The Tor Browser: security/nss/lib/util/portreg.c@b8a032363ba2 (annotated)

security/nss/lib/util/portreg.c@b8a032363ba2 (annotated)

security/nss/lib/util/portreg.c

Thu, 22 Jan 2015 13:21:57 +0100

author: Michael Schloh von Bennewitz <michael@schloh.com>
date: Thu, 22 Jan 2015 13:21:57 +0100
branch: TOR_BUG_9701
changeset 15: b8a032363ba2
permissions: -rw-r--r--

Incorporate requested changes from Mozilla in review:
https://bugzilla.mozilla.org/show_bug.cgi?id=1123480#c6

 /* This Source Code Form is subject to the terms of the Mozilla Public
  * License, v. 2.0. If a copy of the MPL was not distributed with this
  * file, You can obtain one at http://mozilla.org/MPL/2.0/. */
 /*
  * shexp.c: shell-like wildcard match routines
  *
  * See shexp.h for public documentation.
  */
 #include "seccomon.h"
 #include "portreg.h"
 /* ----------------------------- shexp_valid ------------------------------ */
 static int
 _valid_subexp(const char *exp, char stop1, char stop2)
 {
     register int x;
     int nsc = 0;     /* Number of special characters */
     int np;          /* Number of pipe characters in union */
     int tld = 0;     /* Number of tilde characters */
     for (x = 0; exp[x] && (exp[x] != stop1) && (exp[x] != stop2); ++x) {
         switch(exp[x]) {
 	case '~':
             if(tld)                 /* at most one exclusion */
                 return INVALID_SXP;
             if (stop1)              /* no exclusions within unions */
                 return INVALID_SXP;
             if (!exp[x+1])          /* exclusion cannot be last character */
                 return INVALID_SXP;
             if (!x)                 /* exclusion cannot be first character */
                 return INVALID_SXP;
             ++tld;
 	    /* fall through */
 	case '*':
 	case '?':
 	case '$':
             ++nsc;
             break;
 	case '[':
             ++nsc;
             if((!exp[++x]) || (exp[x] == ']'))
                 return INVALID_SXP;
             for(; exp[x] && (exp[x] != ']'); ++x) {
                 if(exp[x] == '\\' && !exp[++x])
                     return INVALID_SXP;
             }
             if(!exp[x])
                 return INVALID_SXP;
             break;
 	case '(':
             ++nsc;
 	    if (stop1)			/* no nested unions */
 		return INVALID_SXP;
             np = -1;
             do {
                 int t = _valid_subexp(&exp[++x], ')', '|');
                 if(t == 0 || t == INVALID_SXP)
                     return INVALID_SXP;
                 x+=t;
 		if(!exp[x])
 		    return INVALID_SXP;
 		++np;
             } while (exp[x] == '|' );
 	    if(np < 1)  /* must be at least one pipe */
 		return INVALID_SXP;
             break;
 	case ')':
 	case '|':
 	case ']':
             return INVALID_SXP;
 	case '\\':
 	    ++nsc;
             if(!exp[++x])
                 return INVALID_SXP;
             break;
 	default:
             break;
         }
     }
     if((!stop1) && (!nsc)) /* must be at least one special character */
         return NON_SXP;
     return ((exp[x] == stop1 || exp[x] == stop2) ? x : INVALID_SXP);
 }
 int
 PORT_RegExpValid(const char *exp)
 {
     int x;
     x = _valid_subexp(exp, '\0', '\0');
     return (x < 0 ? x : VALID_SXP);
 }
 /* ----------------------------- shexp_match ----------------------------- */
 #define MATCH 0
 #define NOMATCH 1
 #define ABORTED -1
 static int
 _shexp_match(const char *str, const char *exp, PRBool case_insensitive,
              unsigned int level);
 /* Count characters until we reach a NUL character or either of the
  * two delimiter characters, stop1 or stop2.  If we encounter a bracketed
  * expression, look only for NUL or ']' inside it.  Do not look for stop1
  * or stop2 inside it. Return ABORTED if bracketed expression is unterminated.
  * Handle all escaping.
  * Return index in input string of first stop found, or ABORTED if not found.
  * If "dest" is non-NULL, copy counted characters to it and NUL terminate.
  */
 static int
 _scan_and_copy(const char *exp, char stop1, char stop2, char *dest)
 {
     register int sx;     /* source index */
     register char cc;
     for (sx = 0; (cc = exp[sx]) && cc != stop1 && cc != stop2; sx++) {
 	if (cc == '\\') {
 	    if (!exp[++sx])
 		return ABORTED; /* should be impossible */
 	} else if (cc == '[') {
 	    while ((cc = exp[++sx]) && cc != ']') {
 		if(cc == '\\' && !exp[++sx])
 		    return ABORTED;
 	    }
 	    if (!cc)
 		return ABORTED; /* should be impossible */
 	}
     }
     if (dest && sx) {
 	/* Copy all but the closing delimiter. */
 	memcpy(dest, exp, sx);
 	dest[sx] = 0;
     }
     return cc ? sx : ABORTED; /* index of closing delimiter */
 }
 /* On input, exp[0] is the opening parenthesis of a union.
  * See if any of the alternatives in the union matches as a pattern.
  * The strategy is to take each of the alternatives, in turn, and append
  * the rest of the expression (after the closing ')' that marks the end of
  * this union) to that alternative, and then see if the resultant expression
  * matches the input string.  Repeat this until some alternative matches,
  * or we have an abort.
  */
 static int
 _handle_union(const char *str, const char *exp, PRBool case_insensitive,
               unsigned int level)
 {
     register int sx;     /* source index */
     int cp;              /* source index of closing parenthesis */
     int count;
     int ret   = NOMATCH;
     char *e2;
     /* Find the closing parenthesis that ends this union in the expression */
     cp = _scan_and_copy(exp, ')', '\0', NULL);
     if (cp == ABORTED || cp < 4) /* must be at least "(a|b" before ')' */
     	return ABORTED;
     ++cp;                /* now index of char after closing parenthesis */
     e2 = (char *) PORT_Alloc(1 + strlen(exp));
     if (!e2)
     	return ABORTED;
     for (sx = 1; ; ++sx) {
 	/* Here, exp[sx] is one character past the preceding '(' or '|'. */
 	/* Copy everything up to the next delimiter to e2 */
 	count = _scan_and_copy(exp + sx, ')', '|', e2);
 	if (count == ABORTED || !count) {
 	    ret = ABORTED;
 	    break;
 	}
 	sx += count;
 	/* Append everything after closing parenthesis to e2. This is safe. */
 	strcpy(e2+count, exp+cp);
         ret = _shexp_match(str, e2, case_insensitive, level + 1);
 	if (ret != NOMATCH || !exp[sx] || exp[sx] == ')')
             break;
     }
     PORT_Free(e2);
     if (sx < 2)
     	ret = ABORTED;
     return ret;
 }
 /* returns 1 if val is in range from start..end, case insensitive. */
 static int
 _is_char_in_range(int start, int end, int val)
 {
     char map[256];
     memset(map, 0, sizeof map);
     while (start <= end)
 	map[tolower(start++)] = 1;
     return map[tolower(val)];
 }
 static int
 _shexp_match(const char *str, const char *exp, PRBool case_insensitive,
              unsigned int level)
 {
     register int x;   /* input string index */
     register int y;   /* expression index */
     int ret,neg;
     if (level > 20)      /* Don't let the stack get too deep. */
     	return ABORTED;
     for(x = 0, y = 0; exp[y]; ++y, ++x) {
         if((!str[x]) && (exp[y] != '$') && (exp[y] != '*')) {
             return NOMATCH;
 	}
 	switch(exp[y]) {
 	case '$':
 	    if(str[x])
 		return NOMATCH;
 	    --x;                 /* we don't want loop to increment x */
 	    break;
 	case '*':
 	    while(exp[++y] == '*'){}
 	    if(!exp[y])
 		return MATCH;
 	    while(str[x]) {
 	        ret = _shexp_match(&str[x++], &exp[y], case_insensitive,
 				   level + 1);
 		switch(ret) {
 		case NOMATCH:
 		    continue;
 		case ABORTED:
 		    return ABORTED;
 		default:
 		    return MATCH;
 		}
 	    }
 	    if((exp[y] == '$') && (exp[y+1] == '\0') && (!str[x]))
 		return MATCH;
 	    else
 		return NOMATCH;
 	case '[': {
 	    int start, end = 0, i;
 	    neg = ((exp[++y] == '^') && (exp[y+1] != ']'));
 	    if (neg)
 		++y;
 	    i = y;
 	    start = (unsigned char)(exp[i++]);
 	    if (start == '\\')
 	    	start = (unsigned char)(exp[i++]);
 	    if (isalnum(start) && exp[i++] == '-') {
 		end = (unsigned char)(exp[i++]);
 		if (end == '\\')
 		    end = (unsigned char)(exp[i++]);
 	    }
 	    if (isalnum(end) && exp[i] == ']') {
 		/* This is a range form: a-b */
 		int val   = (unsigned char)(str[x]);
 		if (end < start) { /* swap them */
 		    start ^= end;
 		    end ^= start;
 		    start ^= end;
 		}
 		if (case_insensitive && isalpha(val)) {
 		    val = _is_char_in_range(start, end, val);
 		    if (neg == val)
 			return NOMATCH;
 		} else if (neg != ((val < start) || (val > end))) {
 		    return NOMATCH;
 		}
 		y = i;
 	    } else {
 		/* Not range form */
 		int matched = 0;
 		for (; exp[y] != ']'; y++) {
 		    if (exp[y] == '\\')
 			++y;
 		    if(case_insensitive) {
 			matched |= (toupper(str[x]) == toupper(exp[y]));
 		    } else {
 			matched |= (str[x] == exp[y]);
 		    }
 		}
 		if (neg == matched)
 		    return NOMATCH;
 	    }
 	}
 	break;
 	case '(':
 	    if (!exp[y+1])
 	    	return ABORTED;
 	    return _handle_union(&str[x], &exp[y], case_insensitive, level);
 	case '?':
 	    break;
 	case '|':
 	case ']':
 	case ')':
 	    return ABORTED;
 	case '\\':
 	    ++y;
 	    /* fall through */
 	default:
 	    if(case_insensitive) {
 		if(toupper(str[x]) != toupper(exp[y]))
 		    return NOMATCH;
 	    } else {
 		if(str[x] != exp[y])
 		    return NOMATCH;
 	    }
 	    break;
 	}
     }
     return (str[x] ? NOMATCH : MATCH);
 }
 static int
 port_RegExpMatch(const char *str, const char *xp, PRBool case_insensitive)
 {
     char *exp = 0;
     int x, ret = MATCH;
     if (!strchr(xp, '~'))
     	return _shexp_match(str, xp, case_insensitive, 0);
     exp = PORT_Strdup(xp);
     if(!exp)
 	return NOMATCH;
     x = _scan_and_copy(exp, '~', '\0', NULL);
     if (x != ABORTED && exp[x] == '~') {
 	exp[x++] = '\0';
 	ret = _shexp_match(str, &exp[x], case_insensitive, 0);
 	switch (ret) {
 	case NOMATCH: ret = MATCH;   break;
 	case MATCH:   ret = NOMATCH; break;
 	default:                     break;
         }
     }
     if (ret == MATCH)
 	ret = _shexp_match(str, exp, case_insensitive, 0);
     PORT_Free(exp);
     return ret;
 }
 /* ------------------------------ shexp_cmp ------------------------------- */
 int
 PORT_RegExpSearch(const char *str, const char *exp)
 {
     switch(PORT_RegExpValid(exp))
 	  {
         case INVALID_SXP:
             return -1;
         case NON_SXP:
             return (strcmp(exp,str) ? 1 : 0);
         default:
             return port_RegExpMatch(str, exp, PR_FALSE);
       }
 }
 int
 PORT_RegExpCaseSearch(const char *str, const char *exp)
 {
     switch(PORT_RegExpValid(exp))
       {
         case INVALID_SXP:
             return -1;
         case NON_SXP:
             return (PORT_Strcasecmp(exp,str) ? 1 : 0);
         default:
             return port_RegExpMatch(str, exp, PR_TRUE);
       }
 }

The Tor Browser / annotate

security/nss/lib/util/portreg.c@b8a032363ba2 (annotated)

security/nss/lib/util/portreg.c