LibCrypto: Implement SHA1 Hash Function

Libraries/LibCrypto/Hash/SHA1.cpp

@@ -0,0 +1,159 @@
+/*
+ * Copyright (c) 2020, Ali Mohammad Pur <ali.mpfard@gmail.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:
+ *
+ * 1. Redistributions of source code must retain the above copyright notice, this
+ *    list of conditions and the following disclaimer.
+ *
+ * 2. 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.
+ *
+ * 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 COPYRIGHT HOLDER 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.
+ */
+
+#include <AK/Types.h>
+#include <LibCrypto/Hash/SHA1.h>
+
+namespace Crypto {
+namespace Hash {
+
+inline static constexpr auto ROTATE_LEFT(u32 value, size_t bits)
+{
+    return (value << bits) | (value >> (32 - bits));
+}
+
+inline void SHA1::transform(const u8* data)
+{
+    u32 blocks[80];
+    for (size_t i = 0; i < 16; ++i)
+        blocks[i] = convert_between_host_and_network(((const u32*)data)[i]);
+
+    // w[i] = (w[i-3] xor w[i-8] xor w[i-14] xor w[i-16]) leftrotate 1
+    for (size_t i = 16; i < Rounds; ++i)
+        blocks[i] = ROTATE_LEFT(blocks[i - 3] ^ blocks[i - 8] ^ blocks[i - 14] ^ blocks[i - 16], 1);
+
+    auto a = m_state[0], b = m_state[1], c = m_state[2], d = m_state[3], e = m_state[4];
+    u32 f, k;
+
+    for (size_t i = 0; i < Rounds; ++i) {
+        if (i <= 19) {
+            f = (b & c) | ((~b) & d);
+            k = SHA1Constants::RoundConstants[0];
+        } else if (i <= 39) {
+            f = b ^ c ^ d;
+            k = SHA1Constants::RoundConstants[1];
+        } else if (i <= 59) {
+            f = (b & c) | (b & d) | (c & d);
+            k = SHA1Constants::RoundConstants[2];
+        } else {
+            f = b ^ c ^ d;
+            k = SHA1Constants::RoundConstants[3];
+        }
+        auto temp = ROTATE_LEFT(a, 5) + f + e + k + blocks[i];
+        e = d;
+        d = c;
+        c = ROTATE_LEFT(b, 30);
+        b = a;
+        a = temp;
+    }
+
+    m_state[0] += a;
+    m_state[1] += b;
+    m_state[2] += c;
+    m_state[3] += d;
+    m_state[4] += e;
+
+    // "security" measures, as if SHA1 is secure
+    a = 0;
+    b = 0;
+    c = 0;
+    d = 0;
+    e = 0;
+    __builtin_memset(blocks, 0, 16 * sizeof(u32));
+}
+
+void SHA1::update(const u8* message, size_t length)
+{
+    for (size_t i = 0; i < length; ++i) {
+        if (m_data_length == BlockSize) {
+            transform(m_data_buffer);
+            m_bit_length += 512;
+            m_data_length = 0;
+        }
+        m_data_buffer[m_data_length++] = message[i];
+    }
+}
+
+SHA1::DigestType SHA1::digest()
+{
+    auto digest = peek();
+    reset();
+    return digest;
+}
+
+SHA1::DigestType SHA1::peek()
+{
+    DigestType digest;
+    size_t i = m_data_length;
+
+    // make a local copy of the data as we modify it
+    u8 data[BlockSize];
+    u32 state[5];
+    __builtin_memcpy(data, m_data_buffer, m_data_length);
+    __builtin_memcpy(state, m_state, 20);
+
+    if (m_data_length < FinalBlockDataSize) {
+        m_data_buffer[i++] = 0x80;
+        while (i < FinalBlockDataSize)
+            m_data_buffer[i++] = 0x00;
+
+    } else {
+        m_data_buffer[i++] = 0x80;
+        while (i < BlockSize)
+            m_data_buffer[i++] = 0x00;
+
+        transform(m_data_buffer);
+        __builtin_memset(m_data_buffer, 0, FinalBlockDataSize);
+    }
+
+    // append total message length
+    m_bit_length += m_data_length * 8;
+    m_data_buffer[BlockSize - 1] = m_bit_length;
+    m_data_buffer[BlockSize - 2] = m_bit_length >> 8;
+    m_data_buffer[BlockSize - 3] = m_bit_length >> 16;
+    m_data_buffer[BlockSize - 4] = m_bit_length >> 24;
+    m_data_buffer[BlockSize - 5] = m_bit_length >> 32;
+    m_data_buffer[BlockSize - 6] = m_bit_length >> 40;
+    m_data_buffer[BlockSize - 7] = m_bit_length >> 48;
+    m_data_buffer[BlockSize - 8] = m_bit_length >> 56;
+
+    transform(m_data_buffer);
+
+    for (size_t i = 0; i < 4; ++i) {
+        digest.data[i + 0] = (m_state[0] >> (24 - i * 8)) & 0x000000ff;
+        digest.data[i + 4] = (m_state[1] >> (24 - i * 8)) & 0x000000ff;
+        digest.data[i + 8] = (m_state[2] >> (24 - i * 8)) & 0x000000ff;
+        digest.data[i + 12] = (m_state[3] >> (24 - i * 8)) & 0x000000ff;
+        digest.data[i + 16] = (m_state[4] >> (24 - i * 8)) & 0x000000ff;
+    }
+    // restore the data
+    __builtin_memcpy(m_data_buffer, data, m_data_length);
+    __builtin_memcpy(m_state, state, 20);
+    return digest;
+}
+
+}
+}