diff --git a/py/circuitpy_defns.mk b/py/circuitpy_defns.mk index 78ab41e12..60606da3d 100644 --- a/py/circuitpy_defns.mk +++ b/py/circuitpy_defns.mk @@ -136,6 +136,9 @@ endif ifeq ($(CIRCUITPY_BUSIO),1) SRC_PATTERNS += busio/% bitbangio/OneWire.% endif +ifeq ($(CIRCUITPY_CRYPTO),1) +SRC_PATTERNS += crypto/% +endif ifeq ($(CIRCUITPY_DIGITALIO),1) SRC_PATTERNS += digitalio/% endif @@ -342,6 +345,8 @@ SRC_SHARED_MODULE_ALL = \ bitbangio/__init__.c \ board/__init__.c \ busio/OneWire.c \ + crypto/__init__.c \ + crypto/aes.c \ displayio/Bitmap.c \ displayio/ColorConverter.c \ displayio/Display.c \ diff --git a/py/circuitpy_mpconfig.h b/py/circuitpy_mpconfig.h index 497fd9523..11479c3d6 100644 --- a/py/circuitpy_mpconfig.h +++ b/py/circuitpy_mpconfig.h @@ -321,6 +321,13 @@ extern const struct _mp_obj_module_t busio_module; #define BUSIO_MODULE #endif +#if CIRCUITPY_CRYPTO +extern const struct _mp_obj_module_t crypto_module; +#define CRYPTO_MODULE { MP_OBJ_NEW_QSTR(MP_QSTR_Crypto), (mp_obj_t)&crypto_module }, +#else +#define CRYPTO_MODULE +#endif + #if CIRCUITPY_DIGITALIO extern const struct _mp_obj_module_t digitalio_module; #define DIGITALIO_MODULE { MP_OBJ_NEW_QSTR(MP_QSTR_digitalio), (mp_obj_t)&digitalio_module }, @@ -637,6 +644,7 @@ extern const struct _mp_obj_module_t ustack_module; BLEIO_MODULE \ BOARD_MODULE \ BUSIO_MODULE \ + CRYPTO_MODULE \ DIGITALIO_MODULE \ DISPLAYIO_MODULE \ FONTIO_MODULE \ diff --git a/py/circuitpy_mpconfig.mk b/py/circuitpy_mpconfig.mk index 601f1c4e4..2e490a5ad 100644 --- a/py/circuitpy_mpconfig.mk +++ b/py/circuitpy_mpconfig.mk @@ -139,6 +139,11 @@ CIRCUITPY_BUSIO = $(CIRCUITPY_DEFAULT_BUILD) endif CFLAGS += -DCIRCUITPY_BUSIO=$(CIRCUITPY_BUSIO) +ifndef CIRCUITPY_CRYPTO +CIRCUITPY_CRYPTO = $(CIRCUITPY_FULL_BUILD) +endif +CFLAGS += -DCIRCUITPY_CRYPTO=$(CIRCUITPY_CRYPTO) + ifndef CIRCUITPY_DIGITALIO CIRCUITPY_DIGITALIO = $(CIRCUITPY_DEFAULT_BUILD) endif diff --git a/shared-bindings/crypto/__init__.c b/shared-bindings/crypto/__init__.c new file mode 100644 index 000000000..45da22bd4 --- /dev/null +++ b/shared-bindings/crypto/__init__.c @@ -0,0 +1,71 @@ +/* + * This file is part of the MicroPython project, http://micropython.org/ + * + * The MIT License (MIT) + * + * Copyright (c) 2017 Scott Shawcroft for Adafruit Industries + * + * Permission is hereby granted, free of charge, to any person obtaining a copy + * of this software and associated documentation files (the "Software"), to deal + * in the Software without restriction, including without limitation the rights + * to use, copy, modify, merge, publish, distribute, sublicense, and/or sell + * copies of the Software, and to permit persons to whom the Software is + * furnished to do so, subject to the following conditions: + * + * The above copyright notice and this permission notice shall be included in + * all copies or substantial portions of the Software. + * + * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR + * IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY, + * FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE + * AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER + * LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM, + * OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN + * THE SOFTWARE. + */ + +#include + +#include "py/obj.h" +#include "py/runtime.h" + +#include "__init__.h" + +//| :mod:`aes` --- AES encryption and decryption routines +//| ======================================================== +//| +//| .. module:: aes +//| :synopsis: Routines for performing AES encryption and decryption +//| +//| The `audiocore` module contains core classes for audio IO +//| +//| Libraries +//| +//| .. toctree:: +//| :maxdepth: 3 +//| +//| + +STATIC const mp_rom_map_elem_t cipher_module_globals_table[] = { + {MP_ROM_QSTR(MP_QSTR___name__), MP_ROM_QSTR(MP_QSTR_Cipher)}, + {MP_OBJ_NEW_QSTR(MP_QSTR_AES), MP_ROM_PTR(&aes_module)}, +}; + +STATIC MP_DEFINE_CONST_DICT(cipher_module_globals, cipher_module_globals_table); + +const mp_obj_module_t cipher_module = { + {&mp_type_module}, + .globals = (mp_obj_dict_t *)&cipher_module_globals, +}; + +STATIC const mp_rom_map_elem_t crypto_module_globals_table[] = { + {MP_ROM_QSTR(MP_QSTR___name__), MP_ROM_QSTR(MP_QSTR_Crypto)}, + {MP_OBJ_NEW_QSTR(MP_QSTR_Cipher), MP_ROM_PTR(&cipher_module)}, +}; + +STATIC MP_DEFINE_CONST_DICT(crypto_module_globals, crypto_module_globals_table); + +const mp_obj_module_t crypto_module = { + .base = {&mp_type_module}, + .globals = (mp_obj_dict_t *)&crypto_module_globals, +}; diff --git a/shared-bindings/crypto/__init__.h b/shared-bindings/crypto/__init__.h new file mode 100644 index 000000000..c9071ee52 --- /dev/null +++ b/shared-bindings/crypto/__init__.h @@ -0,0 +1,48 @@ +/* + * This file is part of the Micro Python project, http://micropython.org/ + * + * The MIT License (MIT) + * + * Copyright (c) 2017 Scott Shawcroft for Adafruit Industries + * + * Permission is hereby granted, free of charge, to any person obtaining a copy + * of this software and associated documentation files (the "Software"), to deal + * in the Software without restriction, including without limitation the rights + * to use, copy, modify, merge, publish, distribute, sublicense, and/or sell + * copies of the Software, and to permit persons to whom the Software is + * furnished to do so, subject to the following conditions: + * + * The above copyright notice and this permission notice shall be included in + * all copies or substantial portions of the Software. + * + * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR + * IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY, + * FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE + * AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER + * LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM, + * OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN + * THE SOFTWARE. + */ + +#ifndef MICROPY_INCLUDED_SHARED_BINDINGS_CRYPTO_H +#define MICROPY_INCLUDED_SHARED_BINDINGS_CRYPTO_H + +#include "shared-module/crypto/__init__.h" + +extern const mp_obj_module_t crypto_module; +extern const mp_obj_module_t aes_module; + +void common_hal_aes_construct(aes_obj_t* self, + const uint8_t* key, + uint32_t key_length, + const uint8_t* iv, + int mode, + int counter); +void common_hal_aes_encrypt(aes_obj_t* self, + uint8_t* buffer, + size_t len); +void common_hal_aes_decrypt(aes_obj_t* self, + uint8_t* buffer, + size_t len); + +#endif // MICROPY_INCLUDED_SHARED_BINDINGS_CRYPTO_H diff --git a/shared-bindings/crypto/aes.c b/shared-bindings/crypto/aes.c new file mode 100644 index 000000000..61a46dbc5 --- /dev/null +++ b/shared-bindings/crypto/aes.c @@ -0,0 +1,207 @@ +#include +#include + +#include "py/obj.h" +#include "py/runtime.h" + +#include "shared-bindings/crypto/__init__.h" + +// Defined at the end of this file +extern const mp_obj_type_t aescipher_type; + +STATIC mp_obj_t aescipher_make_new(size_t n_args, const mp_obj_t *pos_args, + mp_map_t *kw_args) { + enum { ARG_key, ARG_mode, ARG_IV, ARG_counter, ARG_segment_size }; + static const mp_arg_t allowed_args[] = { + {MP_QSTR_key, MP_ARG_OBJ | MP_ARG_REQUIRED}, + {MP_QSTR_mode, MP_ARG_INT}, + {MP_QSTR_IV, MP_ARG_OBJ}, + {MP_QSTR_counter, MP_ARG_OBJ}, + {MP_QSTR_segment_size, MP_ARG_INT}, + }; + mp_arg_val_t args[MP_ARRAY_SIZE(allowed_args)]; + // Set defaults. These will be overridden in mp_arg_parse_all() if an + // argument is provided. + args[ARG_mode].u_int = AES_MODE_ECB; + args[ARG_IV].u_obj = NULL; + args[ARG_counter].u_int = 0; + args[ARG_segment_size].u_int = + 8; // Only useful in CFB mode, which we don't support + mp_arg_parse_all(n_args, pos_args, kw_args, MP_ARRAY_SIZE(allowed_args), + allowed_args, args); + + aes_obj_t *self = m_new_obj(aes_obj_t); + self->base.type = &aescipher_type; + + mp_buffer_info_t bufinfo; + + const uint8_t *key = NULL; + uint32_t key_length = 0; + if (mp_get_buffer(args[ARG_key].u_obj, &bufinfo, MP_BUFFER_READ)) { + if ((bufinfo.len != 16) && (bufinfo.len != 24) && (bufinfo.len != 32)) { + mp_raise_TypeError(translate("key must be 16, 24, or 32 bytes long")); + } + key = bufinfo.buf; + key_length = bufinfo.len; + } else { + mp_raise_TypeError(translate("no key was specified")); + } + + int mode = args[ARG_mode].u_int; + switch (args[ARG_mode].u_int) { + case AES_MODE_CBC: /* CBC */ + break; + case AES_MODE_ECB: /* ECB */ + break; + case AES_MODE_CTR: /* CTR */ + break; + default: + mp_raise_TypeError(translate("requested AES mode is unsupported")); + } + + // IV is required for CBC mode and is ignored for other modes. + const uint8_t *iv = NULL; + if (args[ARG_IV].u_obj != NULL && + mp_get_buffer(args[ARG_IV].u_obj, &bufinfo, MP_BUFFER_READ)) { + if (bufinfo.len != AES_BLOCKLEN) { + mp_raise_TypeError_varg(translate("iv must be %d bytes long"), + AES_BLOCKLEN); + } + iv = bufinfo.buf; + } + + common_hal_aes_construct(self, key, key_length, iv, mode, args[ARG_counter].u_int); + return MP_OBJ_FROM_PTR(self); +} + +// Used when constructing with `new AESCipher` +STATIC mp_obj_t aescipher_make_new_new(const mp_obj_type_t *type, size_t n_args, + const mp_obj_t *pos_args, + mp_map_t *kw_args) { + return aescipher_make_new(n_args, pos_args, kw_args); +} + +STATIC byte *duplicate_data(const byte *src_buf, size_t len) { + byte *dest_buf = m_new(byte, len); + memcpy(dest_buf, src_buf, len); + return dest_buf; +} + +STATIC mp_obj_t aescipher_encrypt_in_place(mp_obj_t aes_obj, mp_obj_t buf) { + if (!MP_OBJ_IS_TYPE(aes_obj, &aescipher_type)) { + mp_raise_TypeError_varg(translate("Expected a %q"), aescipher_type.name); + } + // Convert parameters into expected types. + aes_obj_t *aes = MP_OBJ_TO_PTR(aes_obj); + mp_buffer_info_t bufinfo; + mp_get_buffer_raise(buf, &bufinfo, MP_BUFFER_READ); + if ((bufinfo.len & (AES_BLOCKLEN - 1)) != 0) { + mp_raise_ValueError(translate("Buffer must be a multiple of 16 bytes")); + } + + common_hal_aes_encrypt(aes, (uint8_t *)bufinfo.buf, bufinfo.len); + return mp_const_none; +} +STATIC MP_DEFINE_CONST_FUN_OBJ_2(aescipher_encrypt_in_place_obj, + aescipher_encrypt_in_place); + +STATIC mp_obj_t aescipher_encrypt(mp_obj_t aes_obj, mp_obj_t buf) { + if (!MP_OBJ_IS_TYPE(aes_obj, &aescipher_type)) { + mp_raise_TypeError_varg(translate("Expected a %q"), aescipher_type.name); + } + // Convert parameters into expected types. + aes_obj_t *aes = MP_OBJ_TO_PTR(aes_obj); + mp_buffer_info_t bufinfo; + mp_get_buffer_raise(buf, &bufinfo, MP_BUFFER_READ); + if ((bufinfo.len & (AES_BLOCKLEN - 1)) != 0) { + mp_raise_ValueError(translate("Buffer must be a multiple of 16 bytes")); + } + + byte *dest_buf = duplicate_data((const byte *)bufinfo.buf, bufinfo.len); + common_hal_aes_encrypt(aes, (uint8_t *)dest_buf, bufinfo.len); + + return mp_obj_new_bytearray_by_ref(bufinfo.len, dest_buf); +} +STATIC MP_DEFINE_CONST_FUN_OBJ_2(aescipher_encrypt_obj, aescipher_encrypt); + +STATIC mp_obj_t aescipher_decrypt_in_place(mp_obj_t aes_obj, mp_obj_t buf) { + if (!MP_OBJ_IS_TYPE(aes_obj, &aescipher_type)) { + mp_raise_TypeError_varg(translate("Expected a %q"), aescipher_type.name); + } + // Convert parameters into expected types. + aes_obj_t *aes = MP_OBJ_TO_PTR(aes_obj); + mp_buffer_info_t bufinfo; + mp_get_buffer_raise(buf, &bufinfo, MP_BUFFER_READ); + if ((bufinfo.len & (AES_BLOCKLEN - 1)) != 0) { + mp_raise_ValueError(translate("Buffer must be a multiple of 16 bytes")); + } + common_hal_aes_decrypt(aes, (uint8_t *)bufinfo.buf, bufinfo.len); + return mp_const_none; +} +STATIC MP_DEFINE_CONST_FUN_OBJ_2(aescipher_decrypt_in_place_obj, + aescipher_decrypt_in_place); + +STATIC mp_obj_t aescipher_decrypt(mp_obj_t aes_obj, mp_obj_t buf) { + if (!MP_OBJ_IS_TYPE(aes_obj, &aescipher_type)) { + mp_raise_TypeError_varg(translate("Expected a %q"), aescipher_type.name); + } + // Convert parameters into expected types. + aes_obj_t *aes = MP_OBJ_TO_PTR(aes_obj); + mp_buffer_info_t bufinfo; + mp_get_buffer_raise(buf, &bufinfo, MP_BUFFER_READ); + if ((bufinfo.len & (AES_BLOCKLEN - 1)) != 0) { + mp_raise_ValueError(translate("Buffer must be a multiple of 16 bytes")); + } + + byte *dest_buf = duplicate_data((const byte *)bufinfo.buf, bufinfo.len); + common_hal_aes_decrypt(aes, (uint8_t *)dest_buf, bufinfo.len); + return mp_obj_new_bytearray_by_ref(bufinfo.len, dest_buf); +} +STATIC MP_DEFINE_CONST_FUN_OBJ_2(aescipher_decrypt_obj, aescipher_decrypt); + +STATIC const mp_obj_tuple_t mp_crypto_aes_key_size_obj = { + {&mp_type_tuple}, + 3, + { + MP_OBJ_NEW_SMALL_INT(16), + MP_OBJ_NEW_SMALL_INT(24), + MP_OBJ_NEW_SMALL_INT(32), + }}; + +STATIC const mp_rom_map_elem_t aescipher_locals_dict_table[] = { + // Methods + {MP_ROM_QSTR(MP_QSTR___name__), MP_OBJ_NEW_QSTR(MP_QSTR_AES)}, + {MP_ROM_QSTR(MP_QSTR_encrypt), (mp_obj_t)&aescipher_encrypt_obj}, + {MP_ROM_QSTR(MP_QSTR_decrypt), (mp_obj_t)&aescipher_decrypt_obj}, + {MP_ROM_QSTR(MP_QSTR_encrypt_in_place), + (mp_obj_t)&aescipher_encrypt_in_place_obj}, + {MP_ROM_QSTR(MP_QSTR_decrypt_in_place), + (mp_obj_t)&aescipher_decrypt_in_place_obj}, + +}; +STATIC MP_DEFINE_CONST_DICT(aescipher_locals_dict, aescipher_locals_dict_table); + +const mp_obj_type_t aescipher_type = { + {&mp_type_type}, + .name = MP_QSTR_AESCipher, + .make_new = aescipher_make_new_new, + .locals_dict = (mp_obj_dict_t *)&aescipher_locals_dict, +}; + +MP_DEFINE_CONST_FUN_OBJ_KW(aescipher_make_new_obj, 1, aescipher_make_new); + +STATIC const mp_rom_map_elem_t aes_module_globals_table[] = { + {MP_ROM_QSTR(MP_QSTR_MODE_ECB), MP_ROM_INT(AES_MODE_ECB)}, + {MP_ROM_QSTR(MP_QSTR_MODE_CBC), MP_ROM_INT(AES_MODE_CBC)}, + {MP_ROM_QSTR(MP_QSTR_MODE_CTR), MP_ROM_INT(AES_MODE_CTR)}, + {MP_ROM_QSTR(MP_QSTR_block_size), MP_ROM_INT(AES_BLOCKLEN)}, + {MP_ROM_QSTR(MP_QSTR_key_size), (mp_obj_t)&mp_crypto_aes_key_size_obj}, + {MP_ROM_QSTR(MP_QSTR_new), MP_ROM_PTR(&aescipher_make_new_obj)}, +}; + +STATIC MP_DEFINE_CONST_DICT(aes_module_globals, aes_module_globals_table); + +const mp_obj_module_t aes_module = { + {&mp_type_module}, + .globals = (mp_obj_dict_t *)&aes_module_globals, +}; diff --git a/shared-module/crypto/__init__.c b/shared-module/crypto/__init__.c new file mode 100644 index 000000000..cfb28a2f1 --- /dev/null +++ b/shared-module/crypto/__init__.c @@ -0,0 +1,65 @@ +#include + +#include "py/runtime.h" + +#include "shared-module/crypto/__init__.h" + +void common_hal_aes_construct(aes_obj_t* self, + const uint8_t* key, + uint32_t key_length, + const uint8_t* iv, + int mode, + int counter) { + memset(&self->ctx, 0, sizeof(self->ctx)); + if (iv != NULL) { + AES_init_ctx_iv(&self->ctx, key, key_length, iv); + } else { + AES_init_ctx(&self->ctx, key, key_length); + } + self->mode = mode; + self->counter = counter; +} + +void common_hal_aes_encrypt(aes_obj_t* self, + uint8_t* buffer, + size_t length) { + switch (self->mode) { + case AES_MODE_ECB: + if (length != 16) + mp_raise_msg(&mp_type_ValueError, translate("ecb only operates on 16 bytes at a time")); + AES_ECB_encrypt(&self->ctx, buffer); + break; + case AES_MODE_CBC: + if ((length & 15) != 0) + mp_raise_msg(&mp_type_ValueError, translate("cbc blocks must be multiples of 16 bytes")); + AES_CBC_encrypt_buffer(&self->ctx, buffer, length); + break; + case AES_MODE_CTR: + AES_CTR_xcrypt_buffer(&self->ctx, buffer, length); + break; + default: + mp_raise_msg(&mp_type_ValueError, translate("unknown encryption mode")); + } +} + +void common_hal_aes_decrypt(aes_obj_t* self, + uint8_t* buffer, + size_t length) { + switch (self->mode) { + case AES_MODE_ECB: + if (length != 16) + mp_raise_msg(&mp_type_ValueError, translate("ecp only operates on 16 bytes at a time")); + AES_ECB_decrypt(&self->ctx, buffer); + break; + case AES_MODE_CBC: + if ((length & 15) != 0) + mp_raise_msg(&mp_type_ValueError, translate("cbc blocks must be multiples of 16 bytes")); + AES_CBC_decrypt_buffer(&self->ctx, buffer, length); + break; + case AES_MODE_CTR: + AES_CTR_xcrypt_buffer(&self->ctx, buffer, length); + break; + default: + mp_raise_msg(&mp_type_ValueError, translate("unknown encryption mode")); + } +} diff --git a/shared-module/crypto/__init__.h b/shared-module/crypto/__init__.h new file mode 100644 index 000000000..f16e64161 --- /dev/null +++ b/shared-module/crypto/__init__.h @@ -0,0 +1,57 @@ +/* + * This file is part of the MicroPython project, http://micropython.org/ + * + * The MIT License (MIT) + * + * Copyright (c) 2018 Dan Halbert for Adafruit Industries + * + * Permission is hereby granted, free of charge, to any person obtaining a copy + * of this software and associated documentation files (the "Software"), to deal + * in the Software without restriction, including without limitation the rights + * to use, copy, modify, merge, publish, distribute, sublicense, and/or sell + * copies of the Software, and to permit persons to whom the Software is + * furnished to do so, subject to the following conditions: + * + * The above copyright notice and this permission notice shall be included in + * all copies or substantial portions of the Software. + * + * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR + * IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY, + * FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE + * AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER + * LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM, + * OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN + * THE SOFTWARE. + */ + +#ifndef MICROPY_INCLUDED_SHARED_MODULE_CRYPTO__INIT__H +#define MICROPY_INCLUDED_SHARED_MODULE_CRYPTO__INIT__H + +#include +#include + +#include "py/obj.h" +#include "py/proto.h" + +#include "shared-module/crypto/aes.h" + +enum AES_MODE { + AES_MODE_ECB = 1, + AES_MODE_CBC = 2, + AES_MODE_CTR = 6, +}; + +typedef struct { + mp_obj_base_t base; + + // The tinyaes context + struct AES_ctx ctx; + + // Which AES mode this instance of the object is configured to use + enum AES_MODE mode; + + // Counter for running in CTR mode + uint32_t counter; +} aes_obj_t; + +#endif // MICROPY_INCLUDED_SHARED_MODULE_CRYPTO__INIT__H diff --git a/shared-module/crypto/aes.c b/shared-module/crypto/aes.c new file mode 100644 index 000000000..b62b5afc4 --- /dev/null +++ b/shared-module/crypto/aes.c @@ -0,0 +1,608 @@ +/* + +This is an implementation of the AES algorithm, specifically ECB, CTR and CBC mode. +Block size can be chosen in aes.h - available choices are AES128, AES192, AES256. + +The implementation is verified against the test vectors in: + National Institute of Standards and Technology Special Publication 800-38A 2001 ED + +ECB-AES128 +---------- + + plain-text: + 6bc1bee22e409f96e93d7e117393172a + ae2d8a571e03ac9c9eb76fac45af8e51 + 30c81c46a35ce411e5fbc1191a0a52ef + f69f2445df4f9b17ad2b417be66c3710 + + key: + 2b7e151628aed2a6abf7158809cf4f3c + + resulting cipher + 3ad77bb40d7a3660a89ecaf32466ef97 + f5d3d58503b9699de785895a96fdbaaf + 43b1cd7f598ece23881b00e3ed030688 + 7b0c785e27e8ad3f8223207104725dd4 + + +NOTE: String length must be evenly divisible by 16byte (str_len % 16 == 0) + You should pad the end of the string with zeros if this is not the case. + For AES192/256 the key size is proportionally larger. + +*/ + +/*****************************************************************************/ +/* Includes: */ +/*****************************************************************************/ +#include // CBC mode, for memset +#include "aes.h" + +/*****************************************************************************/ +/* Defines: */ +/*****************************************************************************/ +// The number of columns comprising a state in AES. This is a constant in AES. +// Value=4 +#define Nb 4UL + +#if defined(AES256) && (AES256 == 1) + #define Nk256 8UL + #define Nr256 14UL +#endif +#if defined(AES192) && (AES192 == 1) + #define Nk192 6UL + #define Nr192 12UL +#endif +#if defined(AES128) && (AES128 == 1) + #define Nk128 4UL // The number of 32 bit words in a key. + #define Nr128 10UL // The number of rounds in AES Cipher. +#endif + +// jcallan@github points out that declaring Multiply as a function reduces code +// size considerably with the Keil ARM compiler. See this link for more +// information: https://github.com/kokke/tiny-AES-C/pull/3 +#ifndef MULTIPLY_AS_A_FUNCTION + #define MULTIPLY_AS_A_FUNCTION 0 +#endif + + + + +/*****************************************************************************/ +/* Private variables: */ +/*****************************************************************************/ +// state - array holding the intermediate results during decryption. +typedef uint8_t state_t[4][4]; + + + +// The lookup-tables are marked const so they can be placed in read-only storage +// instead of RAM The numbers below can be computed dynamically trading ROM for +// RAM - This can be useful in (embedded) bootloader applications, where ROM is +// often limited. +static const uint8_t sbox[256] = { + //0 1 2 3 4 5 6 7 8 9 A B C D E F + 0x63, 0x7c, 0x77, 0x7b, 0xf2, 0x6b, 0x6f, 0xc5, 0x30, 0x01, 0x67, 0x2b, 0xfe, 0xd7, 0xab, 0x76, + 0xca, 0x82, 0xc9, 0x7d, 0xfa, 0x59, 0x47, 0xf0, 0xad, 0xd4, 0xa2, 0xaf, 0x9c, 0xa4, 0x72, 0xc0, + 0xb7, 0xfd, 0x93, 0x26, 0x36, 0x3f, 0xf7, 0xcc, 0x34, 0xa5, 0xe5, 0xf1, 0x71, 0xd8, 0x31, 0x15, + 0x04, 0xc7, 0x23, 0xc3, 0x18, 0x96, 0x05, 0x9a, 0x07, 0x12, 0x80, 0xe2, 0xeb, 0x27, 0xb2, 0x75, + 0x09, 0x83, 0x2c, 0x1a, 0x1b, 0x6e, 0x5a, 0xa0, 0x52, 0x3b, 0xd6, 0xb3, 0x29, 0xe3, 0x2f, 0x84, + 0x53, 0xd1, 0x00, 0xed, 0x20, 0xfc, 0xb1, 0x5b, 0x6a, 0xcb, 0xbe, 0x39, 0x4a, 0x4c, 0x58, 0xcf, + 0xd0, 0xef, 0xaa, 0xfb, 0x43, 0x4d, 0x33, 0x85, 0x45, 0xf9, 0x02, 0x7f, 0x50, 0x3c, 0x9f, 0xa8, + 0x51, 0xa3, 0x40, 0x8f, 0x92, 0x9d, 0x38, 0xf5, 0xbc, 0xb6, 0xda, 0x21, 0x10, 0xff, 0xf3, 0xd2, + 0xcd, 0x0c, 0x13, 0xec, 0x5f, 0x97, 0x44, 0x17, 0xc4, 0xa7, 0x7e, 0x3d, 0x64, 0x5d, 0x19, 0x73, + 0x60, 0x81, 0x4f, 0xdc, 0x22, 0x2a, 0x90, 0x88, 0x46, 0xee, 0xb8, 0x14, 0xde, 0x5e, 0x0b, 0xdb, + 0xe0, 0x32, 0x3a, 0x0a, 0x49, 0x06, 0x24, 0x5c, 0xc2, 0xd3, 0xac, 0x62, 0x91, 0x95, 0xe4, 0x79, + 0xe7, 0xc8, 0x37, 0x6d, 0x8d, 0xd5, 0x4e, 0xa9, 0x6c, 0x56, 0xf4, 0xea, 0x65, 0x7a, 0xae, 0x08, + 0xba, 0x78, 0x25, 0x2e, 0x1c, 0xa6, 0xb4, 0xc6, 0xe8, 0xdd, 0x74, 0x1f, 0x4b, 0xbd, 0x8b, 0x8a, + 0x70, 0x3e, 0xb5, 0x66, 0x48, 0x03, 0xf6, 0x0e, 0x61, 0x35, 0x57, 0xb9, 0x86, 0xc1, 0x1d, 0x9e, + 0xe1, 0xf8, 0x98, 0x11, 0x69, 0xd9, 0x8e, 0x94, 0x9b, 0x1e, 0x87, 0xe9, 0xce, 0x55, 0x28, 0xdf, + 0x8c, 0xa1, 0x89, 0x0d, 0xbf, 0xe6, 0x42, 0x68, 0x41, 0x99, 0x2d, 0x0f, 0xb0, 0x54, 0xbb, 0x16 }; + +static const uint8_t rsbox[256] = { + 0x52, 0x09, 0x6a, 0xd5, 0x30, 0x36, 0xa5, 0x38, 0xbf, 0x40, 0xa3, 0x9e, 0x81, 0xf3, 0xd7, 0xfb, + 0x7c, 0xe3, 0x39, 0x82, 0x9b, 0x2f, 0xff, 0x87, 0x34, 0x8e, 0x43, 0x44, 0xc4, 0xde, 0xe9, 0xcb, + 0x54, 0x7b, 0x94, 0x32, 0xa6, 0xc2, 0x23, 0x3d, 0xee, 0x4c, 0x95, 0x0b, 0x42, 0xfa, 0xc3, 0x4e, + 0x08, 0x2e, 0xa1, 0x66, 0x28, 0xd9, 0x24, 0xb2, 0x76, 0x5b, 0xa2, 0x49, 0x6d, 0x8b, 0xd1, 0x25, + 0x72, 0xf8, 0xf6, 0x64, 0x86, 0x68, 0x98, 0x16, 0xd4, 0xa4, 0x5c, 0xcc, 0x5d, 0x65, 0xb6, 0x92, + 0x6c, 0x70, 0x48, 0x50, 0xfd, 0xed, 0xb9, 0xda, 0x5e, 0x15, 0x46, 0x57, 0xa7, 0x8d, 0x9d, 0x84, + 0x90, 0xd8, 0xab, 0x00, 0x8c, 0xbc, 0xd3, 0x0a, 0xf7, 0xe4, 0x58, 0x05, 0xb8, 0xb3, 0x45, 0x06, + 0xd0, 0x2c, 0x1e, 0x8f, 0xca, 0x3f, 0x0f, 0x02, 0xc1, 0xaf, 0xbd, 0x03, 0x01, 0x13, 0x8a, 0x6b, + 0x3a, 0x91, 0x11, 0x41, 0x4f, 0x67, 0xdc, 0xea, 0x97, 0xf2, 0xcf, 0xce, 0xf0, 0xb4, 0xe6, 0x73, + 0x96, 0xac, 0x74, 0x22, 0xe7, 0xad, 0x35, 0x85, 0xe2, 0xf9, 0x37, 0xe8, 0x1c, 0x75, 0xdf, 0x6e, + 0x47, 0xf1, 0x1a, 0x71, 0x1d, 0x29, 0xc5, 0x89, 0x6f, 0xb7, 0x62, 0x0e, 0xaa, 0x18, 0xbe, 0x1b, + 0xfc, 0x56, 0x3e, 0x4b, 0xc6, 0xd2, 0x79, 0x20, 0x9a, 0xdb, 0xc0, 0xfe, 0x78, 0xcd, 0x5a, 0xf4, + 0x1f, 0xdd, 0xa8, 0x33, 0x88, 0x07, 0xc7, 0x31, 0xb1, 0x12, 0x10, 0x59, 0x27, 0x80, 0xec, 0x5f, + 0x60, 0x51, 0x7f, 0xa9, 0x19, 0xb5, 0x4a, 0x0d, 0x2d, 0xe5, 0x7a, 0x9f, 0x93, 0xc9, 0x9c, 0xef, + 0xa0, 0xe0, 0x3b, 0x4d, 0xae, 0x2a, 0xf5, 0xb0, 0xc8, 0xeb, 0xbb, 0x3c, 0x83, 0x53, 0x99, 0x61, + 0x17, 0x2b, 0x04, 0x7e, 0xba, 0x77, 0xd6, 0x26, 0xe1, 0x69, 0x14, 0x63, 0x55, 0x21, 0x0c, 0x7d }; + +// The round constant word array, Rcon[i], contains the values given by x to the +// power (i-1) being powers of x (x is denoted as {02}) in the field GF(2^8) +static const uint8_t Rcon[11] = { + 0x8d, 0x01, 0x02, 0x04, 0x08, 0x10, 0x20, 0x40, 0x80, 0x1b, 0x36 }; + +/* + * Jordan Goulder points out in PR #12 + * (https://github.com/kokke/tiny-AES-C/pull/12), that you can remove most of + * the elements in the Rcon array, because they are unused. + * + * From Wikipedia's article on the Rijndael key schedule @ + * https://en.wikipedia.org/wiki/Rijndael_key_schedule#Rcon + * + * "Only the first some of these constants are actually used – up to rcon[10] + * for AES-128 (as 11 round keys are needed), up to rcon[8] for AES-192, up to + * rcon[7] for AES-256. rcon[0] is not used in AES algorithm." + */ + + +/*****************************************************************************/ +/* Private functions: */ +/*****************************************************************************/ +static const uint8_t *GetRoundKey(const struct AES_ctx *ctx) { + switch (ctx->KeyLength) { +#if defined(AES128) && (AES128 == 1) + case 16: return ctx->RoundKey128; +#endif +#if defined(AES192) && (AES192 == 1) + case 24: return ctx->RoundKey192; +#endif +#if defined(AES256) && (AES256 == 1) + case 32: return ctx->RoundKey256; +#endif + } + return NULL; +} + + +/* +static uint8_t getSBoxValue(uint8_t num) +{ + return sbox[num]; +} +*/ +#define getSBoxValue(num) (sbox[(num)]) +/* +static uint8_t getSBoxInvert(uint8_t num) +{ + return rsbox[num]; +} +*/ +#define getSBoxInvert(num) (rsbox[(num)]) + +// This function produces Nb(Nr+1) round keys. The round keys are used in each +// round to decrypt the states. +static void KeyExpansion(struct AES_ctx* ctx, const uint8_t* Key) +{ + uint8_t* RoundKey = (uint8_t *)GetRoundKey(ctx); + + unsigned i, j, k; + uint8_t tempa[4]; // Used for the column/row operations + + // The first round key is the key itself. + for (i = 0; i < ctx->Nk; ++i) + { + RoundKey[(i * 4) + 0] = Key[(i * 4) + 0]; + RoundKey[(i * 4) + 1] = Key[(i * 4) + 1]; + RoundKey[(i * 4) + 2] = Key[(i * 4) + 2]; + RoundKey[(i * 4) + 3] = Key[(i * 4) + 3]; + } + + // All other round keys are found from the previous round keys. + for (i = ctx->Nk; i < Nb * (ctx->Nr + 1); ++i) + { + { + k = (i - 1) * 4; + tempa[0]=RoundKey[k + 0]; + tempa[1]=RoundKey[k + 1]; + tempa[2]=RoundKey[k + 2]; + tempa[3]=RoundKey[k + 3]; + + } + + if (i % ctx->Nk == 0) + { + // This function shifts the 4 bytes in a word to the left once. + // [a0,a1,a2,a3] becomes [a1,a2,a3,a0] + + // Function RotWord() + { + const uint8_t u8tmp = tempa[0]; + tempa[0] = tempa[1]; + tempa[1] = tempa[2]; + tempa[2] = tempa[3]; + tempa[3] = u8tmp; + } + + // SubWord() is a function that takes a four-byte input word and applies + // the S-box to each of the four bytes to produce an output word. + + // Function Subword() + { + tempa[0] = getSBoxValue(tempa[0]); + tempa[1] = getSBoxValue(tempa[1]); + tempa[2] = getSBoxValue(tempa[2]); + tempa[3] = getSBoxValue(tempa[3]); + } + + tempa[0] = tempa[0] ^ Rcon[i/ctx->Nk]; + } +#if defined(AES256) && (AES256 == 1) + if (ctx->KeyLength == 32) { + if (i % ctx->Nk == 4) + { + // Function Subword() + { + tempa[0] = getSBoxValue(tempa[0]); + tempa[1] = getSBoxValue(tempa[1]); + tempa[2] = getSBoxValue(tempa[2]); + tempa[3] = getSBoxValue(tempa[3]); + } + } + } +#endif + j = i * 4; k=(i - ctx->Nk) * 4; + RoundKey[j + 0] = RoundKey[k + 0] ^ tempa[0]; + RoundKey[j + 1] = RoundKey[k + 1] ^ tempa[1]; + RoundKey[j + 2] = RoundKey[k + 2] ^ tempa[2]; + RoundKey[j + 3] = RoundKey[k + 3] ^ tempa[3]; + } +} + +void AES_init_ctx(struct AES_ctx* ctx, const uint8_t* key, uint32_t keylen) +{ + ctx->KeyLength = keylen; + switch (ctx->KeyLength) { +#if defined(AES128) && (AES128 == 1) + case 16: ctx->Nr = Nr128; ctx->Nk = Nk128; break; +#endif +#if defined(AES192) && (AES192 == 1) + case 24: ctx->Nr = Nr192; ctx->Nk = Nk192; break; +#endif +#if defined(AES256) && (AES256 == 1) + case 32: ctx->Nr = Nr256; ctx->Nk = Nk256; break; +#endif + default: ctx->Nr = 0; ctx->Nk = 0; break; + } + KeyExpansion(ctx, key); +} +#if (defined(CBC) && (CBC == 1)) || (defined(CTR) && (CTR == 1)) +void AES_init_ctx_iv(struct AES_ctx* ctx, const uint8_t* key, uint32_t keylen, const uint8_t* iv) +{ + AES_init_ctx(ctx, key, keylen); + memcpy (ctx->Iv, iv, AES_BLOCKLEN); +} +void AES_ctx_set_iv(struct AES_ctx* ctx, const uint8_t* iv) +{ + memcpy (ctx->Iv, iv, AES_BLOCKLEN); +} +#endif + +// This function adds the round key to state. The round key is added to the +// state by an XOR function. +static void AddRoundKey(uint8_t round, state_t* state, const uint8_t* RoundKey) +{ + uint8_t i,j; + for (i = 0; i < 4; ++i) + { + for (j = 0; j < 4; ++j) + { + (*state)[i][j] ^= RoundKey[(round * Nb * 4) + (i * Nb) + j]; + } + } +} + +// The SubBytes Function Substitutes the values in the state matrix with values +// in an S-box. +static void SubBytes(state_t* state) +{ + uint8_t i, j; + for (i = 0; i < 4; ++i) + { + for (j = 0; j < 4; ++j) + { + (*state)[j][i] = getSBoxValue((*state)[j][i]); + } + } +} + +// The ShiftRows() function shifts the rows in the state to the left. Each row +// is shifted with different offset. Offset = Row number. So the first row is +// not shifted. +static void ShiftRows(state_t* state) +{ + uint8_t temp; + + // Rotate first row 1 columns to left + temp = (*state)[0][1]; + (*state)[0][1] = (*state)[1][1]; + (*state)[1][1] = (*state)[2][1]; + (*state)[2][1] = (*state)[3][1]; + (*state)[3][1] = temp; + + // Rotate second row 2 columns to left + temp = (*state)[0][2]; + (*state)[0][2] = (*state)[2][2]; + (*state)[2][2] = temp; + + temp = (*state)[1][2]; + (*state)[1][2] = (*state)[3][2]; + (*state)[3][2] = temp; + + // Rotate third row 3 columns to left + temp = (*state)[0][3]; + (*state)[0][3] = (*state)[3][3]; + (*state)[3][3] = (*state)[2][3]; + (*state)[2][3] = (*state)[1][3]; + (*state)[1][3] = temp; +} + +static uint8_t xtime(uint8_t x) +{ + return ((x<<1) ^ (((x>>7) & 1) * 0x1b)); +} + +// MixColumns function mixes the columns of the state matrix +static void MixColumns(state_t* state) +{ + uint8_t i; + uint8_t Tmp, Tm, t; + for (i = 0; i < 4; ++i) + { + t = (*state)[i][0]; + Tmp = (*state)[i][0] ^ (*state)[i][1] ^ (*state)[i][2] ^ (*state)[i][3] ; + Tm = (*state)[i][0] ^ (*state)[i][1] ; Tm = xtime(Tm); (*state)[i][0] ^= Tm ^ Tmp ; + Tm = (*state)[i][1] ^ (*state)[i][2] ; Tm = xtime(Tm); (*state)[i][1] ^= Tm ^ Tmp ; + Tm = (*state)[i][2] ^ (*state)[i][3] ; Tm = xtime(Tm); (*state)[i][2] ^= Tm ^ Tmp ; + Tm = (*state)[i][3] ^ t ; Tm = xtime(Tm); (*state)[i][3] ^= Tm ^ Tmp ; + } +} + +// Multiply is used to multiply numbers in the field GF(2^8) +// Note: The last call to xtime() is unneeded, but often ends up generating a smaller binary +// The compiler seems to be able to vectorize the operation better this way. +// See https://github.com/kokke/tiny-AES-c/pull/34 +#if MULTIPLY_AS_A_FUNCTION +static uint8_t Multiply(uint8_t x, uint8_t y) +{ + return (((y & 1) * x) ^ + ((y>>1 & 1) * xtime(x)) ^ + ((y>>2 & 1) * xtime(xtime(x))) ^ + ((y>>3 & 1) * xtime(xtime(xtime(x)))) ^ + ((y>>4 & 1) * xtime(xtime(xtime(xtime(x)))))); /* this last call to xtime() can be omitted */ + } +#else +#define Multiply(x, y) \ + ( ((y & 1) * x) ^ \ + ((y>>1 & 1) * xtime(x)) ^ \ + ((y>>2 & 1) * xtime(xtime(x))) ^ \ + ((y>>3 & 1) * xtime(xtime(xtime(x)))) ^ \ + ((y>>4 & 1) * xtime(xtime(xtime(xtime(x)))))) \ + +#endif + +#if (defined(CBC) && CBC == 1) || (defined(ECB) && ECB == 1) +// MixColumns function mixes the columns of the state matrix. The method used to +// multiply may be difficult to understand for the inexperienced. Please use the +// references to gain more information. +static void InvMixColumns(state_t* state) +{ + int i; + uint8_t a, b, c, d; + for (i = 0; i < 4; ++i) + { + a = (*state)[i][0]; + b = (*state)[i][1]; + c = (*state)[i][2]; + d = (*state)[i][3]; + + (*state)[i][0] = Multiply(a, 0x0e) ^ Multiply(b, 0x0b) ^ Multiply(c, 0x0d) ^ Multiply(d, 0x09); + (*state)[i][1] = Multiply(a, 0x09) ^ Multiply(b, 0x0e) ^ Multiply(c, 0x0b) ^ Multiply(d, 0x0d); + (*state)[i][2] = Multiply(a, 0x0d) ^ Multiply(b, 0x09) ^ Multiply(c, 0x0e) ^ Multiply(d, 0x0b); + (*state)[i][3] = Multiply(a, 0x0b) ^ Multiply(b, 0x0d) ^ Multiply(c, 0x09) ^ Multiply(d, 0x0e); + } +} + + +// The SubBytes Function Substitutes the values in the state matrix with values +// in an S-box. +static void InvSubBytes(state_t* state) +{ + uint8_t i, j; + for (i = 0; i < 4; ++i) + { + for (j = 0; j < 4; ++j) + { + (*state)[j][i] = getSBoxInvert((*state)[j][i]); + } + } +} + +static void InvShiftRows(state_t* state) +{ + uint8_t temp; + + // Rotate first row 1 columns to right + temp = (*state)[3][1]; + (*state)[3][1] = (*state)[2][1]; + (*state)[2][1] = (*state)[1][1]; + (*state)[1][1] = (*state)[0][1]; + (*state)[0][1] = temp; + + // Rotate second row 2 columns to right + temp = (*state)[0][2]; + (*state)[0][2] = (*state)[2][2]; + (*state)[2][2] = temp; + + temp = (*state)[1][2]; + (*state)[1][2] = (*state)[3][2]; + (*state)[3][2] = temp; + + // Rotate third row 3 columns to right + temp = (*state)[0][3]; + (*state)[0][3] = (*state)[1][3]; + (*state)[1][3] = (*state)[2][3]; + (*state)[2][3] = (*state)[3][3]; + (*state)[3][3] = temp; +} +#endif // #if (defined(CBC) && CBC == 1) || (defined(ECB) && ECB == 1) + +// Cipher is the main function that encrypts the PlainText. +static void Cipher(state_t* state, const struct AES_ctx* ctx) +{ + const uint8_t* RoundKey = GetRoundKey(ctx); + uint8_t round = 0; + + // Add the First round key to the state before starting the rounds. + AddRoundKey(0, state, RoundKey); + + // There will be Nr rounds. The first Nr-1 rounds are identical. These Nr + // rounds are executed in the loop below. Last one without MixColumns() + for (round = 1; ; ++round) + { + SubBytes(state); + ShiftRows(state); + if (round == ctx->Nr) { + break; + } + MixColumns(state); + AddRoundKey(round, state, RoundKey); + } + // Add round key to last round + AddRoundKey(ctx->Nr, state, RoundKey); +} + +#if (defined(CBC) && CBC == 1) || (defined(ECB) && ECB == 1) +static void InvCipher(state_t* state, const struct AES_ctx* ctx) +{ + const uint8_t* RoundKey = GetRoundKey(ctx); + uint8_t round = 0; + + // Add the First round key to the state before starting the rounds. + AddRoundKey(ctx->Nr, state, RoundKey); + + // There will be Nr rounds. The first Nr-1 rounds are identical. These Nr + // rounds are executed in the loop below. Last one without InvMixColumn() + for (round = (ctx->Nr - 1); ; --round) + { + InvShiftRows(state); + InvSubBytes(state); + AddRoundKey(round, state, RoundKey); + if (round == 0) { + break; + } + InvMixColumns(state); + } + +} +#endif // #if (defined(CBC) && CBC == 1) || (defined(ECB) && ECB == 1) + +/*****************************************************************************/ +/* Public functions: */ +/*****************************************************************************/ +#if defined(ECB) && (ECB == 1) + + +void AES_ECB_encrypt(const struct AES_ctx* ctx, uint8_t* buf) +{ + // The next function call encrypts the PlainText with the Key using AES + // algorithm. + Cipher((state_t*)buf, ctx); +} + +void AES_ECB_decrypt(const struct AES_ctx* ctx, uint8_t* buf) +{ + // The next function call decrypts the PlainText with the Key using AES + // algorithm. + InvCipher((state_t*)buf, ctx); +} + + +#endif // #if defined(ECB) && (ECB == 1) + + + + + +#if defined(CBC) && (CBC == 1) + + +static void XorWithIv(uint8_t* buf, const uint8_t* Iv) +{ + uint8_t i; + for (i = 0; i < AES_BLOCKLEN; ++i) // The block in AES is always 128bit no matter the key size + { + buf[i] ^= Iv[i]; + } +} + +void AES_CBC_encrypt_buffer(struct AES_ctx *ctx, uint8_t* buf, uint32_t length) +{ + uintptr_t i; + uint8_t *Iv = ctx->Iv; + for (i = 0; i < length; i += AES_BLOCKLEN) + { + XorWithIv(buf, Iv); + Cipher((state_t*)buf, ctx); + Iv = buf; + buf += AES_BLOCKLEN; + } + /* store Iv in ctx for next call */ + memcpy(ctx->Iv, Iv, AES_BLOCKLEN); +} + +void AES_CBC_decrypt_buffer(struct AES_ctx* ctx, uint8_t* buf, uint32_t length) +{ + uintptr_t i; + uint8_t storeNextIv[AES_BLOCKLEN]; + for (i = 0; i < length; i += AES_BLOCKLEN) + { + memcpy(storeNextIv, buf, AES_BLOCKLEN); + InvCipher((state_t*)buf, ctx); + XorWithIv(buf, ctx->Iv); + memcpy(ctx->Iv, storeNextIv, AES_BLOCKLEN); + buf += AES_BLOCKLEN; + } + +} + +#endif // #if defined(CBC) && (CBC == 1) + + + +#if defined(CTR) && (CTR == 1) + +/* Symmetrical operation: same function for encrypting as for decrypting. Note +any IV/nonce should never be reused with the same key */ +void AES_CTR_xcrypt_buffer(struct AES_ctx* ctx, uint8_t* buf, uint32_t length) +{ + uint8_t buffer[AES_BLOCKLEN]; + + unsigned i; + int bi; + for (i = 0, bi = AES_BLOCKLEN; i < length; ++i, ++bi) + { + if (bi == AES_BLOCKLEN) /* we need to regen xor compliment in buffer */ + { + memcpy(buffer, ctx->Iv, AES_BLOCKLEN); + Cipher((state_t*)buffer, ctx); + + /* Increment Iv and handle overflow */ + for (bi = (AES_BLOCKLEN - 1); bi >= 0; --bi) + { + /* inc will overflow */ + if (ctx->Iv[bi] == 255) + { + ctx->Iv[bi] = 0; + continue; + } + ctx->Iv[bi] += 1; + break; + } + bi = 0; + } + + buf[i] = (buf[i] ^ buffer[bi]); + } +} + +#endif // #if defined(CTR) && (CTR == 1) diff --git a/shared-module/crypto/aes.h b/shared-module/crypto/aes.h new file mode 100644 index 000000000..a87fa5be7 --- /dev/null +++ b/shared-module/crypto/aes.h @@ -0,0 +1,105 @@ +#ifndef _AES_H_ +#define _AES_H_ + +#include + +// #define the macros below to 1/0 to enable/disable the mode of operation. +// +// CBC enables AES encryption in CBC-mode of operation. +// CTR enables encryption in counter-mode. +// ECB enables the basic ECB 16-byte block algorithm. All can be enabled simultaneously. + +// The #ifndef-guard allows it to be configured before #include'ing or at compile time. +#ifndef CBC + #define CBC 1 +#endif + +#ifndef ECB + #define ECB 1 +#endif + +#ifndef CTR + #define CTR 1 +#endif + + +#define AES128 1 +#define AES192 1 +#define AES256 1 + +#define AES_BLOCKLEN 16 // Block length in bytes - AES is 128b block only + +#if defined(AES256) && (AES256 == 1) + #define AES_KEYLEN256 32 + #define AES_keyExpSize256 240 +#endif +#if defined(AES192) && (AES192 == 1) + #define AES_KEYLEN192 24 + #define AES_keyExpSize192 208 +#endif +#if defined(AES128) && (AES128 == 1) + #define AES_KEYLEN128 16 // Key length in bytes + #define AES_keyExpSize128 176 +#endif + +struct AES_ctx +{ + union { +#if defined(AES256) && (AES256 == 1) + uint8_t RoundKey256[AES_keyExpSize256]; +#endif +#if defined(AES192) && (AES192 == 1) + uint8_t RoundKey192[AES_keyExpSize192]; +#endif +#if defined(AES128) && (AES128 == 1) + uint8_t RoundKey128[AES_keyExpSize128]; +#endif + }; +#if (defined(CBC) && (CBC == 1)) || (defined(CTR) && (CTR == 1)) + uint8_t Iv[AES_BLOCKLEN]; +#endif + uint32_t KeyLength; + uint8_t Nr; + uint8_t Nk; +}; + +void AES_init_ctx(struct AES_ctx* ctx, const uint8_t* key, uint32_t keylen); +#if (defined(CBC) && (CBC == 1)) || (defined(CTR) && (CTR == 1)) +void AES_init_ctx_iv(struct AES_ctx* ctx, const uint8_t* key, uint32_t keylen, const uint8_t* iv); +void AES_ctx_set_iv(struct AES_ctx* ctx, const uint8_t* iv); +#endif + +#if defined(ECB) && (ECB == 1) +// buffer size is exactly AES_BLOCKLEN bytes; +// you need only AES_init_ctx as IV is not used in ECB +// NB: ECB is considered insecure for most uses +void AES_ECB_encrypt(const struct AES_ctx* ctx, uint8_t* buf); +void AES_ECB_decrypt(const struct AES_ctx* ctx, uint8_t* buf); + +#endif // #if defined(ECB) && (ECB == !) + + +#if defined(CBC) && (CBC == 1) +// buffer size MUST be mutile of AES_BLOCKLEN; +// Suggest https://en.wikipedia.org/wiki/Padding_(cryptography)#PKCS7 for padding scheme +// NOTES: you need to set IV in ctx via AES_init_ctx_iv() or AES_ctx_set_iv() +// no IV should ever be reused with the same key +void AES_CBC_encrypt_buffer(struct AES_ctx* ctx, uint8_t* buf, uint32_t length); +void AES_CBC_decrypt_buffer(struct AES_ctx* ctx, uint8_t* buf, uint32_t length); + +#endif // #if defined(CBC) && (CBC == 1) + + +#if defined(CTR) && (CTR == 1) + +// Same function for encrypting as for decrypting. +// IV is incremented for every block, and used after encryption as XOR-compliment for output +// Suggesting https://en.wikipedia.org/wiki/Padding_(cryptography)#PKCS7 for padding scheme +// NOTES: you need to set IV in ctx with AES_init_ctx_iv() or AES_ctx_set_iv() +// no IV should ever be reused with the same key +void AES_CTR_xcrypt_buffer(struct AES_ctx* ctx, uint8_t* buf, uint32_t length); + +#endif // #if defined(CTR) && (CTR == 1) + + +#endif // _AES_H_