1 files changed, 164 insertions, 0 deletions
diff --git a/mpq-crypto.c b/mpq-crypto.c
new file mode 100644
index 0000000..7ddbad5
--- /dev/null
+++ b/mpq-crypto.c
@@ -0,0 +1,164 @@
+#include <assert.h>
+#include <string.h>
+
+#include "mpq-crypto.h"
+
+static int crypt_table_initialized = 0;
+static uint32_t crypt_table[0x500];
+
+/****TODO****/
+/* Re-implement various endianess fixes. */
+
+const uint32_t *__mpqlib_get_cryptography_table()
+{
+    assert(crypt_table_initialized);
+    return crypt_table;
+}
+
+void __mpqlib_init_cryptography()
+{
+   // Prepare crypt_table
+    uint32_t seed = 0x00100001;
+    uint32_t index1 = 0;
+    uint32_t index2 = 0;
+    int32_t i;
+
+    if (!crypt_table_initialized) {
+        crypt_table_initialized = 1;
+
+        for (index1 = 0; index1 < 0x100; index1++) {
+            for (index2 = index1, i = 0; i < 5; i++, index2 += 0x100) {
+                uint32_t temp1, temp2;
+
+                seed = (seed * 125 + 3) % 0x2AAAAB;
+                temp1 = (seed & 0xFFFF) << 0x10;
+
+                seed = (seed * 125 + 3) % 0x2AAAAB;
+                temp2 = (seed & 0xFFFF);
+
+                crypt_table[index2] = (temp1 | temp2);
+            }
+        }
+    }
+}
+
+void __mpqlib_encrypt(void *_data, uint32_t length, uint32_t key, char disable_input_swapping)
+{
+    char * data = (char *) _data;
+    uint32_t *buffer32 = (uint32_t *) data;
+    uint32_t seed = 0xEEEEEEEE;
+    uint32_t ch;
+    
+    assert(crypt_table_initialized);
+    assert(data);
+
+   // Round to 4 bytes
+    length = length / 4;
+
+   // We duplicate the loop to avoid costly branches
+    if (disable_input_swapping) {
+        while (length-- > 0) {
+            seed += crypt_table[0x400 + (key & 0xFF)];
+            ch = *buffer32 ^ (key + seed);
+
+            key = ((~key << 0x15) + 0x11111111) | (key >> 0x0B);
+            seed = *buffer32 + seed + (seed << 5) + 3;
+
+            *buffer32++ = ch;
+        }
+    } else {
+        while (length-- > 0) {
+            seed += crypt_table[0x400 + (key & 0xFF)];
+            ch = *buffer32 ^ (key + seed);
+
+            key = ((~key << 0x15) + 0x11111111) | (key >> 0x0B);
+            seed = *buffer32 + seed + (seed << 5) + 3;
+
+            *buffer32++ = ch;
+        }
+    }
+}
+
+void __mpqlib_decrypt(void *_data, uint32_t length, uint32_t key, char disable_output_swapping)
+{
+    char * data = (char *) _data;
+    uint32_t *buffer32 = (uint32_t *) data;
+    uint32_t seed = 0xEEEEEEEE;
+    uint32_t ch;
+
+    assert(crypt_table_initialized);
+    assert(data);
+
+   // Round to 4 bytes
+    length = length / 4;
+
+    if (disable_output_swapping) {
+        while (length-- > 0) {
+            ch = *buffer32;
+
+            seed += crypt_table[0x400 + (key & 0xFF)];
+            ch = ch ^ (key + seed);
+
+            key = ((~key << 0x15) + 0x11111111) | (key >> 0x0B);
+            seed = ch + seed + (seed << 5) + 3;
+
+            *buffer32++ = ch;
+        }
+
+    } else {
+        while (length-- > 0) {
+            ch = *buffer32;
+
+            seed += crypt_table[0x400 + (key & 0xFF)];
+            ch = ch ^ (key + seed);
+
+            key = ((~key << 0x15) + 0x11111111) | (key >> 0x0B);
+            seed = ch + seed + (seed << 5) + 3;
+
+            *buffer32++ = ch;
+        }
+    }
+}
+
+uint32_t __mpqlib_hash_cstring(const char *string, uint32_t type)
+{
+    uint32_t seed1 = 0x7FED7FED;
+    uint32_t seed2 = 0xEEEEEEEE;
+    uint32_t shifted_type = (type << 8);
+    int32_t ch;
+
+    assert(crypt_table_initialized);
+    assert(string);
+
+    while (*string != 0) {
+        ch = *string++;
+        if (ch > 0x60 && ch < 0x7b)
+            ch -= 0x20;
+
+        seed1 = crypt_table[shifted_type + ch] ^ (seed1 + seed2);
+        seed2 = ch + seed1 + seed2 + (seed2 << 5) + 3;
+    }
+
+    return seed1;
+}
+
+uint32_t __mpqlib_hash_data(const char *data, uint32_t length, uint32_t type)
+{
+    uint32_t seed1 = 0x7FED7FED;
+    uint32_t seed2 = 0xEEEEEEEE;
+    uint32_t shifted_type = (type << 8);
+    int32_t ch;
+
+    assert(crypt_table_initialized);
+    assert(data);
+
+    while (length > 0) {
+        ch = *data++;
+
+        seed1 = crypt_table[shifted_type + ch] ^ (seed1 + seed2);
+        seed2 = ch + seed1 + seed2 + (seed2 << 5) + 3;
+        length--;
+    }
+
+    return seed1;
+}