initial code for dumping imessages in a reasonable format

dump-imessages/iphone-dataprotection/ramdisk_tools/AppleKeyStore_kdf.c

@@ -0,0 +1,145 @@
+#include <stdio.h>
+#include <stdlib.h>
+#include <stdint.h>
+#include <string.h>
+#include "IOKit.h"
+#include "IOAESAccelerator.h"
+#include "AppleEffaceableStorage.h"
+#include "AppleKeyStore.h"
+#include "bsdcrypto/pbkdf2.h"
+#include "bsdcrypto/rijndael.h"
+#include "bsdcrypto/key_wrap.h"
+
+int AppleKeyStore_derivation(void* data, uint32_t dataLength, uint32_t iter, uint32_t vers);
+uint32_t AppleKeyStore_xorExpand(uint32_t* dst, uint32_t dstLen, uint32_t* input, uint32_t inLen, uint32_t xorKey);
+void AppleKeyStore_xorCompress(uint32_t* input, uint32_t inputLen, uint32_t* output, uint32_t outputLen);
+
+#define DERIVATION_BUFFER_SIZE  4096
+uint8_t buf1[DERIVATION_BUFFER_SIZE];
+uint8_t buf2[DERIVATION_BUFFER_SIZE];
+
+IOByteCount IOAESStructSize1 = sizeof(IOAESStruct);
+IOAESStruct in ={buf1,buf2,DERIVATION_BUFFER_SIZE,{0},0,128,{0},kIOAESAcceleratorUIDMask,0};
+IOAESStruct out = {0};
+
+int AppleKeyStore_getPasscodeKey(KeyBag* keybag,
+                                 const char* passcode,
+                                 size_t passcodeLen,
+                                 uint8_t* passcodeKey)
+{
+    //One PBKDF2 iter, hardcoded salt length
+    pkcs5_pbkdf2(passcode, passcodeLen, keybag->salt, 20, passcodeKey, 32, 1);
+    
+    return AppleKeyStore_derivation(passcodeKey, 32, keybag->iter, keybag->version);
+}
+    
+int AppleKeyStore_derivation(void* data, uint32_t dataLength, uint32_t iter, uint32_t vers)
+{
+    IOReturn ret;
+    io_connect_t conn = IOAESAccelerator_getIOconnect();
+    memset(in.iv, 0, 16);
+    
+    uint32_t r4;
+    uint32_t nBlocks = DERIVATION_BUFFER_SIZE / dataLength;    //4096/32=128
+    uint32_t xorkey = 1;
+    
+    uint32_t* buffer2 = data;
+    if (vers >= 2)
+    {
+        buffer2 = malloc(dataLength);
+        memcpy(buffer2, data, dataLength);
+    }
+    while (iter > 0) 
+    {
+        //version=1 xorKey alawys=1, buffer2 changes at each iter
+        //version=2 xorKey changes at each iter, buffer2 is always the input (pbkdf2(passcode))
+        r4 = AppleKeyStore_xorExpand((uint32_t*)buf1, DERIVATION_BUFFER_SIZE, buffer2, dataLength, xorkey);
+        if (vers >= 2)
+            xorkey = r4;
+        
+        if((ret = IOConnectCallStructMethod(conn, kIOAESAcceleratorTask, &in, IOAESStructSize1, &out, &IOAESStructSize1)) != kIOReturnSuccess)
+        {
+            fprintf(stderr, "IOConnectCallStructMethod fail : %x\n", ret);
+            return -1;
+        }
+        memcpy(in.iv, out.iv, 16);
+
+        r4 = nBlocks;
+        if (r4 >= iter)
+        {
+            r4 = iter;
+        }
+        AppleKeyStore_xorCompress((uint32_t*) buf2,  r4 * dataLength, data, dataLength);
+        iter -= r4;
+    }
+    if (vers >= 2)
+    {
+        free(buffer2);
+    }
+    return 0;
+}
+
+/*
+uint32_t paddedLen = (inLen + 3) & (~3);//aligne sur 4 octets
+if (dstLen % paddedLen)
+    return;
+uint32_t localBuf[inLen/4];
+
+memcpy(localBuf, input, inLen);
+memset(&localBuf[inLen], 0, paddedLen - inLen);*/
+uint32_t AppleKeyStore_xorExpand(uint32_t* dst, uint32_t dstLen, uint32_t* input, uint32_t inLen, uint32_t xorKey)
+{
+    uint32_t* dstEnd = &dst[dstLen/4];
+    uint32_t i = 0;
+
+    while (dst < dstEnd)
+    {
+        i = 0;
+        while (i < inLen/4)
+        {
+            *dst = input[i] ^ xorKey;
+            dst++;
+            i++;
+        }
+        xorKey++;
+    }
+    return xorKey;
+}
+
+void AppleKeyStore_xorCompress(uint32_t* input, uint32_t inputLen, uint32_t* output, uint32_t outputLen)
+{
+    uint32_t i;
+
+    for (i=0; i < (inputLen/4); i++)
+    {
+        output[i%(outputLen/4)] ^= input[i];
+    }
+}
+
+int AppleKeyStore_unlockKeybagFromUserland(KeyBag* kb, const char* passcode, size_t passcodeLen, uint8_t* key835)
+{
+    u_int8_t passcodeKey[32]={0};
+    u_int8_t unwrappedKey[40]={0};
+    aes_key_wrap_ctx ctx;
+    int i;
+
+    AppleKeyStore_getPasscodeKey(kb, passcode, passcodeLen, passcodeKey);
+    aes_key_wrap_set_key(&ctx, passcodeKey, 32);
+
+    for (i=0; i < kb->numKeys; i++)
+    {
+        if (kb->keys[i].wrap & 2)
+        {
+            if(aes_key_unwrap(&ctx, kb->keys[i].wpky, unwrappedKey, 4))
+                return 0;
+            memcpy(kb->keys[i].wpky, unwrappedKey, 32);
+            kb->keys[i].wrap &= ~2;
+        }
+        if (kb->keys[i].wrap & 1)
+        {
+            doAES(kb->keys[i].wpky, kb->keys[i].wpky, 32, kIOAESAcceleratorCustomMask, key835, NULL, kIOAESAcceleratorDecrypt, 128);
+            kb->keys[i].wrap &= ~1;
+        }
+    }
+    return 1;
+}