# else
+#  define ossl_toascii(c)       (c)
+#  define ossl_fromascii(c)     (c)
+# endif
+int ossl_ctype_check(int c, unsigned int mask);
+int ossl_tolower(int c);
+int ossl_toupper(int c);
+
+# define ossl_isalnum(c)        (ossl_ctype_check((c), CTYPE_MASK_alnum))
+# define ossl_isalpha(c)        (ossl_ctype_check((c), CTYPE_MASK_alpha))
+# ifdef CHARSET_EBCDIC
+# define ossl_isascii(c)        (ossl_ctype_check((c), CTYPE_MASK_ascii))
+# else
+# define ossl_isascii(c)        (((c) & ~127) == 0)
+# endif
+# define ossl_isblank(c)        (ossl_ctype_check((c), CTYPE_MASK_blank))
+# define ossl_iscntrl(c)        (ossl_ctype_check((c), CTYPE_MASK_cntrl))
+# define ossl_isdigit(c)        (ossl_ctype_check((c), CTYPE_MASK_digit))
+# define ossl_isgraph(c)        (ossl_ctype_check((c), CTYPE_MASK_graph))
+# define ossl_islower(c)        (ossl_ctype_check((c), CTYPE_MASK_lower))
+# define ossl_isprint(c)        (ossl_ctype_check((c), CTYPE_MASK_print))
+# define ossl_ispunct(c)        (ossl_ctype_check((c), CTYPE_MASK_punct))
+# define ossl_isspace(c)        (ossl_ctype_check((c), CTYPE_MASK_space))
+# define ossl_isupper(c)        (ossl_ctype_check((c), CTYPE_MASK_upper))
+# define ossl_isxdigit(c)       (ossl_ctype_check((c), CTYPE_MASK_xdigit))
+# define ossl_isbase64(c)       (ossl_ctype_check((c), CTYPE_MASK_base64))
+# define ossl_isasn1print(c)    (ossl_ctype_check((c), CTYPE_MASK_asn1print))
+
+#endif