From 07f040ea0baf97bceddc8da01c21b49ea4e143f9 Mon Sep 17 00:00:00 2001
From: DL6ER <dl6er@dl6er.de>
Date: Mon, 20 Nov 2023 08:58:48 +0100
Subject: [PATCH] Switch from libidn to libidn2 to get IDN conversion
 conforming to IDNA2008 + TR46 specifications (RFC 5890, RFC 5891, RFC 5892,
 RFC 5893, TR 46)

Signed-off-by: DL6ER <dl6er@dl6er.de>
---
 src/CMakeLists.txt   |  7 +++++--
 src/api/list.c       | 13 ++++++-------
 src/api/search.c     | 10 +++++-----
 src/dnsmasq/config.h |  2 +-
 4 files changed, 17 insertions(+), 15 deletions(-)

diff --git a/src/CMakeLists.txt b/src/CMakeLists.txt
index 4b02c2e9..3428cedb 100644
--- a/src/CMakeLists.txt
+++ b/src/CMakeLists.txt
@@ -283,9 +283,12 @@ find_package(Threads REQUIRED)
 find_library(LIBHOGWEED NAMES libhogweed${CMAKE_STATIC_LIBRARY_SUFFIX} hogweed HINTS /usr/local/lib64)
 find_library(LIBGMP NAMES libgmp${CMAKE_STATIC_LIBRARY_SUFFIX} gmp)
 find_library(LIBNETTLE NAMES libnettle${CMAKE_STATIC_LIBRARY_SUFFIX} nettle HINTS /usr/local/lib64)
-find_library(LIBIDN NAMES libidn${CMAKE_STATIC_LIBRARY_SUFFIX} idn)
 
-target_link_libraries(pihole-FTL rt Threads::Threads ${LIBHOGWEED} ${LIBGMP} ${LIBNETTLE} ${LIBIDN})
+# for IDN2 we need the idn2 library which in turn depends on the unistring library
+find_library(LIBIDN2 NAMES libidn2${CMAKE_STATIC_LIBRARY_SUFFIX} idn)
+find_library(LIBUNISTRING NAMES libunistring${CMAKE_STATIC_LIBRARY_SUFFIX} unistring)
+
+target_link_libraries(pihole-FTL rt Threads::Threads ${LIBHOGWEED} ${LIBGMP} ${LIBNETTLE} ${LIBIDN2} ${LIBUNISTRING})
 
 if(LUA_DL STREQUAL "true")
     find_library(LIBDL dl)
diff --git a/src/api/list.c b/src/api/list.c
index 0502f5ec..42f71441 100644
--- a/src/api/list.c
+++ b/src/api/list.c
@@ -19,8 +19,7 @@
 #include "database/network-table.h"
 // valid_domain()
 #include "tools/gravity-parseList.h"
-
-#include <idna.h>
+#include <idn2.h>
 
 static int api_list_read(struct ftl_conn *api,
                          const int code,
@@ -75,9 +74,9 @@ static int api_list_read(struct ftl_conn *api,
 		else // domainlists
 		{
 			char *unicode = NULL;
-			const Idna_rc rc = idna_to_unicode_lzlz(table.domain, &unicode, 0);
+			const int rc = idn2_to_unicode_lzlz(table.domain, &unicode, IDN2_NONTRANSITIONAL);
 			JSON_COPY_STR_TO_OBJECT(row, "domain", table.domain);
-			if(rc == IDNA_SUCCESS)
+			if(rc == IDN2_OK)
 				JSON_COPY_STR_TO_OBJECT(row, "unicode", unicode);
 			else
 				JSON_COPY_STR_TO_OBJECT(row, "unicode", table.domain);
@@ -417,14 +416,14 @@ static int api_list_write(struct ftl_conn *api,
 			   listtype == GRAVITY_DOMAINLIST_DENY_EXACT)
 			{
 				char *punycode = NULL;
-				const Idna_rc rc = idna_to_ascii_lz(it->valuestring, &punycode, 0);
-				if (rc != IDNA_SUCCESS)
+				const int rc = idn2_to_ascii_lz(it->valuestring, &punycode, IDN2_NONTRANSITIONAL);
+				if (rc != IDN2_OK)
 				{
 					// Invalid domain name
 					return send_json_error(api, 400,
 					                       "bad_request",
 					                       "Invalid request: Invalid domain name",
-					                       idna_strerror(rc));
+					                       idn2_strerror(rc));
 				}
 				// Convert punycode domain to lowercase
 				for(unsigned int i = 0u; i < strlen(punycode); i++)
diff --git a/src/api/search.c b/src/api/search.c
index 0ed5a3bf..511d9c97 100644
--- a/src/api/search.c
+++ b/src/api/search.c
@@ -15,7 +15,7 @@
 #include "database/gravity-db.h"
 // match_regex()
 #include "regex_r.h"
-#include <idna.h>
+#include <idn2.h>
 
 #define MAX_SEARCH_RESULTS 10000u
 
@@ -182,18 +182,18 @@ int api_search(struct ftl_conn *api)
 	// use characters drawn from a large repertoire (Unicode), but IDNA
 	// allows the non-ASCII characters to be represented using only the
 	// ASCII characters already allowed in so-called host names today.
-	// idna_to_ascii_lz() convert domain name in the locale’s encoding to an
+	// idn2_to_ascii_lz() convert domain name in the locale’s encoding to an
 	// ASCII string. The domain name may contain several labels, separated
 	// by dots. The output buffer must be deallocated by the caller.
 	char *punycode = NULL;
-	const Idna_rc rc = idna_to_ascii_lz(domain, &punycode, 0);
-	if (rc != IDNA_SUCCESS)
+	const int rc = idn2_to_ascii_lz(domain, &punycode, IDN2_NONTRANSITIONAL);
+	if (rc != IDN2_OK)
 	{
 		// Invalid domain name
 		return send_json_error(api, 400,
 		                       "bad_request",
 		                       "Invalid request: Invalid domain name",
-		                       idna_strerror(rc));
+		                       idn2_strerror(rc));
 	}
 
 	// Convert punycode domain to lowercase
diff --git a/src/dnsmasq/config.h b/src/dnsmasq/config.h
index df302fbd..d73359be 100644
--- a/src/dnsmasq/config.h
+++ b/src/dnsmasq/config.h
@@ -205,7 +205,7 @@ RESOLVFILE
 
 /* Pi-hole definitions */
 #define HAVE_LUASCRIPT
-#define HAVE_IDN
+#define HAVE_LIBIDN2
 #define HAVE_DNSSEC
 #ifdef DNSMASQ_ALL_OPTS
   #define HAVE_DBUS