From: Joseph Sutton <josephsutton@catalyst.net.nz>
Date: Thu, 13 Jul 2023 02:59:52 +0000 (+1200)
Subject: libndr:ndr: Allow only one string encoding flag
X-Git-Tag: talloc-2.4.2~689
X-Git-Url: http://git.ipfire.org/cgi-bin/gitweb.cgi?a=commitdiff_plain;h=5b693597b0db6425e5d11b067f5b8aea301dca76;p=thirdparty%2Fsamba.git

libndr:ndr: Allow only one string encoding flag

Signed-off-by: Joseph Sutton <josephsutton@catalyst.net.nz>
Reviewed-by: Andrew Bartlett <abartlet@samba.org>
---

diff --git a/librpc/ndr/libndr.h b/librpc/ndr/libndr.h
index 3a453b5b168..5f84b0be7df 100644
--- a/librpc/ndr/libndr.h
+++ b/librpc/ndr/libndr.h
@@ -170,6 +170,12 @@ struct ndr_print {
 		LIBNDR_FLAG_STR_RAW8 | \
 		0)
 
+#define LIBNDR_ENCODING_FLAGS		(0U | \
+		LIBNDR_FLAG_STR_ASCII | \
+		LIBNDR_FLAG_STR_UTF8 | \
+		LIBNDR_FLAG_STR_RAW8 | \
+		0)
+
 /*
  * Mark an element as SECRET, it won't be printed by
  * via ndr_print* unless NDR_PRINT_SECRETS is specified.
diff --git a/librpc/ndr/ndr_string.c b/librpc/ndr/ndr_string.c
index ab34324139d..bb157b08492 100644
--- a/librpc/ndr/ndr_string.c
+++ b/librpc/ndr/ndr_string.c
@@ -44,29 +44,36 @@ _PUBLIC_ enum ndr_err_code ndr_pull_string(struct ndr_pull *ndr, ndr_flags_type
 		chset = CH_UTF16BE;
 	}
 
-	if (flags & LIBNDR_FLAG_STR_ASCII) {
-		chset = CH_DOS;
-		byte_mul = 1;
-		flags &= ~LIBNDR_FLAG_STR_ASCII;
-	}
-
 	/*
 	 * We will check this flag, but from the unmodified
 	 * ndr->flags, so just remove it from flags
 	 */
 	flags &= ~LIBNDR_FLAG_STR_NO_EMBEDDED_NUL;
 
-	if (flags & LIBNDR_FLAG_STR_UTF8) {
+	switch (flags & LIBNDR_ENCODING_FLAGS) {
+	case 0:
+		break;
+
+	case LIBNDR_FLAG_STR_ASCII:
+		chset = CH_DOS;
+		byte_mul = 1;
+		break;
+
+	case LIBNDR_FLAG_STR_UTF8:
 		chset = CH_UTF8;
 		byte_mul = 1;
-		flags &= ~LIBNDR_FLAG_STR_UTF8;
-	}
+		break;
 
-	if (flags & LIBNDR_FLAG_STR_RAW8) {
+	case LIBNDR_FLAG_STR_RAW8:
 		do_convert = 0;
 		byte_mul = 1;
-		flags &= ~LIBNDR_FLAG_STR_RAW8;
+		break;
+
+	default:
+		return ndr_pull_error(ndr, NDR_ERR_STRING, "Bad string flags 0x%"PRI_LIBNDR_FLAGS"\n",
+				      ndr->flags & LIBNDR_STRING_FLAGS);
 	}
+	flags &= ~LIBNDR_ENCODING_FLAGS;
 
 	flags &= ~LIBNDR_FLAG_STR_CONFORMANT;
 	if (flags & LIBNDR_FLAG_STR_CHARLEN) {
@@ -260,29 +267,36 @@ _PUBLIC_ enum ndr_err_code ndr_push_string(struct ndr_push *ndr, ndr_flags_type
 
 	s_len = s?strlen(s):0;
 
-	if (flags & LIBNDR_FLAG_STR_ASCII) {
-		chset = CH_DOS;
-		byte_mul = 1;
-		flags &= ~LIBNDR_FLAG_STR_ASCII;
-	}
-
 	/*
 	 * We will check this flag, but from the unmodified
 	 * ndr->flags, so just remove it from flags
 	 */
 	flags &= ~LIBNDR_FLAG_STR_NO_EMBEDDED_NUL;
 
-	if (flags & LIBNDR_FLAG_STR_UTF8) {
+	switch (flags & LIBNDR_ENCODING_FLAGS) {
+	case 0:
+		break;
+
+	case LIBNDR_FLAG_STR_ASCII:
+		chset = CH_DOS;
+		byte_mul = 1;
+		break;
+
+	case LIBNDR_FLAG_STR_UTF8:
 		chset = CH_UTF8;
 		byte_mul = 1;
-		flags &= ~LIBNDR_FLAG_STR_UTF8;
-	}
+		break;
 
-	if (flags & LIBNDR_FLAG_STR_RAW8) {
+	case LIBNDR_FLAG_STR_RAW8:
 		do_convert = 0;
 		byte_mul = 1;
-		flags &= ~LIBNDR_FLAG_STR_RAW8;
+		break;
+
+	default:
+		return ndr_push_error(ndr, NDR_ERR_STRING, "Bad string flags 0x%"PRI_LIBNDR_FLAGS"\n",
+				      ndr->flags & LIBNDR_STRING_FLAGS);
 	}
+	flags &= ~LIBNDR_ENCODING_FLAGS;
 
 	flags &= ~LIBNDR_FLAG_STR_CONFORMANT;