# Radare2 ## Command line options ``` -L: List of supported IO plugins -q: Exit after processing commands -w: Write mode enabled -i [file]: Interprets a r2 script -A: Analyze executable at load time (xrefs, etc) -n: Bare load. Do not load executable info as the entrypoint -c 'cmds': Run r2 and execute commands (eg: r2 -wqc'wx 3c @ main') -p [prj]: Creates a project for the file being analyzed (CC add a comment when opening a file as a project) -: Opens r2 with the malloc plugin that gives a 512 bytes memory area to play with (size can be changed) Similar to r2 malloc://512 ``` ## Configuration properties They can be used in evaluations:`? ${asm.tabs}` ``` e: Returns configuration properties e : Checks a specific property: e asm.tabs => false e =: Change property value e asm.arch=ppc e? help about a configuration property e? cmd.stack ``` You will want to set your favourite options in `~/.radare2rc` since every line there will be interpreted at the beginning of each session. Mine for reference: ``` # Show comments at right of disassembly if they fit in screen e asm.cmt.right=true # Shows pseudocode in disassembly. Eg mov eax, str.ok = > eax = str.ok e asm.pseudo = true # Solarized theme eco solarized # Use UTF-8 to show cool arrows that do not look like crap :) e scr.utf8 = true ``` There is an easier interface accessible from the Visual mode, just typing `Ve` ## Basic Commands Command syntax: `[.][times][cmd][~grep][@[@iter]addr!size][|>pipe]` * `;` Command chaining: `x 3;s+3;pi 3;s+3;pxo 4;` * `|` Pipe with shell commands: `pd | less` * `!` Run shell commands: `!cat /etc/passwd` * `!!` Escapes to shell, run command and pass output to radare buffer * Note: The double exclamation mark tells radare to skip the plugin list to find an IO plugin handling this command to launch it directly to the shell. A single one will walk through the io plugin list. * `` ` `` Radare commands: `` wx `!ragg2 -i exec` `` * `~` grep * `~!` grep -v * `~[n]` grep by columns `afl~[0]` * `~:n` grep by rows `afl~:0` ``` pi~mov,eax ; lines with mov or eax pi~mov&eax ; lines with mov and eax pi~mov,eax:6 ; 6 first lines with mov or eax pd 20~call[0]:0 ; grep first column of the first row matching 'call' ``` * `.cmd` Interprets command output ``` is* prints symbols .is* interprets output and define the symbols in radare (normally they are already loaded if r2 was not invoked with -n) ``` * `..` repeats last commands (same as enter \n) * `(` Used to define and run macros * `$` Used to define alias * `$$`: Resolves to current address * Offsets (`@`) are absolute, we can use $$ for relative ones `@ $$+4` * `?` Evaluate expression ``` [0x00000000]> ? 33 +2 35 0x23 043 0000:0023 35 00100011 35.0 0.000000 Note: | and & need to be escaped ``` * `?$?` Help for variables used in expressions * `$$`: Here * `$s`: File size * `$b`: Block size * `$l`: Opcode length * `$j`: When `$$` is at a `jmp`, `$j` is the address where we are going to jump to * `$f`: Same for `jmp` fail address * `$m`: Opcode memory reference (e.g. mov eax,[0x10] => 0x10) * `???` Help for `?` command * `?i` Takes input from stdin. Eg `?i username` * `??` Result from previous operations * `?s from to [step]`: Generates sequence from to every * `?p`: Get physical address for given virtual address * `?P`: Get virtual address for given physical one * `?v` Show hex value of math expr ``` ?v 0x1625d4ca ^ 0x72ca4247 = 0x64ef968d ?v 0x4141414a - 0x41414140 = 0xa ``` * `?l str`: Returns the length of string * `@@`: Used for iterations ``` wx ff @@10 20 30 Writes ff at offsets 10, 20 and 30 wx ff @@`?s 1 10 2` Writes ff at offsets 1, 2 and 3 wx 90 @@ sym.* Writes a nop on every symbol ``` ## Positioning ``` s address: Move cursor to address or symbol s-5 (5 bytes backwards) s- undo seek s+ redo seek ``` ## Block size The block size is the default view size for radare. All commands will work with this constraint, but you can always temporally change the block size just giving a numeric argument to the print commands for example (px 20) ``` b size: Change block size ``` ## JSON Output Most of commands such as (i)nfo and (p)rint commands accept a `j` to print their output in `json` ``` [0x100000d78]> ij {"bin":{"type":"mach0","class":"MACH064","endian":"little","machine":"x86 64 all","arch":"x86","os":"osx","lang":"c","pic":true,"canary":false,"nx":false,"crypto":false,"va":true,"bits":64,"stripped":true,"static":false,"linenums":false,"syms":false,"relocs":false},"core":{"type":"Executable file","os":"osx","arch":"x86 64 all","bits":64,"endian":"little","file":"/bin/ls","fd":6,"size":34640,"mode":"r--","block":256,"uri":"/bin/ls","format":"mach064"}} ``` ## Analyze ``` aa: Analyze all (fcns + bbs) same that running r2 with -A ahl : fake opcode length for a range of bytes ad: Analyze data ad@rsp (analyze the stack) ``` Function analysis (normal mode) ``` af: Analyze functions afl: List all functions number of functions: afl~? afi: Returns information about the functions we are currently at afr: Rename function: structure and flag afr off: Restore function name set by r2 afn: Rename function afn strlen 0x080483f0 af-: Removes metadata generated by the function analysis af+: Define a function manually given the start address and length af+ 0xd6f 403 checker_loop axt: Returns cross references to (xref to) axf: Returns cross references from (xref from) ``` Function analysis (visual mode) ``` d, f: Function analysis d, u: Remove metadata generated by function analysis ``` Opcode analysis: ``` ao x: Analyze x opcodes from current offset a8 bytes: Analyze the instruction represented by specified bytes ``` ## Information ``` iI: File info iz: Strings in data section izz: Strings in the whole binary iS: Sections iS~w returns writable sections is: Symbols is~FUNC exports il: Linked libraries ii: Imports ie: Entrypoint ``` Mitigations: ``` i~pic : check if the binary has position-independent-code i~nx : check if the binary has non-executable stack i~canary : check if the binary has canaries ``` Get function address in GOT table: `pd 1 @ sym.imp` Returns a `jmp [addr]` where `addr` is the address of function in the GOT. Similar to `objdump -R | grep ` # Print ``` psz n @ offset: Print n zero terminated String px n @ offset: Print hexdump (or just x) of n bytes pxw n @ offset: Print hexdump of n words pxw size@offset prints hexadecimal words at address pd n @ offset: Print n opcodes disassembled pD n @ offset: Print n bytes disassembled pi n @ offset: Print n instructions disassembled (no address, XREFs, etc. just instructions) pdf @ offset: Print disassembled function pdf~XREF (grep: XREFs) pdf~call (grep: calls) pcp n @ offset: Print n bytes in python string output. pcp 0x20@0x8048550 import struct buf = struct.pack ("32B", 0x55,0x89,0xe5,0x83,0xzz,0xzz,0xzz,0xzz,0xf0,0x00,0x00, 0x00,0x00,0xc7,0x45,0xf4,0x00,0x00,0x00,0x00,0xeb,0x20, 0xc7,0x44,0x24,0x04,0x01,0x00,0x00,0x00,0xzz,0xzz) p8 n @ offset: Print n bytes (8bits) (no hexdump) pv: Print file contents as IDA bar and shows metadata for each byte (flags , ...) pt: Interpret data as dates pf: Print with format pf.: list all formats p=: Print entropy ascii graph ``` ## Write ``` wx: Write hex values in current offset wx 123456 wx ff @ 4 wa: Write assembly wa jnz 0x400d24 wc: Write cache commit wv: Writes value doing endian conversion and padding to byte wo[x]: Write result of operation wow 11223344 @102!10 write looped value from 102 to 102+10 0x00000066 1122 3344 1122 3344 1122 0000 0000 0000 wox 0x90 XOR the current block with 0x90. Equivalent to wox 0x90 $$!$b (write from current position, a whole block) wox 67 @4!10 XOR from offset 4 to 10 with value 67 wf file: Writes the content of the file at the current address or specified offset (ASCII characters only) wF file: Writes the content of the file at the current address or specified offset wt file [sz]: Write to file (from current seek, blocksize or sz bytes) Eg: Dump ELF files with wt @@ hit0* (after searching for ELF headers: \x7fELF) wopO 41424344 : get the index in the De Bruijn Pattern of the given word ``` ## Flags Flags are labels for offsets. They can be grouped in namespaces as `sym` for symbols ... ``` f: List flags f label @ offset: Define a flag `label` at offset f str.pass_len @ 0x804999c f-label: Removes flag fr: Rename flag fd: Returns position from nearest flag (looking backwards). Eg => entry+21 fs: Show all flag spaces fs flagspace: Change to the specified flag space ``` ## yank & paste ``` y n: Copies n bytes from current position y: Shows yank buffer content with address and length where each entry was copied from yp: Prints yank buffer yy offset: Paste the contents of the yank buffer at the specified offset yt n target @ source: Yank to. Copy n bytes from source to target address ``` ## Visual Mode: `V` enters visual mode ``` q: Exits visual mode hjkl: move around (or HJKL) (left-down-up-right) o: go/seek to given offset ?: Help .: Seek EIP : Follow address of the current jump/call :cmd: Enter radare commands. Eg: x @ esi d[f?]: Define cursor as a string, data, code, a function, or simply to undefine it. dr: Rename a function df: Define a function v: Get into the visual code analysis menu to edit/look closely at the current function. p/P: Rotate print (visualization) modes hex, the hexadecimal view disasm, the disassembly listing Use numbers in [] to follow jump Use "u" to go back debug, the debugger words, the word-hexidecimal view buf, the C-formatted buffer annotated, the annotated hexdump. c: Changes to cursor mode or exits the cursor mode select: Shift+[hjkl] i: Insert mode a: assembly inline A: Assembly in visual mode y: Copy Y: Paste f: Creates a flag where cursor points to in the hexdump view to toggle between hex and strings columns V: View ascii-art basic block graph of current function W: WebUI x, X: XREFs to current function. ("u" to go back) t: track flags (browse symbols, functions..) gG: Begin or end of file HUD _ Show HUD backspace: Exits HUD We can add new commands to HUD in: radare2/shlr/hud/main ;[-]cmt: Add/remove comment m: Define a bookmark ': Go to previously defined bookmark ``` ## ROP ``` /R opcodes: Search opcodes /R pop,pop,ret /Rl opcodes: Search opcodes and print them in linear way /Rl jmp eax,call ebx /a: Search assembly /a jmp eax pda: Returns a library of gadgets that can be use. These gadgets are obtained by disassembling byte per byte instead of obeying to opcode length ``` Search depth can be configure with following properties: ``` e search.roplen = 4 (change the depth of the search, to speed-up the hunt) ``` ## Searching ``` / bytes: Search bytes \x7fELF ``` Example: Searching function preludes: ``` push ebp mov ebp, esp Opcodes: 5589e5 /x 5589e5 [# ]hits: 54c0f4 < 0x0804c600 hits = 1 0x08049f70 hit0_0 5589e557565383e4f081ec 0x0804c31a hit0_1 5589e583ec18c704246031 0x0804c353 hit0_2 5589e583ec1889442404c7 0x0804c379 hit0_3 5589e583ec08e87cffffff 0x0804c3a2 hit0_4 5589e583ec18c70424302d pi 5 @@hit* (Print 5 first instructions of every hit) ``` Its possible to run a command for each hit. Use the `cmd.hit` property: ``` e cmd.hit=px ``` ## Comments and defines ``` Cd [size]: Define as data C- [size]: Define as code Cs [size]: Define as String Cf [size]: Define as struct We can define structures to be shown in the disassembly CC: List all comments or add a new comment in console mode C* Show all comments/metadata CC add new comment CC- remove comment ``` ## Magic files ``` pm: Print Magic files analysis [0x00000000]> pm 0x00000000 1 ELF 32-bit LSB executable, Intel 80386, version 1 ``` Search for magic numbers ``` /m [magicfile]: Search magic number headers with libmagic ``` Search can be controlled with following properties: ``` search.align search.from (0 = beginning) search.to (0 = end) search.asmstr search.in ``` ## Yara Yara can also be used for detecting file signatures to determine compiler types, shellcodes, protections and more. ``` :yara scan ``` ## Zignatures Zignatures are useful when dealing with stripped binaries. We can take a non-stripped binary, run zignatures on it and apply it to a different binary that was compiled statically with the same libraries. ``` zg : Generate signatures eg: zg go go.z Run the generated script to load signatures eg: . go.z z: To show signatures loaded: ``` Zignatures are applied as comments: ``` r2-(pid2)> pd 35 @ 0x08049adb-10 | 0x08049adb call fcn.0805b030 | fcn.0805b030(unk, unk, unk, unk) ; sign.sign.b.sym.fmt.Println | 0x08049ae0 add esp, 0xc | 0x08049ae3 call fcn.08095580 ``` ## Compare files ``` r2 -m 0xf0000 /etc/fstab ; Open source file o /etc/issue ; Open file2 at offset 0 o ; List both files cc offset: Diff by columns between current offset address and "offset" ``` ## Graphs Basic block graphs ``` af: Load function metadata ag $$ > a.dot: Dump basic block graph to file ag $$ | xdot -: Show current function basic block graph ``` Call graphs ``` af: Load function metadata agc $$ > b.dot: Dump basic block graph to file ``` Convert .dot in .png ``` dot -Tpng -o /tmp/b.png b.dot ``` Generate graph for file: ``` radiff2 -g main crackme.bin crackme.bin > /tmp/a xdot /tmp/a ``` ## Debugger Start r2 in debugger mode. r2 will fork and attach ``` r2 -d [pid|cmd|ptrace] (if command contains spaces use quotes: r2 -d "ls /") ptrace://pid (debug backend does not notice, only access to mapped memory) ``` To pass arguments: ``` r2 -d rarun2 program=pwn1 arg1=$(python exploit.py) ``` To pass stdin: ``` r2 -d rarun2 program=/bin/ls stdin=$(python exploit.py) ``` Commands ``` do: Reopen program dp: Shows debugged process, child processes and threads dc: Continue dcu
: Continue until symbol (sets bp in address, continua until bp and remove bp) dc[sfcp]: Continue until syscall(eg: write), fork, call, program address (To exit a library) ds: Step in dso: Step out dss: Skip instruction dr register=value: Change register value dr(=)?: Show register values db address: Sets a breakpoint at address db sym.main add breakpoint into sym.main db 0x804800 add breakpoint db -0x804800 remove breakpoint dsi (conditional step): Eg: "dsi eax==3,ecx>0" dbt: Shows backtrace drr: Display in colors and words all the refs from registers or memory dm: Shows memory map (* indicates current section) [0xb776c110]> dm sys 0x08048000 - 0x08062000 s r-x /usr/bin/ls sys 0x08062000 - 0x08064000 s rw- /usr/bin/ls sys 0xb776a000 - 0xb776b000 s r-x [vdso] sys 0xb776b000 * 0xb778b000 s r-x /usr/lib/ld-2.17.so sys 0xb778b000 - 0xb778d000 s rw- /usr/lib/ld-2.17.so sys 0xbfe5d000 - 0xbfe7e000 s rw- [stack] ``` To follow child processes in forks (set-follow-fork-mode in gdb) ``` dcf until a fork happen then use dp to select what process you want to debug. ``` PEDA like details: `drr;pd 10@-10;pxr 40@esp` Debug in visual mode ``` toggl breakpoints with F2 single-step with F7 (s) step-over with F8 (S) continue with F9 ``` ## WebGUI (Enyo) ``` =h: Start the server =H: Start server and browser ``` # Radare2 suite commands All suite commands include a `-r` flag to generate instructions for r2 ## rax2 - Base conversion ``` -e: Change endian -K: random ASCII art to represent a number/hash. Similar to how SSH represents keys -s: hexstr -> raw -S: raw -> hexstr ``` ## rahash2 - Entropy, hashes and checksums ``` -a: Specify the algorithm -b XXX: Block size -B: Print all blocks -a entropy: Show file entropy or entropy per block (-B -b 512 -a entropy) ``` ## radiff2 - File diffing ``` -s: Calculate text distance from two files. -d: Delta diffing (For files with different sizes. Its not byte per byte) -C: Code diffing (instead of data) ``` Examples: ``` Diff original and patched on x86_32, using graphdiff algorithm radiff2 -a x86 -b32 -C original patched Show differences between original and patched on x86_32 radiff2 -a x86 -b32 original patched : ``` ## rasm2 - Assembly/Disassembly ``` -L: Supported architectures -a arch instruction: Sets architecture rasm2 -a x86 'mov eax,30' => b81e000000 -b tam: Sets block size -d: Disassembly rasm2 -d b81e000000 => mov eax, 0x1e -C: Assembly in C output rasm2 -C 'mov eax,30' => "\xb8\x1e\x00\x00\x00" -D: Disassemble showing hexpair and opcode rasm2 -D b81e0000 => 0x00000000 5 b81e000000 mov eax, 0x1e -f: Read data from file instead of ARG. -O filename: Write data to file ``` ## rafind2 - Search ``` -Z: Look for Zero terminated strings -s str: Look for specific string ``` ## ragg2 - Shellcode generator, C/opcode compiler ``` -P: Generate De Bruijn patterns ragg2 -P 300 -r -a arch: Configure architecture -b bits: Specify architecture bits (32/64) -i shellcode: Specify shellcode to generate -e encoder: Specify encoder ``` Example: ``` Generate a x86, 32 bits exec shellcode ragg2 -a x86 -b 32 -i exec ``` ## rabin2 - Executable analysis: symbols, imports, strings ... ``` -I: Executable information -c: Returns classes. Useful to list Java Classes -l: Dynamic linked libraries -s: Symbols -z: Strings ``` ## rarun2 - Launcher to run programs with different environments, args, stdin, permissions, fds Examples: ``` r2 -b 32 -d rarun2 program=pwn1 arg1=$(ragg2 -P 300 -r) : runs pwn1 with a De Bruijn Pattern as first argument, inside radare2's debugger, and force 32 bits r2 -d rarun2 program=/bin/ls stdin=$(python exploit.py) : runs /bin/ls with the output of exploit.py directed to stdin ```