--- /dev/null
+/* cast5.c */
+/*
+ This file is part of the AVR-Crypto-Lib.
+ Copyright (C) 2008 Daniel Otte (daniel.otte@rub.de)
+
+ This program is free software: you can redistribute it and/or modify
+ it under the terms of the GNU General Public License as published by
+ the Free Software Foundation, either version 3 of the License, or
+ (at your option) any later version.
+
+ This program is distributed in the hope that it will be useful,
+ but WITHOUT ANY WARRANTY; without even the implied warranty of
+ MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
+ GNU General Public License for more details.
+
+ You should have received a copy of the GNU General Public License
+ along with this program. If not, see <http://www.gnu.org/licenses/>.
+*/
+/*
+ * \file cast5.c
+ * \author Daniel Otte
+ * \email daniel.otte@rub.de
+ * \date 2006-07-26
+ * \par License:
+ * GPLv3 or later
+ * \brief Implementation of the CAST5 (aka CAST-128) cipher algorithm as described in RFC 2144
+ *
+ */
+
+ #include <stdint.h>
+ #include <string.h>
+ #include "cast5.h"
+ #include "config.h"
+ #include "debug.h"
+
+ #undef DEBUG
+
+ #ifdef DEBUG
+ #include "cli.h"
+ #endif
+
+#include "cast5-sbox.h"
+
+
+
+#define S5(x) pgm_read_dword(&s5[(x)])
+#define S6(x) pgm_read_dword(&s6[(x)])
+#define S7(x) pgm_read_dword(&s7[(x)])
+#define S8(x) pgm_read_dword(&s8[(x)])
+
+static
+void cast5_init_A(uint8_t *dest, uint8_t *src, bool bmode){
+ uint8_t mask = bmode?0x8:0;
+ *((uint32_t*)(&dest[0x0])) = *((uint32_t*)(&src[0x0^mask]))
+ ^ S5(src[0xD^mask]) ^ S6(src[0xF^mask])
+ ^ S7(src[0xC^mask]) ^ S8(src[0xE^mask])
+ ^ S7(src[0x8^mask]);
+ *((uint32_t*)(&dest[0x4])) = *((uint32_t*)(&src[0x8^mask]))
+ ^ S5(dest[0x0]) ^ S6(dest[0x2])
+ ^ S7(dest[0x1]) ^ S8(dest[0x3])
+ ^ S8(src[0xA^mask]);
+ *((uint32_t*)(&dest[0x8])) = *((uint32_t*)(&src[0xC^mask]))
+ ^ S5(dest[0x7]) ^ S6(dest[0x6])
+ ^ S7(dest[0x5]) ^ S8(dest[0x4])
+ ^ S5(src[0x9^mask]);
+ *((uint32_t*)(&dest[0xC])) = *((uint32_t*)(&src[0x4^mask]))
+ ^ S5(dest[0xA])
+ ^ S6(dest[0x9])
+ ^ S7(dest[0xB])
+ ^ S8(dest[0x8])
+ ^ S6(src[0xB^mask]);
+}
+
+static
+void cast5_init_M(uint8_t *dest, uint8_t *src, bool nmode, bool xmode){
+ uint8_t nmt[] = {0xB, 0xA, 0x9, 0x8,
+ 0xF, 0xE, 0xD, 0xC,
+ 0x3, 0x2, 0x1, 0x0,
+ 0x7, 0x6, 0x5, 0x4}; /* nmode table */
+ uint8_t xmt[4][4] = {{0x2, 0x6, 0x9, 0xC},
+ {0x8, 0xD, 0x3, 0x7},
+ {0x3, 0x7, 0x8, 0xD},
+ {0x9, 0xC, 0x2, 0x6}};
+ #define NMT(x) (src[nmode?nmt[(x)]:(x)])
+ #define XMT(x) (src[xmt[(xmode<<1) + nmode][(x)]])
+ *((uint32_t*)(&dest[0x0])) = S5(NMT(0x8)) ^ S6(NMT(0x9)) ^ S7(NMT(0x7)) ^ S8(NMT(0x6)) ^ S5(XMT(0));
+ *((uint32_t*)(&dest[0x4])) = S5(NMT(0xA)) ^ S6(NMT(0xB)) ^ S7(NMT(0x5)) ^ S8(NMT(0x4)) ^ S6(XMT(1));
+ *((uint32_t*)(&dest[0x8])) = S5(NMT(0xC)) ^ S6(NMT(0xD)) ^ S7(NMT(0x3)) ^ S8(NMT(0x2)) ^ S7(XMT(2));
+ *((uint32_t*)(&dest[0xC])) = S5(NMT(0xE)) ^ S6(NMT(0xF)) ^ S7(NMT(0x1)) ^ S8(NMT(0x0)) ^ S8(XMT(3));
+}
+
+#define S5B(x) pgm_read_byte(3+(uint8_t*)(&s5[(x)]))
+#define S6B(x) pgm_read_byte(3+(uint8_t*)(&s6[(x)]))
+#define S7B(x) pgm_read_byte(3+(uint8_t*)(&s7[(x)]))
+#define S8B(x) pgm_read_byte(3+(uint8_t*)(&s8[(x)]))
+
+static
+void cast5_init_rM(uint8_t *klo, uint8_t *khi, uint8_t offset, uint8_t *src, bool nmode, bool xmode){
+ uint8_t nmt[] = {0xB, 0xA, 0x9, 0x8, 0xF, 0xE, 0xD, 0xC, 0x3, 0x2, 0x1, 0x0, 0x7, 0x6, 0x5, 0x4}; /* nmode table */
+ uint8_t xmt[4][4] = {{0x2, 0x6, 0x9, 0xC}, {0x8, 0xD, 0x3, 0x7}, {0x3, 0x7, 0x8, 0xD}, {0x9, 0xC, 0x2, 0x6}};
+ uint8_t t, h=0;
+ t = S5B(NMT(0x8)) ^ S6B(NMT(0x9)) ^ S7B(NMT(0x7)) ^ S8B(NMT(0x6)) ^ S5B(XMT(0));
+ klo[offset*2] |= (t & 0x0f);
+ h |= (t&0x10); h>>=1;
+ t = S5B(NMT(0xA)) ^ S6B(NMT(0xB)) ^ S7B(NMT(0x5)) ^ S8B(NMT(0x4)) ^ S6B(XMT(1));
+ klo[offset*2] |= (t<<4) & 0xf0;
+ h |= t&0x10; h>>=1;
+ t = S5B(NMT(0xC)) ^ S6B(NMT(0xD)) ^ S7B(NMT(0x3)) ^ S8B(NMT(0x2)) ^ S7B(XMT(2));
+ klo[offset*2+1] |= t&0xf;
+ h |= t&0x10; h>>=1;
+ t = S5B(NMT(0xE)) ^ S6B(NMT(0xF)) ^ S7B(NMT(0x1)) ^ S8B(NMT(0x0)) ^ S8B(XMT(3));
+ klo[offset*2+1] |= t<<4;
+ h |= t&0x10; h >>=1;
+ #ifdef DEBUG
+ cli_putstr("\r\n\t h="); cli_hexdump(&h,1);
+ #endif
+ khi[offset>>1] |= h<<((offset&0x1)?4:0);
+}
+
+#define S_5X(s) pgm_read_dword(&s5[BPX[(s)]])
+#define S_6X(s) pgm_read_dword(&s6[BPX[(s)]])
+#define S_7X(s) pgm_read_dword(&s7[BPX[(s)]])
+#define S_8X(s) pgm_read_dword(&s8[BPX[(s)]])
+
+#define S_5Z(s) pgm_read_dword(&s5[BPZ[(s)]])
+#define S_6Z(s) pgm_read_dword(&s6[BPZ[(s)]])
+#define S_7Z(s) pgm_read_dword(&s7[BPZ[(s)]])
+#define S_8Z(s) pgm_read_dword(&s8[BPZ[(s)]])
+
+
+
+
+void cast5_init(const void* key, uint16_t keylength_b, cast5_ctx_t* s){
+ /* we migth return if the key is valid and if setup was successful */
+ uint32_t x[4], z[4];
+ #define BPX ((uint8_t*)&(x[0]))
+ #define BPZ ((uint8_t*)&(z[0]))
+ s->shortkey = (keylength_b<=80);
+ /* littel endian only! */
+ memset(&(x[0]), 0 ,16); /* set x to zero */
+ if(keylength_b > 128)
+ keylength_b=128;
+ memcpy(&(x[0]), key, (keylength_b+7)/8);
+
+
+ /* todo: merge a and b and compress the whole stuff */
+ /***** A *****/
+ cast5_init_A((uint8_t*)(&z[0]), (uint8_t*)(&x[0]), false);
+ /***** M *****/
+ cast5_init_M((uint8_t*)(&(s->mask[0])), (uint8_t*)(&z[0]), false, false);
+ /***** B *****/
+ cast5_init_A((uint8_t*)(&x[0]), (uint8_t*)(&z[0]), true);
+ /***** N *****/
+ cast5_init_M((uint8_t*)(&(s->mask[4])), (uint8_t*)(&x[0]), true, false);
+ /***** A *****/
+ cast5_init_A((uint8_t*)(&z[0]), (uint8_t*)(&x[0]), false);
+ /***** N' *****/
+ cast5_init_M((uint8_t*)(&(s->mask[8])), (uint8_t*)(&z[0]), true, true);
+ /***** B *****/
+ cast5_init_A((uint8_t*)(&x[0]), (uint8_t*)(&z[0]), true);
+ /***** M' *****/
+ cast5_init_M((uint8_t*)(&(s->mask[12])), (uint8_t*)(&x[0]), false, true);
+
+ /* that were the masking keys, now the rotation keys */
+ /* set the keys to zero */
+ memset(&(s->rotl[0]),0,8);
+ s->roth[0]=s->roth[1]=0;
+ /***** A *****/
+ cast5_init_A((uint8_t*)(&z[0]), (uint8_t*)(&x[0]), false);
+ /***** M *****/
+ cast5_init_rM(&(s->rotl[0]), &(s->roth[0]), 0, (uint8_t*)(&z[0]), false, false);
+ /***** B *****/
+ cast5_init_A((uint8_t*)(&x[0]), (uint8_t*)(&z[0]), true);
+ /***** N *****/
+ cast5_init_rM(&(s->rotl[0]), &(s->roth[0]), 1, (uint8_t*)(&x[0]), true, false);
+ /***** A *****/
+ cast5_init_A((uint8_t*)(&z[0]), (uint8_t*)(&x[0]), false);
+ /***** N' *****/
+ cast5_init_rM(&(s->rotl[0]), &(s->roth[0]), 2, (uint8_t*)(&z[0]), true, true);
+ /***** B *****/
+ cast5_init_A((uint8_t*)(&x[0]), (uint8_t*)(&z[0]), true);
+ /***** M' *****/
+ cast5_init_rM(&(s->rotl[0]), &(s->roth[0]), 3, (uint8_t*)(&x[0]), false, true);
+ /* done ;-) */
+}
+
+
+
+/********************************************************************************************************/
+
+#define ROTL32(a,n) ((a)<<(n) | (a)>>(32-(n)))
+#define CHANGE_ENDIAN32(x) ((x)<<24 | (x)>>24 | ((x)&0xff00)<<8 | ((x)&0xff0000)>>8 )
+
+typedef uint32_t cast5_f_t(uint32_t,uint32_t,uint8_t);
+
+#define IA 3
+#define IB 2
+#define IC 1
+#define ID 0
+
+static
+uint32_t cast5_f1(uint32_t d, uint32_t m, uint8_t r){
+ uint32_t t;
+ t = ROTL32((d + m),r);
+#ifdef DEBUG
+ uint32_t ia,ib,ic,id;
+ cli_putstr("\r\n f1("); cli_hexdump(&d, 4); cli_putc(',');
+ cli_hexdump(&m , 4); cli_putc(','); cli_hexdump(&r, 1);cli_putstr("): I=");
+ cli_hexdump(&t, 4);
+ ia = pgm_read_dword(&s1[((uint8_t*)&t)[IA]] );
+ ib = pgm_read_dword(&s2[((uint8_t*)&t)[IB]] );
+ ic = pgm_read_dword(&s3[((uint8_t*)&t)[IC]] );
+ id = pgm_read_dword(&s4[((uint8_t*)&t)[ID]] );
+ cli_putstr("\r\n\tIA="); cli_hexdump(&ia, 4);
+ cli_putstr("\r\n\tIB="); cli_hexdump(&ib, 4);
+ cli_putstr("\r\n\tIC="); cli_hexdump(&ic, 4);
+ cli_putstr("\r\n\tID="); cli_hexdump(&id, 4);
+
+ return (((ia ^ ib) - ic) + id);
+
+#else
+
+ return ((( pgm_read_dword(&s1[((uint8_t*)&t)[IA]])
+ ^ pgm_read_dword(&s2[((uint8_t*)&t)[IB]]) )
+ - pgm_read_dword(&s3[((uint8_t*)&t)[IC]]) )
+ + pgm_read_dword(&s4[((uint8_t*)&t)[ID]]) );
+
+#endif
+}
+
+static
+uint32_t cast5_f2(uint32_t d, uint32_t m, uint8_t r){
+ uint32_t t;
+ t = ROTL32((d ^ m),r);
+#ifdef DEBUG
+ uint32_t ia,ib,ic,id;
+ cli_putstr("\r\n f2("); cli_hexdump(&d, 4); cli_putc(',');
+ cli_hexdump(&m , 4); cli_putc(','); cli_hexdump(&r, 1);cli_putstr("): I=");
+ cli_hexdump(&t, 4);
+
+ ia = pgm_read_dword(&s1[((uint8_t*)&t)[IA]] );
+ ib = pgm_read_dword(&s2[((uint8_t*)&t)[IB]] );
+ ic = pgm_read_dword(&s3[((uint8_t*)&t)[IC]] );
+ id = pgm_read_dword(&s4[((uint8_t*)&t)[ID]] );
+
+ cli_putstr("\r\n\tIA="); cli_hexdump(&ia, 4);
+ cli_putstr("\r\n\tIB="); cli_hexdump(&ib, 4);
+ cli_putstr("\r\n\tIC="); cli_hexdump(&ic, 4);
+ cli_putstr("\r\n\tID="); cli_hexdump(&id, 4);
+
+ return (((ia - ib) + ic) ^ id);
+#else
+
+ return ((( pgm_read_dword(&s1[((uint8_t*)&t)[IA]])
+ - pgm_read_dword(&s2[((uint8_t*)&t)[IB]]) )
+ + pgm_read_dword(&s3[((uint8_t*)&t)[IC]]) )
+ ^ pgm_read_dword(&s4[((uint8_t*)&t)[ID]]) );
+
+#endif
+}
+
+static
+uint32_t cast5_f3(uint32_t d, uint32_t m, uint8_t r){
+ uint32_t t;
+ t = ROTL32((m - d),r);
+
+#ifdef DEBUG
+ uint32_t ia,ib,ic,id;
+
+ cli_putstr("\r\n f3("); cli_hexdump(&d, 4); cli_putc(',');
+ cli_hexdump(&m , 4); cli_putc(','); cli_hexdump(&r, 1);cli_putstr("): I=");
+ cli_hexdump(&t, 4);
+
+ ia = pgm_read_dword(&s1[((uint8_t*)&t)[IA]] );
+ ib = pgm_read_dword(&s2[((uint8_t*)&t)[IB]] );
+ ic = pgm_read_dword(&s3[((uint8_t*)&t)[IC]] );
+ id = pgm_read_dword(&s4[((uint8_t*)&t)[ID]] );
+
+ cli_putstr("\r\n\tIA="); cli_hexdump(&ia, 4);
+ cli_putstr("\r\n\tIB="); cli_hexdump(&ib, 4);
+ cli_putstr("\r\n\tIC="); cli_hexdump(&ic, 4);
+ cli_putstr("\r\n\tID="); cli_hexdump(&id, 4);
+ return (((ia + ib) ^ ic) - id);
+#else
+ return (( pgm_read_dword(&s1[((uint8_t*)&t)[IA]] )
+ + pgm_read_dword(&s2[((uint8_t*)&t)[IB]] ))
+ ^ pgm_read_dword(&s3[((uint8_t*)&t)[IC]] ))
+ - pgm_read_dword(&s4[((uint8_t*)&t)[ID]] );
+
+#endif
+}
+
+/******************************************************************************/
+
+void cast5_enc(void* block, const cast5_ctx_t *s){
+ uint32_t l,r, x, y;
+ uint8_t i;
+ cast5_f_t* f[]={cast5_f1,cast5_f2,cast5_f3};
+ l=((uint32_t*)block)[0];
+ r=((uint32_t*)block)[1];
+// cli_putstr("\r\n round[-1] = ");
+// cli_hexdump(&r, 4);
+ for (i=0;i<(s->shortkey?12:16);++i){
+ x = r;
+ y = (f[i%3])(CHANGE_ENDIAN32(r), CHANGE_ENDIAN32(s->mask[i]),
+ (((s->roth[i>>3]) & (1<<(i&0x7)))?0x10:0x00)
+ + ( ((s->rotl[i>>1])>>((i&1)?4:0)) & 0x0f) );
+ r = l ^ CHANGE_ENDIAN32(y);
+// cli_putstr("\r\n round["); DEBUG_B(i); cli_putstr("] = ");
+// cli_hexdump(&r, 4);
+ l = x;
+ }
+ ((uint32_t*)block)[0]=r;
+ ((uint32_t*)block)[1]=l;
+}
+
+/******************************************************************************/
+
+void cast5_dec(void* block, const cast5_ctx_t *s){
+ uint32_t l,r, x, y;
+ int8_t i, rounds;
+ cast5_f_t* f[]={cast5_f1,cast5_f2,cast5_f3};
+ l=((uint32_t*)block)[0];
+ r=((uint32_t*)block)[1];
+ rounds = (s->shortkey?12:16);
+ for (i=rounds-1; i>=0 ;--i){
+ x = r;
+ y = (f[i%3])(CHANGE_ENDIAN32(r), CHANGE_ENDIAN32(s->mask[i]),
+ (((s->roth[i>>3]) & (1<<(i&0x7)))?0x10:0x00)
+ + ( ((s->rotl[i>>1])>>((i&1)?4:0)) & 0x0f) );
+ r = l ^ CHANGE_ENDIAN32(y);
+ l = x;
+ }
+ ((uint32_t*)block)[0]=r;
+ ((uint32_t*)block)[1]=l;
+}
+
+
+/******************************************************************************/
+
+
+
+
projects / avr-crypto-lib.git / blobdiff