xnu-2050.7.9.tar.gz

[apple/xnu.git] / libkern / crypto / corecrypto_aesxts.c

diff --git a/libkern/crypto/corecrypto_aesxts.c b/libkern/crypto/corecrypto_aesxts.c
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+++ b/libkern/crypto/corecrypto_aesxts.c
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+/*
+ * Copyright (c) 2012 Apple Computer, Inc. All rights reserved.
+ *
+ * @APPLE_OSREFERENCE_LICENSE_HEADER_START@
+ * 
+ * This file contains Original Code and/or Modifications of Original Code
+ * as defined in and that are subject to the Apple Public Source License
+ * Version 2.0 (the 'License'). You may not use this file except in
+ * compliance with the License. The rights granted to you under the License
+ * may not be used to create, or enable the creation or redistribution of,
+ * unlawful or unlicensed copies of an Apple operating system, or to
+ * circumvent, violate, or enable the circumvention or violation of, any
+ * terms of an Apple operating system software license agreement.
+ * 
+ * Please obtain a copy of the License at
+ * http://www.opensource.apple.com/apsl/ and read it before using this file.
+ * 
+ * The Original Code and all software distributed under the License are
+ * distributed on an 'AS IS' basis, WITHOUT WARRANTY OF ANY KIND, EITHER
+ * EXPRESS OR IMPLIED, AND APPLE HEREBY DISCLAIMS ALL SUCH WARRANTIES,
+ * INCLUDING WITHOUT LIMITATION, ANY WARRANTIES OF MERCHANTABILITY,
+ * FITNESS FOR A PARTICULAR PURPOSE, QUIET ENJOYMENT OR NON-INFRINGEMENT.
+ * Please see the License for the specific language governing rights and
+ * limitations under the License.
+ * 
+ * @APPLE_OSREFERENCE_LICENSE_HEADER_END@
+ */
+ 
+#include <libkern/crypto/crypto_internal.h>
+#include <libkern/libkern.h>
+#include <libkern/crypto/aesxts.h>
+#include <corecrypto/ccmode.h>
+#include <corecrypto/ccpad.h>
+#include <kern/debug.h>
+
+/*
+ * These are the interfaces required for XTS-AES support
+ */
+
+uint32_t
+xts_start(uint32_t cipher __unused, // ignored - we're doing this for xts-aes only
+                 const uint8_t *IV __unused, // ignored
+                 const uint8_t *key1, int keylen,
+                 const uint8_t *key2, int tweaklen __unused, // both keys are the same size for xts
+                 uint32_t num_rounds __unused, // ignored
+                 uint32_t options __unused,    // ignored
+                 symmetric_xts *xts)
+{
+               const struct ccmode_xts *enc, *dec;
+               
+               if(!g_crypto_funcs)
+                       panic("%s: corecrypto not registered!\n", __FUNCTION__);
+               
+               enc = g_crypto_funcs->ccaes_xts_encrypt;
+               dec = g_crypto_funcs->ccaes_xts_decrypt;
+
+               if(!enc && !dec)
+                       panic("%s: xts mode not registered? enc=%p, dec=%p\n", __FUNCTION__, enc, dec);
+                       
+               /* Make sure the context size for the mode fits in the one we have */
+               if((enc->size>sizeof(xts->enc)) || (dec->size>sizeof(xts->dec)))
+                       panic("%s: inconsistent size for AES-XTS context", __FUNCTION__);
+
+               enc->init(enc, xts->enc, keylen, key1, key2);
+               dec->init(dec, xts->dec, keylen, key1, key2);
+
+               return 0; //never fails
+}
+
+int xts_encrypt(const uint8_t *pt, unsigned long ptlen,
+                       uint8_t *ct,
+                       const uint8_t *iv, // this can be considered the sector IV for this use
+                       symmetric_xts *xts)
+{
+       const struct ccmode_xts *xtsenc = g_crypto_funcs->ccaes_xts_encrypt;
+       ccxts_tweak_decl(xtsenc->tweak_size, tweak);
+               
+       if(ptlen%16) panic("xts encrypt not a multiple of block size\n");
+
+       xtsenc->set_tweak(xts->enc, tweak, iv);
+       xtsenc->xts(xts->enc, tweak, ptlen/16, pt, ct);
+       
+       return 0; //never fails
+}
+
+int xts_decrypt(const uint8_t *ct, unsigned long ptlen,
+                       uint8_t *pt,
+                               const uint8_t *iv, // this can be considered the sector IV for this use
+                       symmetric_xts *xts)
+{
+       const struct ccmode_xts *xtsdec = g_crypto_funcs->ccaes_xts_decrypt;
+       ccxts_tweak_decl(xtsdec->tweak_size, tweak);
+
+       if(ptlen%16) panic("xts decrypt not a multiple of block size\n");
+
+       xtsdec->set_tweak(xts->dec, tweak, iv);
+       xtsdec->xts(xts->dec, tweak, ptlen/16, ct, pt);
+
+       return 0; //never fails
+}
+
+void xts_done(symmetric_xts *xts __unused)
+{
+
+}