diff options
Diffstat (limited to 'Source/SPDataAdditions.m')
| -rw-r--r-- | Source/SPDataAdditions.m | 83 |
1 files changed, 83 insertions, 0 deletions
diff --git a/Source/SPDataAdditions.m b/Source/SPDataAdditions.m index edac9baa..1af06f5b 100644 --- a/Source/SPDataAdditions.m +++ b/Source/SPDataAdditions.m @@ -4,6 +4,11 @@ // SPDataAdditions.m // sequel-pro // +// dataEncryptedWithPassword and dataDecryptedWithPassword: +// License: FREEWARE http://aquaticmac.com/cocoa.php +// Copyright (c) 2005, Lucas Newman +// All rights reserved. +// // Created by Hans-Jörg Bibiko on June 19, 2009 // // This program is free software; you can redistribute it and/or modify @@ -24,6 +29,8 @@ #import "SPDataAdditions.h" #include <zlib.h> +#include <openssl/aes.h> +#include <openssl/sha.h> static char base64encodingTable[64] = { 'A','B','C','D','E','F','G','H','I','J','K','L','M','N','O','P', @@ -101,6 +108,82 @@ static char base64encodingTable[64] = { return base64; } +- (NSData*)dataEncryptedWithPassword:(NSString*)password +{ + // Create a random 128-bit initialization vector + srand(time(NULL)); + int ivIndex; + unsigned char iv[16]; + for (ivIndex = 0; ivIndex < 16; ivIndex++) + iv[ivIndex] = rand() & 0xff; + + // Calculate the 16-byte AES block padding + int dataLength = [self length]; + int paddedLength = dataLength + (32 - (dataLength % 16)); + int totalLength = paddedLength + 16; // Data plus IV + + // Allocate enough space for the IV + ciphertext + unsigned char *encryptedBytes = calloc(1, totalLength); + // The first block of the ciphertext buffer is the IV + memcpy(encryptedBytes, iv, 16); + + unsigned char *paddedBytes = calloc(1, paddedLength); + memcpy(paddedBytes, [self bytes], dataLength); + + // The last 32-bit chunk is the size of the plaintext, which is encrypted with the plaintext + int bigIntDataLength = NSSwapHostIntToBig(dataLength); + memcpy(paddedBytes + (paddedLength - 4), &bigIntDataLength, 4); + + // Create the key from first 128-bits of the 160-bit password hash + unsigned char passwordDigest[20]; + SHA1((const unsigned char *)[password UTF8String], strlen([password UTF8String]), passwordDigest); + AES_KEY aesKey; + AES_set_encrypt_key(passwordDigest, 128, &aesKey); + + // AES-128-cbc encrypt the data, filling in the buffer after the IV + AES_cbc_encrypt(paddedBytes, encryptedBytes + 16, paddedLength, &aesKey, iv, AES_ENCRYPT); + free(paddedBytes); + + return [NSData dataWithBytesNoCopy:encryptedBytes length:totalLength]; +} + +- (NSData*)dataDecryptedWithPassword:(NSString*)password +{ + // Create the key from the password hash + unsigned char passwordDigest[20]; + SHA1((const unsigned char *)[password UTF8String], strlen([password UTF8String]), passwordDigest); + + // AES-128-cbc decrypt the data + AES_KEY aesKey; + AES_set_decrypt_key(passwordDigest, 128, &aesKey); + + // Total length = encrypted length + IV + int totalLength = [self length]; + int encryptedLength = totalLength - 16; + + // Take the IV from the first 128-bit block + unsigned char iv[16]; + memcpy(iv, [self bytes], 16); + + // Decrypt the data + unsigned char *decryptedBytes = (unsigned char*)malloc(encryptedLength); + AES_cbc_encrypt([self bytes] + 16, decryptedBytes, encryptedLength, &aesKey, iv, AES_DECRYPT); + + // If decryption was successful, these blocks will be zeroed + if ( *((unsigned int*)decryptedBytes + ((encryptedLength / 4) - 4)) || + *((unsigned int*)decryptedBytes + ((encryptedLength / 4) - 3)) || + *((unsigned int*)decryptedBytes + ((encryptedLength / 4) - 2)) ) + { + return nil; + } + + // Get the size of the data from the last 32-bit chunk + int bigIntDataLength = *((unsigned int*)decryptedBytes + ((encryptedLength / 4) - 1)); + int dataLength = NSSwapBigIntToHost(bigIntDataLength); + + return [NSData dataWithBytesNoCopy:decryptedBytes length:dataLength]; +} + - (NSData *)decompress { if ([self length] == 0) return self; |