add support for smartcards in charon by using the ENGINE API provided by OpenSSL, based on patches by Michael Roßberg.

src/libstrongswan/credentials/builder.c

@@ -35,6 +35,8 @@ ENUM(builder_part_names, BUILD_FROM_FILE, BUILD_END,
 	"BUILD_CA_CERT",
 	"BUILD_CERT",
 	"BUILD_X509_FLAG",
+	"BUILD_SMARTCARD_KEYID",
+	"BUILD_SMARTCARD_PIN",
 	"BUILD_END",
 );
 

src/libstrongswan/credentials/builder.h

@@ -76,6 +76,10 @@ enum builder_part_t {
 	BUILD_CERT,
 	/** enforce an additional X509 flag, x509_flag_t */
 	BUILD_X509_FLAG,
+	/** key ID of a key on a smartcard, null terminated char* ([slot:]keyid) */
+	BUILD_SMARTCARD_KEYID,
+	/** pin to access a key on a smartcard, null terminated char* */
+	BUILD_SMARTCARD_PIN,
 	/** end of variable argument builder list */
 	BUILD_END,
 };

src/libstrongswan/credentials/credential_factory.c

@@ -184,6 +184,8 @@ static void* create(private_credential_factory_t *this, credential_type_t type,
 				case BUILD_CA_CERT:
 				case BUILD_CERT:
 				case BUILD_IETF_GROUP_ATTR:
+				case BUILD_SMARTCARD_KEYID:
+				case BUILD_SMARTCARD_PIN:
 					builder->add(builder, part, va_arg(args, void*));
 					continue;
 				/* no default to get a compiler warning */