*************************************************/
/* Copyright (c) University of Cambridge 1995 - 2018 */
+/* Copyright (c) The Exim Maintainers 2020 */
/* See the file NOTICE for conditions of use and distribution. */
/* Miscellaneous string-handling functions. Some are not required for
uschar *
string_format_size(int size, uschar *buffer)
{
-if (size == 0) Ustrcpy(buffer, " ");
+if (size == 0) Ustrcpy(buffer, US" ");
else if (size < 1024) sprintf(CS buffer, "%5d", size);
else if (size < 10*1024)
sprintf(CS buffer, "%4.1fK", (double)size / 1024.0);
Arguments:
pp points a pointer to the initiating "\" in the string;
the pointer gets updated to point to the final character
+ If the backslash is the last character in the string, it
+ is not interpreted.
Returns: the value of the character escape
*/
int ch;
const uschar *p = *pp;
ch = *(++p);
+if (ch == '\0') return **pp;
if (isdigit(ch) && ch != '8' && ch != '9')
{
ch -= '0';
/* Get a new block of store guaranteed big enough to hold the
expanded string. */
-ss = store_get(length + nonprintcount * 3 + 1);
+ss = store_get(length + nonprintcount * 3 + 1, is_tainted(s));
/* Copy everything, escaping non printers. */
if (!p) return s;
len = Ustrlen(s) + 1;
-ss = store_get(len);
+ss = store_get(len, is_tainted(s));
q = ss;
off = p - s;
-#ifdef HAVE_LOCAL_SCAN
+#if (defined(HAVE_LOCAL_SCAN) || defined(EXPAND_DLFUNC)) \
+ && !defined(MACRO_PREDEF) && !defined(COMPILE_UTILITY)
/*************************************************
* Copy and save string *
*************************************************/
-/* This function assumes that memcpy() is faster than strcpy().
-
+/*
Argument: string to copy
-Returns: copy of string in new store
+Returns: copy of string in new store with the same taint status
*/
uschar *
string_copy_function(const uschar *s)
{
+return string_copy_taint(s, is_tainted(s));
+}
+
+/* This function assumes that memcpy() is faster than strcpy().
+As above, but explicitly specifying the result taint status
+*/
+
+uschar *
+string_copy_taint_function(const uschar * s, BOOL tainted)
+{
int len = Ustrlen(s) + 1;
-uschar *ss = store_get(len);
+uschar *ss = store_get(len, tainted);
memcpy(ss, s, len);
return ss;
}
+
/*************************************************
* Copy and save string, given length *
*************************************************/
uschar *
string_copyn_function(const uschar *s, int n)
{
-uschar *ss = store_get(n + 1);
+uschar *ss = store_get(n + 1, is_tainted(s));
Ustrncpy(ss, s, n);
ss[n] = 0;
return ss;
string_copy_dnsdomain(uschar *s)
{
uschar *yield;
-uschar *ss = yield = store_get(Ustrlen(s) + 1);
+uschar *ss = yield = store_get(Ustrlen(s) + 1, is_tainted(s));
while (*s != 0)
{
if (*s != '\\')
- {
*ss++ = *s++;
- }
else if (isdigit(s[1]))
{
*ss++ = (s[1] - '0')*100 + (s[2] - '0')*10 + s[3] - '0';
s += 4;
}
else if (*(++s) != 0)
- {
*ss++ = *s++;
- }
}
*ss = 0;
/* Get enough store to copy into */
-t = yield = store_get(s - *sptr + 1);
+t = yield = store_get(s - *sptr + 1, is_tainted(*sptr));
s = *sptr;
/* Do the copy */
if (*s != '\"')
- {
while (*s != 0 && !isspace(*s)) *t++ = *s++;
- }
else
{
s++;
while (*s != 0 && *s != '\"')
{
- if (*s == '\\') *t++ = string_interpret_escape(&s);
- else *t++ = *s;
+ *t++ = *s == '\\' ? string_interpret_escape(&s) : *s;
s++;
}
- if (*s != 0) s++;
+ if (*s) s++;
}
/* Update the pointer and return the terminated copy */
*************************************************/
/* The formatting is done by string_vformat, which checks the length of
-everything.
+everything. Taint is taken from the worst of the arguments.
Arguments:
format a printf() format - deliberately char * rather than uschar *
*/
uschar *
-string_sprintf(const char *format, ...)
+string_sprintf_trc(const char *format, const uschar * func, unsigned line, ...)
{
#ifdef COMPILE_UTILITY
uschar buffer[STRING_SPRINTF_BUFFER_SIZE];
-gstring g = { .size = STRING_SPRINTF_BUFFER_SIZE, .ptr = 0, .s = buffer };
-gstring * gp = &g;
+gstring gs = { .size = STRING_SPRINTF_BUFFER_SIZE, .ptr = 0, .s = buffer };
+gstring * g = &gs;
+unsigned flags = 0;
#else
-gstring * gp = string_get(STRING_SPRINTF_BUFFER_SIZE);
+gstring * g = NULL;
+unsigned flags = SVFMT_REBUFFER|SVFMT_EXTEND;
#endif
-gstring * gp2;
-va_list ap;
-va_start(ap, format);
-gp2 = string_vformat(gp, FALSE, format, ap);
-gp->s[gp->ptr] = '\0';
+va_list ap;
+va_start(ap, line);
+g = string_vformat_trc(g, func, line, STRING_SPRINTF_BUFFER_SIZE,
+ flags, format, ap);
va_end(ap);
-if (!gp2)
+if (!g)
log_write(0, LOG_MAIN|LOG_PANIC_DIE,
"string_sprintf expansion was longer than %d; format string was (%s)\n"
- "expansion started '%.32s'",
- gp->size, format, gp->s);
+ " called from %s %d\n",
+ STRING_SPRINTF_BUFFER_SIZE, format, func, line);
#ifdef COMPILE_UTILITY
-return string_copy(gp->s);
+return string_copyn(g->s, g->ptr);
#else
-gstring_release_unused(gp);
-return gp->s;
+gstring_release_unused(g);
+return string_from_gstring(g);
#endif
}
#ifdef COMPILE_UTILITY
/* Dummy version for this function; it should never be called */
static void
-gstring_grow(gstring * g, int p, int count)
+gstring_grow(gstring * g, int count)
{
assert(FALSE);
}
*/
uschar *
-string_nextinlist(const uschar **listptr, int *separator, uschar *buffer, int buflen)
+string_nextinlist_trc(const uschar **listptr, int *separator, uschar *buffer, int buflen,
+ const uschar * func, int line)
{
int sep = *separator;
const uschar *s = *listptr;
if (buffer)
{
int p = 0;
+ if (is_tainted(s) && !is_tainted(buffer))
+ die_tainted(US"string_nextinlist", func, line);
for (; *s; s++)
{
if (*s == sep && (*(++s) != sep || sep_is_special)) break;
/************************************************/
-/* Add more space to a growable-string.
+/* Add more space to a growable-string. The caller should check
+first if growth is required. The gstring struct is modified on
+return; specifically, the string-base-pointer may have been changed.
Arguments:
g the growable-string
- p current end of data
- count amount to grow by
+ count amount needed for g->ptr to increase by
*/
static void
-gstring_grow(gstring * g, int p, int count)
+gstring_grow(gstring * g, int count)
{
+int p = g->ptr;
int oldsize = g->size;
+BOOL tainted = is_tainted(g->s);
/* Mostly, string_cat() is used to build small strings of a few hundred
characters at most. There are times, however, when the strings are very much
existing length of the string. */
unsigned inc = oldsize < 4096 ? 127 : 1023;
-g->size = ((p + count + inc) & ~inc) + 1;
+
+if (count <= 0) return;
+g->size = (p + count + inc + 1) & ~inc; /* one for a NUL */
/* Try to extend an existing allocation. If the result of calling
store_extend() is false, either there isn't room in the current memory block,
was the last item on the dynamic memory stack. This is the case if it matches
store_last_get. */
-if (!store_extend(g->s, oldsize, g->size))
- g->s = store_newblock(g->s, g->size, p);
+if (!store_extend(g->s, tainted, oldsize, g->size))
+ g->s = store_newblock(g->s, tainted, g->size, p);
}
string_catn(gstring * g, const uschar *s, int count)
{
int p;
+BOOL srctaint = is_tainted(s);
if (!g)
{
unsigned inc = count < 4096 ? 127 : 1023;
unsigned size = ((count + inc) & ~inc) + 1;
- g = string_get(size);
+ g = string_get_tainted(size, srctaint);
}
+else if (srctaint && !is_tainted(g->s))
+ gstring_rebuffer(g);
p = g->ptr;
if (p + count >= g->size)
- gstring_grow(g, p, count);
+ gstring_grow(g, count);
/* Because we always specify the exact number of characters to copy, we can
use memcpy(), which is likely to be more efficient than strncopy() because the
g->ptr = p + count;
return g;
}
-
-
+
+
gstring *
string_cat(gstring *string, const uschar *s)
{
*/
BOOL
-string_format(uschar * buffer, int buflen, const char * format, ...)
+string_format_trc(uschar * buffer, int buflen,
+ const uschar * func, unsigned line, const char * format, ...)
{
gstring g = { .size = buflen, .ptr = 0, .s = buffer }, *gp;
va_list ap;
va_start(ap, format);
-gp = string_vformat(&g, FALSE, format, ap);
+gp = string_vformat_trc(&g, func, line, STRING_SPRINTF_BUFFER_SIZE,
+ 0, format, ap);
va_end(ap);
g.s[g.ptr] = '\0';
return !!gp;
+/* Build or append to a growing-string, sprintf-style.
-/* Bulid or append to a growing-string, sprintf-style.
-
-If the "extend" argument is true, the string passed in can be NULL,
-empty, or non-empty.
-
-If the "extend" argument is false, the string passed in may not be NULL,
+Arguments:
+ g a growable-string
+ func called-from function name, for debug
+ line called-from file line number, for debug
+ limit maximum string size
+ flags see below
+ format printf-like format string
+ ap variable-args pointer
+
+Flags:
+ SVFMT_EXTEND buffer can be created or exteded as needed
+ SVFMT_REBUFFER buffer can be recopied to tainted mem as needed
+ SVFMT_TAINT_NOCHK do not check inputs for taint
+
+If the "extend" flag is true, the string passed in can be NULL,
+empty, or non-empty. Growing is subject to an overall limit given
+by the limit argument.
+
+If the "extend" flag is false, the string passed in may not be NULL,
will not be grown, and is usable in the original place after return.
The return value can be NULL to signify overflow.
-Returns the possibly-new (if copy for growth was needed) string,
-not nul-terminated.
+Returns the possibly-new (if copy for growth or taint-handling was needed)
+string, not nul-terminated.
*/
gstring *
-string_vformat(gstring * g, BOOL extend, const char *format, va_list ap)
+string_vformat_trc(gstring * g, const uschar * func, unsigned line,
+ unsigned size_limit, unsigned flags, const char *format, va_list ap)
{
enum ltypes { L_NORMAL=1, L_SHORT=2, L_LONG=3, L_LONGLONG=4, L_LONGDOUBLE=5, L_SIZE=6 };
-int width, precision, off, lim;
+int width, precision, off, lim, need;
const char * fp = format; /* Deliberately not unsigned */
+BOOL dest_tainted = FALSE;
string_datestamp_offset = -1; /* Datestamp not inserted */
string_datestamp_length = 0; /* Datestamp not inserted */
string_datestamp_type = 0; /* Datestamp not inserted */
#ifdef COMPILE_UTILITY
-assert(!extend);
+assert(!(flags & SVFMT_EXTEND));
assert(g);
#else
/* Ensure we have a string, to save on checking later */
if (!g) g = string_get(16);
+else if (!(flags & SVFMT_TAINT_NOCHK)) dest_tainted = is_tainted(g->s);
+
+if (!(flags & SVFMT_TAINT_NOCHK) && !dest_tainted && is_tainted(format))
+ {
+#ifndef MACRO_PREDEF
+ if (!(flags & SVFMT_REBUFFER))
+ die_tainted(US"string_vformat", func, line);
+#endif
+ gstring_rebuffer(g);
+ dest_tainted = TRUE;
+ }
#endif /*!COMPILE_UTILITY*/
lim = g->size - 1; /* leave one for a nul */
if (*fp != '%')
{
/* Avoid string_copyn() due to COMPILE_UTILITY */
- if (g->ptr >= lim - 1)
+ if ((need = g->ptr + 1) > lim)
{
- if (!extend) return NULL;
- gstring_grow(g, g->ptr, 1);
+ if (!(flags & SVFMT_EXTEND) || need > size_limit) return NULL;
+ gstring_grow(g, 1);
lim = g->size - 1;
}
g->s[g->ptr++] = (uschar) *fp++;
case 'x':
case 'X':
width = length > L_LONG ? 24 : 12;
- if (g->ptr >= lim - width)
+ if ((need = g->ptr + width) > lim)
{
- if (!extend) return NULL;
- gstring_grow(g, g->ptr, width);
+ if (!(flags & SVFMT_EXTEND) || need >= size_limit) return NULL;
+ gstring_grow(g, width);
lim = g->size - 1;
gp = CS g->s + g->ptr;
}
case 'p':
{
void * ptr;
- if (g->ptr >= lim - 24)
+ if ((need = g->ptr + 24) > lim)
{
- if (!extend) return NULL;
- gstring_grow(g, g->ptr, 24);
+ if (!(flags & SVFMT_EXTEND || need >= size_limit)) return NULL;
+ gstring_grow(g, 24);
lim = g->size - 1;
gp = CS g->s + g->ptr;
}
case 'g':
case 'G':
if (precision < 0) precision = 6;
- if (g->ptr >= lim - precision - 8)
+ if ((need = g->ptr + precision + 8) > lim)
{
- if (!extend) return NULL;
- gstring_grow(g, g->ptr, precision+8);
+ if (!(flags & SVFMT_EXTEND || need >= size_limit)) return NULL;
+ gstring_grow(g, precision+8);
lim = g->size - 1;
gp = CS g->s + g->ptr;
}
/* String types */
case '%':
- if (g->ptr >= lim - 1)
+ if ((need = g->ptr + 1) > lim)
{
- if (!extend) return NULL;
- gstring_grow(g, g->ptr, 1);
+ if (!(flags & SVFMT_EXTEND || need >= size_limit)) return NULL;
+ gstring_grow(g, 1);
lim = g->size - 1;
}
g->s[g->ptr++] = (uschar) '%';
break;
case 'c':
- if (g->ptr >= lim - 1)
+ if ((need = g->ptr + 1) > lim)
{
- if (!extend) return NULL;
- gstring_grow(g, g->ptr, 1);
+ if (!(flags & SVFMT_EXTEND || need >= size_limit)) return NULL;
+ gstring_grow(g, 1);
lim = g->size - 1;
}
g->s[g->ptr++] = (uschar) va_arg(ap, int);
if (!s) s = null;
slen = Ustrlen(s);
+ if (!(flags & SVFMT_TAINT_NOCHK) && !dest_tainted && is_tainted(s))
+ if (flags & SVFMT_REBUFFER)
+ {
+ gstring_rebuffer(g);
+ gp = CS g->s + g->ptr;
+ dest_tainted = TRUE;
+ }
+#ifndef MACRO_PREDEF
+ else
+ die_tainted(US"string_vformat", func, line);
+#endif
+
INSERT_STRING: /* Come to from %D or %M above */
{
else
width = precision = slen;
- if (!extend)
+ if ((need = g->ptr + width) >= size_limit || !(flags & SVFMT_EXTEND))
{
if (g->ptr == lim) return NULL;
- if (g->ptr >= lim - width)
+ if (need > lim)
{
truncated = TRUE;
width = precision = lim - g->ptr - 1;
if (precision < 0) precision = 0;
}
}
- else if (g->ptr >= lim - width)
+ else if (need > lim)
{
- gstring_grow(g, g->ptr, width - (lim - g->ptr));
+ gstring_grow(g, width);
lim = g->size - 1;
gp = CS g->s + g->ptr;
}
}
}
+if (g->ptr > g->size)
+ log_write(0, LOG_MAIN|LOG_PANIC_DIE,
+ "string_format internal error: caller %s %d", func, line);
return g;
}
#ifndef COMPILE_UTILITY
-
-gstring *
-string_fmt_append(gstring * g, const char *format, ...)
-{
-va_list ap;
-va_start(ap, format);
-g = string_vformat(g, TRUE, format, ap);
-va_end(ap);
-return g;
-}
-
-
-
/*************************************************
* Generate an "open failed" message *
*************************************************/
*/
uschar *
-string_open_failed(int eno, const char *format, ...)
+string_open_failed_trc(int eno, const uschar * func, unsigned line,
+ const char *format, ...)
{
va_list ap;
gstring * g = string_get(1024);
doesn't seem much we can do about that. */
va_start(ap, format);
-(void) string_vformat(g, FALSE, format, ap);
+(void) string_vformat_trc(g, func, line, STRING_SPRINTF_BUFFER_SIZE,
+ SVFMT_REBUFFER, format, ap);
string_from_gstring(g);
gstring_release_unused(g);
va_end(ap);
projects / exim.git / blobdiff