kernel/arch/powerpc/crypto/aes-spe-keys.S

   1 /*
   2  * Key handling functions for PPC AES implementation
   3  *
   4  * Copyright (c) 2015 Markus Stockhausen <stockhausen@collogia.de>
   5  *
   6  * This program is free software; you can redistribute it and/or modify it
   7  * under the terms of the GNU General Public License as published by the Free
   8  * Software Foundation; either version 2 of the License, or (at your option)
   9  * any later version.
  10  *
  11  */
  12
  13 #include <asm/ppc_asm.h>
  14
  15 #ifdef __BIG_ENDIAN__
  16 #define LOAD_KEY(d, s, off) \
  17         lwz             d,off(s);
  18 #else
  19 #define LOAD_KEY(d, s, off) \
  20         li              r0,off; \
  21         lwbrx           d,s,r0;
  22 #endif
  23
  24 #define INITIALIZE_KEY \
  25         stwu            r1,-32(r1);     /* create stack frame           */ \
  26         stw             r14,8(r1);      /* save registers               */ \
  27         stw             r15,12(r1);                                        \
  28         stw             r16,16(r1);
  29
  30 #define FINALIZE_KEY \
  31         lwz             r14,8(r1);      /* restore registers            */ \
  32         lwz             r15,12(r1);                                        \
  33         lwz             r16,16(r1);                                        \
  34         xor             r5,r5,r5;       /* clear sensitive data         */ \
  35         xor             r6,r6,r6;                                          \
  36         xor             r7,r7,r7;                                          \
  37         xor             r8,r8,r8;                                          \
  38         xor             r9,r9,r9;                                          \
  39         xor             r10,r10,r10;                                       \
  40         xor             r11,r11,r11;                                       \
  41         xor             r12,r12,r12;                                       \
  42         addi            r1,r1,32;       /* cleanup stack                */
  43
  44 #define LS_BOX(r, t1, t2) \
  45         lis             t2,PPC_AES_4K_ENCTAB@h;                            \
  46         ori             t2,t2,PPC_AES_4K_ENCTAB@l;                         \
  47         rlwimi          t2,r,4,20,27;                                      \
  48         lbz             t1,8(t2);                                          \
  49         rlwimi          r,t1,0,24,31;                                      \
  50         rlwimi          t2,r,28,20,27;                                     \
  51         lbz             t1,8(t2);                                          \
  52         rlwimi          r,t1,8,16,23;                                      \
  53         rlwimi          t2,r,20,20,27;                                     \
  54         lbz             t1,8(t2);                                          \
  55         rlwimi          r,t1,16,8,15;                                      \
  56         rlwimi          t2,r,12,20,27;                                     \
  57         lbz             t1,8(t2);                                          \
  58         rlwimi          r,t1,24,0,7;
  59
  60 #define GF8_MUL(out, in, t1, t2) \
  61         lis t1,0x8080;                  /* multiplication in GF8        */ \
  62         ori t1,t1,0x8080;                                                  \
  63         and t1,t1,in;                                                      \
  64         srwi t1,t1,7;                                                      \
  65         mulli t1,t1,0x1b;                                                  \
  66         lis t2,0x7f7f;                                                     \
  67         ori t2,t2,0x7f7f;                                                  \
  68         and t2,t2,in;                                                      \
  69         slwi t2,t2,1;                                                      \
  70         xor out,t1,t2;
  71
  72 /*
  73  * ppc_expand_key_128(u32 *key_enc, const u8 *key)
  74  *
  75  * Expand 128 bit key into 176 bytes encryption key. It consists of
  76  * key itself plus 10 rounds with 16 bytes each
  77  *
  78  */
  79 _GLOBAL(ppc_expand_key_128)
  80         INITIALIZE_KEY
  81         LOAD_KEY(r5,r4,0)
  82         LOAD_KEY(r6,r4,4)
  83         LOAD_KEY(r7,r4,8)
  84         LOAD_KEY(r8,r4,12)
  85         stw             r5,0(r3)        /* key[0..3] = input data       */
  86         stw             r6,4(r3)
  87         stw             r7,8(r3)
  88         stw             r8,12(r3)
  89         li              r16,10          /* 10 expansion rounds          */
  90         lis             r0,0x0100       /* RCO(1)                       */
  91 ppc_expand_128_loop:
  92         addi            r3,r3,16
  93         mr              r14,r8          /* apply LS_BOX to 4th temp     */
  94         rotlwi          r14,r14,8
  95         LS_BOX(r14, r15, r4)
  96         xor             r14,r14,r0
  97         xor             r5,r5,r14       /* xor next 4 keys              */
  98         xor             r6,r6,r5
  99         xor             r7,r7,r6
 100         xor             r8,r8,r7
 101         stw             r5,0(r3)        /* store next 4 keys            */
 102         stw             r6,4(r3)
 103         stw             r7,8(r3)
 104         stw             r8,12(r3)
 105         GF8_MUL(r0, r0, r4, r14)        /* multiply RCO by 2 in GF      */
 106         subi            r16,r16,1
 107         cmpwi           r16,0
 108         bt              eq,ppc_expand_128_end
 109         b               ppc_expand_128_loop
 110 ppc_expand_128_end:
 111         FINALIZE_KEY
 112         blr
 113
 114 /*
 115  * ppc_expand_key_192(u32 *key_enc, const u8 *key)
 116  *
 117  * Expand 192 bit key into 208 bytes encryption key. It consists of key
 118  * itself plus 12 rounds with 16 bytes each
 119  *
 120  */
 121 _GLOBAL(ppc_expand_key_192)
 122         INITIALIZE_KEY
 123         LOAD_KEY(r5,r4,0)
 124         LOAD_KEY(r6,r4,4)
 125         LOAD_KEY(r7,r4,8)
 126         LOAD_KEY(r8,r4,12)
 127         LOAD_KEY(r9,r4,16)
 128         LOAD_KEY(r10,r4,20)
 129         stw             r5,0(r3)
 130         stw             r6,4(r3)
 131         stw             r7,8(r3)
 132         stw             r8,12(r3)
 133         stw             r9,16(r3)
 134         stw             r10,20(r3)
 135         li              r16,8           /* 8 expansion rounds           */
 136         lis             r0,0x0100       /* RCO(1)                       */
 137 ppc_expand_192_loop:
 138         addi            r3,r3,24
 139         mr              r14,r10         /* apply LS_BOX to 6th temp     */
 140         rotlwi          r14,r14,8
 141         LS_BOX(r14, r15, r4)
 142         xor             r14,r14,r0
 143         xor             r5,r5,r14       /* xor next 6 keys              */
 144         xor             r6,r6,r5
 145         xor             r7,r7,r6
 146         xor             r8,r8,r7
 147         xor             r9,r9,r8
 148         xor             r10,r10,r9
 149         stw             r5,0(r3)
 150         stw             r6,4(r3)
 151         stw             r7,8(r3)
 152         stw             r8,12(r3)
 153         subi            r16,r16,1
 154         cmpwi           r16,0           /* last round early kick out    */
 155         bt              eq,ppc_expand_192_end
 156         stw             r9,16(r3)
 157         stw             r10,20(r3)
 158         GF8_MUL(r0, r0, r4, r14)        /* multiply RCO GF8             */
 159         b               ppc_expand_192_loop
 160 ppc_expand_192_end:
 161         FINALIZE_KEY
 162         blr
 163
 164 /*
 165  * ppc_expand_key_256(u32 *key_enc, const u8 *key)
 166  *
 167  * Expand 256 bit key into 240 bytes encryption key. It consists of key
 168  * itself plus 14 rounds with 16 bytes each
 169  *
 170  */
 171 _GLOBAL(ppc_expand_key_256)
 172         INITIALIZE_KEY
 173         LOAD_KEY(r5,r4,0)
 174         LOAD_KEY(r6,r4,4)
 175         LOAD_KEY(r7,r4,8)
 176         LOAD_KEY(r8,r4,12)
 177         LOAD_KEY(r9,r4,16)
 178         LOAD_KEY(r10,r4,20)
 179         LOAD_KEY(r11,r4,24)
 180         LOAD_KEY(r12,r4,28)
 181         stw             r5,0(r3)
 182         stw             r6,4(r3)
 183         stw             r7,8(r3)
 184         stw             r8,12(r3)
 185         stw             r9,16(r3)
 186         stw             r10,20(r3)
 187         stw             r11,24(r3)
 188         stw             r12,28(r3)
 189         li              r16,7           /* 7 expansion rounds           */
 190         lis             r0,0x0100       /* RCO(1)                       */
 191 ppc_expand_256_loop:
 192         addi            r3,r3,32
 193         mr              r14,r12         /* apply LS_BOX to 8th temp     */
 194         rotlwi          r14,r14,8
 195         LS_BOX(r14, r15, r4)
 196         xor             r14,r14,r0
 197         xor             r5,r5,r14       /* xor 4 keys                   */
 198         xor             r6,r6,r5
 199         xor             r7,r7,r6
 200         xor             r8,r8,r7
 201         mr              r14,r8
 202         LS_BOX(r14, r15, r4)            /* apply LS_BOX to 4th temp     */
 203         xor             r9,r9,r14       /* xor 4 keys                   */
 204         xor             r10,r10,r9
 205         xor             r11,r11,r10
 206         xor             r12,r12,r11
 207         stw             r5,0(r3)
 208         stw             r6,4(r3)
 209         stw             r7,8(r3)
 210         stw             r8,12(r3)
 211         subi            r16,r16,1
 212         cmpwi           r16,0           /* last round early kick out    */
 213         bt              eq,ppc_expand_256_end
 214         stw             r9,16(r3)
 215         stw             r10,20(r3)
 216         stw             r11,24(r3)
 217         stw             r12,28(r3)
 218         GF8_MUL(r0, r0, r4, r14)
 219         b               ppc_expand_256_loop
 220 ppc_expand_256_end:
 221         FINALIZE_KEY
 222         blr
 223
 224 /*
 225  * ppc_generate_decrypt_key: derive decryption key from encryption key
 226  * number of bytes to handle are calculated from length of key (16/24/32)
 227  *
 228  */
 229 _GLOBAL(ppc_generate_decrypt_key)
 230         addi            r6,r5,24
 231         slwi            r6,r6,2
 232         lwzx            r7,r4,r6        /* first/last 4 words are same  */
 233         stw             r7,0(r3)
 234         lwz             r7,0(r4)
 235         stwx            r7,r3,r6
 236         addi            r6,r6,4
 237         lwzx            r7,r4,r6
 238         stw             r7,4(r3)
 239         lwz             r7,4(r4)
 240         stwx            r7,r3,r6
 241         addi            r6,r6,4
 242         lwzx            r7,r4,r6
 243         stw             r7,8(r3)
 244         lwz             r7,8(r4)
 245         stwx            r7,r3,r6
 246         addi            r6,r6,4
 247         lwzx            r7,r4,r6
 248         stw             r7,12(r3)
 249         lwz             r7,12(r4)
 250         stwx            r7,r3,r6
 251         addi            r3,r3,16
 252         add             r4,r4,r6
 253         subi            r4,r4,28
 254         addi            r5,r5,20
 255         srwi            r5,r5,2
 256 ppc_generate_decrypt_block:
 257         li      r6,4
 258         mtctr   r6
 259 ppc_generate_decrypt_word:
 260         lwz             r6,0(r4)
 261         GF8_MUL(r7, r6, r0, r7)
 262         GF8_MUL(r8, r7, r0, r8)
 263         GF8_MUL(r9, r8, r0, r9)
 264         xor             r10,r9,r6
 265         xor             r11,r7,r8
 266         xor             r11,r11,r9
 267         xor             r12,r7,r10
 268         rotrwi          r12,r12,24
 269         xor             r11,r11,r12
 270         xor             r12,r8,r10
 271         rotrwi          r12,r12,16
 272         xor             r11,r11,r12
 273         rotrwi          r12,r10,8
 274         xor             r11,r11,r12
 275         stw             r11,0(r3)
 276         addi            r3,r3,4
 277         addi            r4,r4,4
 278         bdnz            ppc_generate_decrypt_word
 279         subi            r4,r4,32
 280         subi            r5,r5,1
 281         cmpwi           r5,0
 282         bt              gt,ppc_generate_decrypt_block
 283         blr