Allow flexible specification of methods provided by an implementation

4 files changed, 26 insertions, 14 deletions

diff --git a/src/methods/aes128_gcm/aes128_gcm.c b/src/methods/aes128_gcm/aes128_gcm.c
index 59e6914..8a6325e 100644
--- a/src/methods/aes128_gcm/aes128_gcm.c
+++ b/src/methods/aes128_gcm/aes128_gcm.c
@@ -40,6 +40,10 @@ struct fastd_method_session_state {
 };
 
 
+static bool method_provides(fastd_context_t *ctx UNUSED, const char *name) {
+	return !strcmp(name, "aes128-gcm");
+}
+
 static size_t method_max_packet_size(fastd_context_t *ctx) {
 	return (fastd_max_packet_size(ctx) + COMMON_NONCEBYTES + sizeof(fastd_block128_t));
 }
@@ -66,7 +70,7 @@ static size_t method_key_length(fastd_context_t *ctx UNUSED) {
 	return sizeof(fastd_block128_t);
 }
 
-static fastd_method_session_state_t* method_session_init(fastd_context_t *ctx, const uint8_t *secret, bool initiator) {
+static fastd_method_session_state_t* method_session_init(fastd_context_t *ctx, const char *name UNUSED, const uint8_t *secret, bool initiator) {
 	fastd_method_session_state_t *session = malloc(sizeof(fastd_method_session_state_t));
 
 	fastd_method_common_init(ctx, &session->common, initiator);
@@ -87,11 +91,11 @@ static fastd_method_session_state_t* method_session_init(fastd_context_t *ctx, c
 	return session;
 }
 
-static fastd_method_session_state_t* method_session_init_compat(fastd_context_t *ctx, const uint8_t *secret, size_t length, bool initiator) {
+static fastd_method_session_state_t* method_session_init_compat(fastd_context_t *ctx, const char *name, const uint8_t *secret, size_t length, bool initiator) {
 	if (length < sizeof(fastd_block128_t))
 		exit_bug(ctx, "aes128-gcm: tried to init with short secret");
 
-	return method_session_init(ctx, secret, initiator);
+	return method_session_init(ctx, name, secret, initiator);
 }
 
 static bool method_session_is_valid(fastd_context_t *ctx, fastd_method_session_state_t *session) {
@@ -235,7 +239,7 @@ static bool method_decrypt(fastd_context_t *ctx, fastd_peer_t *peer, fastd_metho
 }
 
 const fastd_method_t fastd_method_aes128_gcm = {
-	.name = "aes128-gcm",
+	.provides = method_provides,
 
 	.max_packet_size = method_max_packet_size,
 	.min_encrypt_head_space = method_min_encrypt_head_space,
diff --git a/src/methods/methods.c.in b/src/methods/methods.c.in
index 8f5bb10..f39fbc1 100644
--- a/src/methods/methods.c.in
+++ b/src/methods/methods.c.in
@@ -33,10 +33,10 @@ static const fastd_method_t *const methods[] = { @METHOD_LIST@
 };
 
 
-const fastd_method_t* fastd_method_get_by_name(const char *name) {
+const fastd_method_t* fastd_method_get_by_name(fastd_context_t *ctx, const char *name) {
 	size_t i;
 	for (i = 0; i < array_size(methods); i++) {
-		if (!strcmp(methods[i]->name, name))
+		if (methods[i]->provides(ctx, name))
 			return methods[i];
 	}
 
diff --git a/src/methods/null/null.c b/src/methods/null/null.c
index f49d94a..cba7931 100644
--- a/src/methods/null/null.c
+++ b/src/methods/null/null.c
@@ -33,6 +33,10 @@ struct fastd_method_session_state {
 };
 
 
+static bool method_provides(fastd_context_t *ctx UNUSED, const char *name) {
+	return !strcmp(name, "null");
+}
+
 static size_t method_max_packet_size(fastd_context_t *ctx) {
 	return fastd_max_packet_size(ctx);
 }
@@ -45,7 +49,7 @@ static size_t method_key_length(fastd_context_t *ctx UNUSED) {
 	return 0;
 }
 
-static fastd_method_session_state_t* method_session_init(fastd_context_t *ctx UNUSED, const uint8_t *secret UNUSED, bool initiator) {
+static fastd_method_session_state_t* method_session_init(fastd_context_t *ctx UNUSED, const char *name UNUSED, const uint8_t *secret UNUSED, bool initiator) {
 	fastd_method_session_state_t *session = malloc(sizeof(fastd_method_session_state_t));
 
 	session->valid = true;
@@ -54,8 +58,8 @@ static fastd_method_session_state_t* method_session_init(fastd_context_t *ctx UN
 	return session;
 }
 
-static fastd_method_session_state_t* method_session_init_compat(fastd_context_t *ctx, const uint8_t *secret, size_t length UNUSED, bool initiator) {
-	return method_session_init(ctx, secret, initiator);
+static fastd_method_session_state_t* method_session_init_compat(fastd_context_t *ctx, const char *name, const uint8_t *secret, size_t length UNUSED, bool initiator) {
+	return method_session_init(ctx, name, secret, initiator);
 }
 
 static bool method_session_is_valid(fastd_context_t *ctx UNUSED, fastd_method_session_state_t *session) {
@@ -84,7 +88,7 @@ static bool method_passthrough(fastd_context_t *ctx UNUSED, fastd_peer_t *peer U
 }
 
 const fastd_method_t fastd_method_null = {
-	.name = "null",
+	.provides = method_provides,
 
 	.max_packet_size = method_max_packet_size,
 	.min_encrypt_head_space = method_min_head_tail_space,
diff --git a/src/methods/xsalsa20_poly1305/xsalsa20_poly1305.c b/src/methods/xsalsa20_poly1305/xsalsa20_poly1305.c
index 768e5c8..220e913 100644
--- a/src/methods/xsalsa20_poly1305/xsalsa20_poly1305.c
+++ b/src/methods/xsalsa20_poly1305/xsalsa20_poly1305.c
@@ -37,6 +37,10 @@ struct fastd_method_session_state {
 };
 
 
+static bool method_provides(fastd_context_t *ctx UNUSED, const char *name) {
+	return !strcmp(name, "xsalsa20-poly1305");
+}
+
 static size_t method_max_packet_size(fastd_context_t *ctx) {
 	return (fastd_max_packet_size(ctx) + COMMON_NONCEBYTES + crypto_secretbox_xsalsa20poly1305_ZEROBYTES - crypto_secretbox_xsalsa20poly1305_BOXZEROBYTES);
 }
@@ -58,7 +62,7 @@ static size_t method_key_length(fastd_context_t *ctx UNUSED) {
 	return crypto_secretbox_xsalsa20poly1305_KEYBYTES;
 }
 
-static fastd_method_session_state_t* method_session_init(fastd_context_t *ctx, const uint8_t *secret, bool initiator) {
+static fastd_method_session_state_t* method_session_init(fastd_context_t *ctx, const char *name UNUSED, const uint8_t *secret, bool initiator) {
 	fastd_method_session_state_t *session = malloc(sizeof(fastd_method_session_state_t));
 
 	fastd_method_common_init(ctx, &session->common, initiator);
@@ -68,11 +72,11 @@ static fastd_method_session_state_t* method_session_init(fastd_context_t *ctx, c
 	return session;
 }
 
-static fastd_method_session_state_t* method_session_init_compat(fastd_context_t *ctx, const uint8_t *secret, size_t length, bool initiator) {
+static fastd_method_session_state_t* method_session_init_compat(fastd_context_t *ctx, const char *name, const uint8_t *secret, size_t length, bool initiator) {
 	if (length < crypto_secretbox_xsalsa20poly1305_KEYBYTES)
 		exit_bug(ctx, "xsalsa20-poly1305: tried to init with short secret");
 
-	return method_session_init(ctx, secret, initiator);
+	return method_session_init(ctx, name, secret, initiator);
 }
 
 static bool method_session_is_valid(fastd_context_t *ctx, fastd_method_session_state_t *session) {
@@ -162,7 +166,7 @@ static bool method_decrypt(fastd_context_t *ctx, fastd_peer_t *peer, fastd_metho
 }
 
 const fastd_method_t fastd_method_xsalsa20_poly1305 = {
-	.name = "xsalsa20-poly1305",
+	.provides = method_provides,
 
 	.max_packet_size = method_max_packet_size,
 	.min_encrypt_head_space = method_min_encrypt_head_space,