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ruanhaishen
Tiny AES C
Commits
c26fb6a5
Commit
c26fb6a5
authored
Jun 05, 2017
by
Matteo Brichese
Browse files
adding Key Expansion for AES192 and AES256
parent
200274e3
Changes
2
Show whitespace changes
Inline
Side-by-side
aes.c
View file @
c26fb6a5
...
@@ -37,18 +37,28 @@ NOTE: String length must be evenly divisible by 16byte (str_len % 16 == 0)
...
@@ -37,18 +37,28 @@ NOTE: String length must be evenly divisible by 16byte (str_len % 16 == 0)
#include <string.h> // CBC mode, for memset
#include <string.h> // CBC mode, for memset
#include "aes.h"
#include "aes.h"
/*****************************************************************************/
/*****************************************************************************/
/* Defines: */
/* Defines: */
/*****************************************************************************/
/*****************************************************************************/
// The number of columns comprising a state in AES. This is a constant in AES. Value=4
// The number of columns comprising a state in AES. This is a constant in AES. Value=4
#define Nb 4
#define Nb 4
// The number of 32 bit words in a key.
#define Nk 4
#ifdef AES256
// Key length in bytes [128 bit]
#define Nk 8
#define KEYLEN 16
#define KEYLEN 32
// The number of rounds in AES Cipher.
#define Nr 14
#define Nr 10
#define keyExpSize 240
#elif defined(AES192)
#define Nk 6
#define KEYLEN 24
#define Nr 12
#define keyExpSize 208
#else
#define Nk 4 // The number of 32 bit words in a key.
#define KEYLEN 16 // Key length in bytes
#define Nr 10 // The number of rounds in AES Cipher.
#define keyExpSize 176
#endif
// jcallan@github points out that declaring Multiply as a function
// jcallan@github points out that declaring Multiply as a function
// reduces code size considerably with the Keil ARM compiler.
// reduces code size considerably with the Keil ARM compiler.
...
@@ -66,7 +76,7 @@ typedef uint8_t state_t[4][4];
...
@@ -66,7 +76,7 @@ typedef uint8_t state_t[4][4];
static
state_t
*
state
;
static
state_t
*
state
;
// The array that stores the round keys.
// The array that stores the round keys.
static
uint8_t
RoundKey
[
176
];
static
uint8_t
RoundKey
[
keyExpSize
];
// The Key input to the AES Program
// The Key input to the AES Program
static
const
uint8_t
*
Key
;
static
const
uint8_t
*
Key
;
...
@@ -116,11 +126,9 @@ static const uint8_t rsbox[256] =
...
@@ -116,11 +126,9 @@ static const uint8_t rsbox[256] =
0xa0
,
0xe0
,
0x3b
,
0x4d
,
0xae
,
0x2a
,
0xf5
,
0xb0
,
0xc8
,
0xeb
,
0xbb
,
0x3c
,
0x83
,
0x53
,
0x99
,
0x61
,
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
};
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
// The round constant word array, Rcon[i], contains the values given by
// x to th e power (i-1) being powers of x (x is denoted as {02}) in the field GF(2^8)
// x to th e power (i-1) being powers of x (x is denoted as {02}) in the field GF(2^8)
// Note that i starts at 1, not 0).
static
const
uint8_t
Rcon
[
256
]
=
{
static
const
uint8_t
Rcon
[
255
]
=
{
0x8d
,
0x01
,
0x02
,
0x04
,
0x08
,
0x10
,
0x20
,
0x40
,
0x80
,
0x1b
,
0x36
,
0x6c
,
0xd8
,
0xab
,
0x4d
,
0x9a
,
0x8d
,
0x01
,
0x02
,
0x04
,
0x08
,
0x10
,
0x20
,
0x40
,
0x80
,
0x1b
,
0x36
,
0x6c
,
0xd8
,
0xab
,
0x4d
,
0x9a
,
0x2f
,
0x5e
,
0xbc
,
0x63
,
0xc6
,
0x97
,
0x35
,
0x6a
,
0xd4
,
0xb3
,
0x7d
,
0xfa
,
0xef
,
0xc5
,
0x91
,
0x39
,
0x2f
,
0x5e
,
0xbc
,
0x63
,
0xc6
,
0x97
,
0x35
,
0x6a
,
0xd4
,
0xb3
,
0x7d
,
0xfa
,
0xef
,
0xc5
,
0x91
,
0x39
,
0x72
,
0xe4
,
0xd3
,
0xbd
,
0x61
,
0xc2
,
0x9f
,
0x25
,
0x4a
,
0x94
,
0x33
,
0x66
,
0xcc
,
0x83
,
0x1d
,
0x3a
,
0x72
,
0xe4
,
0xd3
,
0xbd
,
0x61
,
0xc2
,
0x9f
,
0x25
,
0x4a
,
0x94
,
0x33
,
0x66
,
0xcc
,
0x83
,
0x1d
,
0x3a
,
...
@@ -136,7 +144,7 @@ static const uint8_t Rcon[255] = {
...
@@ -136,7 +144,7 @@ static const uint8_t Rcon[255] = {
0x25
,
0x4a
,
0x94
,
0x33
,
0x66
,
0xcc
,
0x83
,
0x1d
,
0x3a
,
0x74
,
0xe8
,
0xcb
,
0x8d
,
0x01
,
0x02
,
0x04
,
0x25
,
0x4a
,
0x94
,
0x33
,
0x66
,
0xcc
,
0x83
,
0x1d
,
0x3a
,
0x74
,
0xe8
,
0xcb
,
0x8d
,
0x01
,
0x02
,
0x04
,
0x08
,
0x10
,
0x20
,
0x40
,
0x80
,
0x1b
,
0x36
,
0x6c
,
0xd8
,
0xab
,
0x4d
,
0x9a
,
0x2f
,
0x5e
,
0xbc
,
0x63
,
0x08
,
0x10
,
0x20
,
0x40
,
0x80
,
0x1b
,
0x36
,
0x6c
,
0xd8
,
0xab
,
0x4d
,
0x9a
,
0x2f
,
0x5e
,
0xbc
,
0x63
,
0xc6
,
0x97
,
0x35
,
0x6a
,
0xd4
,
0xb3
,
0x7d
,
0xfa
,
0xef
,
0xc5
,
0x91
,
0x39
,
0x72
,
0xe4
,
0xd3
,
0xbd
,
0xc6
,
0x97
,
0x35
,
0x6a
,
0xd4
,
0xb3
,
0x7d
,
0xfa
,
0xef
,
0xc5
,
0x91
,
0x39
,
0x72
,
0xe4
,
0xd3
,
0xbd
,
0x61
,
0xc2
,
0x9f
,
0x25
,
0x4a
,
0x94
,
0x33
,
0x66
,
0xcc
,
0x83
,
0x1d
,
0x3a
,
0x74
,
0xe8
,
0xcb
};
0x61
,
0xc2
,
0x9f
,
0x25
,
0x4a
,
0x94
,
0x33
,
0x66
,
0xcc
,
0x83
,
0x1d
,
0x3a
,
0x74
,
0xe8
,
0xcb
,
0x8d
};
/*****************************************************************************/
/*****************************************************************************/
...
@@ -155,7 +163,7 @@ static uint8_t getSBoxInvert(uint8_t num)
...
@@ -155,7 +163,7 @@ static uint8_t getSBoxInvert(uint8_t num)
// This function produces Nb(Nr+1) round keys. The round keys are used in each round to decrypt the states.
// This function produces Nb(Nr+1) round keys. The round keys are used in each round to decrypt the states.
static
void
KeyExpansion
(
void
)
static
void
KeyExpansion
(
void
)
{
{
uint32_t
i
,
j
,
k
;
uint32_t
i
,
k
;
uint8_t
tempa
[
4
];
// Used for the column/row operations
uint8_t
tempa
[
4
];
// Used for the column/row operations
// The first round key is the key itself.
// The first round key is the key itself.
...
@@ -168,15 +176,19 @@ static void KeyExpansion(void)
...
@@ -168,15 +176,19 @@ static void KeyExpansion(void)
}
}
// All other round keys are found from the previous round keys.
// All other round keys are found from the previous round keys.
for
(;
(
i
<
(
Nb
*
(
Nr
+
1
)));
++
i
)
//i == Nk
for
(
i
=
Nk
;
i
<
Nb
*
(
Nr
+
1
);
++
i
)
{
{
for
(
j
=
0
;
j
<
4
;
++
j
)
{
{
tempa
[
j
]
=
RoundKey
[(
i
-
1
)
*
4
+
j
];
tempa
[
0
]
=
RoundKey
[(
i
-
1
)
*
4
+
0
];
tempa
[
1
]
=
RoundKey
[(
i
-
1
)
*
4
+
1
];
tempa
[
2
]
=
RoundKey
[(
i
-
1
)
*
4
+
2
];
tempa
[
3
]
=
RoundKey
[(
i
-
1
)
*
4
+
3
];
}
}
if
(
i
%
Nk
==
0
)
if
(
i
%
Nk
==
0
)
{
{
// This function
rotate
s the 4 bytes in a word to the left once.
// This function
shift
s the 4 bytes in a word to the left once.
// [a0,a1,a2,a3] becomes [a1,a2,a3,a0]
// [a0,a1,a2,a3] becomes [a1,a2,a3,a0]
// Function RotWord()
// Function RotWord()
...
@@ -201,7 +213,8 @@ static void KeyExpansion(void)
...
@@ -201,7 +213,8 @@ static void KeyExpansion(void)
tempa
[
0
]
=
tempa
[
0
]
^
Rcon
[
i
/
Nk
];
tempa
[
0
]
=
tempa
[
0
]
^
Rcon
[
i
/
Nk
];
}
}
else
if
(
Nk
>
6
&&
i
%
Nk
==
4
)
#ifdef AES256
if
(
i
%
Nk
==
4
)
{
{
// Function Subword()
// Function Subword()
{
{
...
@@ -211,6 +224,7 @@ static void KeyExpansion(void)
...
@@ -211,6 +224,7 @@ static void KeyExpansion(void)
tempa
[
3
]
=
getSBoxValue
(
tempa
[
3
]);
tempa
[
3
]
=
getSBoxValue
(
tempa
[
3
]);
}
}
}
}
#endif
RoundKey
[
i
*
4
+
0
]
=
RoundKey
[(
i
-
Nk
)
*
4
+
0
]
^
tempa
[
0
];
RoundKey
[
i
*
4
+
0
]
=
RoundKey
[(
i
-
Nk
)
*
4
+
0
]
^
tempa
[
0
];
RoundKey
[
i
*
4
+
1
]
=
RoundKey
[(
i
-
Nk
)
*
4
+
1
]
^
tempa
[
1
];
RoundKey
[
i
*
4
+
1
]
=
RoundKey
[(
i
-
Nk
)
*
4
+
1
]
^
tempa
[
1
];
RoundKey
[
i
*
4
+
2
]
=
RoundKey
[(
i
-
Nk
)
*
4
+
2
]
^
tempa
[
2
];
RoundKey
[
i
*
4
+
2
]
=
RoundKey
[(
i
-
Nk
)
*
4
+
2
]
^
tempa
[
2
];
...
@@ -451,7 +465,7 @@ static void BlockCopy(uint8_t* output, const uint8_t* input)
...
@@ -451,7 +465,7 @@ static void BlockCopy(uint8_t* output, const uint8_t* input)
#if defined(ECB) && ECB
#if defined(ECB) && ECB
void
AES
128
_ECB_encrypt
(
const
uint8_t
*
input
,
const
uint8_t
*
key
,
uint8_t
*
output
)
void
AES_ECB_encrypt
(
const
uint8_t
*
input
,
const
uint8_t
*
key
,
uint8_t
*
output
)
{
{
// Copy input to output, and work in-memory on output
// Copy input to output, and work in-memory on output
BlockCopy
(
output
,
input
);
BlockCopy
(
output
,
input
);
...
@@ -464,7 +478,7 @@ void AES128_ECB_encrypt(const uint8_t* input, const uint8_t* key, uint8_t* outpu
...
@@ -464,7 +478,7 @@ void AES128_ECB_encrypt(const uint8_t* input, const uint8_t* key, uint8_t* outpu
Cipher
();
Cipher
();
}
}
void
AES
128
_ECB_decrypt
(
const
uint8_t
*
input
,
const
uint8_t
*
key
,
uint8_t
*
output
)
void
AES_ECB_decrypt
(
const
uint8_t
*
input
,
const
uint8_t
*
key
,
uint8_t
*
output
)
{
{
// Copy input to output, and work in-memory on output
// Copy input to output, and work in-memory on output
BlockCopy
(
output
,
input
);
BlockCopy
(
output
,
input
);
...
@@ -496,7 +510,7 @@ static void XorWithIv(uint8_t* buf)
...
@@ -496,7 +510,7 @@ static void XorWithIv(uint8_t* buf)
}
}
}
}
void
AES
128
_CBC_encrypt_buffer
(
uint8_t
*
output
,
uint8_t
*
input
,
uint32_t
length
,
const
uint8_t
*
key
,
const
uint8_t
*
iv
)
void
AES_CBC_encrypt_buffer
(
uint8_t
*
output
,
uint8_t
*
input
,
uint32_t
length
,
const
uint8_t
*
key
,
const
uint8_t
*
iv
)
{
{
uintptr_t
i
;
uintptr_t
i
;
uint8_t
remainders
=
length
%
KEYLEN
;
/* Remaining bytes in the last non-full block */
uint8_t
remainders
=
length
%
KEYLEN
;
/* Remaining bytes in the last non-full block */
...
@@ -536,7 +550,7 @@ void AES128_CBC_encrypt_buffer(uint8_t* output, uint8_t* input, uint32_t length,
...
@@ -536,7 +550,7 @@ void AES128_CBC_encrypt_buffer(uint8_t* output, uint8_t* input, uint32_t length,
}
}
}
}
void
AES
128
_CBC_decrypt_buffer
(
uint8_t
*
output
,
uint8_t
*
input
,
uint32_t
length
,
const
uint8_t
*
key
,
const
uint8_t
*
iv
)
void
AES_CBC_decrypt_buffer
(
uint8_t
*
output
,
uint8_t
*
input
,
uint32_t
length
,
const
uint8_t
*
key
,
const
uint8_t
*
iv
)
{
{
uintptr_t
i
;
uintptr_t
i
;
uint8_t
remainders
=
length
%
KEYLEN
;
/* Remaining bytes in the last non-full block */
uint8_t
remainders
=
length
%
KEYLEN
;
/* Remaining bytes in the last non-full block */
...
@@ -577,7 +591,4 @@ void AES128_CBC_decrypt_buffer(uint8_t* output, uint8_t* input, uint32_t length,
...
@@ -577,7 +591,4 @@ void AES128_CBC_decrypt_buffer(uint8_t* output, uint8_t* input, uint32_t length,
}
}
}
}
#endif // #if defined(CBC) && CBC
#endif // #if defined(CBC) && CBC
aes.h
View file @
c26fb6a5
...
@@ -19,22 +19,20 @@
...
@@ -19,22 +19,20 @@
#endif
#endif
#if defined(ECB) && ECB
#if defined(ECB) && ECB
void
AES
128
_ECB_encrypt
(
const
uint8_t
*
input
,
const
uint8_t
*
key
,
uint8_t
*
output
);
void
AES_ECB_encrypt
(
const
uint8_t
*
input
,
const
uint8_t
*
key
,
uint8_t
*
output
);
void
AES
128
_ECB_decrypt
(
const
uint8_t
*
input
,
const
uint8_t
*
key
,
uint8_t
*
output
);
void
AES_ECB_decrypt
(
const
uint8_t
*
input
,
const
uint8_t
*
key
,
uint8_t
*
output
);
#endif // #if defined(ECB) && ECB
#endif // #if defined(ECB) && ECB
#if defined(CBC) && CBC
#if defined(CBC) && CBC
void
AES
128
_CBC_encrypt_buffer
(
uint8_t
*
output
,
uint8_t
*
input
,
uint32_t
length
,
const
uint8_t
*
key
,
const
uint8_t
*
iv
);
void
AES_CBC_encrypt_buffer
(
uint8_t
*
output
,
uint8_t
*
input
,
uint32_t
length
,
const
uint8_t
*
key
,
const
uint8_t
*
iv
);
void
AES
128
_CBC_decrypt_buffer
(
uint8_t
*
output
,
uint8_t
*
input
,
uint32_t
length
,
const
uint8_t
*
key
,
const
uint8_t
*
iv
);
void
AES_CBC_decrypt_buffer
(
uint8_t
*
output
,
uint8_t
*
input
,
uint32_t
length
,
const
uint8_t
*
key
,
const
uint8_t
*
iv
);
#endif // #if defined(CBC) && CBC
#endif // #if defined(CBC) && CBC
#endif //_AES_H_
#endif //_AES_H_
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