1 files changed, 120 insertions, 0 deletions
diff --git a/src/lib/term/getpass.c b/src/lib/term/getpass.c
new file mode 100644
index 0000000000..c6459f250f
--- /dev/null
+++ b/src/lib/term/getpass.c
@@ -0,0 +1,120 @@
+/* Copyright (c) 2003-2004, Roger Dingledine
+ * Copyright (c) 2004-2006, Roger Dingledine, Nick Mathewson.
+ * Copyright (c) 2007-2019, The Tor Project, Inc. */
+/* See LICENSE for licensing information */
+
+/**
+ * \file getpass.c
+ * \brief Cross-platform wrapper to read passphrases from the terminal.
+ **/
+
+#include "lib/term/getpass.h"
+
+#include "lib/log/util_bug.h"
+#include "lib/malloc/malloc.h"
+
+#ifdef _WIN32
+#include <windows.h>
+#include <conio.h>
+#include <wchar.h>
+/* Some mingw headers lack these. :p */
+#if defined(HAVE_DECL__GETWCH) && !HAVE_DECL__GETWCH
+wint_t _getwch(void);
+#endif
+#ifndef WEOF
+#define WEOF (wchar_t)(0xFFFF)
+#endif
+#if defined(HAVE_DECL_SECUREZEROMEMORY) && !HAVE_DECL_SECUREZEROMEMORY
+static inline void
+SecureZeroMemory(PVOID ptr, SIZE_T cnt)
+{
+  volatile char *vcptr = (volatile char*)ptr;
+  while (cnt--)
+    *vcptr++ = 0;
+}
+#endif /* defined(HAVE_DECL_SECUREZEROMEMORY) && !HAVE_DECL_SECUREZEROMEMORY */
+#elif defined(HAVE_READPASSPHRASE_H)
+#include <readpassphrase.h>
+#else
+#include "tor_readpassphrase.h"
+#endif /* defined(_WIN32) || ... */
+
+#include <stdlib.h>
+#include <string.h>
+
+/** Emit the password prompt <b>prompt</b>, then read up to <b>buflen</b>
+ * bytes of passphrase into <b>output</b>. Return the number of bytes in
+ * the passphrase, excluding terminating NUL.
+ */
+ssize_t
+tor_getpass(const char *prompt, char *output, size_t buflen)
+{
+  tor_assert(buflen <= SSIZE_MAX);
+  tor_assert(buflen >= 1);
+#if defined(HAVE_READPASSPHRASE)
+  char *pwd = readpassphrase(prompt, output, buflen, RPP_ECHO_OFF);
+  if (pwd == NULL)
+    return -1;
+  return strlen(pwd);
+#elif defined(_WIN32)
+  int r = -1;
+  while (*prompt) {
+    _putch(*prompt++);
+  }
+
+  tor_assert(buflen <= INT_MAX);
+  wchar_t *buf = tor_calloc(buflen, sizeof(wchar_t));
+
+  wchar_t *ptr = buf, *lastch = buf + buflen - 1;
+  while (ptr < lastch) {
+    wint_t ch = _getwch();
+    switch (ch) {
+      case '\r':
+      case '\n':
+      case WEOF:
+        goto done_reading;
+      case 3:
+        goto done; /* Can't actually read ctrl-c this way. */
+      case '\b':
+        if (ptr > buf)
+          --ptr;
+        continue;
+      case 0:
+      case 0xe0:
+        ch = _getwch(); /* Ignore; this is a function or arrow key */
+        break;
+      default:
+        *ptr++ = ch;
+        break;
+    }
+  }
+ done_reading:
+  ;
+
+#ifndef WC_ERR_INVALID_CHARS
+#define WC_ERR_INVALID_CHARS 0x80
+#endif
+
+  /* Now convert it to UTF-8 */
+  r = WideCharToMultiByte(CP_UTF8,
+                          WC_NO_BEST_FIT_CHARS|WC_ERR_INVALID_CHARS,
+                          buf, (int)(ptr-buf),
+                          output, (int)(buflen-1),
+                          NULL, NULL);
+  if (r <= 0) {
+    r = -1;
+    goto done;
+  }
+
+  tor_assert(r < (int)buflen);
+
+  output[r] = 0;
+
+ done:
+  SecureZeroMemory(buf, sizeof(wchar_t)*buflen);
+  tor_free(buf);
+  return r;
+#else
+#error "No implementation for tor_getpass found!"
+#endif /* defined(HAVE_READPASSPHRASE) || ... */
+}