1 files changed, 111 insertions, 0 deletions
diff --git a/lib/freebl/chacha20.c b/lib/freebl/chacha20.c
new file mode 100644
index 000000000..687be6639
--- /dev/null
+++ b/lib/freebl/chacha20.c
@@ -0,0 +1,111 @@
+/* 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/. */
+
+/* Adopted from the public domain code in NaCl by djb. */
+
+#include <string.h>
+#include <stdio.h>
+
+#include "prtypes.h"
+#include "secport.h"
+#include "chacha20.h"
+
+#if defined(_MSC_VER)
+#pragma intrinsic(_lrotl)
+#define ROTL32(x, n) _lrotl(x, n)
+#else
+#define ROTL32(x, n) ((x << n) | (x >> ((8 * sizeof x) - n)))
+#endif
+
+#define ROTATE(v, c) ROTL32((v), (c))
+
+#define U32TO8_LITTLE(p, v)                                                    \
+    { (p)[0] = ((v)      ) & 0xff; (p)[1] = ((v) >>  8) & 0xff;                \
+      (p)[2] = ((v) >> 16) & 0xff; (p)[3] = ((v) >> 24) & 0xff; }
+#define U8TO32_LITTLE(p)                                                       \
+    (((PRUint32)((p)[0])      ) | ((PRUint32)((p)[1]) <<  8) |                 \
+     ((PRUint32)((p)[2]) << 16) | ((PRUint32)((p)[3]) << 24))
+
+#define QUARTERROUND(x, a, b, c, d)                                            \
+    x[a] = x[a] + x[b]; x[d] = ROTATE(x[d] ^ x[a], 16);                        \
+    x[c] = x[c] + x[d]; x[b] = ROTATE(x[b] ^ x[c], 12);                        \
+    x[a] = x[a] + x[b]; x[d] = ROTATE(x[d] ^ x[a],  8);                        \
+    x[c] = x[c] + x[d]; x[b] = ROTATE(x[b] ^ x[c],  7);
+
+static void
+ChaChaCore(unsigned char output[64], const PRUint32 input[16], int num_rounds)
+{
+    PRUint32 x[16];
+    int i;
+
+    PORT_Memcpy(x, input, sizeof(PRUint32) * 16);
+    for (i = num_rounds; i > 0; i -= 2) {
+        QUARTERROUND(x, 0, 4, 8, 12)
+        QUARTERROUND(x, 1, 5, 9, 13)
+        QUARTERROUND(x, 2, 6, 10, 14)
+        QUARTERROUND(x, 3, 7, 11, 15)
+        QUARTERROUND(x, 0, 5, 10, 15)
+        QUARTERROUND(x, 1, 6, 11, 12)
+        QUARTERROUND(x, 2, 7, 8, 13)
+        QUARTERROUND(x, 3, 4, 9, 14)
+    }
+
+    for (i = 0; i < 16; ++i) {
+        x[i] = x[i] + input[i];
+    }
+    for (i = 0; i < 16; ++i) {
+        U32TO8_LITTLE(output + 4 * i, x[i]);
+    }
+}
+
+static const unsigned char sigma[16] = "expand 32-byte k";
+
+void
+ChaCha20XOR(unsigned char *out, const unsigned char *in, unsigned int inLen,
+            const unsigned char key[32], const unsigned char nonce[12],
+            uint32_t counter)
+{
+    unsigned char block[64];
+    PRUint32 input[16];
+    unsigned int i;
+
+    input[4] = U8TO32_LITTLE(key + 0);
+    input[5] = U8TO32_LITTLE(key + 4);
+    input[6] = U8TO32_LITTLE(key + 8);
+    input[7] = U8TO32_LITTLE(key + 12);
+
+    input[8] = U8TO32_LITTLE(key + 16);
+    input[9] = U8TO32_LITTLE(key + 20);
+    input[10] = U8TO32_LITTLE(key + 24);
+    input[11] = U8TO32_LITTLE(key + 28);
+
+    input[0] = U8TO32_LITTLE(sigma + 0);
+    input[1] = U8TO32_LITTLE(sigma + 4);
+    input[2] = U8TO32_LITTLE(sigma + 8);
+    input[3] = U8TO32_LITTLE(sigma + 12);
+
+    input[12] = counter;
+    input[13] = U8TO32_LITTLE(nonce + 0);
+    input[14] = U8TO32_LITTLE(nonce + 4);
+    input[15] = U8TO32_LITTLE(nonce + 8);
+
+    while (inLen >= 64) {
+        ChaChaCore(block, input, 20);
+        for (i = 0; i < 64; i++) {
+            out[i] = in[i] ^ block[i];
+        }
+
+        input[12]++;
+        inLen -= 64;
+        in += 64;
+        out += 64;
+    }
+
+    if (inLen > 0) {
+        ChaChaCore(block, input, 20);
+        for (i = 0; i < inLen; i++) {
+            out[i] = in[i] ^ block[i];
+        }
+    }
+}