1 files changed, 67 insertions, 0 deletions
diff --git a/security/nss/lib/freebl/det_rng.c b/security/nss/lib/freebl/det_rng.c
new file mode 100644
index 000000000..fcbf9b34a
--- /dev/null
+++ b/security/nss/lib/freebl/det_rng.c
@@ -0,0 +1,67 @@
+/* This Source Code Form is subject to the terms of the Mozilla Public
+ * License, v. 2.0. If a copy of the MPL was not distributed with this
+ * file, You can obtain one at http://mozilla.org/MPL/2.0/. */
+
+#include "blapi.h"
+#include "blapit.h"
+#include "chacha20.h"
+#include "nssilock.h"
+#include "seccomon.h"
+#include "secerr.h"
+
+static unsigned long globalNumCalls = 0;
+
+SECStatus
+prng_ResetForFuzzing(PZLock *rng_lock)
+{
+    /* Check for a valid RNG lock. */
+    PORT_Assert(rng_lock != NULL);
+    if (rng_lock == NULL) {
+        PORT_SetError(SEC_ERROR_INVALID_ARGS);
+        return SECFailure;
+    }
+
+    /* --- LOCKED --- */
+    PZ_Lock(rng_lock);
+    globalNumCalls = 0;
+    PZ_Unlock(rng_lock);
+    /* --- UNLOCKED --- */
+
+    return SECSuccess;
+}
+
+SECStatus
+prng_GenerateDeterministicRandomBytes(PZLock *rng_lock, void *dest, size_t len)
+{
+    static const uint8_t key[32];
+    uint8_t nonce[12] = { 0 };
+
+    /* Check for a valid RNG lock. */
+    PORT_Assert(rng_lock != NULL);
+    if (rng_lock == NULL) {
+        PORT_SetError(SEC_ERROR_INVALID_ARGS);
+        return SECFailure;
+    }
+
+    /* --- LOCKED --- */
+    PZ_Lock(rng_lock);
+
+    memcpy(nonce, &globalNumCalls, sizeof(globalNumCalls));
+    globalNumCalls++;
+
+    ChaCha20Poly1305Context *cx =
+        ChaCha20Poly1305_CreateContext(key, sizeof(key), 16);
+    if (!cx) {
+        PORT_SetError(SEC_ERROR_NO_MEMORY);
+        PZ_Unlock(rng_lock);
+        return SECFailure;
+    }
+
+    memset(dest, 0, len);
+    ChaCha20XOR(dest, dest, len, key, nonce, 0);
+    ChaCha20Poly1305_DestroyContext(cx, PR_TRUE);
+
+    PZ_Unlock(rng_lock);
+    /* --- UNLOCKED --- */
+    return SECSuccess;
+}