1 ! Copyright (C) 2013 Fred Alger
2 ! Some parts Copyright (C) 2008 Doug Coleman.
3 ! See http://factorcode.org/license.txt for BSD license.
4 USING: accessors arrays assocs combinators crypto.aes.utils
5 generalizations grouping kernel locals math math.bitwise
6 math.ranges memoize namespaces sequences sequences.private
10 CONSTANT: AES_BLOCK_SIZE 16
12 #! input block, state, output block -- 4 32-bit words
14 { 128 10 } #! aes-128 -- Key(4) Block(4) Rounds(10)
15 { 192 12 } #! aes-192 -- Key(6) Block(4) Rounds(12)
16 { 256 14 } #! aes-256 -- Key(8) Block(4) Rounds(14)
21 : (nrounds) ( byte-array -- rounds )
22 length 8 * FIPS-197 at ;
26 0x63 0x7c 0x77 0x7b 0xf2 0x6b 0x6f 0xc5
27 0x30 0x01 0x67 0x2b 0xfe 0xd7 0xab 0x76
28 0xca 0x82 0xc9 0x7d 0xfa 0x59 0x47 0xf0
29 0xad 0xd4 0xa2 0xaf 0x9c 0xa4 0x72 0xc0
30 0xb7 0xfd 0x93 0x26 0x36 0x3f 0xf7 0xcc
31 0x34 0xa5 0xe5 0xf1 0x71 0xd8 0x31 0x15
32 0x04 0xc7 0x23 0xc3 0x18 0x96 0x05 0x9a
33 0x07 0x12 0x80 0xe2 0xeb 0x27 0xb2 0x75
34 0x09 0x83 0x2c 0x1a 0x1b 0x6e 0x5a 0xa0
35 0x52 0x3b 0xd6 0xb3 0x29 0xe3 0x2f 0x84
36 0x53 0xd1 0x00 0xed 0x20 0xfc 0xb1 0x5b
37 0x6a 0xcb 0xbe 0x39 0x4a 0x4c 0x58 0xcf
38 0xd0 0xef 0xaa 0xfb 0x43 0x4d 0x33 0x85
39 0x45 0xf9 0x02 0x7f 0x50 0x3c 0x9f 0xa8
40 0x51 0xa3 0x40 0x8f 0x92 0x9d 0x38 0xf5
41 0xbc 0xb6 0xda 0x21 0x10 0xff 0xf3 0xd2
42 0xcd 0x0c 0x13 0xec 0x5f 0x97 0x44 0x17
43 0xc4 0xa7 0x7e 0x3d 0x64 0x5d 0x19 0x73
44 0x60 0x81 0x4f 0xdc 0x22 0x2a 0x90 0x88
45 0x46 0xee 0xb8 0x14 0xde 0x5e 0x0b 0xdb
46 0xe0 0x32 0x3a 0x0a 0x49 0x06 0x24 0x5c
47 0xc2 0xd3 0xac 0x62 0x91 0x95 0xe4 0x79
48 0xe7 0xc8 0x37 0x6d 0x8d 0xd5 0x4e 0xa9
49 0x6c 0x56 0xf4 0xea 0x65 0x7a 0xae 0x08
50 0xba 0x78 0x25 0x2e 0x1c 0xa6 0xb4 0xc6
51 0xe8 0xdd 0x74 0x1f 0x4b 0xbd 0x8b 0x8a
52 0x70 0x3e 0xb5 0x66 0x48 0x03 0xf6 0x0e
53 0x61 0x35 0x57 0xb9 0x86 0xc1 0x1d 0x9e
54 0xe1 0xf8 0x98 0x11 0x69 0xd9 0x8e 0x94
55 0x9b 0x1e 0x87 0xe9 0xce 0x55 0x28 0xdf
56 0x8c 0xa1 0x89 0x0d 0xbf 0xe6 0x42 0x68
57 0x41 0x99 0x2d 0x0f 0xb0 0x54 0xbb 0x16
60 : inv-sbox ( -- array )
62 dup 256 [ dup sbox nth rot set-nth ] with each-integer ;
64 #! applies sbox to each byte of word
65 : subword ( word -- word' )
66 [ gb0 sbox nth ] keep [ gb1 sbox nth ] keep
67 [ gb2 sbox nth ] keep gb3 sbox nth >ui32 ;
69 #! applies inverse sbox to each byte of word
70 : inv-subword ( word -- word' )
71 [ gb0 inv-sbox nth ] keep [ gb1 inv-sbox nth ] keep
72 [ gb2 inv-sbox nth ] keep gb3 inv-sbox nth >ui32 ;
74 : rotword ( n -- n ) 8 bitroll-32 ;
76 #! round constants, 2^n over GF(2^8)
79 0x00 0x01 0x02 0x04 0x08 0x10
80 0x20 0x40 0x80 0x1b 0x36
83 : (rcon-nth) ( n -- rcon[n] ) rcon nth 24 shift ;
85 #! Galois field product related
88 [ 0x80 bitand 0 = 0 0x1b ? ] bi bitxor 8 bits ;
96 a3 a1 a1 a2 >ui32 i T set-nth
97 a1 a1 a2 a3 >ui32 i 0x100 + T set-nth
98 a1 a2 a3 a1 >ui32 i 0x200 + T set-nth
99 a2 a3 a1 a1 >ui32 i 0x300 + T set-nth ;
101 MEMO:: t-table ( -- array )
103 dup 256 [ set-t ] with each-integer ;
105 #! generate inverse t-box
114 a8 a4 a2 bitxor bitxor :> ae
116 ab ad a9 ae >ui32 i D set-nth
117 ad a9 ae ab >ui32 i 0x100 + D set-nth
118 a9 ae ab ad >ui32 i 0x200 + D set-nth
119 ae ab ad a9 >ui32 i 0x300 + D set-nth ;
121 MEMO:: d-table ( -- array )
123 dup 256 [ set-d ] with each-integer ;
126 :: (transform) ( a0 a1 a2 a3 table -- word' )
128 [ 0x100 + ] [ 0x200 + ] [ 0x300 + ] tri*
129 [ table nth ] 4 napply
130 bitxor bitxor bitxor ; inline
132 : t-transform ( a0 a1 a2 a3 -- word' ) t-table (transform) ;
133 : d-transform ( a0 a1 a2 a3 -- word' ) d-table (transform) ;
136 #! expands an 128/192/256 bit key into an 176/208/240 byte schedule
138 SYMBOL: aes-expand-inner
139 HOOK: key-expand-round aes-expand-inner ( temp i -- temp' )
141 SINGLETON: aes-128-key
142 SINGLETON: aes-256-key
144 : (add-rcon) ( word rcon-ndx -- word' )
145 (rcon-nth) [ rotword subword ] dip bitxor ;
147 M: aes-128-key key-expand-round ( temp i -- temp' )
148 4 /mod 0 = swap and [ (add-rcon) ] when* ;
150 ERROR: aes-192-256-not-implemented ;
151 M: aes-256-key key-expand-round ( temp i -- temp' )
152 throw-aes-192-256-not-implemented ;
154 : (key-sched-round) ( output temp i -- output' )
156 [ dup 4th-from-end ] dip bitxor suffix! ; inline
158 : (sched-interval) ( K Nr -- seq )
159 [ length ] dip 1 + 4 * [a,b) ; #! over the interval Nk...Nb(Nr + 1)
161 : (init-round) ( out -- out temp quot )
166 6 > [ aes-256-key ] [ aes-128-key ] if
169 #! K -- input key (byte-array), Nr -- number of rounds
170 #! output: sched, Nb(Nr+1) byte key schedule
171 : (expand-enc-key) ( K Nr -- sched )
173 [ drop (init-round) ]
174 [ (sched-interval) ] 2bi
176 [ aes-expand-inner set ] dip
177 [ (key-sched-round) dup last ] each
181 TUPLE: aes-state nrounds key state ;
183 : <aes> ( nrounds key state -- aes-state ) \ aes-state boa ;
185 #! grabs the 4n...4(n+1) words of the key
186 : (key-at-nth-round) ( nth aes -- seq )
187 [ 4 * dup 4 + ] [ key>> ] bi* <slice> ;
190 HOOK: (expand-key) aes-strategy ( K Nr -- sched )
191 HOOK: (first-round) aes-strategy ( aes -- aes' )
192 HOOK: (counter) aes-strategy ( nrounds -- seq )
193 HOOK: (round) aes-strategy ( state -- )
194 HOOK: (add-key) aes-strategy ( aes -- aes' )
195 HOOK: (final-round) aes-strategy ( aes -- aes' )
197 SINGLETON: aes-decrypt
198 SINGLETON: aes-encrypt
201 #! rotates the 2nd row left by one element
202 #! rotates the 3rd row left by two elements
203 #! rotates the 4th row left by three elements
205 #! Kind of ugly because the algorithm is specified and
206 #! implemented in terms of columns. This approach is very
207 #! efficient in terms of execution and only requires one new
208 #! word to implement.
210 #! The alternative is to split into arrays of bytes, transpose,
211 #! rotate each row n times, transpose again, and then
212 #! smash them back into 4-byte words.
213 :: (shift-rows) ( c0 c1 c2 c3 -- c0' c1' c2' c3' )
214 c3 gb0 c2 gb1 c1 gb2 c0 gb3 >ui32 #! c0'
215 c0 gb0 c3 gb1 c2 gb2 c1 gb3 >ui32 #! c1'
216 c1 gb0 c0 gb1 c3 gb2 c2 gb3 >ui32 #! c2'
217 c2 gb0 c1 gb1 c0 gb2 c3 gb3 >ui32 ; #! c3'
219 :: (unshift-rows) ( c0 c1 c2 c3 -- c0' c1' c2' c3' )
220 c1 gb0 c2 gb1 c3 gb2 c0 gb3 >ui32 #! c0'
221 c2 gb0 c3 gb1 c0 gb2 c1 gb3 >ui32 #! c1'
222 c3 gb0 c0 gb1 c1 gb2 c2 gb3 >ui32 #! c2'
223 c0 gb0 c1 gb1 c2 gb2 c3 gb3 >ui32 ; #! c3'
225 : (add-round-key) ( key state -- state' )
226 4 [ bitxor ] unrolled-2map ;
228 : add-round-key ( aes n -- aes' )
229 over (key-at-nth-round) swap
230 [ (add-round-key) ] change-state ;
232 : add-final-round-key ( aes -- aes' )
233 dup nrounds>> add-round-key ;
235 : add-first-round-key ( aes -- aes' )
238 : aes-round ( state -- )
240 { [ first-diag t-transform ]
241 [ second-diag t-transform ]
242 [ third-diag t-transform ]
243 [ fourth-diag t-transform ] } 4 ncleave
247 : shift-rows ( state -- state' )
248 first4 (shift-rows) 4array ;
250 : unshift-rows ( state -- state' )
251 first4 (unshift-rows) 4array ;
253 : final-round ( state -- state' )
254 4 [ subword ] unrolled-map shift-rows ;
256 : (do-round) ( aes -- aes' )
257 [ state>> (round) ] keep ;
259 M: aes-encrypt (expand-key) (expand-enc-key) ;
260 M: aes-encrypt (first-round) add-first-round-key ;
261 M: aes-encrypt (counter) 0 swap (a,b) ;
262 M: aes-encrypt (round) aes-round ;
263 M: aes-encrypt (final-round) [ final-round ] change-state add-final-round-key ;
265 M:: aes-decrypt (expand-key) ( K Nr -- sched )
266 K Nr (expand-enc-key) dup length :> key-length
268 [ 4 >= ] [ key-length 4 - < ] bi and
269 [ subword ui32-rev> d-transform ]
273 M: aes-decrypt (first-round) ( aes -- aes' )
274 add-final-round-key ;
276 M: aes-decrypt (counter) ( nrounds -- seq ) 0 swap (a,b) <reversed> ;
277 M: aes-decrypt (final-round) ( aes -- aes' )
278 [ [ inv-subword ] map unshift-rows ] change-state
279 add-first-round-key ;
281 M: aes-decrypt (round) ( state -- )
283 { [ -first-diag d-transform ]
284 [ -fourth-diag d-transform ]
285 [ -third-diag d-transform ]
286 [ -second-diag d-transform ] } 4 ncleave
290 : (aes-crypt) ( aes -- aes' )
292 dup nrounds>> (counter)
293 [ [ (do-round) ] dip add-round-key drop ] with each
297 : (aes-expand-key) ( key -- nrounds expanded-key )
298 [ (nrounds) ] keep over (expand-key) ;
300 : (aes-crypt-block-inner) ( nrounds key block -- crypted-block )
301 <aes> (aes-crypt) state>> ;
303 : (aes-crypt-block) ( key block -- output-block )
304 [ (aes-expand-key) ] dip bytes>words (aes-crypt-block-inner) ;
308 : aes-encrypt-block ( key block -- output )
309 [ aes-encrypt aes-strategy set (aes-crypt-block) ] with-scope
310 [ ui32> 4array reverse ] map concat ;
312 : aes-decrypt-block ( key block -- output )
313 [ aes-decrypt aes-strategy set (aes-crypt-block) ] with-scope
314 [ ui32> 4array reverse ] map concat ;