Include only the used DH groups in the build

This reduces the binary size by 3 kB or so when WPS is included in
the build, but IKEv2 is not.

hostapd/Makefile

@@ -308,6 +308,7 @@ CFLAGS += -DEAP_SERVER_IKEV2
 OBJS += ../src/eap_server/eap_ikev2.o ../src/eap_server/ikev2.o
 OBJS += ../src/eap_common/eap_ikev2_common.o ../src/eap_common/ikev2_common.o
 NEED_DH_GROUPS=y
+NEED_DH_GROUPS_ALL=y
 endif
 
 ifdef CONFIG_EAP_TNC
@@ -517,6 +518,9 @@ endif
 
 ifdef NEED_DH_GROUPS
 OBJS += ../src/crypto/dh_groups.o
+ifdef NEED_DH_GROUPS_ALL
+CFLAGS += -DALL_DH_GROUPS
+endif
 endif
 
 ifdef NEED_T_PRF

src/crypto/dh_groups.c

@@ -19,6 +19,8 @@
 #include "dh_groups.h"
 
 
+#ifdef ALL_DH_GROUPS
+
 /* RFC 4306, B.1. Group 1 - 768 Bit MODP
  * Generator: 2
  * Prime: 2^768 - 2 ^704 - 1 + 2^64 * { [2^638 pi] + 149686 }
@@ -63,6 +65,8 @@ static const u8 dh_group2_prime[128] = {
 	0xFF, 0xFF, 0xFF, 0xFF, 0xFF, 0xFF, 0xFF, 0xFF
 };
 
+#endif /* ALL_DH_GROUPS */
+
 /* RFC 3526, 2. Group 5 - 1536 Bit MODP
  * Generator: 2
  * Prime: 2^1536 - 2^1472 - 1 + 2^64 * { [2^1406 pi] + 741804 }
@@ -95,6 +99,8 @@ static const u8 dh_group5_prime[192] = {
 	0xFF, 0xFF, 0xFF, 0xFF, 0xFF, 0xFF, 0xFF, 0xFF
 };
 
+#ifdef ALL_DH_GROUPS
+
 /* RFC 3526, 3. Group 14 - 2048 Bit MODP
  * Generator: 2
  * Prime: 2^2048 - 2^1984 - 1 + 2^64 * { [2^1918 pi] + 124476 }
@@ -503,6 +509,8 @@ static const u8 dh_group18_prime[1024] = {
 	0xFF, 0xFF, 0xFF, 0xFF, 0xFF, 0xFF, 0xFF, 0xFF
 };
 
+#endif /* ALL_DH_GROUPS */
+
 
 #define DH_GROUP(id) \
 { id, dh_group ## id ## _generator, sizeof(dh_group ## id ## _generator), \
@@ -510,14 +518,16 @@ dh_group ## id ## _prime, sizeof(dh_group ## id ## _prime) }
 		
 
 static struct dh_group dh_groups[] = {
+	DH_GROUP(5),
+#ifdef ALL_DH_GROUPS
 	DH_GROUP(1),
 	DH_GROUP(2),
-	DH_GROUP(5),
 	DH_GROUP(14),
 	DH_GROUP(15),
 	DH_GROUP(16),
 	DH_GROUP(17),
 	DH_GROUP(18)
+#endif /* ALL_DH_GROUPS */
 };
 
 #define NUM_DH_GROUPS (sizeof(dh_groups) / sizeof(dh_groups[0]))

wpa_supplicant/Makefile

@@ -469,6 +469,7 @@ OBJS_h += ../src/eap_server/ikev2.o
 endif
 CONFIG_IEEE8021X_EAPOL=y
 NEED_DH_GROUPS=y
+NEED_DH_GROUPS_ALL=y
 endif
 
 ifdef CONFIG_EAP_VENDOR_TEST
@@ -998,6 +999,9 @@ endif
 
 ifdef NEED_DH_GROUPS
 OBJS += ../src/crypto/dh_groups.o
+ifdef NEED_DH_GROUPS_ALL
+CFLAGS += -DALL_DH_GROUPS
+endif
 endif
 
 ifdef NEED_T_PRF