; Name:         mysqluuid.asm
; Build:        nasm "-felf64" mysqluuid.asm -l mysqluuid.lst -o mysqluuid.o
;               ld -s -melf_x86_64 -o mysqluuid mysqluuid.o -lc --dynamic-linker 
; /lib64/ld-linux-x86-64.so.2 -lmysqlclient
; ; Description: As an alternative for the uuid example, we can get a uuid from mysql server. ; Benefit : mysql keeps track of unique uids ; Disadvantage : mysql server must be running on your system. ; Remark: ; libmysqlclient is needed, to install execute sudo apt-get install libmysqlclient-dev bits 64 section .bss section .data [list -] extern mysql_close extern mysql_errno extern mysql_error extern mysql_fetch_row extern mysql_free_result extern mysql_init extern mysql_query extern mysql_real_connect extern mysql_server_end extern mysql_server_init extern mysql_use_result %include "unistd.inc" %include "sys/stat.inc" [list +] conn: dq 0 result: dq 0 heapstart: dq 0 fd: dq 0 host: dq 0 port: dq 0 user: dq 0 password: dq 0 database: dq 0 socket: dq 0 clientflag: dq 0 string: .filenotfound: db "configuration file not found", 10 .filenotfound.length: equ $-.filenotfound .fileread: db "error reading configuration file", 10 .fileread.length: equ $-.fileread .filestatus: db "error reading configuration file status", 10 .filestatus.length: equ $-.filestatus .fileclose: db "error closing configuration file", 10 .fileclose.length: equ $-.fileclose .notenoughmemory: db "not enough memory", 10 .notenoughmemory.length: equ $-.notenoughmemory .deallocmemory: db "error deallocating memory", 10 .deallocmemory.length: equ $-.deallocmemory .mysqlserverinit: db "MySQL library could not be initialized",10 .mysqlserverinit.length: equ $-.mysqlserverinit .mysqlobjinit: db "MySQL init object failed", 10 .mysqlobjinit.length: equ $-.mysqlobjinit .mysqlresult: db "MySQL result error", 10 .mysqlresult.length: equ $-.mysqlresult .mysqlfetchrow: db "MySQL fetch row error", 10 .mysqlfetchrow.length: equ $-.mysqlfetchrow query: db "select uuid()",0 configfilename: db "./mysql.cfg",0 hoststring: db "DBHOST=" .length: equ $-hoststring userstring: db "DBUSER=" .length: equ $-userstring passwordstring: db "DBPASSWORD=" .length: equ $-passwordstring portstring: db "DBPORT=" .length: equ $-portstring ; file status structure STAT stat section .text global _start _start: ; open configuration file syscall open, configfilename, O_RDONLY and rax, rax jl Error.filenotfound mov qword[fd], rax ; save filedescriptor ; get the filesize syscall fstat, rax, stat and rax, rax jl Error.filestatus ; reserve memory for file contents ; get memory break syscall brk, 0 and rax, rax jle Error.notenoughmemory mov qword[heapstart], rax ; save pointer to memory break add rax, qword[stat.st_size] ; add filesize to allocate memory inc rax ; one extra byte, to be sure the string ends with 00 ; try to allocate additional memory syscall brk, rax sub rax, rdi ; new memory break equal to calculated one? and rax, rax jnz Error.notenoughmemory ; read the file in the allocated memory syscall read, qword[fd], qword[heapstart], rdx, qword[stat.st_size] and rax, rax jl Error.fileread ; close file syscall close, qword[fd] and rax, rax jnz Error.fileclose ; loop through our string, replacing each 0x0A and 0x0D with 00 mov rsi, qword[heapstart] mov rdi, qword[stat.st_size] call String.ZeroCRLF ; get the values for host, user, password, port, database, socket and clientflag, if socket and clientflag are ; empty strings then the values for these are NULL instead of the pointer to the socket and clientflag string. ; Port need to be stored as an unsigned integer. ; get pointer to HOST mov rdi, hoststring.length mov rsi, hoststring call String.Search mov qword[host], rax ; get pointer to USER mov rdi, userstring.length mov rsi, userstring call String.Search mov qword[user], rax ; get pointer to PASSWORD mov rdi, passwordstring.length mov rsi, passwordstring call String.Search mov qword[password], rax ; get pointer to PORT mov rdi, portstring.length mov rsi, portstring call String.Search ; parse PORT to integer mov rdi, rax call String.ToInt mov qword[port], rax ; all values are known, now connect to mysql server and get an uuid ; not an embedded MySQL so all arguments must be zero xor rdi, rdi xor rsi, rsi xor rdx, rdx call mysql_server_init and rax, rax jnz Error.mysqlserverinit ; From this point we need to cleanup the library!!!! xor rdi, rdi call mysql_init and rax, rax jz Error.mysqlobjinit ; no errors, connect and login mov qword [conn], rax ; save *mysql mov rdi, rax ; value of mysql = pointer to mysql instance of connection push qword 0 ;[clientflag] ; the value of clientflags or NULL if none push qword 0 ;[socket] ; the value of socket or NULL if none mov r9d, dword [port] ; the value of the port to connect to xor r8, r8 ; pointer to zero terminated database string mov rcx, qword [password] ; pointer to zero terminated password string mov rdx, qword [user] ; pointer to zero terminated user string mov rsi, qword [host] ; pointer to zero terminated host string call mysql_real_connect ; connect pop rdx ; restore stackpointer pop rdx sub rax, qword [conn] ; if conn == pointer to mysql instance then succes and rax, rax jnz Error.mysqlconnect ; We are connected, execute the query mov rsi, query ; pointer to zero terminated query string mov rdi, qword [conn] ; value of mysql = pointer to mysql instance of connection call mysql_query ; query the server ; check for errors mov rdi, qword [conn] ; check if an error occured call mysql_errno and rax, rax jnz Error.mysqlerror mov rdi, qword[conn] call mysql_use_result ; we don't ask all the records at once (less client side memory) and rax, rax jz Error.mysqlresult ; get uuid from resultset mov qword [result], rax mov rdi, rax call mysql_fetch_row and rax, rax cmp rax, 2000 ; unknown error je Error.mysqlerror cmp rax, 2013 ; connection lost je Error.mysqlerror jz NoRows mov rsi, [rax] ; get result mov rdi, rsi call String.Length ; result length mov rdx, rax ; length in rdx inc rdx add rax, rsi mov byte [rax], 0x0A syscall write, stdout NoRows: mov rdi, qword[conn] call mysql_errno and rax, rax jnz Error.mysqlerror ; free result mov rdi, qword[result] call mysql_free_result CloseConnection: mov rdi, qword[conn] call mysql_close ServerEnd: call mysql_server_end FreeHeap: syscall brk, qword[heapstart] and rax, rax jl Error.deallocmemory Exit: syscall exit, 0 Error: .mysqlserverinit: mov rsi, string.mysqlserverinit mov rdx, string.mysqlserverinit.length call String.ToStdErr jmp Exit .mysqlobjinit: mov rsi, string.mysqlobjinit mov rdx, string.mysqlobjinit.length call String.ToStdErr jmp ServerEnd .mysqlconnect: push ServerEnd jmp ._error .mysqlerror: push CloseConnection ._error: mov rdi, qword[conn] call mysql_error mov rsi, rax mov rdi, rax call String.Length mov rdx, rax inc rdx add rax, rsi mov byte[rax], 0x0A call String.ToStdErr ret .mysqlresult: mov rsi, string.mysqlresult mov rdx, string.mysqlresult.length call String.ToStdErr jmp CloseConnection .mysqlfetchrow: mov rsi, string.mysqlfetchrow mov rdx, string.mysqlfetchrow.length call String.ToStdErr jmp CloseConnection .notenoughmemory: mov rsi, string.notenoughmemory mov rdx, string.notenoughmemory.length jmp Exit .deallocmemory: mov rsi, string.deallocmemory mov rdx, string.deallocmemory.length call String.ToStdErr jmp Exit .fileread: mov rsi, string.fileread mov rdx, string.fileread.length call String.ToStdErr jmp Exit .filenotfound: mov rsi, string.filenotfound mov rdx, string.filenotfound.length call String.ToStdErr jmp Exit .filestatus: mov rsi, string.filestatus mov rdx, string.filestatus.length call String.ToStdErr jmp Exit .fileclose: mov rsi, string.fileclose mov rdx, string.fileclose.length call String.ToStdErr jmp Exit String.ToStdErr: push rcx push r11 mov rdi, stderr jmp _syscallwrite String.ToStdOut: push rcx push r11 mov rdi, stdout _syscallwrite: syscall write, rdi, rsi, rdx pop r11 pop rcx ret ; Search for a substring in a string ; on succes CF=0 and RAX has pointer String.Search: mov rax, rdi ; the length in rax mov rbx, rsi ; the stringpointer in rbx mov rsi, qword[heapstart] mov rdx, qword[stat.st_size] sub rdx, rdi .@1: mov rdi, rbx mov rcx, rax cld repe cmpsb je .@2 dec rdx and rdx, rdx jnz .@1 stc ret .@2: mov rax, rsi clc ret ; convert string to unsigned integer value String.ToInt: mov rsi, rdi xor rdx, rdx .@1: xor rax, rax lodsb and al, al ; end of string? jz .@2 and al, 0x0F ; un-ascii and rdx, rdx jz .@3 mov rcx, rax mov rax, rdx xor rdx, rdx mov rbx, 10 mul rbx mov rdx, rcx .@3: add rax, rdx mov rdx, rax jmp .@1 .@2: mov rax, rdx ret ; determine string length of a string in RDI String.Length: xor rcx, rcx dec rcx xor rax, rax repne scasb neg rcx dec rcx dec rcx and rcx, rcx mov rax, rcx ; return length in RAX ret ; replaces LF en CR by NULL String.ZeroCRLF: mov rcx, rdi inc rcx .@1: cld lodsb cmp al, 0x0A je .@2 cmp al, 0x0D jne .@3 .@2: dec rsi xor al, al mov byte[rsi], al .@3: loop .@1 ret

Config file