diff --git a/src/feature/control/control_auth.c b/src/feature/control/control_auth.c
index 927115a308..8204290489 100644
--- a/src/feature/control/control_auth.c
+++ b/src/feature/control/control_auth.c
@@ -17,6 +17,7 @@
#include "lib/crypt_ops/crypto_rand.h"
#include "lib/crypt_ops/crypto_util.h"
#include "lib/encoding/confline.h"
+#include "lib/encoding/qstring.h"
#include "lib/crypt_ops/crypto_s2k.h"
@@ -149,8 +150,8 @@ handle_control_authchallenge(control_connection_t *conn, uint32_t len,
cp += strspn(cp, " \t\n\r");
if (*cp == '"') {
const char *newcp =
- decode_escaped_string(cp, len - (cp - body),
- &client_nonce, &client_nonce_len);
+ decode_qstring(cp, len - (cp - body),
+ &client_nonce, &client_nonce_len);
if (newcp == NULL) {
connection_write_str_to_buf("513 Invalid quoted client nonce\r\n",
conn);
@@ -275,7 +276,7 @@ handle_control_authenticate(control_connection_t *conn, uint32_t len,
return 0;
}
} else {
- if (!decode_escaped_string(body, len, &password, &password_len)) {
+ if (!decode_qstring(body, len, &password, &password_len)) {
connection_write_str_to_buf("551 Invalid quoted string. You need "
"to put the password in double quotes.\r\n", conn);
connection_mark_for_close(TO_CONN(conn));
diff --git a/src/feature/control/control_fmt.c b/src/feature/control/control_fmt.c
index 427f4288fc..b2ab4f10bb 100644
--- a/src/feature/control/control_fmt.c
+++ b/src/feature/control/control_fmt.c
@@ -305,80 +305,6 @@ send_control_done(control_connection_t *conn)
connection_write_str_to_buf("250 OK\r\n", conn);
}
-/** If the first in_len_max characters in start contain a
- * double-quoted string with escaped characters, return the length of that
- * string (as encoded, including quotes). Otherwise return -1. */
-static inline int
-get_escaped_string_length(const char *start, size_t in_len_max,
- int *chars_out)
-{
- const char *cp, *end;
- int chars = 0;
-
- if (*start != '\"')
- return -1;
-
- cp = start+1;
- end = start+in_len_max;
-
- /* Calculate length. */
- while (1) {
- if (cp >= end) {
- return -1; /* Too long. */
- } else if (*cp == '\\') {
- if (++cp == end)
- return -1; /* Can't escape EOS. */
- ++cp;
- ++chars;
- } else if (*cp == '\"') {
- break;
- } else {
- ++cp;
- ++chars;
- }
- }
- if (chars_out)
- *chars_out = chars;
- return (int)(cp - start+1);
-}
-
-/** Given a pointer to a string starting at start containing
- * in_len_max characters, decode a string beginning with one double
- * quote, containing any number of non-quote characters or characters escaped
- * with a backslash, and ending with a final double quote. Place the resulting
- * string (unquoted, unescaped) into a newly allocated string in *out;
- * store its length in out_len. On success, return a pointer to the
- * character immediately following the escaped string. On failure, return
- * NULL. */
-const char *
-decode_escaped_string(const char *start, size_t in_len_max,
- char **out, size_t *out_len)
-{
- const char *cp, *end;
- char *outp;
- int len, n_chars = 0;
-
- len = get_escaped_string_length(start, in_len_max, &n_chars);
- if (len<0)
- return NULL;
-
- end = start+len-1; /* Index of last quote. */
- tor_assert(*end == '\"');
- outp = *out = tor_malloc(len+1);
- *out_len = n_chars;
-
- cp = start+1;
- while (cp < end) {
- if (*cp == '\\')
- ++cp;
- *outp++ = *cp++;
- }
- *outp = '\0';
- tor_assert((outp - *out) == (int)*out_len);
-
- return end+1;
-}
-
/** Return a longname the node whose identity is id_digest. If
* node_get_by_id() returns NULL, base 16 encoding of id_digest is
* returned instead.
diff --git a/src/feature/control/control_fmt.h b/src/feature/control/control_fmt.h
index 08acf85181..8bbbaa95d0 100644
--- a/src/feature/control/control_fmt.h
+++ b/src/feature/control/control_fmt.h
@@ -25,8 +25,6 @@ char *circuit_describe_status_for_controller(origin_circuit_t *circ);
size_t write_escaped_data(const char *data, size_t len, char **out);
size_t read_escaped_data(const char *data, size_t len, char **out);
-const char *decode_escaped_string(const char *start, size_t in_len_max,
- char **out, size_t *out_len);
void send_control_done(control_connection_t *conn);
MOCK_DECL(const char *, node_describe_longname_by_id,(const char *id_digest));
diff --git a/src/lib/encoding/include.am b/src/lib/encoding/include.am
index 83e9211b6f..8272e4e5fa 100644
--- a/src/lib/encoding/include.am
+++ b/src/lib/encoding/include.am
@@ -11,6 +11,7 @@ src_lib_libtor_encoding_a_SOURCES = \
src/lib/encoding/keyval.c \
src/lib/encoding/kvline.c \
src/lib/encoding/pem.c \
+ src/lib/encoding/qstring.c \
src/lib/encoding/time_fmt.c
src_lib_libtor_encoding_testing_a_SOURCES = \
@@ -25,4 +26,5 @@ noinst_HEADERS += \
src/lib/encoding/keyval.h \
src/lib/encoding/kvline.h \
src/lib/encoding/pem.h \
+ src/lib/encoding/qstring.h \
src/lib/encoding/time_fmt.h
diff --git a/src/lib/encoding/qstring.c b/src/lib/encoding/qstring.c
new file mode 100644
index 0000000000..a92d28c706
--- /dev/null
+++ b/src/lib/encoding/qstring.c
@@ -0,0 +1,90 @@
+/* Copyright (c) 2004-2006, Roger Dingledine, Nick Mathewson.
+ * Copyright (c) 2007-2019, The Tor Project, Inc. */
+/* See LICENSE for licensing information */
+
+/**
+ * \file qstring.c
+ * \brief Implement QuotedString parsing.
+ *
+ * Note that this is only used for controller authentication; do not
+ * create new users for this. Instead, prefer the cstring.c functions.
+ **/
+
+#include "orconfig.h"
+#include "lib/encoding/qstring.h"
+#include "lib/malloc/malloc.h"
+#include "lib/log/util_bug.h"
+
+/** If the first in_len_max characters in start contain a
+ * QuotedString, return the length of that
+ * string (as encoded, including quotes). Otherwise return -1. */
+static inline int
+get_qstring_length(const char *start, size_t in_len_max,
+ int *chars_out)
+{
+ const char *cp, *end;
+ int chars = 0;
+
+ if (*start != '\"')
+ return -1;
+
+ cp = start+1;
+ end = start+in_len_max;
+
+ /* Calculate length. */
+ while (1) {
+ if (cp >= end) {
+ return -1; /* Too long. */
+ } else if (*cp == '\\') {
+ if (++cp == end)
+ return -1; /* Can't escape EOS. */
+ ++cp;
+ ++chars;
+ } else if (*cp == '\"') {
+ break;
+ } else {
+ ++cp;
+ ++chars;
+ }
+ }
+ if (chars_out)
+ *chars_out = chars;
+ return (int)(cp - start+1);
+}
+
+/** Given a pointer to a string starting at start containing
+ * in_len_max characters, decode a string beginning with one double
+ * quote, containing any number of non-quote characters or characters escaped
+ * with a backslash, and ending with a final double quote. Place the resulting
+ * string (unquoted, unescaped) into a newly allocated string in *out;
+ * store its length in out_len. On success, return a pointer to the
+ * character immediately following the escaped string. On failure, return
+ * NULL. */
+const char *
+decode_qstring(const char *start, size_t in_len_max,
+ char **out, size_t *out_len)
+{
+ const char *cp, *end;
+ char *outp;
+ int len, n_chars = 0;
+
+ len = get_qstring_length(start, in_len_max, &n_chars);
+ if (len<0)
+ return NULL;
+
+ end = start+len-1; /* Index of last quote. */
+ tor_assert(*end == '\"');
+ outp = *out = tor_malloc(len+1);
+ *out_len = n_chars;
+
+ cp = start+1;
+ while (cp < end) {
+ if (*cp == '\\')
+ ++cp;
+ *outp++ = *cp++;
+ }
+ *outp = '\0';
+ tor_assert((outp - *out) == (int)*out_len);
+
+ return end+1;
+}
diff --git a/src/lib/encoding/qstring.h b/src/lib/encoding/qstring.h
new file mode 100644
index 0000000000..fe15b655f1
--- /dev/null
+++ b/src/lib/encoding/qstring.h
@@ -0,0 +1,18 @@
+/* Copyright (c) 2004-2006, Roger Dingledine, Nick Mathewson.
+ * Copyright (c) 2007-2019, The Tor Project, Inc. */
+/* See LICENSE for licensing information */
+
+/**
+ * \file qstring.h
+ * \brief Header for qstring.c
+ */
+
+#ifndef TOR_ENCODING_QSTRING_H
+#define TOR_ENCODING_QSTRING_H
+
+#include
+
+const char *decode_qstring(const char *start, size_t in_len_max,
+ char **out, size_t *out_len);
+
+#endif