Added DRBG automatic reseeding tests

3 files changed, 220 insertions, 170 deletions

diff --git a/man/strongswan.conf.5.in b/man/strongswan.conf.5.in
index 3ff61c33e..088bcc92a 100644
--- a/man/strongswan.conf.5.in
+++ b/man/strongswan.conf.5.in
@@ -867,6 +867,10 @@ Enable logging of SQL IP pool leases
 .BR libstrongswan.plugins.gcrypt.quick_random " [no]"
 Use faster random numbers in gcrypt; for testing only, produces weak keys!
 .TP
+.BR libstrongswan.plugins.ntru.max_drbg_requests " [4294967294]"
+Number of pseudo-random bit requests from the DRBG before an automatic
+reseeding occurs.
+.TP
 .BR libstrongswan.plugins.ntru.parameter_set " [optimum]"
 The following parameter sets are available: 'x9_98_speed', 'x9_98_bandwidth',
 'x9_98_balance' and 'optimum', the last set not being part of the X9.98
diff --git a/src/libstrongswan/plugins/ntru/ntru_drbg.c b/src/libstrongswan/plugins/ntru/ntru_drbg.c
index f9feb98ff..e6b29ab09 100644
--- a/src/libstrongswan/plugins/ntru/ntru_drbg.c
+++ b/src/libstrongswan/plugins/ntru/ntru_drbg.c
@@ -18,7 +18,7 @@
 #include <utils/debug.h>
 
 #define	MAX_STRENGTH_BITS	256
-#define MAX_DRBG_REQUESTS	0xffffffff
+#define MAX_DRBG_REQUESTS	0xfffffffe
 
 typedef struct private_ntru_drbg_t private_ntru_drbg_t;
 
@@ -149,7 +149,7 @@ METHOD(ntru_drbg_t, generate, bool,
 	}
 	output = chunk_create(out, len); 
 
-	if (this->reseed_counter >= this->max_requests)
+	if (this->reseed_counter > this->max_requests)
 	{
 		if (!reseed(this))
 		{
diff --git a/src/libstrongswan/tests/suites/test_ntru.c b/src/libstrongswan/tests/suites/test_ntru.c
index bdebf53fa..8dd22a5e4 100644
--- a/src/libstrongswan/tests/suites/test_ntru.c
+++ b/src/libstrongswan/tests/suites/test_ntru.c
@@ -100,161 +100,207 @@ START_TEST(test_ntru_drbg_strength)
 }
 END_TEST
 
+typedef struct {
+	chunk_t pers_str;
+	chunk_t entropy;
+	chunk_t out;
+} drbg_test_t;
+
+/**
+ * NIST SP 800-90A Deterministic Random Generator Validation System (DRBGVS)
+ */
+drbg_test_t drbg_tests[] = {
+	/* SHA-256 test case 1 - count 0 */
+	{ { NULL, 0 },
+	  chunk_from_chars(0x06, 0x03, 0x2c, 0xd5, 0xee, 0xd3, 0x3f, 0x39,
+					   0x26, 0x5f, 0x49, 0xec, 0xb1, 0x42, 0xc5, 0x11,
+					   0xda, 0x9a, 0xff, 0x2a, 0xf7, 0x12, 0x03, 0xbf,
+					   0xfa, 0xf3, 0x4a, 0x9c, 0xa5, 0xbd, 0x9c, 0x0d,
+					   0x0e, 0x66, 0xf7, 0x1e, 0xdc, 0x43, 0xe4, 0x2a,
+					   0x45, 0xad, 0x3c, 0x6f, 0xc6, 0xcd, 0xc4, 0xdf,
+					   0x01, 0x92, 0x0a, 0x4e, 0x66, 0x9e, 0xd3, 0xa8,
+					   0x5a, 0xe8, 0xa3, 0x3b, 0x35, 0xa7, 0x4a, 0xd7,
+					   0xfb, 0x2a, 0x6b, 0xb4, 0xcf, 0x39, 0x5c, 0xe0,
+					   0x03, 0x34, 0xa9, 0xc9, 0xa5, 0xa5, 0xd5, 0x52),
+	  chunk_from_chars(0x76, 0xfc, 0x79, 0xfe, 0x9b, 0x50, 0xbe, 0xcc,
+					   0xc9, 0x91, 0xa1, 0x1b, 0x56, 0x35, 0x78, 0x3a,
+					   0x83, 0x53, 0x6a, 0xdd, 0x03, 0xc1, 0x57, 0xfb,
+					   0x30, 0x64, 0x5e, 0x61, 0x1c, 0x28, 0x98, 0xbb,
+					   0x2b, 0x1b, 0xc2, 0x15, 0x00, 0x02, 0x09, 0x20,
+					   0x8c, 0xd5, 0x06, 0xcb, 0x28, 0xda, 0x2a, 0x51,
+					   0xbd, 0xb0, 0x38, 0x26, 0xaa, 0xf2, 0xbd, 0x23,
+					   0x35, 0xd5, 0x76, 0xd5, 0x19, 0x16, 0x08, 0x42,
+					   0xe7, 0x15, 0x8a, 0xd0, 0x94, 0x9d, 0x1a, 0x9e,
+					   0xc3, 0xe6, 0x6e, 0xa1, 0xb1, 0xa0, 0x64, 0xb0,
+					   0x05, 0xde, 0x91, 0x4e, 0xac, 0x2e, 0x9d, 0x4f,
+					   0x2d, 0x72, 0xa8, 0x61, 0x6a, 0x80, 0x22, 0x54,
+					   0x22, 0x91, 0x82, 0x50, 0xff, 0x66, 0xa4, 0x1b,
+					   0xd2, 0xf8, 0x64, 0xa6, 0xa3, 0x8c, 0xc5, 0xb6,
+					   0x49, 0x9d, 0xc4, 0x3f, 0x7f, 0x2b, 0xd0, 0x9e,
+					   0x1e, 0x0f, 0x8f, 0x58, 0x85, 0x93, 0x51, 0x24)
+	},
+	/* SHA-256 test case 3 - count 0 */
+	{ chunk_from_chars(0xf2, 0xe5, 0x8f, 0xe6, 0x0a, 0x3a, 0xfc, 0x59,
+					   0xda, 0xd3, 0x75, 0x95, 0x41, 0x5f, 0xfd, 0x31,
+					   0x8c, 0xcf, 0x69, 0xd6, 0x77, 0x80, 0xf6, 0xfa,
+					   0x07, 0x97, 0xdc, 0x9a, 0xa4, 0x3e, 0x14, 0x4c),
+	  chunk_from_chars(0xfa, 0x0e, 0xe1, 0xfe, 0x39, 0xc7, 0xc3, 0x90,
+					   0xaa, 0x94, 0x15, 0x9d, 0x0d, 0xe9, 0x75, 0x64,
+					   0x34, 0x2b, 0x59, 0x17, 0x77, 0xf3, 0xe5, 0xf6,
+					   0xa4, 0xba, 0x2a, 0xea, 0x34, 0x2e, 0xc8, 0x40,
+					   0xdd, 0x08, 0x20, 0x65, 0x5c, 0xb2, 0xff, 0xdb,
+					   0x0d, 0xa9, 0xe9, 0x31, 0x0a, 0x67, 0xc9, 0xe5,
+					   0xe0, 0x62, 0x9b, 0x6d, 0x79, 0x75, 0xdd, 0xfa,
+					   0x96, 0xa3, 0x99, 0x64, 0x87, 0x40, 0xe6, 0x0f,
+					   0x1f, 0x95, 0x57, 0xdc, 0x58, 0xb3, 0xd7, 0x41,
+					   0x5f, 0x9b, 0xa9, 0xd4, 0xdb, 0xb5, 0x01, 0xf6),
+	  chunk_from_chars(0xf9, 0x2d, 0x4c, 0xf9, 0x9a, 0x53, 0x5b, 0x20,
+					   0x22, 0x2a, 0x52, 0xa6, 0x8d, 0xb0, 0x4c, 0x5a,
+					   0xf6, 0xf5, 0xff, 0xc7, 0xb6, 0x6a, 0x47, 0x3a,
+					   0x37, 0xa2, 0x56, 0xbd, 0x8d, 0x29, 0x8f, 0x9b,
+					   0x4a, 0xa4, 0xaf, 0x7e, 0x8d, 0x18, 0x1e, 0x02,
+					   0x36, 0x79, 0x03, 0xf9, 0x3b, 0xdb, 0x74, 0x4c,
+					   0x6c, 0x2f, 0x3f, 0x34, 0x72, 0x62, 0x6b, 0x40,
+					   0xce, 0x9b, 0xd6, 0xa7, 0x0e, 0x7b, 0x8f, 0x93,
+					   0x99, 0x2a, 0x16, 0xa7, 0x6f, 0xab, 0x6b, 0x5f,
+					   0x16, 0x25, 0x68, 0xe0, 0x8e, 0xe6, 0xc3, 0xe8,
+					   0x04, 0xae, 0xfd, 0x95, 0x2d, 0xdd, 0x3a, 0xcb,
+					   0x79, 0x1c, 0x50, 0xf2, 0xad, 0x69, 0xe9, 0xa0,
+					   0x40, 0x28, 0xa0, 0x6a, 0x9c, 0x01, 0xd3, 0xa6,
+					   0x2a, 0xca, 0x2a, 0xaf, 0x6e, 0xfe, 0x69, 0xed,
+					   0x97, 0xa0, 0x16, 0x21, 0x3a, 0x2d, 0xd6, 0x42,
+					   0xb4, 0x88, 0x67, 0x64, 0x07, 0x2d, 0x9c, 0xbe)
+	},
+	/* SHA-256 test case 5 - count 0 */
+	{ { NULL, 0 },
+	  chunk_from_chars(0xff, 0x0c, 0xdd, 0x55, 0x5c, 0x60, 0x46, 0x47,
+					   0x60, 0xb2, 0x89, 0xb7, 0xbc, 0x1f, 0x81, 0x1a,
+					   0x41, 0xff, 0xf7, 0x2d, 0xe5, 0x90, 0x83, 0x85,
+					   0x8c, 0x02, 0x0a, 0x10, 0x53, 0xbd, 0xc7, 0x4a,
+					   0x7b, 0xc0, 0x99, 0x28, 0x5a, 0xd5, 0x62, 0x19,
+					   0x93, 0xb6, 0x39, 0xc4, 0xa9, 0x4c, 0x37, 0x6b,
+					   0x14, 0xfc, 0x6c, 0x9b, 0x17, 0x8d, 0xb6, 0x44,
+					   0xa8, 0xcd, 0x71, 0x30, 0xa4, 0xcf, 0x05, 0x16,
+					   0x78, 0xc8, 0xf4, 0xfa, 0x8f, 0x24, 0xc2, 0x7b,
+					   0x0a, 0x53, 0x13, 0x38, 0xa5, 0xce, 0x85, 0x89),
+	  chunk_from_chars(0x2f, 0x26, 0x20, 0x34, 0x7b, 0xdd, 0xca, 0xa2,
+					   0x94, 0x36, 0x85, 0x34, 0x6b, 0xbf, 0x31, 0xc4,
+					   0x40, 0x81, 0xf8, 0x66, 0x5f, 0x3d, 0xdb, 0x2b,
+					   0x42, 0xae, 0x14, 0x16, 0xa7, 0x4c, 0x4b, 0x77,
+					   0xfa, 0xb3, 0xfa, 0x19, 0xae, 0xec, 0xc5, 0x47,
+					   0xe7, 0x6c, 0x8c, 0xbe, 0x6a, 0xd1, 0xf1, 0x00,
+					   0xa3, 0xfc, 0x8b, 0x2c, 0xe2, 0xa1, 0xea, 0x3a,
+					   0x3d, 0xd7, 0xcf, 0xad, 0x46, 0xc1, 0xb2, 0x78,
+					   0x30, 0xb9, 0x40, 0xba, 0x18, 0xd0, 0x9e, 0x9b,
+					   0x7f, 0xa9, 0x02, 0xbb, 0x76, 0x06, 0x69, 0xb1,
+					   0x73, 0x5c, 0xc7, 0xb7, 0xbd, 0x39, 0x05, 0x2d,
+					   0xa7, 0xf2, 0x62, 0x6f, 0xa8, 0x70, 0x00, 0xcf,
+					   0xfa, 0xda, 0x41, 0x00, 0x19, 0xd0, 0x53, 0x38,
+					   0x6a, 0xd8, 0x08, 0xbd, 0x3c, 0x0c, 0xfc, 0xf5,
+					   0x6b, 0x91, 0x87, 0x9e, 0xb8, 0xd3, 0xf9, 0x32,
+					   0xee, 0x2d, 0x18, 0x5e, 0x54, 0xf3, 0x1b, 0x74)
+	},
+	/* SHA-256 test case 7 - count 0 */
+	{ chunk_from_chars(0x40, 0x93, 0x3f, 0xdc, 0xce, 0x41, 0x59, 0xb0,
+					   0x95, 0x51, 0x11, 0xf8, 0x44, 0x47, 0x1b, 0x0d,
+					   0xb8, 0x5b, 0x73, 0xbd, 0xd2, 0xb7, 0x8c, 0x46,
+					   0x8d, 0xd3, 0x9e, 0x2a, 0x9b, 0x29, 0xae, 0xf2),
+	  chunk_from_chars(0x28, 0xba, 0x1a, 0x66, 0x16, 0x32, 0xef, 0xc8,
+					   0xec, 0xce, 0xd5, 0xf5, 0x1b, 0x79, 0x13, 0x00,
+					   0xfb, 0x3b, 0x55, 0xb0, 0x5d, 0x04, 0x17, 0x08,
+					   0x63, 0x8d, 0xe4, 0xbe, 0xb7, 0x57, 0xa9, 0xe5,
+					   0x76, 0x82, 0x87, 0x96, 0xaf, 0xf0, 0x7f, 0x55,
+					   0x79, 0x5c, 0xb5, 0x47, 0x13, 0xc7, 0x7e, 0xd4,
+					   0xa5, 0xf5, 0x42, 0xb0, 0x4a, 0xaa, 0x5d, 0xbc,
+					   0x93, 0x1e, 0x47, 0x01, 0x9f, 0xeb, 0x38, 0x96,
+					   0x26, 0x16, 0xc5, 0x7a, 0xf0, 0x9b, 0x7c, 0x1d,
+					   0xf8, 0x3f, 0x2b, 0x86, 0x0f, 0xf7, 0x65, 0x86),
+	  chunk_from_chars(0x65, 0xe5, 0xaa, 0x47, 0xb3, 0x85, 0xf1, 0xea,
+					   0x42, 0xb2, 0x31, 0xb9, 0xfe, 0x74, 0x42, 0x53,
+					   0xb8, 0x59, 0x88, 0x59, 0xd7, 0x01, 0x1e, 0x52,
+					   0x5f, 0x5a, 0x2a, 0x1a, 0xd3, 0x2a, 0x97, 0x2a,
+					   0x85, 0x08, 0x02, 0xc6, 0x0a, 0x2b, 0xe1, 0x9b,
+					   0xe2, 0x70, 0x06, 0x3a, 0x3c, 0xfb, 0xea, 0xae,
+					   0x95, 0x4f, 0x10, 0xb1, 0x22, 0x35, 0x2d, 0xe6,
+					   0xa0, 0x8a, 0xc4, 0x10, 0xe0, 0x99, 0x16, 0x53,
+					   0xaa, 0xb2, 0x71, 0xb3, 0x60, 0xfe, 0x91, 0x91,
+					   0xcf, 0x5a, 0xdd, 0xcc, 0xcc, 0xed, 0x8c, 0x4a,
+					   0xcf, 0xb6, 0x14, 0x57, 0x04, 0x99, 0x92, 0x98,
+					   0x8f, 0xd7, 0xa9, 0xac, 0xca, 0x1f, 0x1b, 0xca,
+					   0x35, 0xf1, 0x47, 0x58, 0x13, 0x69, 0x4a, 0x39,
+					   0x98, 0x8e, 0x5f, 0xac, 0x9f, 0x4a, 0xc0, 0x57,
+					   0x22, 0x86, 0xbc, 0x46, 0x25, 0x82, 0xad, 0x0a,
+					   0xf7, 0x8a, 0xb3, 0xb8, 0x5e, 0xc1, 0x7a, 0x25)
+	}
+};
+
 START_TEST(test_ntru_drbg)
 {
-	typedef struct {
-		chunk_t pers_str;
-		chunk_t entropy;
-		chunk_t out;
-	} drbg_test_t;
-
-	/**
-	 * NIST SP 800-90A Deterministic Random Generator Validation System (DRBGVS)
-	 */
-	drbg_test_t drbg_tests[] = {
-		/* SHA-256 test case 1 - count 0 */
-		{ chunk_empty,
-		  chunk_from_chars(0x06, 0x03, 0x2c, 0xd5, 0xee, 0xd3, 0x3f, 0x39,
-						   0x26, 0x5f, 0x49, 0xec, 0xb1, 0x42, 0xc5, 0x11,
-						   0xda, 0x9a, 0xff, 0x2a, 0xf7, 0x12, 0x03, 0xbf,
-						   0xfa, 0xf3, 0x4a, 0x9c, 0xa5, 0xbd, 0x9c, 0x0d,
-						   0x0e, 0x66, 0xf7, 0x1e, 0xdc, 0x43, 0xe4, 0x2a,
-						   0x45, 0xad, 0x3c, 0x6f, 0xc6, 0xcd, 0xc4, 0xdf,
-						   0x01, 0x92, 0x0a, 0x4e, 0x66, 0x9e, 0xd3, 0xa8,
-						   0x5a, 0xe8, 0xa3, 0x3b, 0x35, 0xa7, 0x4a, 0xd7,
-						   0xfb, 0x2a, 0x6b, 0xb4, 0xcf, 0x39, 0x5c, 0xe0,
-						   0x03, 0x34, 0xa9, 0xc9, 0xa5, 0xa5, 0xd5, 0x52),
-		  chunk_from_chars(0x76, 0xfc, 0x79, 0xfe, 0x9b, 0x50, 0xbe, 0xcc,
-						   0xc9, 0x91, 0xa1, 0x1b, 0x56, 0x35, 0x78, 0x3a,
-						   0x83, 0x53, 0x6a, 0xdd, 0x03, 0xc1, 0x57, 0xfb,
-						   0x30, 0x64, 0x5e, 0x61, 0x1c, 0x28, 0x98, 0xbb,
-						   0x2b, 0x1b, 0xc2, 0x15, 0x00, 0x02, 0x09, 0x20,
-						   0x8c, 0xd5, 0x06, 0xcb, 0x28, 0xda, 0x2a, 0x51,
-						   0xbd, 0xb0, 0x38, 0x26, 0xaa, 0xf2, 0xbd, 0x23,
-						   0x35, 0xd5, 0x76, 0xd5, 0x19, 0x16, 0x08, 0x42,
-						   0xe7, 0x15, 0x8a, 0xd0, 0x94, 0x9d, 0x1a, 0x9e,
-						   0xc3, 0xe6, 0x6e, 0xa1, 0xb1, 0xa0, 0x64, 0xb0,
-						   0x05, 0xde, 0x91, 0x4e, 0xac, 0x2e, 0x9d, 0x4f,
-						   0x2d, 0x72, 0xa8, 0x61, 0x6a, 0x80, 0x22, 0x54,
-						   0x22, 0x91, 0x82, 0x50, 0xff, 0x66, 0xa4, 0x1b,
-						   0xd2, 0xf8, 0x64, 0xa6, 0xa3, 0x8c, 0xc5, 0xb6,
-						   0x49, 0x9d, 0xc4, 0x3f, 0x7f, 0x2b, 0xd0, 0x9e,
-						   0x1e, 0x0f, 0x8f, 0x58, 0x85, 0x93, 0x51, 0x24)
-		},
-		/* SHA-256 test case 3 - count 0 */
-		{ chunk_from_chars(0xf2, 0xe5, 0x8f, 0xe6, 0x0a, 0x3a, 0xfc, 0x59,
-						   0xda, 0xd3, 0x75, 0x95, 0x41, 0x5f, 0xfd, 0x31,
-						   0x8c, 0xcf, 0x69, 0xd6, 0x77, 0x80, 0xf6, 0xfa,
-						   0x07, 0x97, 0xdc, 0x9a, 0xa4, 0x3e, 0x14, 0x4c),
-		  chunk_from_chars(0xfa, 0x0e, 0xe1, 0xfe, 0x39, 0xc7, 0xc3, 0x90,
-						   0xaa, 0x94, 0x15, 0x9d, 0x0d, 0xe9, 0x75, 0x64,
-						   0x34, 0x2b, 0x59, 0x17, 0x77, 0xf3, 0xe5, 0xf6,
-						   0xa4, 0xba, 0x2a, 0xea, 0x34, 0x2e, 0xc8, 0x40,
-						   0xdd, 0x08, 0x20, 0x65, 0x5c, 0xb2, 0xff, 0xdb,
-						   0x0d, 0xa9, 0xe9, 0x31, 0x0a, 0x67, 0xc9, 0xe5,
-						   0xe0, 0x62, 0x9b, 0x6d, 0x79, 0x75, 0xdd, 0xfa,
-						   0x96, 0xa3, 0x99, 0x64, 0x87, 0x40, 0xe6, 0x0f,
-						   0x1f, 0x95, 0x57, 0xdc, 0x58, 0xb3, 0xd7, 0x41,
-						   0x5f, 0x9b, 0xa9, 0xd4, 0xdb, 0xb5, 0x01, 0xf6),
-		  chunk_from_chars(0xf9, 0x2d, 0x4c, 0xf9, 0x9a, 0x53, 0x5b, 0x20,
-						   0x22, 0x2a, 0x52, 0xa6, 0x8d, 0xb0, 0x4c, 0x5a,
-						   0xf6, 0xf5, 0xff, 0xc7, 0xb6, 0x6a, 0x47, 0x3a,
-						   0x37, 0xa2, 0x56, 0xbd, 0x8d, 0x29, 0x8f, 0x9b,
-						   0x4a, 0xa4, 0xaf, 0x7e, 0x8d, 0x18, 0x1e, 0x02,
-						   0x36, 0x79, 0x03, 0xf9, 0x3b, 0xdb, 0x74, 0x4c,
-						   0x6c, 0x2f, 0x3f, 0x34, 0x72, 0x62, 0x6b, 0x40,
-						   0xce, 0x9b, 0xd6, 0xa7, 0x0e, 0x7b, 0x8f, 0x93,
-						   0x99, 0x2a, 0x16, 0xa7, 0x6f, 0xab, 0x6b, 0x5f,
-						   0x16, 0x25, 0x68, 0xe0, 0x8e, 0xe6, 0xc3, 0xe8,
-						   0x04, 0xae, 0xfd, 0x95, 0x2d, 0xdd, 0x3a, 0xcb,
-						   0x79, 0x1c, 0x50, 0xf2, 0xad, 0x69, 0xe9, 0xa0,
-						   0x40, 0x28, 0xa0, 0x6a, 0x9c, 0x01, 0xd3, 0xa6,
-						   0x2a, 0xca, 0x2a, 0xaf, 0x6e, 0xfe, 0x69, 0xed,
-						   0x97, 0xa0, 0x16, 0x21, 0x3a, 0x2d, 0xd6, 0x42,
-						   0xb4, 0x88, 0x67, 0x64, 0x07, 0x2d, 0x9c, 0xbe)
-		},
-		/* SHA-256 test case 5 - count 0 */
-		{ chunk_empty,
-		  chunk_from_chars(0xff, 0x0c, 0xdd, 0x55, 0x5c, 0x60, 0x46, 0x47,
-						   0x60, 0xb2, 0x89, 0xb7, 0xbc, 0x1f, 0x81, 0x1a,
-						   0x41, 0xff, 0xf7, 0x2d, 0xe5, 0x90, 0x83, 0x85,
-						   0x8c, 0x02, 0x0a, 0x10, 0x53, 0xbd, 0xc7, 0x4a,
-						   0x7b, 0xc0, 0x99, 0x28, 0x5a, 0xd5, 0x62, 0x19,
-						   0x93, 0xb6, 0x39, 0xc4, 0xa9, 0x4c, 0x37, 0x6b,
-						   0x14, 0xfc, 0x6c, 0x9b, 0x17, 0x8d, 0xb6, 0x44,
-						   0xa8, 0xcd, 0x71, 0x30, 0xa4, 0xcf, 0x05, 0x16,
-						   0x78, 0xc8, 0xf4, 0xfa, 0x8f, 0x24, 0xc2, 0x7b,
-						   0x0a, 0x53, 0x13, 0x38, 0xa5, 0xce, 0x85, 0x89),
-		  chunk_from_chars(0x2f, 0x26, 0x20, 0x34, 0x7b, 0xdd, 0xca, 0xa2,
-						   0x94, 0x36, 0x85, 0x34, 0x6b, 0xbf, 0x31, 0xc4,
-						   0x40, 0x81, 0xf8, 0x66, 0x5f, 0x3d, 0xdb, 0x2b,
-						   0x42, 0xae, 0x14, 0x16, 0xa7, 0x4c, 0x4b, 0x77,
-						   0xfa, 0xb3, 0xfa, 0x19, 0xae, 0xec, 0xc5, 0x47,
-						   0xe7, 0x6c, 0x8c, 0xbe, 0x6a, 0xd1, 0xf1, 0x00,
-						   0xa3, 0xfc, 0x8b, 0x2c, 0xe2, 0xa1, 0xea, 0x3a,
-						   0x3d, 0xd7, 0xcf, 0xad, 0x46, 0xc1, 0xb2, 0x78,
-						   0x30, 0xb9, 0x40, 0xba, 0x18, 0xd0, 0x9e, 0x9b,
-						   0x7f, 0xa9, 0x02, 0xbb, 0x76, 0x06, 0x69, 0xb1,
-						   0x73, 0x5c, 0xc7, 0xb7, 0xbd, 0x39, 0x05, 0x2d,
-						   0xa7, 0xf2, 0x62, 0x6f, 0xa8, 0x70, 0x00, 0xcf,
-						   0xfa, 0xda, 0x41, 0x00, 0x19, 0xd0, 0x53, 0x38,
-						   0x6a, 0xd8, 0x08, 0xbd, 0x3c, 0x0c, 0xfc, 0xf5,
-						   0x6b, 0x91, 0x87, 0x9e, 0xb8, 0xd3, 0xf9, 0x32,
-						   0xee, 0x2d, 0x18, 0x5e, 0x54, 0xf3, 0x1b, 0x74)
-		},
-		/* SHA-256 test case 7 - count 0 */
-		{ chunk_from_chars(0x40, 0x93, 0x3f, 0xdc, 0xce, 0x41, 0x59, 0xb0,
-						   0x95, 0x51, 0x11, 0xf8, 0x44, 0x47, 0x1b, 0x0d,
-						   0xb8, 0x5b, 0x73, 0xbd, 0xd2, 0xb7, 0x8c, 0x46,
-						   0x8d, 0xd3, 0x9e, 0x2a, 0x9b, 0x29, 0xae, 0xf2),
-		  chunk_from_chars(0x28, 0xba, 0x1a, 0x66, 0x16, 0x32, 0xef, 0xc8,
-						   0xec, 0xce, 0xd5, 0xf5, 0x1b, 0x79, 0x13, 0x00,
-						   0xfb, 0x3b, 0x55, 0xb0, 0x5d, 0x04, 0x17, 0x08,
-						   0x63, 0x8d, 0xe4, 0xbe, 0xb7, 0x57, 0xa9, 0xe5,
-						   0x76, 0x82, 0x87, 0x96, 0xaf, 0xf0, 0x7f, 0x55,
-						   0x79, 0x5c, 0xb5, 0x47, 0x13, 0xc7, 0x7e, 0xd4,
-						   0xa5, 0xf5, 0x42, 0xb0, 0x4a, 0xaa, 0x5d, 0xbc,
-						   0x93, 0x1e, 0x47, 0x01, 0x9f, 0xeb, 0x38, 0x96,
-						   0x26, 0x16, 0xc5, 0x7a, 0xf0, 0x9b, 0x7c, 0x1d,
-						   0xf8, 0x3f, 0x2b, 0x86, 0x0f, 0xf7, 0x65, 0x86),
-		  chunk_from_chars(0x65, 0xe5, 0xaa, 0x47, 0xb3, 0x85, 0xf1, 0xea,
-						   0x42, 0xb2, 0x31, 0xb9, 0xfe, 0x74, 0x42, 0x53,
-						   0xb8, 0x59, 0x88, 0x59, 0xd7, 0x01, 0x1e, 0x52,
-						   0x5f, 0x5a, 0x2a, 0x1a, 0xd3, 0x2a, 0x97, 0x2a,
-						   0x85, 0x08, 0x02, 0xc6, 0x0a, 0x2b, 0xe1, 0x9b,
-						   0xe2, 0x70, 0x06, 0x3a, 0x3c, 0xfb, 0xea, 0xae,
-						   0x95, 0x4f, 0x10, 0xb1, 0x22, 0x35, 0x2d, 0xe6,
-						   0xa0, 0x8a, 0xc4, 0x10, 0xe0, 0x99, 0x16, 0x53,
-						   0xaa, 0xb2, 0x71, 0xb3, 0x60, 0xfe, 0x91, 0x91,
-						   0xcf, 0x5a, 0xdd, 0xcc, 0xcc, 0xed, 0x8c, 0x4a,
-						   0xcf, 0xb6, 0x14, 0x57, 0x04, 0x99, 0x92, 0x98,
-						   0x8f, 0xd7, 0xa9, 0xac, 0xca, 0x1f, 0x1b, 0xca,
-						   0x35, 0xf1, 0x47, 0x58, 0x13, 0x69, 0x4a, 0x39,
-						   0x98, 0x8e, 0x5f, 0xac, 0x9f, 0x4a, 0xc0, 0x57,
-						   0x22, 0x86, 0xbc, 0x46, 0x25, 0x82, 0xad, 0x0a,
-						   0xf7, 0x8a, 0xb3, 0xb8, 0x5e, 0xc1, 0x7a, 0x25)
-		}
-	};
+	ntru_drbg_t *drbg;
+	rng_t *entropy;
+	chunk_t out;
 
+	out = chunk_alloc(128);
+	entropy = ntru_test_rng_create(drbg_tests[_i].entropy);
+	drbg = ntru_drbg_create(256, drbg_tests[_i].pers_str, entropy);
+	ck_assert(drbg != NULL);
+	ck_assert(drbg->reseed(drbg));
+	ck_assert(drbg->generate(drbg, 256, 128, out.ptr));
+	ck_assert(drbg->generate(drbg, 256, 128, out.ptr));
+	ck_assert(chunk_equals(out, drbg_tests[_i].out));
+	drbg->destroy(drbg);
+	entropy->destroy(entropy);
+	chunk_free(&out);
+}
+END_TEST
+
+START_TEST(test_ntru_drbg_reseed)
+{
 	ntru_drbg_t *drbg;
 	rng_t *entropy;
 	chunk_t out;
-	int i;
 
+	lib->settings->set_int(lib->settings,
+						  "libstrongswan.plugins.ntru.max_drbg_requests", 2);
 	out = chunk_alloc(128);
-	for (i = 0; i < countof(drbg_tests); i++)
-	{
-		entropy = ntru_test_rng_create(drbg_tests[i].entropy);
-		drbg = ntru_drbg_create(256, drbg_tests[i].pers_str, entropy);
-		ck_assert(drbg != NULL);
-		ck_assert(drbg->reseed(drbg));
-		ck_assert(drbg->generate(drbg, 256, 128, out.ptr));
-		ck_assert(drbg->generate(drbg, 256, 128, out.ptr));
-		ck_assert(chunk_equals(out, drbg_tests[i].out));
-		drbg->destroy(drbg);
-		entropy->destroy(entropy);
-	}
+	entropy = ntru_test_rng_create(drbg_tests[0].entropy);
+	drbg = ntru_drbg_create(256, chunk_empty, entropy);
+
+	/* bad output parameters */
+	ck_assert(!drbg->generate(drbg, 256, 0, out.ptr));
+	ck_assert(!drbg->generate(drbg, 256, 128, NULL));
+
+	/* no reseeding occurs */
+	ck_assert(drbg->generate(drbg, 256, 128, out.ptr));
+	ck_assert(drbg->generate(drbg, 256, 128, out.ptr));
+
+	/* consuming remaining entropy */
+	ck_assert(entropy->get_bytes(entropy, 32, out.ptr));
+
+	/* no entropy available for automatic reseeding */
+	ck_assert(!drbg->generate(drbg, 256, 128, out.ptr));
+	drbg->destroy(drbg);
+
+	/* no entropy available for DRBG instantiation */
+	drbg = ntru_drbg_create(256, chunk_empty, entropy);
+	ck_assert(drbg == NULL);
+	entropy->destroy(entropy);
+
+	/* one automatic reseeding occurs */
+	entropy = ntru_test_rng_create(drbg_tests[0].entropy);
+	drbg = ntru_drbg_create(256, chunk_empty, entropy);
+	ck_assert(drbg->generate(drbg, 256, 128, out.ptr));
+	ck_assert(drbg->generate(drbg, 256, 128, out.ptr));
+	ck_assert(drbg->generate(drbg, 256, 128, out.ptr));
+
+	/* no entropy left */
+	ck_assert(!entropy->get_bytes(entropy, 32, out.ptr));
+
+	drbg->destroy(drbg);
+	entropy->destroy(entropy);
 	chunk_free(&out);
+	lib->settings->set_int(lib->settings,
+						  "libstrongswan.plugins.ntru.max_drbg_requests", 2000);
 }
 END_TEST
 
@@ -333,31 +379,27 @@ START_TEST(test_ntru_retransmission)
 }
 END_TEST
 
+chunk_t oid_tests[] = {
+	{ NULL, 0 },
+	chunk_from_chars(0x00),
+	chunk_from_chars(0x01),
+	chunk_from_chars(0x02),
+	chunk_from_chars(0x02, 0x03, 0x00, 0x03, 0x10),
+	chunk_from_chars(0x01, 0x04, 0x00, 0x03, 0x10),
+	chunk_from_chars(0x01, 0x03, 0x00, 0x03, 0x10),
+	chunk_from_chars(0x01, 0x03, 0xff, 0x03, 0x10),
+};
+
 START_TEST(test_ntru_pubkey_oid)
 {
-	chunk_t test[] = {
-		chunk_empty,
-		chunk_from_chars(0x00),
-		chunk_from_chars(0x01),
-		chunk_from_chars(0x02),
-		chunk_from_chars(0x02, 0x03, 0x00, 0x03, 0x10),
-		chunk_from_chars(0x01, 0x04, 0x00, 0x03, 0x10),
-		chunk_from_chars(0x01, 0x03, 0x00, 0x03, 0x10),
-		chunk_from_chars(0x01, 0x03, 0xff, 0x03, 0x10),
-	};
-
 	diffie_hellman_t *r_ntru;
 	chunk_t cipher_text;
-	int i;
 
-	for (i = 0; i < countof(test); i++)
-	{
-		r_ntru = lib->crypto->create_dh(lib->crypto, NTRU_128_BIT);
-		r_ntru->set_other_public_value(r_ntru, test[i]);
-		r_ntru->get_my_public_value(r_ntru, &cipher_text);
-		ck_assert(cipher_text.len == 0);
-		r_ntru->destroy(r_ntru);
-	}
+	r_ntru = lib->crypto->create_dh(lib->crypto, NTRU_128_BIT);
+	r_ntru->set_other_public_value(r_ntru, oid_tests[_i]);
+	r_ntru->get_my_public_value(r_ntru, &cipher_text);
+	ck_assert(cipher_text.len == 0);
+	r_ntru->destroy(r_ntru);
 }
 END_TEST
 
@@ -461,7 +503,11 @@ Suite *ntru_suite_create()
 	suite_add_tcase(s, tc);
 
 	tc = tcase_create("drbg");
-	tcase_add_test(tc, test_ntru_drbg);
+	tcase_add_loop_test(tc, test_ntru_drbg, 0, countof(drbg_tests));
+	suite_add_tcase(s, tc);
+
+	tc = tcase_create("drgb_reseed");
+	tcase_add_test(tc, test_ntru_drbg_reseed);
 	suite_add_tcase(s, tc);
 
 	tc = tcase_create("ke");
@@ -473,7 +519,7 @@ Suite *ntru_suite_create()
 	suite_add_tcase(s, tc);
 
 	tc = tcase_create("pubkey_oid");
-	tcase_add_test(tc, test_ntru_pubkey_oid);
+	tcase_add_loop_test(tc, test_ntru_pubkey_oid, 0, countof(oid_tests));
 	suite_add_tcase(s, tc);
 
 	tc = tcase_create("wrong_set");