Added a MODP_CUSTOM DH group which takes g and p as constructor arguments

src/libstrongswan/crypto/crypto_factory.c

@@ -308,7 +308,7 @@ METHOD(crypto_factory_t, create_rng, rng_t*,
 }
 
 METHOD(crypto_factory_t, create_dh, diffie_hellman_t*,
-	private_crypto_factory_t *this, diffie_hellman_group_t group)
+	private_crypto_factory_t *this, diffie_hellman_group_t group, ...)
 {
 	enumerator_t *enumerator;
 	entry_t *entry;
@@ -320,7 +320,21 @@ METHOD(crypto_factory_t, create_dh, diffie_hellman_t*,
 	{
 		if (entry->algo == group)
 		{
-			diffie_hellman = entry->create_dh(group);
+			if (group == MODP_CUSTOM)
+			{
+				va_list args;
+				chunk_t g, p;
+
+				va_start(args, group);
+				g = va_arg(args, chunk_t);
+				p = va_arg(args, chunk_t);
+				va_end(args);
+				diffie_hellman = entry->create_dh(MODP_CUSTOM, g, p);
+			}
+			else
+			{
+				diffie_hellman = entry->create_dh(group);
+			}
 			if (diffie_hellman)
 			{
 				break;

src/libstrongswan/crypto/crypto_factory.h

@@ -65,8 +65,11 @@ typedef rng_t* (*rng_constructor_t)(rng_quality_t quality);
 
 /**
  * Constructor function for diffie hellman
+ *
+ * The DH constructor accepts additional arguments for:
+ * - MODP_CUSTOM: chunk_t generator, chunk_t prime
  */
-typedef diffie_hellman_t* (*dh_constructor_t)(diffie_hellman_group_t group);
+typedef diffie_hellman_t* (*dh_constructor_t)(diffie_hellman_group_t group, ...);
 
 /**
  * Handles crypto modules and creates instances.
@@ -129,11 +132,13 @@ struct crypto_factory_t {
 	/**
 	 * Create a diffie hellman instance.
 	 *
+	 * Additional arguments are passed to the DH constructor.
+	 *
 	 * @param group			diffie hellman group
 	 * @return				diffie_hellman_t instance, NULL if not supported
 	 */
 	diffie_hellman_t* (*create_dh)(crypto_factory_t *this,
-								   diffie_hellman_group_t group);
+								   diffie_hellman_group_t group, ...);
 
 	/**
 	 * Register a crypter constructor.

src/libstrongswan/crypto/diffie_hellman.c

@@ -38,9 +38,10 @@ ENUM_NEXT(diffie_hellman_group_names, MODP_1024_160, ECP_224_BIT, ECP_521_BIT,
 	"MODP_2048_256",
 	"ECP_192",
 	"ECP_224");
-ENUM_NEXT(diffie_hellman_group_names, MODP_NULL, MODP_NULL, ECP_224_BIT,
+ENUM_NEXT(diffie_hellman_group_names, MODP_NULL, MODP_CUSTOM, ECP_224_BIT,
-	"MODP_NULL");
+	"MODP_NULL",
-ENUM_END(diffie_hellman_group_names, MODP_NULL);
+	"MODP_CUSTOM");
+ENUM_END(diffie_hellman_group_names, MODP_CUSTOM);
 
 
 /**

src/libstrongswan/crypto/diffie_hellman.h

@@ -57,6 +57,8 @@ enum diffie_hellman_group_t {
 	ECP_224_BIT   = 26,
 	/** insecure NULL diffie hellman group for testing, in PRIVATE USE */
 	MODP_NULL = 1024,
+	/** MODP group with custon generator, prime */
+	MODP_CUSTOM = 1025,
 };
 
 /**