ASN1_STRING_data() has been deprecated since OpenSSL 1.1.0 in favor of
ASN1_STRING_get0_data() with better const semantics. It was removed from
OpenSSL and LibreSSL will soon do the same. I'll send the simple patch
below upstream as well.

Index: Makefile
===================================================================
RCS file: /cvs/ports/mail/sylpheed/Makefile,v
diff -u -p -r1.131 Makefile
--- Makefile	19 Dec 2025 13:42:07 -0000	1.131
+++ Makefile	28 Jan 2026 11:32:58 -0000
@@ -1,7 +1,7 @@
 COMMENT =		lightweight and user-friendly e-mail client
 
 DISTNAME =		sylpheed-3.7.0
-REVISION =		8
+REVISION =		9
 
 SHARED_LIBS += 	 	sylph-0                   4.1 # 4.0
 SHARED_LIBS += 		sylpheed-plugin-0         4.0 # 4.0
Index: patches/patch-libsylph_ssl_hostname_validation_c
===================================================================
RCS file: patches/patch-libsylph_ssl_hostname_validation_c
diff -N patches/patch-libsylph_ssl_hostname_validation_c
--- /dev/null	1 Jan 1970 00:00:00 -0000
+++ patches/patch-libsylph_ssl_hostname_validation_c	28 Jan 2026 11:33:38 -0000
@@ -0,0 +1,32 @@
+Use ASN1_STRING_get0_data() instead of the deprecated ASN1_STRING_data()
+
+Index: libsylph/ssl_hostname_validation.c
+--- libsylph/ssl_hostname_validation.c.orig
++++ libsylph/ssl_hostname_validation.c
+@@ -167,7 +167,7 @@ static SSLHostnameValidationResult matches_common_name
+ 	int common_name_loc = -1;
+ 	X509_NAME_ENTRY *common_name_entry = NULL;
+ 	ASN1_STRING *common_name_asn1 = NULL;
+-	char *common_name_str = NULL;
++	const char *common_name_str = NULL;
+ 
+ 	// Find the position of the CN field in the Subject field of the certificate
+ 	common_name_loc = X509_NAME_get_index_by_NID(X509_get_subject_name((X509 *) server_cert), NID_commonName, -1);
+@@ -186,7 +186,7 @@ static SSLHostnameValidationResult matches_common_name
+ 	if (common_name_asn1 == NULL) {
+ 		return SSL_HOSTNAME_ERROR;
+ 	}			
+-	common_name_str = (char *) ASN1_STRING_data(common_name_asn1);
++	common_name_str = (const char *) ASN1_STRING_get0_data(common_name_asn1);
+ 
+ 	debug_print("matches_common_name: %s\n", common_name_str);
+ 
+@@ -227,7 +227,7 @@ static SSLHostnameValidationResult matches_subject_alt
+ 
+ 		if (current_name->type == GEN_DNS) {
+ 			// Current name is a DNS name, let's check it
+-			char *dns_name = (char *) ASN1_STRING_data(current_name->d.dNSName);
++			const char *dns_name = (const char *) ASN1_STRING_get0_data(current_name->d.dNSName);
+ 
+ 			debug_print("matches_subject_alternative_name: %s\n", dns_name);
+