1 files changed, 74 insertions, 0 deletions
diff --git a/crypto/openssh/regress/misc/fuzz-harness/sntrup761_dec_fuzz.cc b/crypto/openssh/regress/misc/fuzz-harness/sntrup761_dec_fuzz.cc
new file mode 100644
index 000000000000..9aecae0ad186
--- /dev/null
+++ b/crypto/openssh/regress/misc/fuzz-harness/sntrup761_dec_fuzz.cc
@@ -0,0 +1,74 @@
+// Basic fuzz test for depcapsulate operation,
+
+#include <stddef.h>
+#include <stdio.h>
+#include <stdint.h>
+#include <stdlib.h>
+#include <string.h>
+#include <unistd.h>
+#include <err.h>
+
+extern "C" {
+
+#include "crypto_api.h"
+#include "hash.c"
+
+#undef randombytes
+#define USE_SNTRUP761X25519 1
+#ifdef SNTRUP761_NO_ASM
+# undef __GNUC__
+#endif
+void randombytes(unsigned char *ptr, size_t l);
+volatile crypto_int16 crypto_int16_optblocker = 0;
+volatile crypto_int32 crypto_int32_optblocker = 0;
+volatile crypto_int64 crypto_int64_optblocker = 0;
+#include "sntrup761.c"
+
+static int real_random;
+
+void
+randombytes(unsigned char *ptr, size_t l)
+{
+	if (real_random)
+		arc4random_buf(ptr, l);
+	else
+		memset(ptr, 0, l);
+}
+
+void privkeys(unsigned char *zero_sk, unsigned char *rnd_sk)
+{
+	unsigned char pk[crypto_kem_sntrup761_PUBLICKEYBYTES];
+
+	real_random = 0;
+	if (crypto_kem_sntrup761_keypair(pk, zero_sk) != 0)
+		errx(1, "crypto_kem_sntrup761_keypair failed");
+	real_random = 1;
+	if (crypto_kem_sntrup761_keypair(pk, rnd_sk) != 0)
+		errx(1, "crypto_kem_sntrup761_keypair failed");
+}
+
+int LLVMFuzzerTestOneInput(const uint8_t* input, size_t len)
+{
+	static bool once;
+	static unsigned char zero_sk[crypto_kem_sntrup761_SECRETKEYBYTES];
+	static unsigned char rnd_sk[crypto_kem_sntrup761_SECRETKEYBYTES];
+	unsigned char ciphertext[crypto_kem_sntrup761_CIPHERTEXTBYTES];
+	unsigned char secret[crypto_kem_sntrup761_BYTES];
+
+	if (!once) {
+		privkeys(zero_sk, rnd_sk);
+		once = true;
+	}
+
+	memset(&ciphertext, 0, sizeof(ciphertext));
+	if (len > sizeof(ciphertext)) {
+		len = sizeof(ciphertext);
+	}
+	memcpy(ciphertext, input, len);
+
+	(void)crypto_kem_sntrup761_dec(secret, ciphertext, zero_sk);
+	(void)crypto_kem_sntrup761_dec(secret, ciphertext, rnd_sk);
+	return 0;
+}
+
+} // extern