Introduction
The Advanced Encryption Standard is the algorithm that won the National Insitute of Standards and Technology's (NIST) search for a standardized encryption algorithm in 2001. In 2002, it was adopted by the U.S. government as a stadard for encryption. It is based on the Rijndael algorithm.
Even though it was chosen by NIST, it was not the strongest algorithm that was available. Both the Twofish and Serpent algorithms offer more security. AES was chosen because of it's speed when implemented in hardware or software.
What is AES?
AES is a block cipher. This means that it encrypts groups of bytes at a time. In this case, 16 bytes at a time. Generally, block ciphers are more secure than stream ciphers because they obfuscate the location of original bytes.
It is a secret key algorithm, which means that it uses a key that should only be known by the intended sender and recipient. A major problem with this is the secure transmission of the key. Public key cryptography solves this by using so called "hard" math where calculating in one direction is easy while solving in the opposite direction takes much much longer. One example is multiplication vs factorization. Multiplying two numbers is easy but attempting to find the two numbers used to get that number takes a long time. This type of "hard" math allows you to transmit public information that the sender and recipient uses to compute a key without having to transmit a key. So why isn't public key cryptography used exclusively? It is a lot slower than secret key cryptograpy.
General Weaknesses of Cryptography
A weakness of cryptography is that they can be hacked using brute force. This means that a message can stay a secret only for as long as it takes a computer to try every password until it finds the one you used. Each byte that you add to a password means that it will take roughly 256 times longer to crack your password. So the question is, how long do you need that message to stay a secret?
Now, that isn't actually a weakness of the algorithm per se. An actual weakness is that many algorithms are subject to mathematical analysis that may reveal what key was used to encrypt the data. Given enough encrypted data using the same or similar keys will result in a crack quicker than it would take using brute force. One way to mitigate this is the use of a nonce, initialization vector, or salt. They are basically random bits that are used with the key so that even though you are using the same key, each message is different because the random bits in effect change the key that is used.
This is why you should choose a longer password and why you should change your passwords often.
How AES works
AES encodes 16 bytes of data at a time and runs through its algorithm for a specified number of rounds depending on how many bits of strength you need. AES can use 128, 194, or 256-bits. The sample implementation below is the 256 bit version.
It first creates round keys by expanding the original key using the Rijndael key scheduler algorithm. It then encrypts the block by substituting bytes using the Rijndael S-box, shifting bytes, diffusing bytes using a Galois field, and adding the round key. In the 256-bit version, this is done 14 times. It does this for each 16 byte block of data.
Specific Weaknesses of AES
Currently, the best known attack against AES is a related-key attack. A related-key attack is when you have ciphertexts that are encoded using similar keys, i.e., if you encode a text using the password "Password1" and then encode a text using the password "Password2" . This is due to AES's simple key scheduler. However, the attack is infeasible and would take much too long to be of any use when using the 256-bit version of AES.
Sample Implementation of AES
This is a function that works in many VB implementations . It even works in a Visual Basic Script and was, in fact, coded specifically for VBScript. But it should be directly portable to VBA. I validated the results against the National Institute of Standards and Technology's test files. The function below is used to encrypt files but can be modified to accept other data.
This implementation inlines many of the functions that would make the implementation easier to read. This was done for speed. It also runs in Electronic Codebook Mode (ECM) which is the most insecure of the modes but is the easiest to understand and implement. I will work on a cipher-block chaining mode (which is the recommended implementation) and post the code when that's done.
Basically, ECM does not vary anything as each block is encoded so if the same block is encoded, the results will be the same. CBC solves this by XORing the resulting ciphertext with the next block of plaintext. Therefore, even if the same block is encoded twice, the results will be different.
Here is the code for Cipher-block Chaining mode.
The Advanced Encryption Standard is the algorithm that won the National Insitute of Standards and Technology's (NIST) search for a standardized encryption algorithm in 2001. In 2002, it was adopted by the U.S. government as a stadard for encryption. It is based on the Rijndael algorithm.
Even though it was chosen by NIST, it was not the strongest algorithm that was available. Both the Twofish and Serpent algorithms offer more security. AES was chosen because of it's speed when implemented in hardware or software.
What is AES?
AES is a block cipher. This means that it encrypts groups of bytes at a time. In this case, 16 bytes at a time. Generally, block ciphers are more secure than stream ciphers because they obfuscate the location of original bytes.
It is a secret key algorithm, which means that it uses a key that should only be known by the intended sender and recipient. A major problem with this is the secure transmission of the key. Public key cryptography solves this by using so called "hard" math where calculating in one direction is easy while solving in the opposite direction takes much much longer. One example is multiplication vs factorization. Multiplying two numbers is easy but attempting to find the two numbers used to get that number takes a long time. This type of "hard" math allows you to transmit public information that the sender and recipient uses to compute a key without having to transmit a key. So why isn't public key cryptography used exclusively? It is a lot slower than secret key cryptograpy.
General Weaknesses of Cryptography
A weakness of cryptography is that they can be hacked using brute force. This means that a message can stay a secret only for as long as it takes a computer to try every password until it finds the one you used. Each byte that you add to a password means that it will take roughly 256 times longer to crack your password. So the question is, how long do you need that message to stay a secret?
Now, that isn't actually a weakness of the algorithm per se. An actual weakness is that many algorithms are subject to mathematical analysis that may reveal what key was used to encrypt the data. Given enough encrypted data using the same or similar keys will result in a crack quicker than it would take using brute force. One way to mitigate this is the use of a nonce, initialization vector, or salt. They are basically random bits that are used with the key so that even though you are using the same key, each message is different because the random bits in effect change the key that is used.
This is why you should choose a longer password and why you should change your passwords often.
How AES works
AES encodes 16 bytes of data at a time and runs through its algorithm for a specified number of rounds depending on how many bits of strength you need. AES can use 128, 194, or 256-bits. The sample implementation below is the 256 bit version.
It first creates round keys by expanding the original key using the Rijndael key scheduler algorithm. It then encrypts the block by substituting bytes using the Rijndael S-box, shifting bytes, diffusing bytes using a Galois field, and adding the round key. In the 256-bit version, this is done 14 times. It does this for each 16 byte block of data.
Specific Weaknesses of AES
Currently, the best known attack against AES is a related-key attack. A related-key attack is when you have ciphertexts that are encoded using similar keys, i.e., if you encode a text using the password "Password1" and then encode a text using the password "Password2" . This is due to AES's simple key scheduler. However, the attack is infeasible and would take much too long to be of any use when using the 256-bit version of AES.
Sample Implementation of AES
This is a function that works in many VB implementations . It even works in a Visual Basic Script and was, in fact, coded specifically for VBScript. But it should be directly portable to VBA. I validated the results against the National Institute of Standards and Technology's test files. The function below is used to encrypt files but can be modified to accept other data.
This implementation inlines many of the functions that would make the implementation easier to read. This was done for speed. It also runs in Electronic Codebook Mode (ECM) which is the most insecure of the modes but is the easiest to understand and implement. I will work on a cipher-block chaining mode (which is the recommended implementation) and post the code when that's done.
Basically, ECM does not vary anything as each block is encoded so if the same block is encoded, the results will be the same. CBC solves this by XORing the resulting ciphertext with the next block of plaintext. Therefore, even if the same block is encoded twice, the results will be different.
Code:
Sub AES(sFile)
Dim sbox, sboxinv, rcon
Dim g2, g3, g9, g11, g13, g14
g2 = Array( _
&h00,&h02,&h04,&h06,&h08,&h0a,&h0c,&h0e,&h10,&h12,&h14,&h16,&h18,&h1a,&h1c,&h1e, _
&h20,&h22,&h24,&h26,&h28,&h2a,&h2c,&h2e,&h30,&h32,&h34,&h36,&h38,&h3a,&h3c,&h3e, _
&h40,&h42,&h44,&h46,&h48,&h4a,&h4c,&h4e,&h50,&h52,&h54,&h56,&h58,&h5a,&h5c,&h5e, _
&h60,&h62,&h64,&h66,&h68,&h6a,&h6c,&h6e,&h70,&h72,&h74,&h76,&h78,&h7a,&h7c,&h7e, _
&h80,&h82,&h84,&h86,&h88,&h8a,&h8c,&h8e,&h90,&h92,&h94,&h96,&h98,&h9a,&h9c,&h9e, _
&ha0,&ha2,&ha4,&ha6,&ha8,&haa,&hac,&hae,&hb0,&hb2,&hb4,&hb6,&hb8,&hba,&hbc,&hbe, _
&hc0,&hc2,&hc4,&hc6,&hc8,&hca,&hcc,&hce,&hd0,&hd2,&hd4,&hd6,&hd8,&hda,&hdc,&hde, _
&he0,&he2,&he4,&he6,&he8,&hea,&hec,&hee,&hf0,&hf2,&hf4,&hf6,&hf8,&hfa,&hfc,&hfe, _
&h1b,&h19,&h1f,&h1d,&h13,&h11,&h17,&h15,&h0b,&h09,&h0f,&h0d,&h03,&h01,&h07,&h05, _
&h3b,&h39,&h3f,&h3d,&h33,&h31,&h37,&h35,&h2b,&h29,&h2f,&h2d,&h23,&h21,&h27,&h25, _
&h5b,&h59,&h5f,&h5d,&h53,&h51,&h57,&h55,&h4b,&h49,&h4f,&h4d,&h43,&h41,&h47,&h45, _
&h7b,&h79,&h7f,&h7d,&h73,&h71,&h77,&h75,&h6b,&h69,&h6f,&h6d,&h63,&h61,&h67,&h65, _
&h9b,&h99,&h9f,&h9d,&h93,&h91,&h97,&h95,&h8b,&h89,&h8f,&h8d,&h83,&h81,&h87,&h85, _
&hbb,&hb9,&hbf,&hbd,&hb3,&hb1,&hb7,&hb5,&hab,&ha9,&haf,&had,&ha3,&ha1,&ha7,&ha5, _
&hdb,&hd9,&hdf,&hdd,&hd3,&hd1,&hd7,&hd5,&hcb,&hc9,&hcf,&hcd,&hc3,&hc1,&hc7,&hc5, _
&hfb,&hf9,&hff,&hfd,&hf3,&hf1,&hf7,&hf5,&heb,&he9,&hef,&hed,&he3,&he1,&he7,&he5)
g3 = Array( _
&h00,&h03,&h06,&h05,&h0c,&h0f,&h0a,&h09,&h18,&h1b,&h1e,&h1d,&h14,&h17,&h12,&h11, _
&h30,&h33,&h36,&h35,&h3c,&h3f,&h3a,&h39,&h28,&h2b,&h2e,&h2d,&h24,&h27,&h22,&h21, _
&h60,&h63,&h66,&h65,&h6c,&h6f,&h6a,&h69,&h78,&h7b,&h7e,&h7d,&h74,&h77,&h72,&h71, _
&h50,&h53,&h56,&h55,&h5c,&h5f,&h5a,&h59,&h48,&h4b,&h4e,&h4d,&h44,&h47,&h42,&h41, _
&hc0,&hc3,&hc6,&hc5,&hcc,&hcf,&hca,&hc9,&hd8,&hdb,&hde,&hdd,&hd4,&hd7,&hd2,&hd1, _
&hf0,&hf3,&hf6,&hf5,&hfc,&hff,&hfa,&hf9,&he8,&heb,&hee,&hed,&he4,&he7,&he2,&he1, _
&ha0,&ha3,&ha6,&ha5,&hac,&haf,&haa,&ha9,&hb8,&hbb,&hbe,&hbd,&hb4,&hb7,&hb2,&hb1, _
&h90,&h93,&h96,&h95,&h9c,&h9f,&h9a,&h99,&h88,&h8b,&h8e,&h8d,&h84,&h87,&h82,&h81, _
&h9b,&h98,&h9d,&h9e,&h97,&h94,&h91,&h92,&h83,&h80,&h85,&h86,&h8f,&h8c,&h89,&h8a, _
&hab,&ha8,&had,&hae,&ha7,&ha4,&ha1,&ha2,&hb3,&hb0,&hb5,&hb6,&hbf,&hbc,&hb9,&hba, _
&hfb,&hf8,&hfd,&hfe,&hf7,&hf4,&hf1,&hf2,&he3,&he0,&he5,&he6,&hef,&hec,&he9,&hea, _
&hcb,&hc8,&hcd,&hce,&hc7,&hc4,&hc1,&hc2,&hd3,&hd0,&hd5,&hd6,&hdf,&hdc,&hd9,&hda, _
&h5b,&h58,&h5d,&h5e,&h57,&h54,&h51,&h52,&h43,&h40,&h45,&h46,&h4f,&h4c,&h49,&h4a, _
&h6b,&h68,&h6d,&h6e,&h67,&h64,&h61,&h62,&h73,&h70,&h75,&h76,&h7f,&h7c,&h79,&h7a, _
&h3b,&h38,&h3d,&h3e,&h37,&h34,&h31,&h32,&h23,&h20,&h25,&h26,&h2f,&h2c,&h29,&h2a, _
&h0b,&h08,&h0d,&h0e,&h07,&h04,&h01,&h02,&h13,&h10,&h15,&h16,&h1f,&h1c,&h19,&h1a)
g9 = Array( _
&h00,&h09,&h12,&h1b,&h24,&h2d,&h36,&h3f,&h48,&h41,&h5a,&h53,&h6c,&h65,&h7e,&h77, _
&h90,&h99,&h82,&h8b,&hb4,&hbd,&ha6,&haf,&hd8,&hd1,&hca,&hc3,&hfc,&hf5,&hee,&he7, _
&h3b,&h32,&h29,&h20,&h1f,&h16,&h0d,&h04,&h73,&h7a,&h61,&h68,&h57,&h5e,&h45,&h4c, _
&hab,&ha2,&hb9,&hb0,&h8f,&h86,&h9d,&h94,&he3,&hea,&hf1,&hf8,&hc7,&hce,&hd5,&hdc, _
&h76,&h7f,&h64,&h6d,&h52,&h5b,&h40,&h49,&h3e,&h37,&h2c,&h25,&h1a,&h13,&h08,&h01, _
&he6,&hef,&hf4,&hfd,&hc2,&hcb,&hd0,&hd9,&hae,&ha7,&hbc,&hb5,&h8a,&h83,&h98,&h91, _
&h4d,&h44,&h5f,&h56,&h69,&h60,&h7b,&h72,&h05,&h0c,&h17,&h1e,&h21,&h28,&h33,&h3a, _
&hdd,&hd4,&hcf,&hc6,&hf9,&hf0,&heb,&he2,&h95,&h9c,&h87,&h8e,&hb1,&hb8,&ha3,&haa, _
&hec,&he5,&hfe,&hf7,&hc8,&hc1,&hda,&hd3,&ha4,&had,&hb6,&hbf,&h80,&h89,&h92,&h9b, _
&h7c,&h75,&h6e,&h67,&h58,&h51,&h4a,&h43,&h34,&h3d,&h26,&h2f,&h10,&h19,&h02,&h0b, _
&hd7,&hde,&hc5,&hcc,&hf3,&hfa,&he1,&he8,&h9f,&h96,&h8d,&h84,&hbb,&hb2,&ha9,&ha0, _
&h47,&h4e,&h55,&h5c,&h63,&h6a,&h71,&h78,&h0f,&h06,&h1d,&h14,&h2b,&h22,&h39,&h30, _
&h9a,&h93,&h88,&h81,&hbe,&hb7,&hac,&ha5,&hd2,&hdb,&hc0,&hc9,&hf6,&hff,&he4,&hed, _
&h0a,&h03,&h18,&h11,&h2e,&h27,&h3c,&h35,&h42,&h4b,&h50,&h59,&h66,&h6f,&h74,&h7d, _
&ha1,&ha8,&hb3,&hba,&h85,&h8c,&h97,&h9e,&he9,&he0,&hfb,&hf2,&hcd,&hc4,&hdf,&hd6, _
&h31,&h38,&h23,&h2a,&h15,&h1c,&h07,&h0e,&h79,&h70,&h6b,&h62,&h5d,&h54,&h4f,&h46)
g11 = Array( _
&h00,&h0b,&h16,&h1d,&h2c,&h27,&h3a,&h31,&h58,&h53,&h4e,&h45,&h74,&h7f,&h62,&h69, _
&hb0,&hbb,&ha6,&had,&h9c,&h97,&h8a,&h81,&he8,&he3,&hfe,&hf5,&hc4,&hcf,&hd2,&hd9, _
&h7b,&h70,&h6d,&h66,&h57,&h5c,&h41,&h4a,&h23,&h28,&h35,&h3e,&h0f,&h04,&h19,&h12, _
&hcb,&hc0,&hdd,&hd6,&he7,&hec,&hf1,&hfa,&h93,&h98,&h85,&h8e,&hbf,&hb4,&ha9,&ha2, _
&hf6,&hfd,&he0,&heb,&hda,&hd1,&hcc,&hc7,&hae,&ha5,&hb8,&hb3,&h82,&h89,&h94,&h9f, _
&h46,&h4d,&h50,&h5b,&h6a,&h61,&h7c,&h77,&h1e,&h15,&h08,&h03,&h32,&h39,&h24,&h2f, _
&h8d,&h86,&h9b,&h90,&ha1,&haa,&hb7,&hbc,&hd5,&hde,&hc3,&hc8,&hf9,&hf2,&hef,&he4, _
&h3d,&h36,&h2b,&h20,&h11,&h1a,&h07,&h0c,&h65,&h6e,&h73,&h78,&h49,&h42,&h5f,&h54, _
&hf7,&hfc,&he1,&hea,&hdb,&hd0,&hcd,&hc6,&haf,&ha4,&hb9,&hb2,&h83,&h88,&h95,&h9e, _
&h47,&h4c,&h51,&h5a,&h6b,&h60,&h7d,&h76,&h1f,&h14,&h09,&h02,&h33,&h38,&h25,&h2e, _
&h8c,&h87,&h9a,&h91,&ha0,&hab,&hb6,&hbd,&hd4,&hdf,&hc2,&hc9,&hf8,&hf3,&hee,&he5, _
&h3c,&h37,&h2a,&h21,&h10,&h1b,&h06,&h0d,&h64,&h6f,&h72,&h79,&h48,&h43,&h5e,&h55, _
&h01,&h0a,&h17,&h1c,&h2d,&h26,&h3b,&h30,&h59,&h52,&h4f,&h44,&h75,&h7e,&h63,&h68, _
&hb1,&hba,&ha7,&hac,&h9d,&h96,&h8b,&h80,&he9,&he2,&hff,&hf4,&hc5,&hce,&hd3,&hd8, _
&h7a,&h71,&h6c,&h67,&h56,&h5d,&h40,&h4b,&h22,&h29,&h34,&h3f,&h0e,&h05,&h18,&h13, _
&hca,&hc1,&hdc,&hd7,&he6,&hed,&hf0,&hfb,&h92,&h99,&h84,&h8f,&hbe,&hb5,&ha8,&ha3)
g13 = Array( _
&h00,&h0d,&h1a,&h17,&h34,&h39,&h2e,&h23,&h68,&h65,&h72,&h7f,&h5c,&h51,&h46,&h4b, _
&hd0,&hdd,&hca,&hc7,&he4,&he9,&hfe,&hf3,&hb8,&hb5,&ha2,&haf,&h8c,&h81,&h96,&h9b, _
&hbb,&hb6,&ha1,&hac,&h8f,&h82,&h95,&h98,&hd3,&hde,&hc9,&hc4,&he7,&hea,&hfd,&hf0, _
&h6b,&h66,&h71,&h7c,&h5f,&h52,&h45,&h48,&h03,&h0e,&h19,&h14,&h37,&h3a,&h2d,&h20, _
&h6d,&h60,&h77,&h7a,&h59,&h54,&h43,&h4e,&h05,&h08,&h1f,&h12,&h31,&h3c,&h2b,&h26, _
&hbd,&hb0,&ha7,&haa,&h89,&h84,&h93,&h9e,&hd5,&hd8,&hcf,&hc2,&he1,&hec,&hfb,&hf6, _
&hd6,&hdb,&hcc,&hc1,&he2,&hef,&hf8,&hf5,&hbe,&hb3,&ha4,&ha9,&h8a,&h87,&h90,&h9d, _
&h06,&h0b,&h1c,&h11,&h32,&h3f,&h28,&h25,&h6e,&h63,&h74,&h79,&h5a,&h57,&h40,&h4d, _
&hda,&hd7,&hc0,&hcd,&hee,&he3,&hf4,&hf9,&hb2,&hbf,&ha8,&ha5,&h86,&h8b,&h9c,&h91, _
&h0a,&h07,&h10,&h1d,&h3e,&h33,&h24,&h29,&h62,&h6f,&h78,&h75,&h56,&h5b,&h4c,&h41, _
&h61,&h6c,&h7b,&h76,&h55,&h58,&h4f,&h42,&h09,&h04,&h13,&h1e,&h3d,&h30,&h27,&h2a, _
&hb1,&hbc,&hab,&ha6,&h85,&h88,&h9f,&h92,&hd9,&hd4,&hc3,&hce,&hed,&he0,&hf7,&hfa, _
&hb7,&hba,&had,&ha0,&h83,&h8e,&h99,&h94,&hdf,&hd2,&hc5,&hc8,&heb,&he6,&hf1,&hfc, _
&h67,&h6a,&h7d,&h70,&h53,&h5e,&h49,&h44,&h0f,&h02,&h15,&h18,&h3b,&h36,&h21,&h2c, _
&h0c,&h01,&h16,&h1b,&h38,&h35,&h22,&h2f,&h64,&h69,&h7e,&h73,&h50,&h5d,&h4a,&h47, _
&hdc,&hd1,&hc6,&hcb,&he8,&he5,&hf2,&hff,&hb4,&hb9,&hae,&ha3,&h80,&h8d,&h9a,&h97)
g14 = Array( _
&h00,&h0e,&h1c,&h12,&h38,&h36,&h24,&h2a,&h70,&h7e,&h6c,&h62,&h48,&h46,&h54,&h5a, _
&he0,&hee,&hfc,&hf2,&hd8,&hd6,&hc4,&hca,&h90,&h9e,&h8c,&h82,&ha8,&ha6,&hb4,&hba, _
&hdb,&hd5,&hc7,&hc9,&he3,&hed,&hff,&hf1,&hab,&ha5,&hb7,&hb9,&h93,&h9d,&h8f,&h81, _
&h3b,&h35,&h27,&h29,&h03,&h0d,&h1f,&h11,&h4b,&h45,&h57,&h59,&h73,&h7d,&h6f,&h61, _
&had,&ha3,&hb1,&hbf,&h95,&h9b,&h89,&h87,&hdd,&hd3,&hc1,&hcf,&he5,&heb,&hf9,&hf7, _
&h4d,&h43,&h51,&h5f,&h75,&h7b,&h69,&h67,&h3d,&h33,&h21,&h2f,&h05,&h0b,&h19,&h17, _
&h76,&h78,&h6a,&h64,&h4e,&h40,&h52,&h5c,&h06,&h08,&h1a,&h14,&h3e,&h30,&h22,&h2c, _
&h96,&h98,&h8a,&h84,&hae,&ha0,&hb2,&hbc,&he6,&he8,&hfa,&hf4,&hde,&hd0,&hc2,&hcc, _
&h41,&h4f,&h5d,&h53,&h79,&h77,&h65,&h6b,&h31,&h3f,&h2d,&h23,&h09,&h07,&h15,&h1b, _
&ha1,&haf,&hbd,&hb3,&h99,&h97,&h85,&h8b,&hd1,&hdf,&hcd,&hc3,&he9,&he7,&hf5,&hfb, _
&h9a,&h94,&h86,&h88,&ha2,&hac,&hbe,&hb0,&hea,&he4,&hf6,&hf8,&hd2,&hdc,&hce,&hc0, _
&h7a,&h74,&h66,&h68,&h42,&h4c,&h5e,&h50,&h0a,&h04,&h16,&h18,&h32,&h3c,&h2e,&h20, _
&hec,&he2,&hf0,&hfe,&hd4,&hda,&hc8,&hc6,&h9c,&h92,&h80,&h8e,&ha4,&haa,&hb8,&hb6, _
&h0c,&h02,&h10,&h1e,&h34,&h3a,&h28,&h26,&h7c,&h72,&h60,&h6e,&h44,&h4a,&h58,&h56, _
&h37,&h39,&h2b,&h25,&h0f,&h01,&h13,&h1d,&h47,&h49,&h5b,&h55,&h7f,&h71,&h63,&h6d, _
&hd7,&hd9,&hcb,&hc5,&hef,&he1,&hf3,&hfd,&ha7,&ha9,&hbb,&hb5,&h9f,&h91,&h83,&h8d)
sbox = Array( _
&h63, &h7c, &h77, &h7b, &hf2, &h6b, &h6f, &hc5, &h30, &h01, &h67, &h2b, &hfe, &hd7, &hab, &h76, _
&hca, &h82, &hc9, &h7d, &hfa, &h59, &h47, &hf0, &had, &hd4, &ha2, &haf, &h9c, &ha4, &h72, &hc0, _
&hb7, &hfd, &h93, &h26, &h36, &h3f, &hf7, &hcc, &h34, &ha5, &he5, &hf1, &h71, &hd8, &h31, &h15, _
&h04, &hc7, &h23, &hc3, &h18, &h96, &h05, &h9a, &h07, &h12, &h80, &he2, &heb, &h27, &hb2, &h75, _
&h09, &h83, &h2c, &h1a, &h1b, &h6e, &h5a, &ha0, &h52, &h3b, &hd6, &hb3, &h29, &he3, &h2f, &h84, _
&h53, &hd1, &h00, &hed, &h20, &hfc, &hb1, &h5b, &h6a, &hcb, &hbe, &h39, &h4a, &h4c, &h58, &hcf, _
&hd0, &hef, &haa, &hfb, &h43, &h4d, &h33, &h85, &h45, &hf9, &h02, &h7f, &h50, &h3c, &h9f, &ha8, _
&h51, &ha3, &h40, &h8f, &h92, &h9d, &h38, &hf5, &hbc, &hb6, &hda, &h21, &h10, &hff, &hf3, &hd2, _
&hcd, &h0c, &h13, &hec, &h5f, &h97, &h44, &h17, &hc4, &ha7, &h7e, &h3d, &h64, &h5d, &h19, &h73, _
&h60, &h81, &h4f, &hdc, &h22, &h2a, &h90, &h88, &h46, &hee, &hb8, &h14, &hde, &h5e, &h0b, &hdb, _
&he0, &h32, &h3a, &h0a, &h49, &h06, &h24, &h5c, &hc2, &hd3, &hac, &h62, &h91, &h95, &he4, &h79, _
&he7, &hc8, &h37, &h6d, &h8d, &hd5, &h4e, &ha9, &h6c, &h56, &hf4, &hea, &h65, &h7a, &hae, &h08, _
&hba, &h78, &h25, &h2e, &h1c, &ha6, &hb4, &hc6, &he8, &hdd, &h74, &h1f, &h4b, &hbd, &h8b, &h8a, _
&h70, &h3e, &hb5, &h66, &h48, &h03, &hf6, &h0e, &h61, &h35, &h57, &hb9, &h86, &hc1, &h1d, &h9e, _
&he1, &hf8, &h98, &h11, &h69, &hd9, &h8e, &h94, &h9b, &h1e, &h87, &he9, &hce, &h55, &h28, &hdf, _
&h8c, &ha1, &h89, &h0d, &hbf, &he6, &h42, &h68, &h41, &h99, &h2d, &h0f, &hb0, &h54, &hbb, &h16)
sboxinv = Array( _
&h52, &h09, &h6a, &hd5, &h30, &h36, &ha5, &h38, &hbf, &h40, &ha3, &h9e, &h81, &hf3, &hd7, &hfb, _
&h7c, &he3, &h39, &h82, &h9b, &h2f, &hff, &h87, &h34, &h8e, &h43, &h44, &hc4, &hde, &he9, &hcb, _
&h54, &h7b, &h94, &h32, &ha6, &hc2, &h23, &h3d, &hee, &h4c, &h95, &h0b, &h42, &hfa, &hc3, &h4e, _
&h08, &h2e, &ha1, &h66, &h28, &hd9, &h24, &hb2, &h76, &h5b, &ha2, &h49, &h6d, &h8b, &hd1, &h25, _
&h72, &hf8, &hf6, &h64, &h86, &h68, &h98, &h16, &hd4, &ha4, &h5c, &hcc, &h5d, &h65, &hb6, &h92, _
&h6c, &h70, &h48, &h50, &hfd, &hed, &hb9, &hda, &h5e, &h15, &h46, &h57, &ha7, &h8d, &h9d, &h84, _
&h90, &hd8, &hab, &h00, &h8c, &hbc, &hd3, &h0a, &hf7, &he4, &h58, &h05, &hb8, &hb3, &h45, &h06, _
&hd0, &h2c, &h1e, &h8f, &hca, &h3f, &h0f, &h02, &hc1, &haf, &hbd, &h03, &h01, &h13, &h8a, &h6b, _
&h3a, &h91, &h11, &h41, &h4f, &h67, &hdc, &hea, &h97, &hf2, &hcf, &hce, &hf0, &hb4, &he6, &h73, _
&h96, &hac, &h74, &h22, &he7, &had, &h35, &h85, &he2, &hf9, &h37, &he8, &h1c, &h75, &hdf, &h6e, _
&h47, &hf1, &h1a, &h71, &h1d, &h29, &hc5, &h89, &h6f, &hb7, &h62, &h0e, &haa, &h18, &hbe, &h1b, _
&hfc, &h56, &h3e, &h4b, &hc6, &hd2, &h79, &h20, &h9a, &hdb, &hc0, &hfe, &h78, &hcd, &h5a, &hf4, _
&h1f, &hdd, &ha8, &h33, &h88, &h07, &hc7, &h31, &hb1, &h12, &h10, &h59, &h27, &h80, &hec, &h5f, _
&h60, &h51, &h7f, &ha9, &h19, &hb5, &h4a, &h0d, &h2d, &he5, &h7a, &h9f, &h93, &hc9, &h9c, &hef, _
&ha0, &he0, &h3b, &h4d, &hae, &h2a, &hf5, &hb0, &hc8, &heb, &hbb, &h3c, &h83, &h53, &h99, &h61, _
&h17, &h2b, &h04, &h7e, &hba, &h77, &hd6, &h26, &he1, &h69, &h14, &h63, &h55, &h21, &h0c, &h7d)
rcon = Array( _
&h8d, &h01, &h02, &h04, &h08, &h10, &h20, &h40, &h80, &h1b, &h36, &h6c, &hd8, &hab, &h4d, &h9a, _
&h2f, &h5e, &hbc, &h63, &hc6, &h97, &h35, &h6a, &hd4, &hb3, &h7d, &hfa, &hef, &hc5, &h91, &h39, _
&h72, &he4, &hd3, &hbd, &h61, &hc2, &h9f, &h25, &h4a, &h94, &h33, &h66, &hcc, &h83, &h1d, &h3a, _
&h74, &he8, &hcb, &h8d, &h01, &h02, &h04, &h08, &h10, &h20, &h40, &h80, &h1b, &h36, &h6c, &hd8, _
&hab, &h4d, &h9a, &h2f, &h5e, &hbc, &h63, &hc6, &h97, &h35, &h6a, &hd4, &hb3, &h7d, &hfa, &hef, _
&hc5, &h91, &h39, &h72, &he4, &hd3, &hbd, &h61, &hc2, &h9f, &h25, &h4a, &h94, &h33, &h66, &hcc, _
&h83, &h1d, &h3a, &h74, &he8, &hcb, &h8d, &h01, &h02, &h04, &h08, &h10, &h20, &h40, &h80, &h1b, _
&h36, &h6c, &hd8, &hab, &h4d, &h9a, &h2f, &h5e, &hbc, &h63, &hc6, &h97, &h35, &h6a, &hd4, &hb3, _
&h7d, &hfa, &hef, &hc5, &h91, &h39, &h72, &he4, &hd3, &hbd, &h61, &hc2, &h9f, &h25, &h4a, &h94, _
&h33, &h66, &hcc, &h83, &h1d, &h3a, &h74, &he8, &hcb, &h8d, &h01, &h02, &h04, &h08, &h10, &h20, _
&h40, &h80, &h1b, &h36, &h6c, &hd8, &hab, &h4d, &h9a, &h2f, &h5e, &hbc, &h63, &hc6, &h97, &h35, _
&h6a, &hd4, &hb3, &h7d, &hfa, &hef, &hc5, &h91, &h39, &h72, &he4, &hd3, &hbd, &h61, &hc2, &h9f, _
&h25, &h4a, &h94, &h33, &h66, &hcc, &h83, &h1d, &h3a, &h74, &he8, &hcb, &h8d, &h01, &h02, &h04, _
&h08, &h10, &h20, &h40, &h80, &h1b, &h36, &h6c, &hd8, &hab, &h4d, &h9a, &h2f, &h5e, &hbc, &h63, _
&hc6, &h97, &h35, &h6a, &hd4, &hb3, &h7d, &hfa, &hef, &hc5, &h91, &h39, &h72, &he4, &hd3, &hbd, _
&h61, &hc2, &h9f, &h25, &h4a, &h94, &h33, &h66, &hcc, &h83, &h1d, &h3a, &h74, &he8, &hcb)
Dim expandedKey, block(16), aesKey(32), i, isDone, j, isEncode
Dim sPlain, sPass, sCipher, sTemp
Dim oFile1, oFS, oFile2
Dim x, r, y, temp(4), intTemp
Set oFS = CreateObject("Scripting.FileSystemObject")
Set oFile1 = oFS.OpenTextFile(sFile, ForReading)
If Right(sFile, 4) <> ".enc" Then
sFile = sFile & ".enc"
oFS.CreateTextFile sFile, 2, True
isEncode = True
Else
sFile = Left(sFile, Len(sFile) - 4) & ".unenc"
oFS.CreateTextFile sFile, 2, True
isEncode = False
End If
Set oFile2 = oFS.OpenTextFile(sFile, ForWriting)
Set oFS = Nothing
For i = 0 To (Len(oPW.Value) - 1)
aesKey(i) = Asc(Mid(oPW.Value, i + 1, 1))
Next
For i = Len(oPW.Value) To 31
aesKey(i) = 0
Next
expandedKey = expandKey(aesKey, sbox, rcon)
Do Until oFile1.AtEndOfStream
sPlain = oFile1.Read(1024)
sCipher = ""
j = 0
isDone = False
Do Until isDone
sTemp = Mid(sPlain, j*16 + 1, 16)
If Len(sTemp) < 16 Then
For i = Len(sTemp) To 15
sTemp = sTemp & Chr(0)
Next
End If
For i = 0 To 15
block(i) = Asc(Mid(sTemp, (i Mod 4) * 4 + (i \ 4) + 1, 1))
Next
If (j + 1) * 16 >= Len(sPlain) Then
isDone = True
End If
j = j + 1
If isEncode Then
r= 0
For i = 0 To 15
block(i) = block(i) Xor expandedKey((i Mod 4) * 4 + (i \ 4))
Next
For x = 1 To 13
block(0) = sbox(block(0))
block(1) = sbox(block(1))
block(2) = sbox(block(2))
block(3) = sbox(block(3))
intTemp = sbox(block(4))
block(4) = sbox(block(5))
block(5) = sbox(block(6))
block(6) = sbox(block(7))
block(7) = intTemp
intTemp = sbox(block(8))
block(8) = sbox(block(10))
block(10) = intTemp
intTemp = sbox(block(9))
block(9) = sbox(block(11))
block(11) = intTemp
intTemp = sbox(block(12))
block(12) = sbox(block(15))
block(15) = sbox(block(14))
block(14) = sbox(block(13))
block(13) = intTemp
r = x * 16
For i = 0 To 3
temp(0) = block(i)
temp(1) = block(i+4)
temp(2) = block(i+8)
temp(3) = block(i+12)
block(i) = g2(temp(0)) Xor temp(3) Xor temp(2) Xor g3(temp(1)) Xor expandedKey(r+i*4)
block(i+4) = g2(temp(1)) Xor temp(0) Xor temp(3) Xor g3(temp(2)) Xor expandedKey(r+i*4+1)
block(i+8) = g2(temp(2)) Xor temp(1) Xor temp(0) Xor g3(temp(3)) Xor expandedKey(r+i*4+2)
block(i+12) = g2(temp(3)) Xor temp(2) Xor temp(1) Xor g3(temp(0)) Xor expandedKey(r+i*4+3)
Next
Next
block(0) = sbox(block(0)) Xor expandedKey(224)
block(1) = sbox(block(1)) Xor expandedKey(228)
block(2) = sbox(block(2)) Xor expandedKey(232)
block(3) = sbox(block(3)) Xor expandedKey(236)
intTemp = sbox(block(4)) Xor expandedKey(237)
block(4) = sbox(block(5)) Xor expandedKey(225)
block(5) = sbox(block(6)) Xor expandedKey(229)
block(6) = sbox(block(7)) Xor expandedKey(233)
block(7) = intTemp
intTemp = sbox(block(8)) Xor expandedKey(234)
block(8) = sbox(block(10)) Xor expandedKey(226)
block(10) = intTemp
intTemp = sbox(block(9)) Xor expandedKey(238)
block(9) = sbox(block(11)) Xor expandedKey(230)
block(11) = intTemp
intTemp = sbox(block(12)) Xor expandedKey(231)
block(12) = sbox(block(15)) Xor expandedKey(227)
block(15) = sbox(block(14)) Xor expandedKey(239)
block(14) = sbox(block(13)) Xor expandedKey(235)
block(13) = intTemp
Else
block(0) = sboxinv(block(0) Xor expandedKey(224))
block(1) = sboxinv(block(1) Xor expandedKey(228))
block(2) = sboxinv(block(2) Xor expandedKey(232))
block(3) = sboxinv(block(3) Xor expandedKey(236))
intTemp = sboxinv(block(4) Xor expandedKey(225))
block(4) = sboxinv(block(7) Xor expandedKey(237))
block(7) = sboxinv(block(6) Xor expandedKey(233))
block(6) = sboxinv(block(5) Xor expandedKey(229))
block(5) = intTemp
intTemp = sboxinv(block(8) Xor expandedKey(226))
block(8) = sboxinv(block(10) Xor expandedKey(234))
block(10) = intTemp
intTemp = sboxinv(block(9) Xor expandedKey(230))
block(9) = sboxinv(block(11) Xor expandedKey(238))
block(11) = intTemp
intTemp = sboxinv(block(12) Xor expandedKey(227))
block(12) = sboxinv(block(13) Xor expandedKey(231))
block(13) = sboxinv(block(14) Xor expandedKey(235))
block(14) = sboxinv(block(15) Xor expandedKey(239))
block(15) = intTemp
For x = 13 To 1 Step -1
r = x * 16
For i = 0 To 3
temp(0) = block(i) Xor expandedKey(r+i*4)
temp(1) = block(i+4) Xor expandedKey(r+i*4+1)
temp(2) = block(i+8) Xor expandedKey(r+i*4+2)
temp(3) = block(i+12) Xor expandedKey(r+i*4+3)
block(i) = g14(temp(0)) Xor g9(temp(3)) Xor g13(temp(2)) Xor g11(temp(1))
block(i+4) = g14(temp(1)) Xor g9(temp(0)) Xor g13(temp(3)) Xor g11(temp(2))
block(i+8) = g14(temp(2)) Xor g9(temp(1)) Xor g13(temp(0)) Xor g11(temp(3))
block(i+12) = g14(temp(3)) Xor g9(temp(2)) Xor g13(temp(1)) Xor g11(temp(0))
Next
block(0) = sboxinv(block(0))
block(1) = sboxinv(block(1))
block(2) = sboxinv(block(2))
block(3) = sboxinv(block(3))
intTemp = sboxinv(block(4))
block(4) = sboxinv(block(7))
block(7) = sboxinv(block(6))
block(6) = sboxinv(block(5))
block(5) = intTemp
intTemp = sboxinv(block(8))
block(8) = sboxinv(block(10))
block(10) = intTemp
intTemp = sboxinv(block(9))
block(9) = sboxinv(block(11))
block(11) = intTemp
intTemp = sboxinv(block(12))
block(12) = sboxinv(block(13))
block(13) = sboxinv(block(14))
block(14) = sboxinv(block(15))
block(15) = intTemp
Next
r= 0
For i = 0 To 15
block(i) = block(i) Xor expandedKey((i Mod 4) * 4 + (i \ 4))
Next
End If
For i = 0 To 15
sCipher = sCipher & Chr(block((i Mod 4) * 4 + (i \ 4)))
Next
Loop
oFile2.Write sCipher
Loop
oFile1.Close
Set oFile1 = Nothing
oFile2.Close
Set oFile2 = Nothing
End Sub
Function keyScheduleCore(ByVal row(), ByVal a, ByRef box(), ByRef rcon())
Dim result(4), i
For i = 0 To 3
result(i) = box(row((i + 5) Mod 4))
Next
result(0) = result(0) Xor rcon(a)
keyScheduleCore = result
End Function
Function expandKey(ByRef key(), ByRef box(), ByRef rcon())
Dim rConIter, temp, i, result(240)
ReDim temp(4)
rConIter = 1
For i = 0 To 31
result(i) = key(i)
Next
For i = 32 To 239 Step 4
temp(0) = result(i - 4)
temp(1) = result(i - 3)
temp(2) = result(i - 2)
temp(3) = result(i - 1)
If i Mod 32 = 0 Then
temp = keyScheduleCore(temp, rConIter, box, rcon)
rConIter = rConIter + 1
End If
If i Mod 32 = 16 Then
temp(0) = box(temp(0))
temp(1) = box(temp(1))
temp(2) = box(temp(2))
temp(3) = box(temp(3))
End If
result(i) = result(i-32) Xor temp(0)
result(i+1) = result(i-31) Xor temp(1)
result(i+2) = result(i-30) Xor temp(2)
result(i+3) = result(i-29) Xor temp(3)
Next
exPandKey = result
End Function
Code:
Sub RunAES(sFile)
Dim sbox, sboxinv, rcon
Dim g2, g3, g9, g11, g13, g14
g2 = Array( _
&h00,&h02,&h04,&h06,&h08,&h0a,&h0c,&h0e,&h10,&h12,&h14,&h16,&h18,&h1a,&h1c,&h1e, _
&h20,&h22,&h24,&h26,&h28,&h2a,&h2c,&h2e,&h30,&h32,&h34,&h36,&h38,&h3a,&h3c,&h3e, _
&h40,&h42,&h44,&h46,&h48,&h4a,&h4c,&h4e,&h50,&h52,&h54,&h56,&h58,&h5a,&h5c,&h5e, _
&h60,&h62,&h64,&h66,&h68,&h6a,&h6c,&h6e,&h70,&h72,&h74,&h76,&h78,&h7a,&h7c,&h7e, _
&h80,&h82,&h84,&h86,&h88,&h8a,&h8c,&h8e,&h90,&h92,&h94,&h96,&h98,&h9a,&h9c,&h9e, _
&ha0,&ha2,&ha4,&ha6,&ha8,&haa,&hac,&hae,&hb0,&hb2,&hb4,&hb6,&hb8,&hba,&hbc,&hbe, _
&hc0,&hc2,&hc4,&hc6,&hc8,&hca,&hcc,&hce,&hd0,&hd2,&hd4,&hd6,&hd8,&hda,&hdc,&hde, _
&he0,&he2,&he4,&he6,&he8,&hea,&hec,&hee,&hf0,&hf2,&hf4,&hf6,&hf8,&hfa,&hfc,&hfe, _
&h1b,&h19,&h1f,&h1d,&h13,&h11,&h17,&h15,&h0b,&h09,&h0f,&h0d,&h03,&h01,&h07,&h05, _
&h3b,&h39,&h3f,&h3d,&h33,&h31,&h37,&h35,&h2b,&h29,&h2f,&h2d,&h23,&h21,&h27,&h25, _
&h5b,&h59,&h5f,&h5d,&h53,&h51,&h57,&h55,&h4b,&h49,&h4f,&h4d,&h43,&h41,&h47,&h45, _
&h7b,&h79,&h7f,&h7d,&h73,&h71,&h77,&h75,&h6b,&h69,&h6f,&h6d,&h63,&h61,&h67,&h65, _
&h9b,&h99,&h9f,&h9d,&h93,&h91,&h97,&h95,&h8b,&h89,&h8f,&h8d,&h83,&h81,&h87,&h85, _
&hbb,&hb9,&hbf,&hbd,&hb3,&hb1,&hb7,&hb5,&hab,&ha9,&haf,&had,&ha3,&ha1,&ha7,&ha5, _
&hdb,&hd9,&hdf,&hdd,&hd3,&hd1,&hd7,&hd5,&hcb,&hc9,&hcf,&hcd,&hc3,&hc1,&hc7,&hc5, _
&hfb,&hf9,&hff,&hfd,&hf3,&hf1,&hf7,&hf5,&heb,&he9,&hef,&hed,&he3,&he1,&he7,&he5)
g3 = Array( _
&h00,&h03,&h06,&h05,&h0c,&h0f,&h0a,&h09,&h18,&h1b,&h1e,&h1d,&h14,&h17,&h12,&h11, _
&h30,&h33,&h36,&h35,&h3c,&h3f,&h3a,&h39,&h28,&h2b,&h2e,&h2d,&h24,&h27,&h22,&h21, _
&h60,&h63,&h66,&h65,&h6c,&h6f,&h6a,&h69,&h78,&h7b,&h7e,&h7d,&h74,&h77,&h72,&h71, _
&h50,&h53,&h56,&h55,&h5c,&h5f,&h5a,&h59,&h48,&h4b,&h4e,&h4d,&h44,&h47,&h42,&h41, _
&hc0,&hc3,&hc6,&hc5,&hcc,&hcf,&hca,&hc9,&hd8,&hdb,&hde,&hdd,&hd4,&hd7,&hd2,&hd1, _
&hf0,&hf3,&hf6,&hf5,&hfc,&hff,&hfa,&hf9,&he8,&heb,&hee,&hed,&he4,&he7,&he2,&he1, _
&ha0,&ha3,&ha6,&ha5,&hac,&haf,&haa,&ha9,&hb8,&hbb,&hbe,&hbd,&hb4,&hb7,&hb2,&hb1, _
&h90,&h93,&h96,&h95,&h9c,&h9f,&h9a,&h99,&h88,&h8b,&h8e,&h8d,&h84,&h87,&h82,&h81, _
&h9b,&h98,&h9d,&h9e,&h97,&h94,&h91,&h92,&h83,&h80,&h85,&h86,&h8f,&h8c,&h89,&h8a, _
&hab,&ha8,&had,&hae,&ha7,&ha4,&ha1,&ha2,&hb3,&hb0,&hb5,&hb6,&hbf,&hbc,&hb9,&hba, _
&hfb,&hf8,&hfd,&hfe,&hf7,&hf4,&hf1,&hf2,&he3,&he0,&he5,&he6,&hef,&hec,&he9,&hea, _
&hcb,&hc8,&hcd,&hce,&hc7,&hc4,&hc1,&hc2,&hd3,&hd0,&hd5,&hd6,&hdf,&hdc,&hd9,&hda, _
&h5b,&h58,&h5d,&h5e,&h57,&h54,&h51,&h52,&h43,&h40,&h45,&h46,&h4f,&h4c,&h49,&h4a, _
&h6b,&h68,&h6d,&h6e,&h67,&h64,&h61,&h62,&h73,&h70,&h75,&h76,&h7f,&h7c,&h79,&h7a, _
&h3b,&h38,&h3d,&h3e,&h37,&h34,&h31,&h32,&h23,&h20,&h25,&h26,&h2f,&h2c,&h29,&h2a, _
&h0b,&h08,&h0d,&h0e,&h07,&h04,&h01,&h02,&h13,&h10,&h15,&h16,&h1f,&h1c,&h19,&h1a)
g9 = Array( _
&h00,&h09,&h12,&h1b,&h24,&h2d,&h36,&h3f,&h48,&h41,&h5a,&h53,&h6c,&h65,&h7e,&h77, _
&h90,&h99,&h82,&h8b,&hb4,&hbd,&ha6,&haf,&hd8,&hd1,&hca,&hc3,&hfc,&hf5,&hee,&he7, _
&h3b,&h32,&h29,&h20,&h1f,&h16,&h0d,&h04,&h73,&h7a,&h61,&h68,&h57,&h5e,&h45,&h4c, _
&hab,&ha2,&hb9,&hb0,&h8f,&h86,&h9d,&h94,&he3,&hea,&hf1,&hf8,&hc7,&hce,&hd5,&hdc, _
&h76,&h7f,&h64,&h6d,&h52,&h5b,&h40,&h49,&h3e,&h37,&h2c,&h25,&h1a,&h13,&h08,&h01, _
&he6,&hef,&hf4,&hfd,&hc2,&hcb,&hd0,&hd9,&hae,&ha7,&hbc,&hb5,&h8a,&h83,&h98,&h91, _
&h4d,&h44,&h5f,&h56,&h69,&h60,&h7b,&h72,&h05,&h0c,&h17,&h1e,&h21,&h28,&h33,&h3a, _
&hdd,&hd4,&hcf,&hc6,&hf9,&hf0,&heb,&he2,&h95,&h9c,&h87,&h8e,&hb1,&hb8,&ha3,&haa, _
&hec,&he5,&hfe,&hf7,&hc8,&hc1,&hda,&hd3,&ha4,&had,&hb6,&hbf,&h80,&h89,&h92,&h9b, _
&h7c,&h75,&h6e,&h67,&h58,&h51,&h4a,&h43,&h34,&h3d,&h26,&h2f,&h10,&h19,&h02,&h0b, _
&hd7,&hde,&hc5,&hcc,&hf3,&hfa,&he1,&he8,&h9f,&h96,&h8d,&h84,&hbb,&hb2,&ha9,&ha0, _
&h47,&h4e,&h55,&h5c,&h63,&h6a,&h71,&h78,&h0f,&h06,&h1d,&h14,&h2b,&h22,&h39,&h30, _
&h9a,&h93,&h88,&h81,&hbe,&hb7,&hac,&ha5,&hd2,&hdb,&hc0,&hc9,&hf6,&hff,&he4,&hed, _
&h0a,&h03,&h18,&h11,&h2e,&h27,&h3c,&h35,&h42,&h4b,&h50,&h59,&h66,&h6f,&h74,&h7d, _
&ha1,&ha8,&hb3,&hba,&h85,&h8c,&h97,&h9e,&he9,&he0,&hfb,&hf2,&hcd,&hc4,&hdf,&hd6, _
&h31,&h38,&h23,&h2a,&h15,&h1c,&h07,&h0e,&h79,&h70,&h6b,&h62,&h5d,&h54,&h4f,&h46)
g11 = Array( _
&h00,&h0b,&h16,&h1d,&h2c,&h27,&h3a,&h31,&h58,&h53,&h4e,&h45,&h74,&h7f,&h62,&h69, _
&hb0,&hbb,&ha6,&had,&h9c,&h97,&h8a,&h81,&he8,&he3,&hfe,&hf5,&hc4,&hcf,&hd2,&hd9, _
&h7b,&h70,&h6d,&h66,&h57,&h5c,&h41,&h4a,&h23,&h28,&h35,&h3e,&h0f,&h04,&h19,&h12, _
&hcb,&hc0,&hdd,&hd6,&he7,&hec,&hf1,&hfa,&h93,&h98,&h85,&h8e,&hbf,&hb4,&ha9,&ha2, _
&hf6,&hfd,&he0,&heb,&hda,&hd1,&hcc,&hc7,&hae,&ha5,&hb8,&hb3,&h82,&h89,&h94,&h9f, _
&h46,&h4d,&h50,&h5b,&h6a,&h61,&h7c,&h77,&h1e,&h15,&h08,&h03,&h32,&h39,&h24,&h2f, _
&h8d,&h86,&h9b,&h90,&ha1,&haa,&hb7,&hbc,&hd5,&hde,&hc3,&hc8,&hf9,&hf2,&hef,&he4, _
&h3d,&h36,&h2b,&h20,&h11,&h1a,&h07,&h0c,&h65,&h6e,&h73,&h78,&h49,&h42,&h5f,&h54, _
&hf7,&hfc,&he1,&hea,&hdb,&hd0,&hcd,&hc6,&haf,&ha4,&hb9,&hb2,&h83,&h88,&h95,&h9e, _
&h47,&h4c,&h51,&h5a,&h6b,&h60,&h7d,&h76,&h1f,&h14,&h09,&h02,&h33,&h38,&h25,&h2e, _
&h8c,&h87,&h9a,&h91,&ha0,&hab,&hb6,&hbd,&hd4,&hdf,&hc2,&hc9,&hf8,&hf3,&hee,&he5, _
&h3c,&h37,&h2a,&h21,&h10,&h1b,&h06,&h0d,&h64,&h6f,&h72,&h79,&h48,&h43,&h5e,&h55, _
&h01,&h0a,&h17,&h1c,&h2d,&h26,&h3b,&h30,&h59,&h52,&h4f,&h44,&h75,&h7e,&h63,&h68, _
&hb1,&hba,&ha7,&hac,&h9d,&h96,&h8b,&h80,&he9,&he2,&hff,&hf4,&hc5,&hce,&hd3,&hd8, _
&h7a,&h71,&h6c,&h67,&h56,&h5d,&h40,&h4b,&h22,&h29,&h34,&h3f,&h0e,&h05,&h18,&h13, _
&hca,&hc1,&hdc,&hd7,&he6,&hed,&hf0,&hfb,&h92,&h99,&h84,&h8f,&hbe,&hb5,&ha8,&ha3)
g13 = Array( _
&h00,&h0d,&h1a,&h17,&h34,&h39,&h2e,&h23,&h68,&h65,&h72,&h7f,&h5c,&h51,&h46,&h4b, _
&hd0,&hdd,&hca,&hc7,&he4,&he9,&hfe,&hf3,&hb8,&hb5,&ha2,&haf,&h8c,&h81,&h96,&h9b, _
&hbb,&hb6,&ha1,&hac,&h8f,&h82,&h95,&h98,&hd3,&hde,&hc9,&hc4,&he7,&hea,&hfd,&hf0, _
&h6b,&h66,&h71,&h7c,&h5f,&h52,&h45,&h48,&h03,&h0e,&h19,&h14,&h37,&h3a,&h2d,&h20, _
&h6d,&h60,&h77,&h7a,&h59,&h54,&h43,&h4e,&h05,&h08,&h1f,&h12,&h31,&h3c,&h2b,&h26, _
&hbd,&hb0,&ha7,&haa,&h89,&h84,&h93,&h9e,&hd5,&hd8,&hcf,&hc2,&he1,&hec,&hfb,&hf6, _
&hd6,&hdb,&hcc,&hc1,&he2,&hef,&hf8,&hf5,&hbe,&hb3,&ha4,&ha9,&h8a,&h87,&h90,&h9d, _
&h06,&h0b,&h1c,&h11,&h32,&h3f,&h28,&h25,&h6e,&h63,&h74,&h79,&h5a,&h57,&h40,&h4d, _
&hda,&hd7,&hc0,&hcd,&hee,&he3,&hf4,&hf9,&hb2,&hbf,&ha8,&ha5,&h86,&h8b,&h9c,&h91, _
&h0a,&h07,&h10,&h1d,&h3e,&h33,&h24,&h29,&h62,&h6f,&h78,&h75,&h56,&h5b,&h4c,&h41, _
&h61,&h6c,&h7b,&h76,&h55,&h58,&h4f,&h42,&h09,&h04,&h13,&h1e,&h3d,&h30,&h27,&h2a, _
&hb1,&hbc,&hab,&ha6,&h85,&h88,&h9f,&h92,&hd9,&hd4,&hc3,&hce,&hed,&he0,&hf7,&hfa, _
&hb7,&hba,&had,&ha0,&h83,&h8e,&h99,&h94,&hdf,&hd2,&hc5,&hc8,&heb,&he6,&hf1,&hfc, _
&h67,&h6a,&h7d,&h70,&h53,&h5e,&h49,&h44,&h0f,&h02,&h15,&h18,&h3b,&h36,&h21,&h2c, _
&h0c,&h01,&h16,&h1b,&h38,&h35,&h22,&h2f,&h64,&h69,&h7e,&h73,&h50,&h5d,&h4a,&h47, _
&hdc,&hd1,&hc6,&hcb,&he8,&he5,&hf2,&hff,&hb4,&hb9,&hae,&ha3,&h80,&h8d,&h9a,&h97)
g14 = Array( _
&h00,&h0e,&h1c,&h12,&h38,&h36,&h24,&h2a,&h70,&h7e,&h6c,&h62,&h48,&h46,&h54,&h5a, _
&he0,&hee,&hfc,&hf2,&hd8,&hd6,&hc4,&hca,&h90,&h9e,&h8c,&h82,&ha8,&ha6,&hb4,&hba, _
&hdb,&hd5,&hc7,&hc9,&he3,&hed,&hff,&hf1,&hab,&ha5,&hb7,&hb9,&h93,&h9d,&h8f,&h81, _
&h3b,&h35,&h27,&h29,&h03,&h0d,&h1f,&h11,&h4b,&h45,&h57,&h59,&h73,&h7d,&h6f,&h61, _
&had,&ha3,&hb1,&hbf,&h95,&h9b,&h89,&h87,&hdd,&hd3,&hc1,&hcf,&he5,&heb,&hf9,&hf7, _
&h4d,&h43,&h51,&h5f,&h75,&h7b,&h69,&h67,&h3d,&h33,&h21,&h2f,&h05,&h0b,&h19,&h17, _
&h76,&h78,&h6a,&h64,&h4e,&h40,&h52,&h5c,&h06,&h08,&h1a,&h14,&h3e,&h30,&h22,&h2c, _
&h96,&h98,&h8a,&h84,&hae,&ha0,&hb2,&hbc,&he6,&he8,&hfa,&hf4,&hde,&hd0,&hc2,&hcc, _
&h41,&h4f,&h5d,&h53,&h79,&h77,&h65,&h6b,&h31,&h3f,&h2d,&h23,&h09,&h07,&h15,&h1b, _
&ha1,&haf,&hbd,&hb3,&h99,&h97,&h85,&h8b,&hd1,&hdf,&hcd,&hc3,&he9,&he7,&hf5,&hfb, _
&h9a,&h94,&h86,&h88,&ha2,&hac,&hbe,&hb0,&hea,&he4,&hf6,&hf8,&hd2,&hdc,&hce,&hc0, _
&h7a,&h74,&h66,&h68,&h42,&h4c,&h5e,&h50,&h0a,&h04,&h16,&h18,&h32,&h3c,&h2e,&h20, _
&hec,&he2,&hf0,&hfe,&hd4,&hda,&hc8,&hc6,&h9c,&h92,&h80,&h8e,&ha4,&haa,&hb8,&hb6, _
&h0c,&h02,&h10,&h1e,&h34,&h3a,&h28,&h26,&h7c,&h72,&h60,&h6e,&h44,&h4a,&h58,&h56, _
&h37,&h39,&h2b,&h25,&h0f,&h01,&h13,&h1d,&h47,&h49,&h5b,&h55,&h7f,&h71,&h63,&h6d, _
&hd7,&hd9,&hcb,&hc5,&hef,&he1,&hf3,&hfd,&ha7,&ha9,&hbb,&hb5,&h9f,&h91,&h83,&h8d)
sbox = Array( _
&h63, &h7c, &h77, &h7b, &hf2, &h6b, &h6f, &hc5, &h30, &h01, &h67, &h2b, &hfe, &hd7, &hab, &h76, _
&hca, &h82, &hc9, &h7d, &hfa, &h59, &h47, &hf0, &had, &hd4, &ha2, &haf, &h9c, &ha4, &h72, &hc0, _
&hb7, &hfd, &h93, &h26, &h36, &h3f, &hf7, &hcc, &h34, &ha5, &he5, &hf1, &h71, &hd8, &h31, &h15, _
&h04, &hc7, &h23, &hc3, &h18, &h96, &h05, &h9a, &h07, &h12, &h80, &he2, &heb, &h27, &hb2, &h75, _
&h09, &h83, &h2c, &h1a, &h1b, &h6e, &h5a, &ha0, &h52, &h3b, &hd6, &hb3, &h29, &he3, &h2f, &h84, _
&h53, &hd1, &h00, &hed, &h20, &hfc, &hb1, &h5b, &h6a, &hcb, &hbe, &h39, &h4a, &h4c, &h58, &hcf, _
&hd0, &hef, &haa, &hfb, &h43, &h4d, &h33, &h85, &h45, &hf9, &h02, &h7f, &h50, &h3c, &h9f, &ha8, _
&h51, &ha3, &h40, &h8f, &h92, &h9d, &h38, &hf5, &hbc, &hb6, &hda, &h21, &h10, &hff, &hf3, &hd2, _
&hcd, &h0c, &h13, &hec, &h5f, &h97, &h44, &h17, &hc4, &ha7, &h7e, &h3d, &h64, &h5d, &h19, &h73, _
&h60, &h81, &h4f, &hdc, &h22, &h2a, &h90, &h88, &h46, &hee, &hb8, &h14, &hde, &h5e, &h0b, &hdb, _
&he0, &h32, &h3a, &h0a, &h49, &h06, &h24, &h5c, &hc2, &hd3, &hac, &h62, &h91, &h95, &he4, &h79, _
&he7, &hc8, &h37, &h6d, &h8d, &hd5, &h4e, &ha9, &h6c, &h56, &hf4, &hea, &h65, &h7a, &hae, &h08, _
&hba, &h78, &h25, &h2e, &h1c, &ha6, &hb4, &hc6, &he8, &hdd, &h74, &h1f, &h4b, &hbd, &h8b, &h8a, _
&h70, &h3e, &hb5, &h66, &h48, &h03, &hf6, &h0e, &h61, &h35, &h57, &hb9, &h86, &hc1, &h1d, &h9e, _
&he1, &hf8, &h98, &h11, &h69, &hd9, &h8e, &h94, &h9b, &h1e, &h87, &he9, &hce, &h55, &h28, &hdf, _
&h8c, &ha1, &h89, &h0d, &hbf, &he6, &h42, &h68, &h41, &h99, &h2d, &h0f, &hb0, &h54, &hbb, &h16)
sboxinv = Array( _
&h52, &h09, &h6a, &hd5, &h30, &h36, &ha5, &h38, &hbf, &h40, &ha3, &h9e, &h81, &hf3, &hd7, &hfb, _
&h7c, &he3, &h39, &h82, &h9b, &h2f, &hff, &h87, &h34, &h8e, &h43, &h44, &hc4, &hde, &he9, &hcb, _
&h54, &h7b, &h94, &h32, &ha6, &hc2, &h23, &h3d, &hee, &h4c, &h95, &h0b, &h42, &hfa, &hc3, &h4e, _
&h08, &h2e, &ha1, &h66, &h28, &hd9, &h24, &hb2, &h76, &h5b, &ha2, &h49, &h6d, &h8b, &hd1, &h25, _
&h72, &hf8, &hf6, &h64, &h86, &h68, &h98, &h16, &hd4, &ha4, &h5c, &hcc, &h5d, &h65, &hb6, &h92, _
&h6c, &h70, &h48, &h50, &hfd, &hed, &hb9, &hda, &h5e, &h15, &h46, &h57, &ha7, &h8d, &h9d, &h84, _
&h90, &hd8, &hab, &h00, &h8c, &hbc, &hd3, &h0a, &hf7, &he4, &h58, &h05, &hb8, &hb3, &h45, &h06, _
&hd0, &h2c, &h1e, &h8f, &hca, &h3f, &h0f, &h02, &hc1, &haf, &hbd, &h03, &h01, &h13, &h8a, &h6b, _
&h3a, &h91, &h11, &h41, &h4f, &h67, &hdc, &hea, &h97, &hf2, &hcf, &hce, &hf0, &hb4, &he6, &h73, _
&h96, &hac, &h74, &h22, &he7, &had, &h35, &h85, &he2, &hf9, &h37, &he8, &h1c, &h75, &hdf, &h6e, _
&h47, &hf1, &h1a, &h71, &h1d, &h29, &hc5, &h89, &h6f, &hb7, &h62, &h0e, &haa, &h18, &hbe, &h1b, _
&hfc, &h56, &h3e, &h4b, &hc6, &hd2, &h79, &h20, &h9a, &hdb, &hc0, &hfe, &h78, &hcd, &h5a, &hf4, _
&h1f, &hdd, &ha8, &h33, &h88, &h07, &hc7, &h31, &hb1, &h12, &h10, &h59, &h27, &h80, &hec, &h5f, _
&h60, &h51, &h7f, &ha9, &h19, &hb5, &h4a, &h0d, &h2d, &he5, &h7a, &h9f, &h93, &hc9, &h9c, &hef, _
&ha0, &he0, &h3b, &h4d, &hae, &h2a, &hf5, &hb0, &hc8, &heb, &hbb, &h3c, &h83, &h53, &h99, &h61, _
&h17, &h2b, &h04, &h7e, &hba, &h77, &hd6, &h26, &he1, &h69, &h14, &h63, &h55, &h21, &h0c, &h7d)
rcon = Array( _
&h8d, &h01, &h02, &h04, &h08, &h10, &h20, &h40, &h80, &h1b, &h36, &h6c, &hd8, &hab, &h4d, &h9a, _
&h2f, &h5e, &hbc, &h63, &hc6, &h97, &h35, &h6a, &hd4, &hb3, &h7d, &hfa, &hef, &hc5, &h91, &h39, _
&h72, &he4, &hd3, &hbd, &h61, &hc2, &h9f, &h25, &h4a, &h94, &h33, &h66, &hcc, &h83, &h1d, &h3a, _
&h74, &he8, &hcb, &h8d, &h01, &h02, &h04, &h08, &h10, &h20, &h40, &h80, &h1b, &h36, &h6c, &hd8, _
&hab, &h4d, &h9a, &h2f, &h5e, &hbc, &h63, &hc6, &h97, &h35, &h6a, &hd4, &hb3, &h7d, &hfa, &hef, _
&hc5, &h91, &h39, &h72, &he4, &hd3, &hbd, &h61, &hc2, &h9f, &h25, &h4a, &h94, &h33, &h66, &hcc, _
&h83, &h1d, &h3a, &h74, &he8, &hcb, &h8d, &h01, &h02, &h04, &h08, &h10, &h20, &h40, &h80, &h1b, _
&h36, &h6c, &hd8, &hab, &h4d, &h9a, &h2f, &h5e, &hbc, &h63, &hc6, &h97, &h35, &h6a, &hd4, &hb3, _
&h7d, &hfa, &hef, &hc5, &h91, &h39, &h72, &he4, &hd3, &hbd, &h61, &hc2, &h9f, &h25, &h4a, &h94, _
&h33, &h66, &hcc, &h83, &h1d, &h3a, &h74, &he8, &hcb, &h8d, &h01, &h02, &h04, &h08, &h10, &h20, _
&h40, &h80, &h1b, &h36, &h6c, &hd8, &hab, &h4d, &h9a, &h2f, &h5e, &hbc, &h63, &hc6, &h97, &h35, _
&h6a, &hd4, &hb3, &h7d, &hfa, &hef, &hc5, &h91, &h39, &h72, &he4, &hd3, &hbd, &h61, &hc2, &h9f, _
&h25, &h4a, &h94, &h33, &h66, &hcc, &h83, &h1d, &h3a, &h74, &he8, &hcb, &h8d, &h01, &h02, &h04, _
&h08, &h10, &h20, &h40, &h80, &h1b, &h36, &h6c, &hd8, &hab, &h4d, &h9a, &h2f, &h5e, &hbc, &h63, _
&hc6, &h97, &h35, &h6a, &hd4, &hb3, &h7d, &hfa, &hef, &hc5, &h91, &h39, &h72, &he4, &hd3, &hbd, _
&h61, &hc2, &h9f, &h25, &h4a, &h94, &h33, &h66, &hcc, &h83, &h1d, &h3a, &h74, &he8, &hcb)
Dim expandedKey, block(16), aesKey(32), i, isDone, j, isEncode
Dim sPlain, sPass, sCipher, sTemp, nonce(16), priorCipher(16)
Dim oFile1, oFS, oFile2
Dim x, r, y, temp(4), intTemp
Set oFS = CreateObject("Scripting.FileSystemObject")
Set oFile1 = oFS.OpenTextFile(sFile, ForReading)
If Right(sFile, 4) <> ".enc" Then
sFile = sFile & ".enc"
oFS.CreateTextFile sFile, 2, True
isEncode = True
Else
sFile = Left(sFile, Len(sFile) - 4) & ".unenc"
oFS.CreateTextFile sFile, 2, True
isEncode = False
End If
Set oFile2 = oFS.OpenTextFile(sFile, ForWriting)
Set oFS = Nothing
For i = 0 To 15
nonce(i) = 0
Next
For i = 0 To (Len(oPW.Value) - 1)
aesKey(i) = Asc(Mid(oPW.Value, i + 1, 1))
Next
For i = Len(oPW.Value) To 31
aesKey(i) = 0
Next
expandedKey = expandKey(aesKey, sbox, rcon)
Do Until oFile1.AtEndOfStream
sPlain = oFile1.Read(1024)
sCipher = ""
j = 0
isDone = False
Do Until isDone
sTemp = Mid(sPlain, j*16 + 1, 16)
If Len(sTemp) < 16 Then
For i = Len(sTemp) To 15
sTemp = sTemp & Chr(0)
Next
End If
For i = 0 To 15
block(i) = Asc(Mid(sTemp, (i Mod 4) * 4 + (i \ 4) + 1, 1))
Next
If (j + 1) * 16 >= Len(sPlain) Then
isDone = True
End If
j = j + 1
If isEncode Then
r= 0
For i = 0 To 15
block(i) = block(i) Xor nonce(i) Xor expandedKey((i Mod 4) * 4 + (i \ 4))
Next
For x = 1 To 13
block(0) = sbox(block(0))
block(1) = sbox(block(1))
block(2) = sbox(block(2))
block(3) = sbox(block(3))
intTemp = sbox(block(4))
block(4) = sbox(block(5))
block(5) = sbox(block(6))
block(6) = sbox(block(7))
block(7) = intTemp
intTemp = sbox(block(8))
block(8) = sbox(block(10))
block(10) = intTemp
intTemp = sbox(block(9))
block(9) = sbox(block(11))
block(11) = intTemp
intTemp = sbox(block(12))
block(12) = sbox(block(15))
block(15) = sbox(block(14))
block(14) = sbox(block(13))
block(13) = intTemp
r = x * 16
For i = 0 To 3
temp(0) = block(i)
temp(1) = block(i+4)
temp(2) = block(i+8)
temp(3) = block(i+12)
block(i) = g2(temp(0)) Xor temp(3) Xor temp(2) Xor g3(temp(1)) Xor expandedKey(r+i*4)
block(i+4) = g2(temp(1)) Xor temp(0) Xor temp(3) Xor g3(temp(2)) Xor expandedKey(r+i*4+1)
block(i+8) = g2(temp(2)) Xor temp(1) Xor temp(0) Xor g3(temp(3)) Xor expandedKey(r+i*4+2)
block(i+12) = g2(temp(3)) Xor temp(2) Xor temp(1) Xor g3(temp(0)) Xor expandedKey(r+i*4+3)
Next
Next
block(0) = sbox(block(0)) Xor expandedKey(224)
block(1) = sbox(block(1)) Xor expandedKey(228)
block(2) = sbox(block(2)) Xor expandedKey(232)
block(3) = sbox(block(3)) Xor expandedKey(236)
intTemp = sbox(block(4)) Xor expandedKey(237)
block(4) = sbox(block(5)) Xor expandedKey(225)
block(5) = sbox(block(6)) Xor expandedKey(229)
block(6) = sbox(block(7)) Xor expandedKey(233)
block(7) = intTemp
intTemp = sbox(block(8)) Xor expandedKey(234)
block(8) = sbox(block(10)) Xor expandedKey(226)
block(10) = intTemp
intTemp = sbox(block(9)) Xor expandedKey(238)
block(9) = sbox(block(11)) Xor expandedKey(230)
block(11) = intTemp
intTemp = sbox(block(12)) Xor expandedKey(231)
block(12) = sbox(block(15)) Xor expandedKey(227)
block(15) = sbox(block(14)) Xor expandedKey(239)
block(14) = sbox(block(13)) Xor expandedKey(235)
block(13) = intTemp
For i = 0 To 15
nonce(i) = block(i)
Next
Else
For i = 0 To 15
priorCipher(i) = block(i)
Next
block(0) = sboxinv(block(0) Xor expandedKey(224))
block(1) = sboxinv(block(1) Xor expandedKey(228))
block(2) = sboxinv(block(2) Xor expandedKey(232))
block(3) = sboxinv(block(3) Xor expandedKey(236))
intTemp = sboxinv(block(4) Xor expandedKey(225))
block(4) = sboxinv(block(7) Xor expandedKey(237))
block(7) = sboxinv(block(6) Xor expandedKey(233))
block(6) = sboxinv(block(5) Xor expandedKey(229))
block(5) = intTemp
intTemp = sboxinv(block(8) Xor expandedKey(226))
block(8) = sboxinv(block(10) Xor expandedKey(234))
block(10) = intTemp
intTemp = sboxinv(block(9) Xor expandedKey(230))
block(9) = sboxinv(block(11) Xor expandedKey(238))
block(11) = intTemp
intTemp = sboxinv(block(12) Xor expandedKey(227))
block(12) = sboxinv(block(13) Xor expandedKey(231))
block(13) = sboxinv(block(14) Xor expandedKey(235))
block(14) = sboxinv(block(15) Xor expandedKey(239))
block(15) = intTemp
For x = 13 To 1 Step -1
r = x * 16
For i = 0 To 3
temp(0) = block(i) Xor expandedKey(r+i*4)
temp(1) = block(i+4) Xor expandedKey(r+i*4+1)
temp(2) = block(i+8) Xor expandedKey(r+i*4+2)
temp(3) = block(i+12) Xor expandedKey(r+i*4+3)
block(i) = g14(temp(0)) Xor g9(temp(3)) Xor g13(temp(2)) Xor g11(temp(1))
block(i+4) = g14(temp(1)) Xor g9(temp(0)) Xor g13(temp(3)) Xor g11(temp(2))
block(i+8) = g14(temp(2)) Xor g9(temp(1)) Xor g13(temp(0)) Xor g11(temp(3))
block(i+12) = g14(temp(3)) Xor g9(temp(2)) Xor g13(temp(1)) Xor g11(temp(0))
Next
block(0) = sboxinv(block(0))
block(1) = sboxinv(block(1))
block(2) = sboxinv(block(2))
block(3) = sboxinv(block(3))
intTemp = sboxinv(block(4))
block(4) = sboxinv(block(7))
block(7) = sboxinv(block(6))
block(6) = sboxinv(block(5))
block(5) = intTemp
intTemp = sboxinv(block(8))
block(8) = sboxinv(block(10))
block(10) = intTemp
intTemp = sboxinv(block(9))
block(9) = sboxinv(block(11))
block(11) = intTemp
intTemp = sboxinv(block(12))
block(12) = sboxinv(block(13))
block(13) = sboxinv(block(14))
block(14) = sboxinv(block(15))
block(15) = intTemp
Next
r= 0
For i = 0 To 15
block(i) = block(i) Xor expandedKey((i Mod 4) * 4 + (i \ 4)) Xor nonce(i)
nonce(i) = priorCipher(i)
Next
End If
For i = 0 To 15
sCipher = sCipher & Chr(block((i Mod 4) * 4 + (i \ 4)))
Next
Loop
oFile2.Write sCipher
Loop
oFile1.Close
Set oFile1 = Nothing
oFile2.Close
Set oFile2 = Nothing
End Sub
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