;;
;; Copyright (c) 2012-2019, Intel Corporation
;;
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;; modification, are permitted provided that the following conditions are met:
;;
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;;       this list of conditions and the following disclaimer.
;;     * Redistributions in binary form must reproduce the above copyright
;;       notice, this list of conditions and the following disclaimer in the
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;;       may be used to endorse or promote products derived from this software
;;       without specific prior written permission.
;;
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;; AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
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;; OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
;;

%include "include/os.asm"
%include "include/memcpy.asm"
%include "include/const.inc"
%include "include/reg_sizes.asm"

; routine to do AES192 CNTR enc/decrypt "by4"
; XMM registers are clobbered. Saving/restoring must be done at a higher level

%ifndef AES_CNTR_192
%define AES_CNTR_192 aes_cntr_192_sse
%define AES_CNTR_BIT_192 aes_cntr_bit_192_sse
%endif

extern byteswap_const, ddq_add_1, ddq_add_2, ddq_add_3, ddq_add_4

%define CONCAT(a,b) a %+ b
%define MOVDQ movdqu

%define xdata0	xmm0
%define xdata1	xmm1
%define xpart	xmm1
%define xdata2	xmm2
%define xdata3	xmm3
%define xdata4	xmm4
%define xdata5	xmm5
%define xdata6	xmm6
%define xdata7	xmm7
%define xcounter xmm8
%define xtmp    xmm8
%define xbyteswap xmm9
%define xtmp2   xmm9
%define xkey0 	xmm10
%define xtmp3   xmm10
%define xkey4 	xmm11
%define xkey8 	xmm12
%define xkey12	xmm13
%define xkeyA	xmm14
%define xkeyB	xmm15

%ifdef LINUX
%define p_in	  rdi
%define p_IV	  rsi
%define p_keys	  rdx
%define p_out	  rcx
%define num_bytes r8
%define num_bits  r8
%define p_ivlen   r9
%else
%define p_in	  rcx
%define p_IV	  rdx
%define p_keys	  r8
%define p_out	  r9
%define num_bytes r10
%define num_bits  r10
%define p_ivlen   qword [rsp + 8*6]
%endif

%define tmp	r11

%define r_bits   r12
%define tmp2    r13
%define mask    r14

%macro do_aes_load 2
	do_aes %1, %2, 1
%endmacro

%macro do_aes_noload 2
	do_aes %1, %2, 0
%endmacro


; do_aes num_in_par load_keys
; This increments p_in, but not p_out
%macro do_aes 3
%define %%by %1
%define %%cntr_type %2
%define %%load_keys %3

%if (%%load_keys)
	movdqa	xkey0, [p_keys + 0*16]
%endif

	movdqa	xdata0, xcounter
	pshufb	xdata0, xbyteswap
%assign i 1
%rep (%%by - 1)
	movdqa	CONCAT(xdata,i), xcounter
	paddd	CONCAT(xdata,i), [rel CONCAT(ddq_add_,i)]
	pshufb	CONCAT(xdata,i), xbyteswap
%assign i (i + 1)
%endrep

	movdqa	xkeyA, [p_keys + 1*16]

	pxor	xdata0, xkey0
%ifidn %%cntr_type, CNTR_BIT
	paddq	xcounter, [rel CONCAT(ddq_add_,%%by)]
%else
	paddd	xcounter, [rel CONCAT(ddq_add_,%%by)]
%endif

%assign i 1
%rep (%%by - 1)
	pxor	CONCAT(xdata,i), xkey0
%assign i (i + 1)
%endrep

	movdqa	xkeyB, [p_keys + 2*16]
%assign i 0
%rep %%by
	aesenc	CONCAT(xdata,i), xkeyA		; key 1
%assign i (i+1)
%endrep

	movdqa	xkeyA, [p_keys + 3*16]
%assign i 0
%rep %%by
	aesenc	CONCAT(xdata,i), xkeyB		; key 2
%assign i (i+1)
%endrep

	add	p_in, 16*%%by

%if (%%load_keys)
	movdqa	xkey4, [p_keys + 4*16]
%endif
%assign i 0
%rep %%by
	aesenc	CONCAT(xdata,i), xkeyA		; key 3
%assign i (i+1)
%endrep

	movdqa	xkeyA, [p_keys + 5*16]
%assign i 0
%rep %%by
	aesenc	CONCAT(xdata,i), xkey4		; key 4
%assign i (i+1)
%endrep

	movdqa	xkeyB, [p_keys + 6*16]
%assign i 0
%rep %%by
	aesenc	CONCAT(xdata,i), xkeyA		; key 5
%assign i (i+1)
%endrep

	movdqa	xkeyA, [p_keys + 7*16]
%assign i 0
%rep %%by
	aesenc	CONCAT(xdata,i), xkeyB		; key 6
%assign i (i+1)
%endrep

%if (%%load_keys)
	movdqa	xkey8, [p_keys + 8*16]
%endif
%assign i 0
%rep %%by
	aesenc	CONCAT(xdata,i), xkeyA		; key 7
%assign i (i+1)
%endrep

	movdqa	xkeyA, [p_keys + 9*16]
%assign i 0
%rep %%by
	aesenc	CONCAT(xdata,i), xkey8		; key 8
%assign i (i+1)
%endrep

	movdqa	xkeyB, [p_keys + 10*16]
%assign i 0
%rep %%by
	aesenc	CONCAT(xdata,i), xkeyA		; key 9
%assign i (i+1)
%endrep

	movdqa	xkeyA, [p_keys + 11*16]
%assign i 0
%rep %%by
	aesenc	CONCAT(xdata,i), xkeyB		; key 10
%assign i (i+1)
%endrep

%if (%%load_keys)
	movdqa	xkey12, [p_keys + 12*16]
%endif
%assign i 0
%rep %%by
	aesenc	CONCAT(xdata,i), xkeyA		; key 11
%assign i (i+1)
%endrep

%assign i 0
%rep %%by
	aesenclast	CONCAT(xdata,i), xkey12	; key 12
%assign i (i+1)
%endrep

%assign i 0
%rep (%%by / 2)
%assign j (i+1)
	MOVDQ	xkeyA, [p_in + i*16 - 16*%%by]
	MOVDQ	xkeyB, [p_in + j*16 - 16*%%by]
	pxor	CONCAT(xdata,i), xkeyA
	pxor	CONCAT(xdata,j), xkeyB
%assign i (i+2)
%endrep
%if (i < %%by)
	MOVDQ	xkeyA, [p_in + i*16 - 16*%%by]
	pxor	CONCAT(xdata,i), xkeyA
%endif

%ifidn %%cntr_type, CNTR_BIT
        ;; check if this is the end of the message
        mov     tmp, num_bytes
        and     tmp, ~(%%by*16)
        jnz     %%skip_preserve
        ;; Check if there is a partial byte
        or      r_bits, r_bits
        jz      %%skip_preserve

%assign idx (%%by - 1)
        ;; Load output to get last partial byte
        movdqu         xtmp, [p_out + idx * 16]

        ;; Save RCX in temporary GP register
        mov             tmp, rcx
        mov             mask, 0xff
        mov             cl, BYTE(r_bits)
        shr             mask, cl ;; e.g. 3 remaining bits -> mask = 00011111
        mov             rcx, tmp

        movq            xtmp2, mask
        pslldq          xtmp2, 15
        ;; At this point, xtmp2 contains a mask with all 0s, but with some ones
        ;; in the partial byte

        ;; Clear all the bits that do not need to be preserved from the output
        pand            xtmp, xtmp2

        ;; Clear all bits from the input that are not to be ciphered
        pandn	        xtmp2, CONCAT(xdata, idx)
        por             xtmp2, xtmp
        movdqa		CONCAT(xdata, idx), xtmp2

%%skip_preserve:
%endif

%assign i 0
%rep %%by
	MOVDQ	[p_out  + i*16], CONCAT(xdata,i)
%assign i (i+1)
%endrep
%endmacro

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section .text

;; Macro performing AES-CTR.
;;
%macro DO_CNTR 1
%define %%CNTR_TYPE %1 ; [in] Type of CNTR operation to do (CNTR/CNTR_BIT)

%ifndef LINUX
	mov	num_bytes, [rsp + 8*5]
%endif

%ifidn %%CNTR_TYPE, CNTR_BIT
        push r12
        push r13
        push r14
%endif

	movdqa	xbyteswap, [rel byteswap_const]
%ifidn %%CNTR_TYPE, CNTR
        test    p_ivlen, 16
        jnz     %%iv_is_16_bytes
        ; Read 12 bytes: Nonce + ESP IV. Then pad with block counter 0x00000001
        mov     DWORD(tmp), 0x01000000
        pinsrq  xcounter, [p_IV], 0
        pinsrd  xcounter, [p_IV + 8], 2
        pinsrd  xcounter, DWORD(tmp), 3

%else ;; CNTR_BIT
        ; Read 16 byte IV: Nonce + 8-byte block counter (BE)
        movdqu  xcounter, [p_IV]
%endif

%%bswap_iv:
	pshufb	xcounter, xbyteswap

        ;; calculate len
        ;; convert bits to bytes (message length in bits for CNTR_BIT)
%ifidn %%CNTR_TYPE, CNTR_BIT
        mov     r_bits, num_bits
        add     num_bits, 7
        shr     num_bits, 3 ; "num_bits" and "num_bytes" registers are the same
        and     r_bits, 7   ; Check if there are remainder bits (0-7)
%endif
	mov	tmp, num_bytes
	and	tmp, 3*16
	jz	%%chk             ; x4 > or < 15 (not 3 lines)

	; 1 <= tmp <= 3
	cmp	tmp, 2*16
	jg	%%eq3
	je	%%eq2
%%eq1:
	do_aes_load	1, %%CNTR_TYPE
	add	p_out, 1*16
        jmp     %%chk

%%eq2:
	do_aes_load	2, %%CNTR_TYPE
	add	p_out, 2*16
        jmp      %%chk

%%eq3:
	do_aes_load	3, %%CNTR_TYPE
	add	p_out, 3*16
	; fall through to chk
%%chk:
        and	num_bytes, ~(3*16)
	jz	%%do_return2

        cmp	num_bytes, 16
        jb	%%last

	; process multiples of 4 blocks
	movdqa	xkey0, [p_keys + 0*16]
	movdqa	xkey4, [p_keys + 4*16]
	movdqa	xkey8, [p_keys + 8*16]
	movdqa	xkey12, [p_keys + 12*16]

align 32
%%main_loop2:
	; num_bytes is a multiple of 4 blocks + partial bytes
	do_aes_noload	4, %%CNTR_TYPE
	add	p_out,	4*16
	sub	num_bytes, 4*16
        cmp	num_bytes, 4*16
	jae	%%main_loop2

        ; Check if there is a partial block
	or      num_bytes, num_bytes
        jnz    %%last

%%do_return2:

%ifidn %%CNTR_TYPE, CNTR_BIT
        pop r14
        pop r13
        pop r12
%endif

	ret

%%last:

	; load partial block into XMM register
	simd_load_sse_15_1 xpart, p_in, num_bytes

%%final_ctr_enc:
	; Encryption of a single partial block
        pshufb	xcounter, xbyteswap
        movdqa	xdata0, xcounter
        pxor    xdata0, [p_keys + 16*0]
%assign i 1
%rep 11
        aesenc  xdata0, [p_keys + 16*i]
%assign i (i+1)
%endrep
	; created keystream
        aesenclast xdata0, [p_keys + 16*i]

	; xor keystream with the message (scratch)
        pxor    xdata0, xpart

%ifidn %%CNTR_TYPE, CNTR_BIT
        ;; Check if there is a partial byte
        or      r_bits, r_bits
        jz      %%store_output

        ;; Load output to get last partial byte
        simd_load_sse_15_1 xtmp, p_out, num_bytes

        ;; Save RCX in temporary GP register
        mov     tmp, rcx
        mov     mask, 0xff
%ifidn r_bits, rcx
%error "r_bits cannot be mapped to rcx!"
%endif
        mov     cl, BYTE(r_bits)
        shr     mask, cl ;; e.g. 3 remaining bits -> mask = 00011111
        mov     rcx, tmp

        movq    xtmp2, mask

        ;; Get number of full bytes in last block of 16 bytes
        mov     tmp, num_bytes
        dec     tmp
        XPSLLB  xtmp2, tmp, xtmp3, tmp2
        ;; At this point, xtmp2 contains a mask with all 0s, but with some ones
        ;; in the partial byte

        ;; Clear all the bits that do not need to be preserved from the output
        pand    xtmp, xtmp2

        ;; Clear the bits from the input that are not to be ciphered
        pandn   xtmp2, xdata0
        por     xtmp2, xtmp
        movdqa  xdata0, xtmp2
%endif

%%store_output:
        ; copy result into the output buffer
        simd_store_sse_15 p_out, xdata0, num_bytes, tmp, rax

        jmp	%%do_return2

%%iv_is_16_bytes:
        ; Read 16 byte IV: Nonce + ESP IV + block counter (BE)
        movdqu  xcounter, [p_IV]
        jmp     %%bswap_iv
%endmacro

align 32
;; aes_cntr_192_sse(void *in, void *IV, void *keys, void *out, UINT64 num_bytes, UINT64 iv_len)
MKGLOBAL(AES_CNTR_192,function,internal)
AES_CNTR_192:
        DO_CNTR CNTR

;; aes_cntr_bit_192_sse(void *in, void *IV, void *keys, void *out, UINT64 num_bits, UINT64 iv_len)
MKGLOBAL(AES_CNTR_BIT_192,function,internal)
AES_CNTR_BIT_192:
        DO_CNTR CNTR_BIT

%ifdef LINUX
section .note.GNU-stack noalloc noexec nowrite progbits
%endif