Introduce a locale-independent version of isspace

The real isspace may give locale-dependent results, so use our own.

This also lets us simplify some of the silliness asn1_string_canon needs
to go through to never pass high bytes into isspace and islower. (I'm
otherwise leaving that function alone because I plan to, later, convert
the whole thing to CBS/CBB.)

Change-Id: Idd349095f3e98bf908bb628ea1089ba05c2c6797
Reviewed-on: https://boringssl-review.googlesource.com/c/boringssl/+/56486
Reviewed-by: Bob Beck <bbe@google.com>
Commit-Queue: David Benjamin <davidben@google.com>

crypto/conf/conf.c

@@ -780,7 +780,7 @@ int CONF_parse_list(const char *list, char sep, int remove_whitespace,
   lstart = list;
   for (;;) {
     if (remove_whitespace) {
-      while (*lstart && isspace((unsigned char)*lstart)) {
+      while (*lstart && OPENSSL_isspace((unsigned char)*lstart)) {
         lstart++;
       }
     }
@@ -794,7 +794,7 @@ int CONF_parse_list(const char *list, char sep, int remove_whitespace,
         tmpend = lstart + strlen(lstart) - 1;
       }
       if (remove_whitespace) {
-        while (isspace((unsigned char)*tmpend)) {
+        while (OPENSSL_isspace((unsigned char)*tmpend)) {
           tmpend--;
         }
       }

crypto/mem.c

@@ -315,6 +315,11 @@ int OPENSSL_tolower(int c) {
   return c;
 }
 
+int OPENSSL_isspace(int c) {
+  return c == '\t' || c == '\n' || c == '\v' || c == '\f' || c == '\r' ||
+         c == ' ';
+}
+
 int OPENSSL_strcasecmp(const char *a, const char *b) {
   for (size_t i = 0;; i++) {
     const int aa = OPENSSL_tolower(a[i]);

crypto/test/file_test.cc

@@ -27,6 +27,7 @@
 #include <string.h>
 
 #include <openssl/err.h>
+#include <openssl/mem.h>
 
 #include "../internal.h"
 #include "./test_util.h"
@@ -57,11 +58,11 @@ static const char *FindDelimiter(const char *str) {
 // leading and trailing whitespace removed.
 static std::string StripSpace(const char *str, size_t len) {
   // Remove leading space.
-  while (len > 0 && isspace(*str)) {
+  while (len > 0 && OPENSSL_isspace(*str)) {
     str++;
     len--;
   }
-  while (len > 0 && isspace(str[len - 1])) {
+  while (len > 0 && OPENSSL_isspace(str[len - 1])) {
     len--;
   }
   return std::string(str, len);

crypto/x509/x_name.c

@@ -443,12 +443,10 @@ static int asn1_string_canon(ASN1_STRING *out, ASN1_STRING *in) {
 
   len = out->length;
 
-  // Convert string in place to canonical form. Ultimately we may need to
-  // handle a wider range of characters but for now ignore anything with
-  // MSB set and rely on the isspace() and tolower() functions.
+  // Convert string in place to canonical form.
 
   // Ignore leading spaces
-  while ((len > 0) && !(*from & 0x80) && isspace(*from)) {
+  while ((len > 0) && OPENSSL_isspace(*from)) {
     from++;
     len--;
   }
@@ -456,7 +454,7 @@ static int asn1_string_canon(ASN1_STRING *out, ASN1_STRING *in) {
   to = from + len;
 
   // Ignore trailing spaces
-  while ((len > 0) && !(to[-1] & 0x80) && isspace(to[-1])) {
+  while ((len > 0) && OPENSSL_isspace(to[-1])) {
     to--;
     len--;
   }
@@ -465,13 +463,8 @@ static int asn1_string_canon(ASN1_STRING *out, ASN1_STRING *in) {
 
   i = 0;
   while (i < len) {
-    // If MSB set just copy across
-    if (*from & 0x80) {
-      *to++ = *from++;
-      i++;
-    }
     // Collapse multiple spaces
-    else if (isspace(*from)) {
+    if (OPENSSL_isspace(*from)) {
       // Copy one space across
       *to++ = ' ';
       // Ignore subsequent spaces. Note: don't need to check len here
@@ -480,7 +473,7 @@ static int asn1_string_canon(ASN1_STRING *out, ASN1_STRING *in) {
       do {
         from++;
         i++;
-      } while (!(*from & 0x80) && isspace(*from));
+      } while (OPENSSL_isspace(*from));
     } else {
       *to++ = OPENSSL_tolower(*from);
       from++;

crypto/x509v3/v3_conf.c

@@ -258,7 +258,7 @@ static int v3_check_critical(const char **value) {
     return 0;
   }
   p += 9;
-  while (isspace((unsigned char)*p)) {
+  while (OPENSSL_isspace((unsigned char)*p)) {
     p++;
   }
   *value = p;
@@ -279,7 +279,7 @@ static int v3_check_generic(const char **value) {
     return 0;
   }
 
-  while (isspace((unsigned char)*p)) {
+  while (OPENSSL_isspace((unsigned char)*p)) {
     p++;
   }
   *value = p;

crypto/x509v3/v3_utl.c

@@ -432,14 +432,14 @@ static char *strip_spaces(char *name) {
   char *p, *q;
   // Skip over leading spaces
   p = name;
-  while (*p && isspace((unsigned char)*p)) {
+  while (*p && OPENSSL_isspace((unsigned char)*p)) {
     p++;
   }
   if (!*p) {
     return NULL;
   }
   q = p + strlen(p) - 1;
-  while ((q != p) && isspace((unsigned char)*q)) {
+  while ((q != p) && OPENSSL_isspace((unsigned char)*q)) {
     q--;
   }
   if (p != q) {

include/openssl/mem.h

@@ -110,9 +110,14 @@ OPENSSL_EXPORT char *OPENSSL_strdup(const char *s);
 // OPENSSL_strnlen has the same behaviour as strnlen(3).
 OPENSSL_EXPORT size_t OPENSSL_strnlen(const char *s, size_t len);
 
-// OPENSSL_tolower is a locale-independent version of tolower(3).
+// OPENSSL_tolower is a locale-independent version of tolower(3). It only
+// lowercases ASCII values. Other values are returned as-is.
 OPENSSL_EXPORT int OPENSSL_tolower(int c);
 
+// OPENSSL_isspace is a locale-independent version of isspace(3). It only
+// recognizes '\t', '\n', '\v', '\f', '\r', and ' '.
+OPENSSL_EXPORT int OPENSSL_isspace(int c);
+
 // OPENSSL_strcasecmp is a locale-independent version of strcasecmp(3).
 OPENSSL_EXPORT int OPENSSL_strcasecmp(const char *a, const char *b);