Diff: wolfcrypt/src/chacha.c

Revision:

0:d92f9d21154c

--- /dev/null	Thu Jan 01 00:00:00 1970 +0000
+++ b/wolfcrypt/src/chacha.c	Fri Jun 26 00:39:20 2015 +0000
@@ -0,0 +1,252 @@
+/* chacha.c
+ *
+ * Copyright (C) 2006-2015 wolfSSL Inc.
+ *
+ * This file is part of wolfSSL. (formerly known as CyaSSL)
+ *
+ * wolfSSL is free software; you can redistribute it and/or modify
+ * it under the terms of the GNU General Public License as published by
+ * the Free Software Foundation; either version 2 of the License, or
+ * (at your option) any later version.
+ *
+ * wolfSSL is distributed in the hope that it will be useful,
+ * but WITHOUT ANY WARRANTY; without even the implied warranty of
+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+ * GNU General Public License for more details.
+ *
+ * You should have received a copy of the GNU General Public License
+ * along with this program; if not, write to the Free Software
+ * Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301, USA
+ *
+ *  based from
+ *  chacha-ref.c version 20080118
+ *  D. J. Bernstein
+ *  Public domain.
+ */
+
+
+#ifdef HAVE_CONFIG_H
+    #include <config.h>
+#endif
+
+#include <wolfssl/wolfcrypt/settings.h>
+
+#ifdef HAVE_CHACHA
+
+#include <wolfssl/wolfcrypt/chacha.h>
+#include <wolfssl/wolfcrypt/error-crypt.h>
+#include <wolfssl/wolfcrypt/logging.h>
+#ifdef NO_INLINE
+    #include <wolfssl/wolfcrypt/misc.h>
+#else
+    #include <wolfcrypt/src/misc.c>
+#endif
+
+#ifdef CHACHA_AEAD_TEST
+    #include <stdio.h>
+#endif
+
+#ifdef BIG_ENDIAN_ORDER
+    #define LITTLE32(x) ByteReverseWord32(x)
+#else
+    #define LITTLE32(x) (x)
+#endif
+
+/* Number of rounds */
+#define ROUNDS  20
+
+#define U32C(v) (v##U)
+#define U32V(v) ((word32)(v) & U32C(0xFFFFFFFF))
+#define U8TO32_LITTLE(p) LITTLE32(((word32*)(p))[0])
+
+#define ROTATE(v,c) rotlFixed(v, c)
+#define XOR(v,w)    ((v) ^ (w))
+#define PLUS(v,w)   (U32V((v) + (w)))
+#define PLUSONE(v)  (PLUS((v),1))
+
+#define QUARTERROUND(a,b,c,d) \
+  x[a] = PLUS(x[a],x[b]); x[d] = ROTATE(XOR(x[d],x[a]),16); \
+  x[c] = PLUS(x[c],x[d]); x[b] = ROTATE(XOR(x[b],x[c]),12); \
+  x[a] = PLUS(x[a],x[b]); x[d] = ROTATE(XOR(x[d],x[a]), 8); \
+  x[c] = PLUS(x[c],x[d]); x[b] = ROTATE(XOR(x[b],x[c]), 7);
+
+
+/**
+  * Set up iv(nonce). Earlier versions used 64 bits instead of 96, this version
+  * uses the typical AEAD 96 bit nonce and can do record sizes of 256 GB.
+  */
+int wc_Chacha_SetIV(ChaCha* ctx, const byte* inIv, word32 counter)
+{
+    word32 temp[3];       /* used for alignment of memory */
+
+#ifdef CHACHA_AEAD_TEST
+    word32 i;
+    printf("NONCE : ");
+    for (i = 0; i < 12; i++) {
+        printf("%02x", inIv[i]);
+    }
+    printf("\n\n");
+#endif
+
+    if (ctx == NULL)
+        return BAD_FUNC_ARG;
+
+    XMEMCPY(temp, inIv, 12);
+
+    ctx->X[12] = LITTLE32(counter); /* block counter */
+    ctx->X[13] = LITTLE32(temp[0]); /* fixed variable from nonce */
+    ctx->X[14] = LITTLE32(temp[1]); /* counter from nonce */
+    ctx->X[15] = LITTLE32(temp[2]); /* counter from nonce */
+
+    return 0;
+}
+
+/* "expand 32-byte k" as unsigned 32 byte */
+static const word32 sigma[4] = {0x61707865, 0x3320646e, 0x79622d32, 0x6b206574};
+/* "expand 16-byte k" as unsigned 16 byte */
+static const word32 tau[4] = {0x61707865, 0x3120646e, 0x79622d36, 0x6b206574};
+
+/**
+  * Key setup. 8 word iv (nonce)
+  */
+int wc_Chacha_SetKey(ChaCha* ctx, const byte* key, word32 keySz)
+{
+    const word32* constants;
+    const byte*   k;
+
+#ifdef XSTREAM_ALIGN
+    word32 alignKey[8];
+#endif
+
+    if (ctx == NULL)
+        return BAD_FUNC_ARG;
+
+    if (keySz != 16 && keySz != 32)
+        return BAD_FUNC_ARG;
+
+#ifdef XSTREAM_ALIGN
+    if ((wolfssl_word)key % 4) {
+        WOLFSSL_MSG("wc_ChachaSetKey unaligned key");
+        XMEMCPY(alignKey, key, keySz);
+        k = (byte*)alignKey;
+    }
+    else {
+        k = key;
+    }
+#else
+    k = key;
+#endif /* XSTREAM_ALIGN */
+
+#ifdef CHACHA_AEAD_TEST
+    word32 i;
+    printf("ChaCha key used :\n");
+    for (i = 0; i < keySz; i++) {
+        printf("%02x", key[i]);
+        if ((i + 1) % 8 == 0)
+           printf("\n");
+    }
+    printf("\n\n");
+#endif
+
+    ctx->X[4] = U8TO32_LITTLE(k +  0);
+    ctx->X[5] = U8TO32_LITTLE(k +  4);
+    ctx->X[6] = U8TO32_LITTLE(k +  8);
+    ctx->X[7] = U8TO32_LITTLE(k + 12);
+    if (keySz == 32) {
+        k += 16;
+        constants = sigma;
+    }
+    else {
+        constants = tau;
+    }
+    ctx->X[ 8] = U8TO32_LITTLE(k +  0);
+    ctx->X[ 9] = U8TO32_LITTLE(k +  4);
+    ctx->X[10] = U8TO32_LITTLE(k +  8);
+    ctx->X[11] = U8TO32_LITTLE(k + 12);
+    ctx->X[ 0] = constants[0];
+    ctx->X[ 1] = constants[1];
+    ctx->X[ 2] = constants[2];
+    ctx->X[ 3] = constants[3];
+
+    return 0;
+}
+
+/**
+  * Converts word into bytes with rotations having been done.
+  */
+static INLINE void wc_Chacha_wordtobyte(word32 output[16], const word32 input[16])
+{
+    word32 x[16];
+    word32 i;
+
+    for (i = 0; i < 16; i++) {
+        x[i] = input[i];
+    }
+
+    for (i = (ROUNDS); i > 0; i -= 2) {
+        QUARTERROUND(0, 4,  8, 12)
+        QUARTERROUND(1, 5,  9, 13)
+        QUARTERROUND(2, 6, 10, 14)
+        QUARTERROUND(3, 7, 11, 15)
+        QUARTERROUND(0, 5, 10, 15)
+        QUARTERROUND(1, 6, 11, 12)
+        QUARTERROUND(2, 7,  8, 13)
+        QUARTERROUND(3, 4,  9, 14)
+    }
+
+    for (i = 0; i < 16; i++) {
+        x[i] = PLUS(x[i], input[i]);
+    }
+
+    for (i = 0; i < 16; i++) {
+        output[i] = LITTLE32(x[i]);
+    }
+}
+
+/**
+  * Encrypt a stream of bytes
+  */
+static void wc_Chacha_encrypt_bytes(ChaCha* ctx, const byte* m, byte* c,
+                                 word32 bytes)
+{
+    byte*  output;
+    word32 temp[16]; /* used to make sure aligned */
+    word32 i;
+
+    output = (byte*)temp;
+
+    if (!bytes) return;
+    for (;;) {
+        wc_Chacha_wordtobyte(temp, ctx->X);
+        ctx->X[12] = PLUSONE(ctx->X[12]);
+        if (bytes <= 64) {
+            for (i = 0; i < bytes; ++i) {
+                c[i] = m[i] ^ output[i];
+            }
+            return;
+        }
+        for (i = 0; i < 64; ++i) {
+            c[i] = m[i] ^ output[i];
+        }
+        bytes -= 64;
+        c += 64;
+        m += 64;
+    }
+}
+
+/**
+  * API to encrypt/decrypt a message of any size.
+  */
+int wc_Chacha_Process(ChaCha* ctx, byte* output, const byte* input, word32 msglen)
+{
+    if (ctx == NULL)
+        return BAD_FUNC_ARG;
+
+    wc_Chacha_encrypt_bytes(ctx, input, output, msglen);
+
+    return 0;
+}
+
+#endif /* HAVE_CHACHA*/
+
+