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-rw-r--r--src/crypt.c319
-rw-r--r--src/crypt.h80
2 files changed, 399 insertions, 0 deletions
diff --git a/src/crypt.c b/src/crypt.c
new file mode 100644
index 0000000..f51ceb8
--- /dev/null
+++ b/src/crypt.c
@@ -0,0 +1,319 @@
+/* Copyright (C) 2009-2011, Martin Johansson <martin@fatbob.nu>
+ Copyright (C) 2005-2011, Thorvald Natvig <thorvald@natvig.com>
+
+ All rights reserved.
+
+ Redistribution and use in source and binary forms, with or without
+ modification, are permitted provided that the following conditions
+ are met:
+
+ - Redistributions of source code must retain the above copyright notice,
+ this list of conditions and the following disclaimer.
+ - Redistributions in binary form must reproduce the above copyright notice,
+ this list of conditions and the following disclaimer in the documentation
+ and/or other materials provided with the distribution.
+ - Neither the name of the Developers nor the names of its contributors may
+ be used to endorse or promote products derived from this software without
+ specific prior written permission.
+
+ THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
+ ``AS IS'' AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT
+ LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR
+ A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE FOUNDATION OR
+ CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL,
+ EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO,
+ PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR
+ PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF
+ LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING
+ NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF THIS
+ SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
+*/
+
+/*
+ * This code implements OCB-AES128.
+ * In the US, OCB is covered by patents. The inventor has given a license
+ * to all programs distributed under the GPL.
+ * uMurmur is BSD (revised) licensed, meaning you can use the code in a
+ * closed-source program. If you do, you'll have to either replace
+ * OCB with something else or get yourself a license.
+ */
+
+#include <string.h>
+#include <arpa/inet.h>
+#include "crypt.h"
+
+static void CryptState_ocb_encrypt(cryptState_t *cs, const unsigned char *plain, unsigned char *encrypted, unsigned int len, const unsigned char *nonce, unsigned char *tag);
+static void CryptState_ocb_decrypt(cryptState_t *cs, const unsigned char *encrypted, unsigned char *plain, unsigned int len, const unsigned char *nonce, unsigned char *tag);
+
+
+void CryptState_init(cryptState_t *cs)
+{
+ memset(cs->decrypt_history, 0, 0xff);
+ memset(cs->raw_key, 0, AES_BLOCK_SIZE);
+ memset(cs->encrypt_iv, 0, AES_BLOCK_SIZE);
+ memset(cs->decrypt_iv, 0, AES_BLOCK_SIZE);
+ cs->bInit = false;
+ cs->uiGood = cs->uiLate = cs->uiLost = cs->uiResync = 0;
+ cs->uiRemoteGood = cs->uiRemoteLate = cs->uiRemoteLost = cs->uiRemoteResync = 0;
+ /*
+ Timer_init(&cs->tLastGood);
+ Timer_init(&cs->tLastRequest);
+ */
+}
+
+void CryptState_setKey(cryptState_t *cs, const unsigned char *rkey, const unsigned char *eiv, const unsigned char *div)
+{
+ memcpy(cs->raw_key, rkey, AES_BLOCK_SIZE);
+ memcpy(cs->encrypt_iv, eiv, AES_BLOCK_SIZE);
+ memcpy(cs->decrypt_iv, div, AES_BLOCK_SIZE);
+
+ AES_set_encrypt_key(cs->raw_key, 128, &cs->encrypt_key);
+ AES_set_decrypt_key(cs->raw_key, 128, &cs->decrypt_key);
+
+ cs->bInit = true;
+}
+
+void CryptState_setDecryptIV(cryptState_t *cs, const unsigned char *iv)
+{
+ memcpy(cs->decrypt_iv, iv, AES_BLOCK_SIZE);
+}
+
+void CryptState_encrypt(cryptState_t *cs, const unsigned char *source, unsigned char *dst, unsigned int plain_length)
+{
+ unsigned char tag[AES_BLOCK_SIZE];
+ int i;
+ // First, increase our IV.
+ for (i = 0; i < AES_BLOCK_SIZE; i++)
+ if (++cs->encrypt_iv[i])
+ break;
+
+ CryptState_ocb_encrypt(cs, source, dst+4, plain_length, cs->encrypt_iv, tag);
+
+ dst[0] = cs->encrypt_iv[0];
+ dst[1] = tag[0];
+ dst[2] = tag[1];
+ dst[3] = tag[2];
+}
+
+bool_t CryptState_decrypt(cryptState_t *cs, const unsigned char *source, unsigned char *dst, unsigned int crypted_length)
+{
+ if (crypted_length < 4)
+ return false;
+
+ unsigned int plain_length = crypted_length - 4;
+
+ unsigned char saveiv[AES_BLOCK_SIZE];
+ unsigned char ivbyte = source[0];
+ bool_t restore = false;
+ unsigned char tag[AES_BLOCK_SIZE];
+
+ int lost = 0;
+ int late = 0;
+
+ memcpy(saveiv, cs->decrypt_iv, AES_BLOCK_SIZE);
+
+ if (((cs->decrypt_iv[0] + 1) & 0xFF) == ivbyte) {
+ // In order as expected.
+ if (ivbyte > cs->decrypt_iv[0]) {
+ cs->decrypt_iv[0] = ivbyte;
+ } else if (ivbyte < cs->decrypt_iv[0]) {
+ int i;
+ cs->decrypt_iv[0] = ivbyte;
+ for (i = 1; i < AES_BLOCK_SIZE; i++)
+ if (++cs->decrypt_iv[i])
+ break;
+ } else {
+ return false;
+ }
+ } else {
+ // This is either out of order or a repeat.
+
+ int diff = ivbyte - cs->decrypt_iv[0];
+ if (diff > 128)
+ diff = diff-256;
+ else if (diff < -128)
+ diff = diff+256;
+
+ if ((ivbyte < cs->decrypt_iv[0]) && (diff > -30) && (diff < 0)) {
+ // Late packet, but no wraparound.
+ late = 1;
+ lost = -1;
+ cs->decrypt_iv[0] = ivbyte;
+ restore = true;
+ } else if ((ivbyte > cs->decrypt_iv[0]) && (diff > -30) && (diff < 0)) {
+ int i;
+ // Last was 0x02, here comes 0xff from last round
+ late = 1;
+ lost = -1;
+ cs->decrypt_iv[0] = ivbyte;
+ for (i = 1; i < AES_BLOCK_SIZE; i++)
+ if (cs->decrypt_iv[i]--)
+ break;
+ restore = true;
+ } else if ((ivbyte > cs->decrypt_iv[0]) && (diff > 0)) {
+ // Lost a few packets, but beyond that we're good.
+ lost = ivbyte - cs->decrypt_iv[0] - 1;
+ cs->decrypt_iv[0] = ivbyte;
+ } else if ((ivbyte < cs->decrypt_iv[0]) && (diff > 0)) {
+ int i;
+ // Lost a few packets, and wrapped around
+ lost = 256 - cs->decrypt_iv[0] + ivbyte - 1;
+ cs->decrypt_iv[0] = ivbyte;
+ for (i = 1; i < AES_BLOCK_SIZE; i++)
+ if (++cs->decrypt_iv[i])
+ break;
+ } else {
+ return false;
+ }
+
+ if (cs->decrypt_history[cs->decrypt_iv[0]] == cs->decrypt_iv[1]) {
+ memcpy(cs->decrypt_iv, saveiv, AES_BLOCK_SIZE);
+ return false;
+ }
+ }
+
+ CryptState_ocb_decrypt(cs, source+4, dst, plain_length, cs->decrypt_iv, tag);
+
+ if (memcmp(tag, source+1, 3) != 0) {
+ memcpy(cs->decrypt_iv, saveiv, AES_BLOCK_SIZE);
+ return false;
+ }
+ cs->decrypt_history[cs->decrypt_iv[0]] = cs->decrypt_iv[1];
+
+ if (restore)
+ memcpy(cs->decrypt_iv, saveiv, AES_BLOCK_SIZE);
+
+ cs->uiGood++;
+ cs->uiLate += late;
+ cs->uiLost += lost;
+
+ //Timer_restart(&cs->tLastGood);
+ return true;
+}
+
+#if defined(__LP64__)
+#define BLOCKSIZE 2
+#define SHIFTBITS 63
+typedef uint64_t subblock;
+
+#if __BYTE_ORDER == __BIG_ENDIAN
+#define SWAPPED(x) (x)
+#else
+#ifdef __x86_64__
+#define SWAPPED(x) ({register uint64_t __out, __in = (x); __asm__("bswap %q0" : "=r"(__out) : "0"(__in)); __out;})
+#else
+#include <byteswap.h>
+#define SWAPPED(x) bswap_64(x)
+#endif
+#endif
+
+#else
+
+#define BLOCKSIZE 4
+#define SHIFTBITS 31
+typedef uint32_t subblock;
+#define SWAPPED(x) htonl(x)
+
+#endif
+
+#define HIGHBIT (1<<SHIFTBITS);
+
+
+static void inline XOR(subblock *dst, const subblock *a, const subblock *b) {
+ int i;
+ for (i=0;i<BLOCKSIZE;i++) {
+ dst[i] = a[i] ^ b[i];
+ }
+}
+
+static void inline S2(subblock *block) {
+ subblock carry = SWAPPED(block[0]) >> SHIFTBITS;
+ int i;
+ for (i=0;i<BLOCKSIZE-1;i++)
+ block[i] = SWAPPED((SWAPPED(block[i]) << 1) | (SWAPPED(block[i+1]) >> SHIFTBITS));
+ block[BLOCKSIZE-1] = SWAPPED((SWAPPED(block[BLOCKSIZE-1]) << 1) ^(carry * 0x87));
+}
+
+static void inline S3(subblock *block) {
+ subblock carry = SWAPPED(block[0]) >> SHIFTBITS;
+ int i;
+ for (i=0;i<BLOCKSIZE-1;i++)
+ block[i] ^= SWAPPED((SWAPPED(block[i]) << 1) | (SWAPPED(block[i+1]) >> SHIFTBITS));
+ block[BLOCKSIZE-1] ^= SWAPPED((SWAPPED(block[BLOCKSIZE-1]) << 1) ^(carry * 0x87));
+}
+
+static void inline ZERO(subblock *block) {
+ int i;
+ for (i=0;i<BLOCKSIZE;i++)
+ block[i]=0;
+}
+
+#define AESencrypt(src, dst, cryptstate) AES_encrypt((unsigned char *)(src), (unsigned char *)(dst), &(cryptstate)->encrypt_key);
+#define AESdecrypt(src, dst, cryptstate) AES_decrypt((unsigned char *)(src), (unsigned char *)(dst), &(cryptstate)->decrypt_key);
+
+void CryptState_ocb_encrypt(cryptState_t *cs, const unsigned char *plain, unsigned char *encrypted, unsigned int len, const unsigned char *nonce, unsigned char *tag) {
+ subblock checksum[BLOCKSIZE], delta[BLOCKSIZE], tmp[BLOCKSIZE], pad[BLOCKSIZE];
+
+ // Initialize
+ AESencrypt(nonce, delta, cs);
+ ZERO(checksum);
+
+ while (len > AES_BLOCK_SIZE) {
+ S2(delta);
+ XOR(tmp, delta, (const subblock *)(plain));
+ AESencrypt(tmp, tmp, cs);
+ XOR((subblock *)(encrypted), delta, tmp);
+ XOR(checksum, checksum, (subblock *)(plain));
+ len -= AES_BLOCK_SIZE;
+ plain += AES_BLOCK_SIZE;
+ encrypted += AES_BLOCK_SIZE;
+ }
+
+ S2(delta);
+ ZERO(tmp);
+ tmp[BLOCKSIZE - 1] = SWAPPED(len * 8);
+ XOR(tmp, tmp, delta);
+ AESencrypt(tmp, pad, cs);
+ memcpy(tmp, plain, len);
+ memcpy((unsigned char *)tmp + len, (unsigned char *)pad + len, AES_BLOCK_SIZE - len);
+ XOR(checksum, checksum, tmp);
+ XOR(tmp, pad, tmp);
+ memcpy(encrypted, tmp, len);
+
+ S3(delta);
+ XOR(tmp, delta, checksum);
+ AESencrypt(tmp, tag, cs);
+}
+
+void CryptState_ocb_decrypt(cryptState_t *cs, const unsigned char *encrypted, unsigned char *plain, unsigned int len, const unsigned char *nonce, unsigned char *tag) {
+ subblock checksum[BLOCKSIZE], delta[BLOCKSIZE], tmp[BLOCKSIZE], pad[BLOCKSIZE];
+ // Initialize
+ AESencrypt(nonce, delta, cs);
+ ZERO(checksum);
+
+ while (len > AES_BLOCK_SIZE) {
+ S2(delta);
+ XOR(tmp, delta, (const subblock *)(encrypted));
+ AESdecrypt(tmp, tmp, cs);
+ XOR((subblock *)(plain), delta, tmp);
+ XOR(checksum, checksum, (const subblock *)(plain));
+ len -= AES_BLOCK_SIZE;
+ plain += AES_BLOCK_SIZE;
+ encrypted += AES_BLOCK_SIZE;
+ }
+
+ S2(delta);
+ ZERO(tmp);
+ tmp[BLOCKSIZE - 1] = SWAPPED(len * 8);
+ XOR(tmp, tmp, delta);
+ AESencrypt(tmp, pad, cs);
+ memset(tmp, 0, AES_BLOCK_SIZE);
+ memcpy(tmp, encrypted, len);
+ XOR(tmp, tmp, pad);
+ XOR(checksum, checksum, tmp);
+ memcpy(plain, tmp, len);
+
+ S3(delta);
+ XOR(tmp, delta, checksum);
+ AESencrypt(tmp, tag, cs);
+}
diff --git a/src/crypt.h b/src/crypt.h
new file mode 100644
index 0000000..30c0298
--- /dev/null
+++ b/src/crypt.h
@@ -0,0 +1,80 @@
+/* Copyright (C) 2009-2011, Martin Johansson <martin@fatbob.nu>
+ Copyright (C) 2005-2011, Thorvald Natvig <thorvald@natvig.com>
+
+ All rights reserved.
+
+ Redistribution and use in source and binary forms, with or without
+ modification, are permitted provided that the following conditions
+ are met:
+
+ - Redistributions of source code must retain the above copyright notice,
+ this list of conditions and the following disclaimer.
+ - Redistributions in binary form must reproduce the above copyright notice,
+ this list of conditions and the following disclaimer in the documentation
+ and/or other materials provided with the distribution.
+ - Neither the name of the Developers nor the names of its contributors may
+ be used to endorse or promote products derived from this software without
+ specific prior written permission.
+
+ THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
+ ``AS IS'' AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT
+ LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR
+ A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE FOUNDATION OR
+ CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL,
+ EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO,
+ PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR
+ PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF
+ LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING
+ NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF THIS
+ SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
+*/
+#ifndef CRYPTSTATE_H_34564356
+#define CRYPTSTATE_H_34564356
+
+#ifdef HAVE_CONFIG_H
+#include <config.h>
+#endif
+
+#include <openssl/rand.h>
+#include <openssl/aes.h>
+
+#include <stdint.h>
+
+#include <glib.h>
+#define bool_t gboolean
+#define false FALSE
+#define true TRUE
+
+typedef struct CryptState {
+ uint8_t raw_key[AES_BLOCK_SIZE];
+ uint8_t encrypt_iv[AES_BLOCK_SIZE];
+ uint8_t decrypt_iv[AES_BLOCK_SIZE];
+ uint8_t decrypt_history[0x100];
+
+ unsigned int uiGood;
+ unsigned int uiLate;
+ unsigned int uiLost;
+ unsigned int uiResync;
+
+ unsigned int uiRemoteGood;
+ unsigned int uiRemoteLate;
+ unsigned int uiRemoteLost;
+ unsigned int uiRemoteResync;
+ AES_KEY encrypt_key;
+ AES_KEY decrypt_key;
+
+ //etimer_t tLastGood;
+ //etimer_t tLastRequest;
+ bool_t bInit;
+} cryptState_t;
+
+void CryptState_init(cryptState_t *cs);
+bool_t CryptState_isValid(cryptState_t *cs);
+void CryptState_setKey(cryptState_t *cs, const unsigned char *rkey, const unsigned char *eiv, const unsigned char *div);
+void CryptState_setDecryptIV(cryptState_t *cs, const unsigned char *iv);
+
+bool_t CryptState_decrypt(cryptState_t *cs, const unsigned char *source, unsigned char *dst, unsigned int crypted_length);
+void CryptState_encrypt(cryptState_t *cs, const unsigned char *source, unsigned char *dst, unsigned int plain_length);
+
+
+#endif
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