crypto: add aes (ecb, ctr, xts)

libraries/libvapours/source/crypto/impl/crypto_xts_mode_impl.cpp

@@ -0,0 +1,140 @@
+/*
+ * Copyright (c) 2018-2020 Atmosphère-NX
+ *
+ * This program is free software; you can redistribute it and/or modify it
+ * under the terms and conditions of the GNU General Public License,
+ * version 2, as published by the Free Software Foundation.
+ *
+ * This program is distributed in the hope 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, see <http://www.gnu.org/licenses/>.
+ */
+#include <vapours.hpp>
+
+namespace ams::crypto::impl {
+
+    namespace {
+
+        /* TODO: Support non-Nintendo Endianness */
+
+        void MultiplyTweakGeneric(u64 *tweak) {
+            const u64 carry = tweak[1] & (static_cast<u64>(1) << (BITSIZEOF(u64) - 1));
+
+            tweak[1] = ((tweak[1] << 1) | (tweak[0] >> (BITSIZEOF(u64) - 1)));
+            tweak[0] = (tweak[0] << 1);
+
+            if (carry) {
+                tweak[0] ^= static_cast<u64>(0x87);
+            }
+        }
+
+    }
+
+    void XtsModeImpl::ProcessBlock(u8 *dst, const u8 *src) {
+        u8 tmp[BlockSize];
+
+        /* Xor. */
+        for (size_t i = 0; i < BlockSize; i++) {
+            tmp[i] = this->tweak[i] ^ src[i];
+        }
+
+        /* Crypt */
+        this->cipher_func(tmp, tmp, this->cipher_ctx);
+
+        /* Xor. */
+        for (size_t i = 0; i < BlockSize; i++) {
+            dst[i] = this->tweak[i] ^ tmp[i];
+        }
+
+        MultiplyTweakGeneric(reinterpret_cast<u64 *>(this->tweak));
+    }
+
+    size_t XtsModeImpl::FinalizeEncryption(void *dst, size_t dst_size) {
+        AMS_ASSERT(this->state == State_Processing);
+
+        u8 *dst_u8 = static_cast<u8 *>(dst);
+        size_t processed = 0;
+
+        if (this->num_buffered == 0) {
+            this->ProcessBlock(dst_u8, this->last_block);
+            processed = BlockSize;
+        } else {
+            this->ProcessBlock(this->last_block, this->last_block);
+
+            std::memcpy(this->buffer + this->num_buffered, this->last_block + this->num_buffered, BlockSize - this->num_buffered);
+
+            this->ProcessBlock(dst_u8, this->buffer);
+
+            std::memcpy(dst_u8 + BlockSize, this->last_block, this->num_buffered);
+
+            processed = BlockSize + this->num_buffered;
+        }
+
+        this->state = State_Done;
+        return processed;
+    }
+
+    size_t XtsModeImpl::FinalizeDecryption(void *dst, size_t dst_size) {
+        AMS_ASSERT(this->state == State_Processing);
+
+        u8 *dst_u8 = static_cast<u8 *>(dst);
+        size_t processed = 0;
+
+        if (this->num_buffered == 0) {
+            this->ProcessBlock(dst_u8, this->last_block);
+            processed = BlockSize;
+        } else {
+            u8 tmp_tweak[BlockSize];
+            std::memcpy(tmp_tweak, this->tweak, BlockSize);
+            MultiplyTweakGeneric(reinterpret_cast<u64 *>(this->tweak));
+
+            this->ProcessBlock(this->last_block, this->last_block);
+
+            std::memcpy(this->buffer + this->num_buffered, this->last_block + this->num_buffered, BlockSize - this->num_buffered);
+
+            std::memcpy(this->tweak, tmp_tweak, BlockSize);
+
+            this->ProcessBlock(dst_u8, this->buffer);
+
+            std::memcpy(dst_u8 + BlockSize, this->last_block, this->num_buffered);
+
+            processed = BlockSize + this->num_buffered;
+        }
+
+        this->state = State_Done;
+        return processed;
+    }
+
+    size_t XtsModeImpl::ProcessPartialData(u8 *dst, const u8 *src, size_t size) {
+        size_t processed = 0;
+
+        std::memcpy(this->buffer + this->num_buffered, src, size);
+        this->num_buffered += size;
+
+        if (this->num_buffered == BlockSize) {
+            if (this->state == State_Processing) {
+                this->ProcessBlock(dst, this->last_block);
+                processed += BlockSize;
+            }
+
+            std::memcpy(this->last_block, this->buffer, BlockSize);
+            this->num_buffered = 0;
+
+            this->state = State_Processing;
+        }
+
+        return processed;
+    }
+
+    size_t XtsModeImpl::ProcessRemainingData(u8 *dst, const u8 *src, size_t size) {
+        std::memcpy(this->buffer, src, size);
+        this->num_buffered = size;
+
+        return 0;
+    }
+
+}