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-rw-r--r--plugins/sudoers/prompt.c171
1 files changed, 171 insertions, 0 deletions
diff --git a/plugins/sudoers/prompt.c b/plugins/sudoers/prompt.c
new file mode 100644
index 0000000..50e9389
--- /dev/null
+++ b/plugins/sudoers/prompt.c
@@ -0,0 +1,171 @@
+/*
+ * SPDX-License-Identifier: ISC
+ *
+ * Copyright (c) 1993-1996,1998-2005, 2007-2015
+ * Todd C. Miller <Todd.Miller@sudo.ws>
+ *
+ * Permission to use, copy, modify, and distribute this software for any
+ * purpose with or without fee is hereby granted, provided that the above
+ * copyright notice and this permission notice appear in all copies.
+ *
+ * THE SOFTWARE IS PROVIDED "AS IS" AND THE AUTHOR DISCLAIMS ALL WARRANTIES
+ * WITH REGARD TO THIS SOFTWARE INCLUDING ALL IMPLIED WARRANTIES OF
+ * MERCHANTABILITY AND FITNESS. IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR
+ * ANY SPECIAL, DIRECT, INDIRECT, OR CONSEQUENTIAL DAMAGES OR ANY DAMAGES
+ * WHATSOEVER RESULTING FROM LOSS OF USE, DATA OR PROFITS, WHETHER IN AN
+ * ACTION OF CONTRACT, NEGLIGENCE OR OTHER TORTIOUS ACTION, ARISING OUT OF
+ * OR IN CONNECTION WITH THE USE OR PERFORMANCE OF THIS SOFTWARE.
+ *
+ * Sponsored in part by the Defense Advanced Research Projects
+ * Agency (DARPA) and Air Force Research Laboratory, Air Force
+ * Materiel Command, USAF, under agreement number F39502-99-1-0512.
+ */
+
+/*
+ * This is an open source non-commercial project. Dear PVS-Studio, please check it.
+ * PVS-Studio Static Code Analyzer for C, C++ and C#: http://www.viva64.com
+ */
+
+#include <config.h>
+
+#include <stdio.h>
+#include <stdlib.h>
+#include <string.h>
+#include <pwd.h>
+
+#include <sudoers.h>
+
+/*
+ * Expand %h and %u escapes (if present) in the prompt and pass back
+ * the dynamically allocated result.
+ */
+char *
+expand_prompt(const struct sudoers_context *ctx,
+ const char *restrict old_prompt, const char *restrict auth_user)
+{
+ size_t len, n;
+ int subst;
+ const char *p;
+ char *np, *new_prompt;
+ debug_decl(expand_prompt, SUDOERS_DEBUG_AUTH);
+
+ /* How much space do we need to malloc for the prompt? */
+ subst = 0;
+ for (p = old_prompt, len = strlen(old_prompt); *p != '\0'; p++) {
+ if (p[0] =='%') {
+ switch (p[1]) {
+ case 'h':
+ p++;
+ len += strlen(ctx->user.shost) - 2;
+ subst = 1;
+ break;
+ case 'H':
+ p++;
+ len += strlen(ctx->user.host) - 2;
+ subst = 1;
+ break;
+ case 'p':
+ p++;
+ len += strlen(auth_user) - 2;
+ subst = 1;
+ break;
+ case 'u':
+ p++;
+ len += strlen(ctx->user.name) - 2;
+ subst = 1;
+ break;
+ case 'U':
+ p++;
+ len += strlen(ctx->runas.pw->pw_name) - 2;
+ subst = 1;
+ break;
+ case '%':
+ p++;
+ len--;
+ subst = 1;
+ break;
+ default:
+ break;
+ }
+ }
+ }
+
+ if ((new_prompt = malloc(++len)) == NULL) {
+ sudo_warnx(U_("%s: %s"), __func__, U_("unable to allocate memory"));
+ debug_return_str(NULL);
+ }
+
+ if (subst) {
+ for (p = old_prompt, np = new_prompt; *p != '\0'; p++) {
+ if (p[0] =='%') {
+ switch (p[1]) {
+ case 'h':
+ p++;
+ n = strlcpy(np, ctx->user.shost, len);
+ if (n >= len)
+ goto oflow;
+ np += n;
+ len -= n;
+ continue;
+ case 'H':
+ p++;
+ n = strlcpy(np, ctx->user.host, len);
+ if (n >= len)
+ goto oflow;
+ np += n;
+ len -= n;
+ continue;
+ case 'p':
+ p++;
+ n = strlcpy(np, auth_user, len);
+ if (n >= len)
+ goto oflow;
+ np += n;
+ len -= n;
+ continue;
+ case 'u':
+ p++;
+ n = strlcpy(np, ctx->user.name, len);
+ if (n >= len)
+ goto oflow;
+ np += n;
+ len -= n;
+ continue;
+ case 'U':
+ p++;
+ n = strlcpy(np, ctx->runas.pw->pw_name, len);
+ if (n >= len)
+ goto oflow;
+ np += n;
+ len -= n;
+ continue;
+ case '%':
+ /* convert %% -> % */
+ p++;
+ break;
+ default:
+ /* no conversion */
+ break;
+ }
+ }
+ if (len < 2) /* len includes NUL */
+ goto oflow;
+ *np++ = *p;
+ len--;
+ }
+ if (len != 1)
+ goto oflow;
+ *np = '\0';
+ } else {
+ /* Nothing to expand. */
+ memcpy(new_prompt, old_prompt, len); /* len includes NUL */
+ }
+
+ debug_return_str(new_prompt);
+
+oflow:
+ /* We pre-allocate enough space, so this should never happen. */
+ free(new_prompt);
+ sudo_warnx(U_("internal error, %s overflow"), __func__);
+ debug_return_str(NULL);
+}