highlighter: do not rely on localized case comparisons

Signed-off-by: Jason A. Donenfeld <Jason@zx2c4.com>

diff --git a/WireGuard/WireGuard/UI/macOS/highlighter.c b/WireGuard/WireGuard/UI/macOS/highlighter.c
index 3c5cd980ff1d8662602dd2dd25f78181e216f8ec..171a84c97066a4e8fa1f9a046660a0d5b65080eb 100644 (file)
--- a/WireGuard/WireGuard/UI/macOS/highlighter.c
+++ b/WireGuard/WireGuard/UI/macOS/highlighter.c
@@ -3,12 +3,10 @@
  * Copyright (C) 2015-2019 Jason A. Donenfeld <Jason@zx2c4.com>. All Rights Reserved.
  */
 
-#include <string.h>
-#include <strings.h>
 #include <stdbool.h>
 #include <stdint.h>
 #include <stdlib.h>
-#include <ctype.h>
+#include <string.h>
 #include <errno.h>
 #include "highlighter.h"
 
@@ -17,16 +15,56 @@ typedef struct {
        size_t len;
 } string_span_t;
 
+static bool is_decimal(char c)
+{
+       return c >= '0' && c <= '9';
+}
+
+static bool is_hexadecimal(char c)
+{
+       return is_decimal(c) || ((c | 32) >= 'a' && (c | 32) <= 'f');
+}
+
+static bool is_alphabet(char c)
+{
+       return (c | 32) >= 'a' && (c | 32) <= 'z';
+}
+
+static bool is_same(string_span_t s, const char *c)
+{
+       size_t len = strlen(c);
+
+       if (len != s.len)
+               return false;
+       return !memcmp(s.s, c, len);
+}
+
+static bool is_caseless_same(string_span_t s, const char *c)
+{
+       size_t len = strlen(c);
+
+       if (len != s.len)
+               return false;
+       for (size_t i = 0; i < len; ++i) {
+               char a = c[i], b = s.s[i];
+               if ((unsigned)a - 'a' < 26)
+                       a &= 95;
+               if ((unsigned)b - 'a' < 26)
+                       b &= 95;
+               if (a != b)
+                       return false;
+       }
+       return true;
+}
+
 static bool is_valid_key(string_span_t s)
 {
        if (s.len != 44 || s.s[43] != '=')
                return false;
 
        for (size_t i = 0; i < 43; ++i) {
-               if (!((s.s[i] >= '/' && s.s[i] <= '9') ||
-                     (s.s[i] >= 'A' && s.s[i] <= 'Z') ||
-                     (s.s[i] >= 'a' && s.s[i] <= 'z') ||
-                     s.s[i] == '+'))
+               if (!is_decimal(s.s[i]) && !is_alphabet(s.s[i]) &&
+                   s.s[i] != '/' && s.s[i] != '+')
                        return false;
        }
        return true;
@@ -44,7 +82,7 @@ static bool is_valid_hostname(string_span_t s)
                return false;
 
        for (size_t i = 0; i < s.len; ++i) {
-               if (isdigit(s.s[i])) {
+               if (is_decimal(s.s[i])) {
                        ++num_digit;
                        continue;
                }
@@ -53,9 +91,7 @@ static bool is_valid_hostname(string_span_t s)
                        continue;
                }
 
-               if (!((s.s[i] >= 'A' && s.s[i] <= 'Z') ||
-                     (s.s[i] >= 'a' && s.s[i] <= 'z') ||
-                     s.s[i] == '-'))
+               if (!is_alphabet(s.s[i]) && s.s[i] != '-')
                        return false;
 
                if (i && s.s[i] == '.' && s.s[i - 1] == '.')
@@ -69,7 +105,7 @@ static bool is_valid_ipv4(string_span_t s)
        for (size_t j, i = 0, pos = 0; i < 4 && pos < s.len; ++i) {
                uint32_t val = 0;
 
-               for (j = 0; j < 3 && pos + j < s.len && isdigit(s.s[pos + j]); ++j)
+               for (j = 0; j < 3 && pos + j < s.len && is_decimal(s.s[pos + j]); ++j)
                        val = 10 * val + s.s[pos + j] - '0';
                if (j == 0 || (j > 1 && s.s[pos] == '0') || val > 255)
                        return false;
@@ -103,7 +139,7 @@ static bool is_valid_ipv6(string_span_t s)
                                return false;
                        continue;
                }
-               for (j = 0; j < 4 && pos + j < s.len && isxdigit(s.s[pos + j]); ++j);
+               for (j = 0; j < 4 && pos + j < s.len && is_hexadecimal(s.s[pos + j]); ++j);
                if (j == 0)
                        return false;
                if (pos + j == s.len && (seen_colon || i == 7))
@@ -139,7 +175,7 @@ static bool is_valid_uint(string_span_t s, bool support_hex, uint64_t min, uint6
                }
        } else {
                for (size_t i = 0; i < s.len; ++i) {
-                       if (!isdigit(s.s[i]))
+                       if (!is_decimal(s.s[i]))
                                return false;
                        val = 10 * val + s.s[i] - '0';
                }
@@ -159,7 +195,7 @@ static bool is_valid_mtu(string_span_t s)
 
 static bool is_valid_persistentkeepalive(string_span_t s)
 {
-       if (s.len == 3 && !memcmp(s.s, "off", 3))
+       if (is_same(s, "off"))
                return true;
        return is_valid_uint(s, false, 0, 65535);
 }
@@ -168,16 +204,16 @@ static bool is_valid_persistentkeepalive(string_span_t s)
 
 static bool is_valid_fwmark(string_span_t s)
 {
-       if (s.len == 3 && !memcmp(s.s, "off", 3))
+       if (is_same(s, "off"))
                return true;
        return is_valid_uint(s, true, 0, 4294967295);
 }
 
 static bool is_valid_table(string_span_t s)
 {
-       if (s.len == 4 && !memcmp(s.s, "auto", 3))
+       if (is_same(s, "auto"))
                return true;
-       if (s.len == 3 && !memcmp(s.s, "off", 3))
+       if (is_same(s, "off"))
                return true;
        /* This pretty much invalidates the other checks, but rt_names.c's
         * fread_id_name does no validation aside from this. */
@@ -188,8 +224,7 @@ static bool is_valid_table(string_span_t s)
 
 static bool is_valid_saveconfig(string_span_t s)
 {
-       return (s.len == 4 && !memcmp(s.s, "true", 4)) ||
-              (s.len == 5 && !memcmp(s.s, "false", 5));
+       return is_same(s, "true") || is_same(s, "false");
 }
 
 static bool is_valid_prepostupdown(string_span_t s)
@@ -205,11 +240,9 @@ static bool is_valid_scope(string_span_t s)
        if (s.len > 64 || !s.len)
                return false;
        for (size_t i = 0; i < s.len; ++i) {
-               if (!((s.s[i] >= 'A' && s.s[i] <= 'Z') ||
-                     (s.s[i] >= 'a' && s.s[i] <= 'z') ||
-                     isdigit(s.s[i]) || s.s[i] == '_' ||
-                     s.s[i] == '=' || s.s[i] == '+' ||
-                     s.s[i] == '.' || s.s[i] == '-'))
+               if (!is_alphabet(s.s[i]) && !is_decimal(s.s[i]) &&
+                   s.s[i] != '_' && s.s[i] != '=' && s.s[i] != '+' &&
+                   s.s[i] != '.' && s.s[i] != '-')
                        return false;
        }
        return true;
@@ -269,7 +302,7 @@ static bool is_valid_network(string_span_t s)
                                return false;
 
                        for (size_t j = 0; j < cidr.len; ++j) {
-                               if (!isdigit(cidr.s[j]))
+                               if (!is_decimal(cidr.s[j]))
                                        return false;
                                cidrval = 10 * cidrval + cidr.s[j] - '0';
                        }
@@ -323,7 +356,7 @@ static enum field section_for_field(enum field t)
 
 static enum field get_field(string_span_t s)
 {
-#define check_enum(t) do { if (s.len == strlen(#t) && !strncasecmp(#t, s.s, s.len)) return t; } while (0)
+#define check_enum(t) do { if (is_caseless_same(s, #t)) return t; } while (0)
        check_enum(PrivateKey);
        check_enum(ListenPort);
        check_enum(Address);
@@ -349,9 +382,9 @@ static enum field get_field(string_span_t s)
 
 static enum field get_sectiontype(string_span_t s)
 {
-       if (s.len == 6 && !strncasecmp("[Peer]", s.s, 6))
+       if (is_caseless_same(s, "[Peer]"))
                return PeerSection;
-       if (s.len == 11 && !strncasecmp("[Interface]", s.s, 11))
+       if (is_caseless_same(s, "[Interface]"))
                return InterfaceSection;
        return Invalid;
 }