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| /* SPDX-License-Identifier: GPL-2.0-or-later */
| /*
| * Key handling functions for PPC AES implementation
| *
| * Copyright (c) 2015 Markus Stockhausen <stockhausen@collogia.de>
| */
|
| #include <asm/ppc_asm.h>
|
| #ifdef __BIG_ENDIAN__
| #define LOAD_KEY(d, s, off) \
| lwz d,off(s);
| #else
| #define LOAD_KEY(d, s, off) \
| li r0,off; \
| lwbrx d,s,r0;
| #endif
|
| #define INITIALIZE_KEY \
| stwu r1,-32(r1); /* create stack frame */ \
| stw r14,8(r1); /* save registers */ \
| stw r15,12(r1); \
| stw r16,16(r1);
|
| #define FINALIZE_KEY \
| lwz r14,8(r1); /* restore registers */ \
| lwz r15,12(r1); \
| lwz r16,16(r1); \
| xor r5,r5,r5; /* clear sensitive data */ \
| xor r6,r6,r6; \
| xor r7,r7,r7; \
| xor r8,r8,r8; \
| xor r9,r9,r9; \
| xor r10,r10,r10; \
| xor r11,r11,r11; \
| xor r12,r12,r12; \
| addi r1,r1,32; /* cleanup stack */
|
| #define LS_BOX(r, t1, t2) \
| lis t2,PPC_AES_4K_ENCTAB@h; \
| ori t2,t2,PPC_AES_4K_ENCTAB@l; \
| rlwimi t2,r,4,20,27; \
| lbz t1,8(t2); \
| rlwimi r,t1,0,24,31; \
| rlwimi t2,r,28,20,27; \
| lbz t1,8(t2); \
| rlwimi r,t1,8,16,23; \
| rlwimi t2,r,20,20,27; \
| lbz t1,8(t2); \
| rlwimi r,t1,16,8,15; \
| rlwimi t2,r,12,20,27; \
| lbz t1,8(t2); \
| rlwimi r,t1,24,0,7;
|
| #define GF8_MUL(out, in, t1, t2) \
| lis t1,0x8080; /* multiplication in GF8 */ \
| ori t1,t1,0x8080; \
| and t1,t1,in; \
| srwi t1,t1,7; \
| mulli t1,t1,0x1b; \
| lis t2,0x7f7f; \
| ori t2,t2,0x7f7f; \
| and t2,t2,in; \
| slwi t2,t2,1; \
| xor out,t1,t2;
|
| /*
| * ppc_expand_key_128(u32 *key_enc, const u8 *key)
| *
| * Expand 128 bit key into 176 bytes encryption key. It consists of
| * key itself plus 10 rounds with 16 bytes each
| *
| */
| _GLOBAL(ppc_expand_key_128)
| INITIALIZE_KEY
| LOAD_KEY(r5,r4,0)
| LOAD_KEY(r6,r4,4)
| LOAD_KEY(r7,r4,8)
| LOAD_KEY(r8,r4,12)
| stw r5,0(r3) /* key[0..3] = input data */
| stw r6,4(r3)
| stw r7,8(r3)
| stw r8,12(r3)
| li r16,10 /* 10 expansion rounds */
| lis r0,0x0100 /* RCO(1) */
| ppc_expand_128_loop:
| addi r3,r3,16
| mr r14,r8 /* apply LS_BOX to 4th temp */
| rotlwi r14,r14,8
| LS_BOX(r14, r15, r4)
| xor r14,r14,r0
| xor r5,r5,r14 /* xor next 4 keys */
| xor r6,r6,r5
| xor r7,r7,r6
| xor r8,r8,r7
| stw r5,0(r3) /* store next 4 keys */
| stw r6,4(r3)
| stw r7,8(r3)
| stw r8,12(r3)
| GF8_MUL(r0, r0, r4, r14) /* multiply RCO by 2 in GF */
| subi r16,r16,1
| cmpwi r16,0
| bt eq,ppc_expand_128_end
| b ppc_expand_128_loop
| ppc_expand_128_end:
| FINALIZE_KEY
| blr
|
| /*
| * ppc_expand_key_192(u32 *key_enc, const u8 *key)
| *
| * Expand 192 bit key into 208 bytes encryption key. It consists of key
| * itself plus 12 rounds with 16 bytes each
| *
| */
| _GLOBAL(ppc_expand_key_192)
| INITIALIZE_KEY
| LOAD_KEY(r5,r4,0)
| LOAD_KEY(r6,r4,4)
| LOAD_KEY(r7,r4,8)
| LOAD_KEY(r8,r4,12)
| LOAD_KEY(r9,r4,16)
| LOAD_KEY(r10,r4,20)
| stw r5,0(r3)
| stw r6,4(r3)
| stw r7,8(r3)
| stw r8,12(r3)
| stw r9,16(r3)
| stw r10,20(r3)
| li r16,8 /* 8 expansion rounds */
| lis r0,0x0100 /* RCO(1) */
| ppc_expand_192_loop:
| addi r3,r3,24
| mr r14,r10 /* apply LS_BOX to 6th temp */
| rotlwi r14,r14,8
| LS_BOX(r14, r15, r4)
| xor r14,r14,r0
| xor r5,r5,r14 /* xor next 6 keys */
| xor r6,r6,r5
| xor r7,r7,r6
| xor r8,r8,r7
| xor r9,r9,r8
| xor r10,r10,r9
| stw r5,0(r3)
| stw r6,4(r3)
| stw r7,8(r3)
| stw r8,12(r3)
| subi r16,r16,1
| cmpwi r16,0 /* last round early kick out */
| bt eq,ppc_expand_192_end
| stw r9,16(r3)
| stw r10,20(r3)
| GF8_MUL(r0, r0, r4, r14) /* multiply RCO GF8 */
| b ppc_expand_192_loop
| ppc_expand_192_end:
| FINALIZE_KEY
| blr
|
| /*
| * ppc_expand_key_256(u32 *key_enc, const u8 *key)
| *
| * Expand 256 bit key into 240 bytes encryption key. It consists of key
| * itself plus 14 rounds with 16 bytes each
| *
| */
| _GLOBAL(ppc_expand_key_256)
| INITIALIZE_KEY
| LOAD_KEY(r5,r4,0)
| LOAD_KEY(r6,r4,4)
| LOAD_KEY(r7,r4,8)
| LOAD_KEY(r8,r4,12)
| LOAD_KEY(r9,r4,16)
| LOAD_KEY(r10,r4,20)
| LOAD_KEY(r11,r4,24)
| LOAD_KEY(r12,r4,28)
| stw r5,0(r3)
| stw r6,4(r3)
| stw r7,8(r3)
| stw r8,12(r3)
| stw r9,16(r3)
| stw r10,20(r3)
| stw r11,24(r3)
| stw r12,28(r3)
| li r16,7 /* 7 expansion rounds */
| lis r0,0x0100 /* RCO(1) */
| ppc_expand_256_loop:
| addi r3,r3,32
| mr r14,r12 /* apply LS_BOX to 8th temp */
| rotlwi r14,r14,8
| LS_BOX(r14, r15, r4)
| xor r14,r14,r0
| xor r5,r5,r14 /* xor 4 keys */
| xor r6,r6,r5
| xor r7,r7,r6
| xor r8,r8,r7
| mr r14,r8
| LS_BOX(r14, r15, r4) /* apply LS_BOX to 4th temp */
| xor r9,r9,r14 /* xor 4 keys */
| xor r10,r10,r9
| xor r11,r11,r10
| xor r12,r12,r11
| stw r5,0(r3)
| stw r6,4(r3)
| stw r7,8(r3)
| stw r8,12(r3)
| subi r16,r16,1
| cmpwi r16,0 /* last round early kick out */
| bt eq,ppc_expand_256_end
| stw r9,16(r3)
| stw r10,20(r3)
| stw r11,24(r3)
| stw r12,28(r3)
| GF8_MUL(r0, r0, r4, r14)
| b ppc_expand_256_loop
| ppc_expand_256_end:
| FINALIZE_KEY
| blr
|
| /*
| * ppc_generate_decrypt_key: derive decryption key from encryption key
| * number of bytes to handle are calculated from length of key (16/24/32)
| *
| */
| _GLOBAL(ppc_generate_decrypt_key)
| addi r6,r5,24
| slwi r6,r6,2
| lwzx r7,r4,r6 /* first/last 4 words are same */
| stw r7,0(r3)
| lwz r7,0(r4)
| stwx r7,r3,r6
| addi r6,r6,4
| lwzx r7,r4,r6
| stw r7,4(r3)
| lwz r7,4(r4)
| stwx r7,r3,r6
| addi r6,r6,4
| lwzx r7,r4,r6
| stw r7,8(r3)
| lwz r7,8(r4)
| stwx r7,r3,r6
| addi r6,r6,4
| lwzx r7,r4,r6
| stw r7,12(r3)
| lwz r7,12(r4)
| stwx r7,r3,r6
| addi r3,r3,16
| add r4,r4,r6
| subi r4,r4,28
| addi r5,r5,20
| srwi r5,r5,2
| ppc_generate_decrypt_block:
| li r6,4
| mtctr r6
| ppc_generate_decrypt_word:
| lwz r6,0(r4)
| GF8_MUL(r7, r6, r0, r7)
| GF8_MUL(r8, r7, r0, r8)
| GF8_MUL(r9, r8, r0, r9)
| xor r10,r9,r6
| xor r11,r7,r8
| xor r11,r11,r9
| xor r12,r7,r10
| rotrwi r12,r12,24
| xor r11,r11,r12
| xor r12,r8,r10
| rotrwi r12,r12,16
| xor r11,r11,r12
| rotrwi r12,r10,8
| xor r11,r11,r12
| stw r11,0(r3)
| addi r3,r3,4
| addi r4,r4,4
| bdnz ppc_generate_decrypt_word
| subi r4,r4,32
| subi r5,r5,1
| cmpwi r5,0
| bt gt,ppc_generate_decrypt_block
| blr
|
|
