127 lines
7.4 KiB
C
127 lines
7.4 KiB
C
/*********************************************************************
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* Filename: aes.h
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* Author: Brad Conte (brad AT bradconte.com)
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* Copyright:
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* Disclaimer: This code is presented "as is" without any guarantees.
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* Details: Defines the API for the corresponding AES implementation.
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*********************************************************************/
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#ifndef AES_H
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#define AES_H
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/*************************** HEADER FILES ***************************/
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#include <stddef.h>
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/****************************** MACROS ******************************/
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#define AES_BLOCK_SIZE 16 // AES operates on 16 bytes at a time
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/**************************** DATA TYPES ****************************/
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typedef unsigned char BYTE; // 8-bit byte
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typedef unsigned int WORD; // 32-bit word, change to "long" for 16-bit machines
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/*********************** FUNCTION DECLARATIONS **********************/
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///////////////////
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// AES
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///////////////////
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// Key setup must be done before any AES en/de-cryption functions can be used.
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void aes_key_setup(const BYTE key[], // The key, must be 128, 192, or 256 bits
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WORD w[], // Output key schedule to be used later
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int keysize); // Bit length of the key, 128, 192, or 256
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void aes_encrypt(const BYTE in[], // 16 bytes of plaintext
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BYTE out[], // 16 bytes of ciphertext
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const WORD key[], // From the key setup
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int keysize); // Bit length of the key, 128, 192, or 256
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void aes_decrypt(const BYTE in[], // 16 bytes of ciphertext
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BYTE out[], // 16 bytes of plaintext
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const WORD key[], // From the key setup
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int keysize); // Bit length of the key, 128, 192, or 256
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///////////////////
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// AES - CBC
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///////////////////
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int aes_encrypt_cbc(const BYTE in[], // Plaintext
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size_t in_len, // Must be a multiple of AES_BLOCK_SIZE
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BYTE out[], // Ciphertext, same length as plaintext
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const WORD key[], // From the key setup
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int keysize, // Bit length of the key, 128, 192, or 256
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const BYTE iv[]); // IV, must be AES_BLOCK_SIZE bytes long
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// Only output the CBC-MAC of the input.
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int aes_encrypt_cbc_mac(const BYTE in[], // plaintext
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size_t in_len, // Must be a multiple of AES_BLOCK_SIZE
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BYTE out[], // Output MAC
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const WORD key[], // From the key setup
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int keysize, // Bit length of the key, 128, 192, or 256
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const BYTE iv[]); // IV, must be AES_BLOCK_SIZE bytes long
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///////////////////
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// AES - CTR
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///////////////////
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void increment_iv(BYTE iv[], // Must be a multiple of AES_BLOCK_SIZE
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int counter_size); // Bytes of the IV used for counting (low end)
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void aes_encrypt_ctr(const BYTE in[], // Plaintext
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size_t in_len, // Any byte length
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BYTE out[], // Ciphertext, same length as plaintext
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const WORD key[], // From the key setup
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int keysize, // Bit length of the key, 128, 192, or 256
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const BYTE iv[]); // IV, must be AES_BLOCK_SIZE bytes long
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void aes_decrypt_ctr(const BYTE in[], // Ciphertext
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size_t in_len, // Any byte length
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BYTE out[], // Plaintext, same length as ciphertext
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const WORD key[], // From the key setup
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int keysize, // Bit length of the key, 128, 192, or 256
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const BYTE iv[]); // IV, must be AES_BLOCK_SIZE bytes long
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///////////////////
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// AES - CCM
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///////////////////
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// Returns True if the input parameters do not violate any constraint.
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int aes_encrypt_ccm(const BYTE plaintext[], // IN - Plaintext.
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WORD plaintext_len, // IN - Plaintext length.
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const BYTE associated_data[], // IN - Associated Data included in authentication, but not encryption.
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unsigned short associated_data_len, // IN - Associated Data length in bytes.
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const BYTE nonce[], // IN - The Nonce to be used for encryption.
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unsigned short nonce_len, // IN - Nonce length in bytes.
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BYTE ciphertext[], // OUT - Ciphertext, a concatination of the plaintext and the MAC.
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WORD *ciphertext_len, // OUT - The length of the ciphertext, always plaintext_len + mac_len.
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WORD mac_len, // IN - The desired length of the MAC, must be 4, 6, 8, 10, 12, 14, or 16.
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const BYTE key[], // IN - The AES key for encryption.
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int keysize); // IN - The length of the key in bits. Valid values are 128, 192, 256.
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// Returns True if the input parameters do not violate any constraint.
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// Use mac_auth to ensure decryption/validation was preformed correctly.
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// If authentication does not succeed, the plaintext is zeroed out. To overwride
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// this, call with mac_auth = NULL. The proper proceedure is to decrypt with
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// authentication enabled (mac_auth != NULL) and make a second call to that
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// ignores authentication explicitly if the first call failes.
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int aes_decrypt_ccm(const BYTE ciphertext[], // IN - Ciphertext, the concatination of encrypted plaintext and MAC.
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WORD ciphertext_len, // IN - Ciphertext length in bytes.
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const BYTE assoc[], // IN - The Associated Data, required for authentication.
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unsigned short assoc_len, // IN - Associated Data length in bytes.
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const BYTE nonce[], // IN - The Nonce to use for decryption, same one as for encryption.
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unsigned short nonce_len, // IN - Nonce length in bytes.
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BYTE plaintext[], // OUT - The plaintext that was decrypted. Will need to be large enough to hold ciphertext_len - mac_len.
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WORD *plaintext_len, // OUT - Length in bytes of the output plaintext, always ciphertext_len - mac_len .
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WORD mac_len, // IN - The length of the MAC that was calculated.
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int *mac_auth, // OUT - TRUE if authentication succeeded, FALSE if it did not. NULL pointer will ignore the authentication.
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const BYTE key[], // IN - The AES key for decryption.
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int keysize); // IN - The length of the key in BITS. Valid values are 128, 192, 256.
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///////////////////
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// Test functions
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///////////////////
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int aes_test();
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int aes_ecb_test();
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int aes_cbc_test();
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int aes_ctr_test();
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int aes_ccm_test();
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#include "aes.c"
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#endif // AES_H
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