From: Aki Tuomi <aki.tuomi@open-xchange.com>
Date: Wed, 10 Jun 2026 12:02:42 +0000 (+0000)
Subject: lib: punycode - Use const unsigned char* input in punycode_decode()
X-Git-Url: http://git.ipfire.org/gitweb.cgi?a=commitdiff_plain;h=025a0d18a958730cee4a1908359bab8bb6cdafc5;p=thirdparty%2Fdovecot%2Fcore.git

lib: punycode - Use const unsigned char* input in punycode_decode()
---

diff --git a/src/lib-mail/rfc822-parser.c b/src/lib-mail/rfc822-parser.c
index 2cee47480c..9af6ba12f8 100644
--- a/src/lib-mail/rfc822-parser.c
+++ b/src/lib-mail/rfc822-parser.c
@@ -426,7 +426,7 @@ void rfc822_decode_punycode(const char *input, size_t len, string_t *result)
 			delim = end;
 		if (str_begins(pos, "xn--", &value)) {
 			str_truncate(decoded, 0);
-			if (punycode_decode(value, delim - value, result) < 0)
+			if (punycode_decode((const unsigned char *)value, delim - value, result) < 0)
 				/* Consider it as data */
 				str_append_data(result, pos, delim - pos + 1);
 			else if (*delim == '.')
diff --git a/src/lib/punycode.c b/src/lib/punycode.c
index 41fe2ea514..4d2dbc066c 100644
--- a/src/lib/punycode.c
+++ b/src/lib/punycode.c
@@ -53,15 +53,15 @@ static unsigned int adapt(unsigned int delta, unsigned int numpoints, bool first
 }
 
 /* Decodes a punycoded string into output, or returns -1 on error. */
-int punycode_decode(const char *input, size_t len, string_t *output)
+int punycode_decode(const unsigned char *input, size_t len, string_t *output)
 {
 	ARRAY(unichar_t) label;
 	size_t i = 0;
 	size_t out = 0;
 	unsigned int n = initialN, bias = initialBias;
-	const char *delim = NULL;
-	const char *end = CONST_PTR_OFFSET(input, len);
-	const char *ptr = input;
+	const unsigned char *delim = NULL;
+	const unsigned char *end = CONST_PTR_OFFSET(input, len);
+	const unsigned char *ptr = input;
 	t_array_init(&label, len);
 
 	/* find the rightmost delimiter, if present in string */
@@ -74,12 +74,12 @@ int punycode_decode(const char *input, size_t len, string_t *output)
 	i_assert(delim <= end);
 
 	for (ptr = input; ptr < delim; ptr++) {
-		if ((unsigned char)*ptr >= 0x80)
+		if (*ptr >= 0x80)
 			/* Has non-ascii input, this cannot be punycoded. */
 			return -1;
 		i_assert(out < sizeof(label));
 		/* Add basic code points to label */
-		unichar_t ch = (unsigned char)*ptr;
+		unichar_t ch = *ptr;
 		array_push_back(&label, &ch);
 	}
 
diff --git a/src/lib/punycode.h b/src/lib/punycode.h
index 40adf3b78f..62e718dd0a 100644
--- a/src/lib/punycode.h
+++ b/src/lib/punycode.h
@@ -3,6 +3,6 @@
 
 /* Parse input as a punycode-encoded string and append it to
    output. Returns 0 on success and -1 on failure. */
-int punycode_decode(const char *input, size_t len, string_t *output);
+int punycode_decode(const unsigned char *input, size_t len, string_t *output);
 
 #endif
diff --git a/src/lib/test-punycode.c b/src/lib/test-punycode.c
index 434ef5fef2..b8a20a8caf 100644
--- a/src/lib/test-punycode.c
+++ b/src/lib/test-punycode.c
@@ -36,7 +36,7 @@ static void test_punycode_decode(void)
 	test_begin("punycode decoding");
 	for (i = 0; i < N_ELEMENTS(cases); i ++) {
 		str_truncate(r, 0);
-		int ret = punycode_decode(cases[i].in, strlen(cases[i].in), r);
+		int ret = punycode_decode((const unsigned char *)cases[i].in, strlen(cases[i].in), r);
 		test_assert_idx(ret == cases[i].ret, i);
 		test_assert_strcmp_idx(str_c(r), cases[i].out, i);
 	}