1 files changed, 219 insertions, 0 deletions
diff --git a/src/Crypto/chacha256.c b/src/Crypto/chacha256.c
new file mode 100644
index 00000000..f32e607b
--- /dev/null
+++ b/src/Crypto/chacha256.c
@@ -0,0 +1,219 @@
+/*
+This code is written by kerukuro for cppcrypto library (http://cppcrypto.sourceforge.net/)
+and released into public domain.
+*/
+
+/* adapted for VeraCrypt */
+
+#include "chacha256.h"
+#include "cpu.h"
+#include "misc.h"
+
+
+
+#define rotater32(x,n)	rotr32(x, n)
+#define rotatel32(x,n)	rotl32(x, n)
+
+#if CRYPTOPP_BOOL_SSE2_INTRINSICS_AVAILABLE
+void chacha_ECRYPT_encrypt_bytes(size_t bytes, uint32* x, const unsigned char* m, unsigned char* out, unsigned char* output, unsigned int r);
+#endif
+
+static VC_INLINE void xor_block_512(const unsigned char* in, const unsigned char* prev, unsigned char* out)
+{
+#if CRYPTOPP_BOOL_SSE2_INTRINSICS_AVAILABLE && !defined(_UEFI) && (!defined (TC_WINDOWS_DRIVER) || (!defined (DEBUG) && defined (_WIN64)))
+    if (HasSSE2())
+    {
+        __m128i b1 = _mm_loadu_si128((const __m128i*) in);
+        __m128i p1 = _mm_loadu_si128((const __m128i*) prev);
+        __m128i b2 = _mm_loadu_si128((const __m128i*) (in + 16));
+        __m128i p2 = _mm_loadu_si128((const __m128i*) (prev + 16));
+
+        _mm_storeu_si128((__m128i*) out, _mm_xor_si128(b1, p1));
+        _mm_storeu_si128((__m128i*) (out + 16), _mm_xor_si128(b2, p2));
+
+        b1 = _mm_loadu_si128((const __m128i*) (in + 32));
+        p1 = _mm_loadu_si128((const __m128i*) (prev + 32));
+        b2 = _mm_loadu_si128((const __m128i*) (in + 48));
+        p2 = _mm_loadu_si128((const __m128i*) (prev + 48));
+
+        _mm_storeu_si128((__m128i*) (out + 32), _mm_xor_si128(b1, p1));
+        _mm_storeu_si128((__m128i*) (out + 48), _mm_xor_si128(b2, p2));
+
+    }
+    else
+#endif
+	{
+		int i;
+        for (i = 0; i < 64; i++)
+            out[i] = in[i] ^ prev[i];
+    }
+
+}
+
+static VC_INLINE void chacha_core(uint32* x, int r)
+{
+	int i;
+    for (i = 0; i < r; i++)
+    {
+        x[0] += x[4];
+        x[12] = rotatel32(x[12] ^ x[0], 16);
+        x[8] += x[12];
+        x[4] = rotatel32(x[4] ^ x[8], 12);
+        x[0] += x[4];
+        x[12] = rotatel32(x[12] ^ x[0], 8);
+        x[8] += x[12];
+        x[4] = rotatel32(x[4] ^ x[8], 7);
+
+        x[1] += x[5];
+        x[13] = rotatel32(x[13] ^ x[1], 16);
+        x[9] += x[13];
+        x[5] = rotatel32(x[5] ^ x[9], 12);
+        x[1] += x[5];
+        x[13] = rotatel32(x[13] ^ x[1], 8);
+        x[9] += x[13];
+        x[5] = rotatel32(x[5] ^ x[9], 7);
+
+        x[2] += x[6];
+        x[14] = rotatel32(x[14] ^ x[2], 16);
+        x[10] += x[14];
+        x[6] = rotatel32(x[6] ^ x[10], 12);
+        x[2] += x[6];
+        x[14] = rotatel32(x[14] ^ x[2], 8);
+        x[10] += x[14];
+        x[6] = rotatel32(x[6] ^ x[10], 7);
+
+        x[3] += x[7];
+        x[15] = rotatel32(x[15] ^ x[3], 16);
+        x[11] += x[15];
+        x[7] = rotatel32(x[7] ^ x[11], 12);
+        x[3] += x[7];
+        x[15] = rotatel32(x[15] ^ x[3], 8);
+        x[11] += x[15];
+        x[7] = rotatel32(x[7] ^ x[11], 7);
+
+        x[0] += x[5];
+        x[15] = rotatel32(x[15] ^ x[0], 16);
+        x[10] += x[15];
+        x[5] = rotatel32(x[5] ^ x[10], 12);
+        x[0] += x[5];
+        x[15] = rotatel32(x[15] ^ x[0], 8);
+        x[10] += x[15];
+        x[5] = rotatel32(x[5] ^ x[10], 7);
+
+        x[1] += x[6];
+        x[12] = rotatel32(x[12] ^ x[1], 16);
+        x[11] += x[12];
+        x[6] = rotatel32(x[6] ^ x[11], 12);
+        x[1] += x[6];
+        x[12] = rotatel32(x[12] ^ x[1], 8);
+        x[11] += x[12];
+        x[6] = rotatel32(x[6] ^ x[11], 7);
+
+        x[2] += x[7];
+        x[13] = rotatel32(x[13] ^ x[2], 16);
+        x[8] += x[13];
+        x[7] = rotatel32(x[7] ^ x[8], 12);
+        x[2] += x[7];
+        x[13] = rotatel32(x[13] ^ x[2], 8);
+        x[8] += x[13];
+        x[7] = rotatel32(x[7] ^ x[8], 7);
+
+        x[3] += x[4];
+        x[14] = rotatel32(x[14] ^ x[3], 16);
+        x[9] += x[14];
+        x[4] = rotatel32(x[4] ^ x[9], 12);
+        x[3] += x[4];
+        x[14] = rotatel32(x[14] ^ x[3], 8);
+        x[9] += x[14];
+        x[4] = rotatel32(x[4] ^ x[9], 7);
+    }
+}
+
+static VC_INLINE void chacha_hash(const uint32* in, uint32* out, int r)
+{
+    uint32 x[16];
+	int i;
+    memcpy(x, in, 64);
+    chacha_core(x, r);
+    for (i = 0; i < 16; ++i)
+        out[i] = x[i] + in[i];
+}
+
+static VC_INLINE void incrementSalsaCounter(uint32* input, uint32* block, int r)
+{
+    chacha_hash(input, block, r);
+    if (!++input[12])
+        ++input[13];
+}
+
+static VC_INLINE void do_encrypt(const unsigned char* in, size_t len, unsigned char* out, int r, size_t* posPtr, uint32* input, uint32* block)
+{
+    size_t i = 0, pos = *posPtr;
+    if (pos)
+    {
+        while (pos < len && pos < 64)
+        {
+            out[i] = in[i] ^ ((unsigned char*)block)[pos++];
+            ++i;
+        }
+        len -= i;
+    }
+    if (len)
+        pos = 0;
+
+#if CRYPTOPP_SSSE3_AVAILABLE && !defined(_UEFI) && (!defined (TC_WINDOWS_DRIVER) || (!defined (DEBUG) && defined (_WIN64)))
+    if (HasSSSE3())
+    {
+        size_t fullblocks = len - len % 64;
+        if (fullblocks)
+        {
+            chacha_ECRYPT_encrypt_bytes(fullblocks, input, in + i, out + i, (unsigned char*)block, r);
+            i += fullblocks;
+            len -= fullblocks;
+        }
+        if (len)
+        {
+            chacha_ECRYPT_encrypt_bytes(len, input, in + i, out + i, (unsigned char*)block, r);
+            pos = len;
+        }
+        *posPtr = pos;
+        return;
+    }
+#endif
+
+    for (; len; len -= VC_MIN(64, len))
+    {
+        incrementSalsaCounter(input, block, r);
+        if (len >= 64)
+        {
+            xor_block_512(in + i, (unsigned char*)block, out + i);
+            i += 64;
+        }
+        else
+        {
+            for (; pos < len; pos++, i++)
+                out[i] = in[i] ^ ((unsigned char*)block)[pos];
+        }
+    }
+    *posPtr = pos;
+}
+
+void ChaCha256Init(ChaCha256Ctx* ctx, const unsigned char* key, const unsigned char* iv, int rounds)
+{    
+    ctx->internalRounds = rounds / 2;
+    ctx->pos = 0;
+    
+    ctx->input_[12] = 0;
+    ctx->input_[13] = 0;
+    memcpy(ctx->input_ + 4, key, 32);
+    memcpy(ctx->input_ + 14, iv, 8);
+    ctx->input_[0] = 0x61707865;
+    ctx->input_[1] = 0x3320646E;
+    ctx->input_[2] = 0x79622D32;
+    ctx->input_[3] = 0x6B206574;
+}
+
+void ChaCha256Encrypt(ChaCha256Ctx* ctx, const unsigned char* in, size_t len, unsigned char* out)
+{
+    do_encrypt(in, len, out, ctx->internalRounds, &ctx->pos, ctx->input_, ctx->block_);
+}