aes_x86_v1.asm

一个用vc编写的aes算法实现

%endif

%macro enc_round 0

    add     ebp,16
    save    0,ebp
    mov     esi,[ebp+8]
    mov     edi,[ebp+12]

    rnd_fun nr_xor, nr_mov

    mov     eax,ebp
    mov     ecx,esi
    mov     edx,edi
    restore ebp,0
    xor     eax,[ebp]
    xor     ebx,[ebp+4]

%endmacro

%macro enc_last_round 0

    add     ebp,16
    save    0,ebp
    mov     esi,[ebp+8]
    mov     edi,[ebp+12]

    rnd_fun lr_xor, lr_mov

    mov     eax,ebp
    restore ebp,0
    xor     eax,[ebp]
    xor     ebx,[ebp+4]

%endmacro

    section .text align=32

; AES Encryption Subroutine

    do_name _aes_encrypt

    sub     esp,stk_spc
    mov     [esp+16],ebp
    mov     [esp+12],ebx
    mov     [esp+ 8],esi
    mov     [esp+ 4],edi

    mov     esi,[esp+in_blk+stk_spc] ; input pointer
    mov     eax,[esi   ]
    mov     ebx,[esi+ 4]
    mov     ecx,[esi+ 8]
    mov     edx,[esi+12]

    mov     ebp,[esp+ctx+stk_spc]    ; key pointer
    movzx   edi,byte [ebp+4*KS_LENGTH]
    xor     eax,[ebp   ]
    xor     ebx,[ebp+ 4]
    xor     ecx,[ebp+ 8]
    xor     edx,[ebp+12]

; determine the number of rounds

    cmp     edi,10*16
    je      .3
    cmp     edi,12*16
    je      .2
    cmp     edi,14*16
    je      .1
    mov     eax,-1
    jmp     .5

.1: enc_round
    enc_round
.2: enc_round
    enc_round
.3: enc_round
    enc_round
    enc_round
    enc_round
    enc_round
    enc_round
    enc_round
    enc_round
    enc_round
    enc_last_round

    mov     edx,[esp+out_blk+stk_spc]
    mov     [edx],eax
    mov     [edx+4],ebx
    mov     [edx+8],esi
    mov     [edx+12],edi
    xor     eax,eax

.5: mov     ebp,[esp+16]
    mov     ebx,[esp+12]
    mov     esi,[esp+ 8]
    mov     edi,[esp+ 4]
    add     esp,stk_spc
    do_exit

%endif

%ifdef  DECRYPTION

    extern  _t_in

%define dtab_0(x)   [_t_in+4*x]
%define dtab_1(x)   [_t_in+1024+4*x]
%define dtab_2(x)   [_t_in+2048+4*x]
%define dtab_3(x)   [_t_in+3072+4*x]

%ifdef LAST_ROUND_TABLES

    extern  _t_il

%define dltab_0(x)  [_t_il+4*x]
%define dltab_1(x)  [_t_il+1024+4*x]
%define dltab_2(x)  [_t_il+2048+4*x]
%define dltab_3(x)  [_t_il+3072+4*x]

%else

    extern  _t_ibox

%define dtab_x(x)   byte [_t_ibox+x]

%endif

%macro irn_fun 2

    rol eax,16
    %1      esi, cl, 0, ebp
    %1      esi, bh, 1, ebp
    %1      esi, al, 2, ebp
    %1      edi, dl, 0, ebp
    %1      edi, ch, 1, ebp
    %1      edi, ah, 3, ebp
    %2      ebp, bl, 0, ebp
    shr     eax,16
    and     ebx,0xffff0000
    or      ebx,eax
    shr     ecx,16
    %1      ebp, bh, 1, eax
    %1      ebp, ch, 3, eax
    %2      eax, cl, 2, ecx
    %1      eax, bl, 0, ecx
    %1      eax, dh, 1, ecx
    shr     ebx,16
    shr     edx,16
    %1      esi, dh, 3, ecx
    %1      ebp, dl, 2, ecx
    %1      eax, bh, 3, ecx
    %1      edi, bl, 2, ecx

%endmacro

; Basic MOV and XOR Operations for normal rounds

%macro  ni_xor  4
    movzx   %4,%2
    xor     %1,dtab_%3(%4)
%endmacro

%macro  ni_mov  4
    movzx   %4,%2
    mov     %1,dtab_%3(%4)
%endmacro

; Basic MOV and XOR Operations for last round

%ifdef LAST_ROUND_TABLES

%macro  li_xor  4
    movzx   %4,%2
    xor     %1,dltab_%3(%4)
%endmacro

%macro  li_mov  4
    movzx   %4,%2
    mov     %1,dltab_%3(%4)
%endmacro

%else

    %macro  li_xor  4
        movzx   %4,%2
        movzx   %4,dtab_x(%4)
    %if %3 != 0
        shl     %4,8*%3
    %endif
        xor     %1,%4
    %endmacro

    %macro  li_mov  4
        movzx   %4,%2
        movzx   %1,dtab_x(%4)
    %if %3 != 0
        shl     %1,8*%3
    %endif
    %endmacro

%endif

%macro dec_round 0

%ifdef AES_REV_DKS
    add     ebp,16
%else
    sub     ebp,16
%endif
    save    0,ebp
    mov     esi,[ebp+8]
    mov     edi,[ebp+12]

    irn_fun ni_xor, ni_mov

    mov     ebx,ebp
    mov     ecx,esi
    mov     edx,edi
    restore ebp,0
    xor     eax,[ebp]
    xor     ebx,[ebp+4]

%endmacro

%macro dec_last_round 0

%ifdef AES_REV_DKS
    add     ebp,16
%else
    sub     ebp,16
%endif
    save    0,ebp
    mov     esi,[ebp+8]
    mov     edi,[ebp+12]

    irn_fun li_xor, li_mov

    mov     ebx,ebp
    restore ebp,0
    xor     eax,[ebp]
    xor     ebx,[ebp+4]

%endmacro

    section .text align=32

; AES Decryption Subroutine

    do_name _aes_decrypt

    sub     esp,stk_spc
    mov     [esp+16],ebp
    mov     [esp+12],ebx
    mov     [esp+ 8],esi
    mov     [esp+ 4],edi

; input four columns and xor in first round key

    mov     esi,[esp+in_blk+stk_spc] ; input pointer
    mov     eax,[esi   ]
    mov     ebx,[esi+ 4]
    mov     ecx,[esi+ 8]
    mov     edx,[esi+12]
    lea     esi,[esi+16]

    mov     ebp,[esp+ctx+stk_spc]    ; key pointer
    movzx   edi,byte[ebp+4*KS_LENGTH]
%ifndef  AES_REV_DKS        ; if decryption key schedule is not reversed
    lea     ebp,[ebp+edi]   ; we have to access it from the top down
%endif
    xor     eax,[ebp   ]    ; key schedule
    xor     ebx,[ebp+ 4]
    xor     ecx,[ebp+ 8]
    xor     edx,[ebp+12]

; determine the number of rounds

    cmp     edi,10*16
    je      .3
    cmp     edi,12*16
    je      .2
    cmp     edi,14*16
    je      .1
    mov     eax,-1
    jmp     .5

.1: dec_round
    dec_round
.2: dec_round
    dec_round
.3: dec_round
    dec_round
    dec_round
    dec_round
    dec_round
    dec_round
    dec_round
    dec_round
    dec_round
    dec_last_round

; move final values to the output array.

    mov     ebp,[esp+out_blk+stk_spc]
    mov     [ebp],eax
    mov     [ebp+4],ebx
    mov     [ebp+8],esi
    mov     [ebp+12],edi
    xor     eax,eax

.5: mov     ebp,[esp+16]
    mov     ebx,[esp+12]
    mov     esi,[esp+ 8]
    mov     edi,[esp+ 4]
    add     esp,stk_spc
    do_exit

%endif

    end