Commit b8532bcb authored by George Kadianakis's avatar George Kadianakis
Browse files

Add utility functions needed for SOCKS argument parsing.

parent d86a45f9

src/common/util.c

+67 −0
Changes for src/common/util.c: 67 added lines, 0 removed lines.
Original line number Diff line number Diff line
@@ -865,6 +865,36 @@ tor_digest_is_zero(const char *digest) 
  return tor_memeq(digest, ZERO_DIGEST, DIGEST_LEN);

}



/** Return true if <b>string</b> is a valid '<key>=<value>' string.

 *  <value> is optional, to indicate the empty string. */

int

string_is_key_value(const char *string)

{

  /* position of equal sign in string */

  char *equal_sign_pos = NULL;



  tor_assert(string);



  if (strlen(string) < 2) { /* "x=a" is shortest args string */

    log_warn(LD_GENERAL, "'%s' is too short to be a k=v value.", string);

    return 0;

  }



  equal_sign_pos = strchr(string, '=');

  if (!equal_sign_pos) {

    log_warn(LD_GENERAL, "'%s' is not a k=v value.", string);

    return 0;

  }



  /* validate that the '=' is not in the beginning of the string. */

  if (equal_sign_pos == string) {

    log_warn(LD_GENERAL, "'%s' is not a valid k=v value.", string);

    return 0;

  }



  return 1;

}



/** Return true iff the DIGEST256_LEN bytes in digest are all zero. */

int

tor_digest256_is_zero(const char *digest)
@@ -1249,6 +1279,43 @@ wrap_string(smartlist_t *out, const char *string, size_t width, 
  }

}



/** Escape every character of <b>string</b> that belongs to the set of

 *  characters <b>set</b>. Use <b>escape_char</b> as the character to

 *  use for escaping. */

char *

tor_escape_str_for_socks_arg(const char *string)

{

  char *new_string = NULL;

  char *new_cp = NULL;

  size_t length, new_length;

  static const char *chars_to_escape = ";\\";



  tor_assert(string);



  length = strlen(string);



  if (!length)

    return NULL;

  /* (new_length > SIZE_MAX) => ((length * 2) + 1 > SIZE_MAX) =>

     (length*2 > SIZE_MAX - 1) => (length > (SIZE_MAX - 1)/2) */

  if (length > (SIZE_MAX - 1)/2) /* check for overflow */

    return NULL;



  /* this should be enough even if all characters must be escaped */

  new_length = (length * 2) + 1;



  new_string = new_cp = tor_malloc_zero(new_length);



  while (*string) {

    if (strchr(chars_to_escape, *string))

      *new_cp++ = '\\';



    *new_cp++ = *string++;

  }



  return new_string;

}



/* =====

 * Time

 * ===== */

src/common/util.h

+4 −0
Changes for src/common/util.h: 4 added lines, 0 removed lines.
Original line number Diff line number Diff line
@@ -209,12 +209,16 @@ const char *find_whitespace_eos(const char *s, const char *eos); 
const char *find_str_at_start_of_line(const char *haystack,

                                      const char *needle);

int string_is_C_identifier(const char *string);

int string_is_key_value(const char *string);



int tor_mem_is_zero(const char *mem, size_t len);

int tor_digest_is_zero(const char *digest);

int tor_digest256_is_zero(const char *digest);

char *esc_for_log(const char *string) ATTR_MALLOC;

const char *escaped(const char *string);



char *tor_escape_str_for_socks_arg(const char *string);



struct smartlist_t;

void wrap_string(struct smartlist_t *out, const char *string, size_t width,

                 const char *prefix0, const char *prefixRest);

src/test/test_util.c

+50 −0
Changes for src/test/test_util.c: 50 added lines, 0 removed lines.
Original line number Diff line number Diff line
@@ -795,6 +795,54 @@ test_util_expand_filename(void) 
}

#endif



/** Test tor_escape_str_for_socks_arg(). */

static void

test_util_escape_string_socks(void)

{

  char *escaped_string = NULL;



  /** Simple backslash escape. */

  escaped_string = tor_escape_str_for_socks_arg("This is a backslash: \\");

  test_assert(escaped_string);

  test_streq(escaped_string, "This is a backslash: \\\\");

  tor_free(escaped_string);



  /** Simple semicolon escape. */

  escaped_string = tor_escape_str_for_socks_arg("First rule: Do not use ;");

  test_assert(escaped_string);

  test_streq(escaped_string, "First rule: Do not use \\;");

  tor_free(escaped_string);



  /** Ilegal: Empty string. */

  escaped_string = tor_escape_str_for_socks_arg("");

  test_assert(!escaped_string);



  /** Escape all characters. */

  escaped_string = tor_escape_str_for_socks_arg(";\\;\\");

  test_assert(escaped_string);

  test_streq(escaped_string, "\\;\\\\\\;\\\\");

  tor_free(escaped_string);



 done:

  tor_free(escaped_string);

}



static void

test_util_string_is_key_value(void *ptr)

{

  (void)ptr;

  test_assert(string_is_key_value("key=value"));

  test_assert(string_is_key_value("k=v"));

  test_assert(string_is_key_value("key="));

  test_assert(!string_is_key_value("=value"));

  test_assert(!string_is_key_value("="));



  /* ??? */

  /* test_assert(!string_is_key_value("===")); */

 done:

  ;

}



/** Test basic string functionality. */

static void

test_util_strmisc(void)
@@ -3271,6 +3319,8 @@ struct testcase_t util_tests[] = { 
#ifndef _WIN32

  UTIL_LEGACY(expand_filename),

#endif

  UTIL_LEGACY(escape_string_socks),

  UTIL_LEGACY(string_is_key_value),

  UTIL_LEGACY(strmisc),

  UTIL_LEGACY(pow2),

  UTIL_LEGACY(gzip),