Merge tag 'pull-duso-tool-docs' of https://github.com/Dusoleil/lib-des-gnux

Pulling an assortment of tools documentation from Dusoleil.  I did fix 1
minor conflict in the readme file.

* tag 'pull-duso-tool-docs' of https://github.com/Dusoleil/lib-des-gnux: (21 commits)
  Remove 'sudo' from install command.
  Fix typo in for loop in asm rep prefix doc
  Add install/uninstall instructions to radare doc
  Add radare2 command cheatsheet
  Add doc about fixing a ptrace error in debugger.
  Add doc about the rep prefix on an x86 instruction
  Add short doc on the one_gadget tool
  Remove curl example line from README
  Add cheatsheet of common flags for curl
  Add a short doc with links to reqbin and hookbin
  Add Short Doc About proxychains
  Add Example that Uses Custom Charset
  Update Incremental Examples to Use Short Flag
  Add Info About Issues with Small Workload
  Add More Mask/Hybrid Attacks to Examples
  Add Examples for Showing Cracks/Identifying Type
  Add --status Flag to Examples
  Fix Paths in Examples
  Remove "LIGHT"/"HEAVY" Descriptors from Examples
  Add hashcat doc
  ...

9 files changed, 572 insertions, 0 deletions

diff --git a/docs/crypto/hashcat.txt b/docs/crypto/hashcat.txt
new file mode 100644
index 0000000..2f969aa
--- /dev/null
+++ b/docs/crypto/hashcat.txt
@@ -0,0 +1,134 @@
+hashcat is a hardware accelerated hash cracking tool
+
+useful one-liners mostly stolen from naive-hashcat:
+https://github.com/Kr4ken-9/naive-hashcat/blob/master/naive-hashcat.sh
+hashcat -I
+hashcat --example-hashes | grep -A2 '\$5\$'
+hashcat --show -m <type> <file>
+# DICTIONARY ATTACK
+hashcat --status -w 3 -m <type> -a 0 <file> dicts/rockyou.txt
+# DICTIONARY ATTACK WITH RULES
+hashcat --status -w 3 -m <type> -a 0 <file> dicts/rockyou.txt -r rules/d3ad0ne.rule
+hashcat --status -w 3 -m <type> -a 0 <file> dicts/rockyou.txt -r rules/rockyou-30000.rule
+hashcat --status -w 3 -m <type> -a 0 <file> dicts/rockyou.txt -r rules/dive.rule
+# MASK ATTACK (BRUTE-FORCE)
+hashcat --status -w 3 -m <type> -a 3 -i -1 ?l?d <file> ?1?1?1?1?1?1?1?1?1?1?1
+hashcat --status -w 3 -m <type> -a 3 -i <file> ?a?a?a?a?a?a?a?a?a?a?a
+hashcat --status -w 3 -m <type> -a 3 <file> masks/rockyou-1-60.hcmask
+# HYBRID ATTACK (DICTIONARY + BRUTE-FORCE)
+hashcat --status -w 3 -m <type> -a 6 -i <file> dicts/rockyou.txt ?a?a?a?a?a?a?a?a?a?a?a
+hashcat --status -w 3 -m <type> -a 6 <file> dicts/rockyou.txt masks/rockyou-1-60.hcmask
+hashcat --status -w 3 -m <type> -a 7 -i <file> ?a?a?a?a?a?a?a?a?a?a?a dicts/rockyou.txt
+hashcat --status -w 3 -m <type> -a 7 <file> masks/rockyou-1-60.hcmask dicts/rockyou.txt
+# COMBINATION ATTACK
+hashcat --status -w 3 -m <type> -a 1 <file> dicts/rockyou.txt dicts/rockyou.txt
+# STDOUT/STDIN (for workload issues)
+hashcat --stdout -w 3 -a 6 dicts/rockyou.txt masks/rockyou-1-60.hcmask | hashcat --status -w 3 -m <type> <file>
+
+general command structure:
+hashcat [options] <file with hashes> [wordlist, mask, or mask file] [-r rule file]
+
+useful options:
+-I                      -- list all installed opencl platforms and devices
+--identify              -- try to detect what type of hash is in the file
+--example-hashes        -- print out an example hash for each hash type
+-D <num>                -- specify a device type to use (1=CPU,2=GPU,3=FPGA)
+-d <num>                -- specify a device to use
+-w <num>                -- workload profile (1-4 where 1 is light on resources and 4 should be run headless)
+-m <num>                -- hash type
+-a <num>                -- attack type
+-i                      -- enable increment mode for mask attacks
+--increment-min <num>   -- minimum length for incrementing
+--increment-max <num>   -- maximum length for incrementing
+-1 <charset>            -- custom charset 1
+-2 <charset>            -- custom charset 2
+-3 <charset>            -- custom charset 3
+-4 <charset>            -- custom charset 4
+-r <file>               -- rules file
+-j <rule>               -- in combinator attack, use single rule for left dictionary
+-k <rule>               -- in combinator attack, use single rule for right dictionary
+-o <file>               -- output file
+--status                -- automatic update of status screen
+--show                  -- if a hash has already been cracked and saved, print it
+--stdout                -- don't crack, just print out candidates. useful to generate a wordlist for another program
+-g <num>                -- randomly generate some number of rules
+
+Hash Type
+You specify what is in your file (e.g. an MD5 hash, an /etc/passwd file, a WPA handshake, etc.) with -m
+You can try to use the --identify and --example-hashes flags to figure out what to use.
+There is also a list of all of the modes in the man page and help output.
+short list of some useful ones:
+0       - MD5
+500     - md5crypt ($1$)
+1       - SHA1
+1400    - SHA256
+7400    - sha256crypt ($5$)
+1700    - SHA512
+1800    - sha512crypt ($6$)
+3200    - bcrypt/blowfish ($2*$)
+11600   - 7zip ($7z$)
+2500    - WPA handshake converted into a .hccapx file
+400     - phpass/wordpress/phpbb3/joomla ($P$)
+16500   - JSON Web Token (JWT)
+
+For WPA handshakes, you need to convert the .pcap into a .hccapx
+This can be done with the hashcat-utils package (may be in package manager, otherwise git)
+$ git clone https://github.com/hashcat/hashcat-utils.git
+Or using aircrack-ng (which you probably used to get it in the first place)
+$ aircrack-ng -j <out-file> <pcap-file>
+
+Attack Type
+0 - "straight mode" or dictionary attack. you can also specify rule files - https://hashcat.net/wiki/doku.php?id=rule_based_attack
+1 - "combinator mode" cartesian product of two dictionaries. can also use a single rule on each side with -j/-k
+3 - "mask mode" or brute force mode. uses a fixed length pattern with wildcards - https://hashcat.net/wiki/doku.php?id=mask_attack
+6 - "hybrid" wordlist+mask
+7 - "hybrid" mask+wordlist
+hybrid - basically a combinator attack but one side is a brute force mask instead of another wordlist
+
+Workload Profiles
+The docs claim that 3 and 4 would cause your system to be unusable, but I wasn't seeing that.
+I also didn't see a very significant improvement from 3 to 4, though.
+The default seems to be around 2, but there was a significant performance increase at 3.
+
+Tweaking Keyspace for Performance
+Straight dictionary attacks will generally be pretty fast, but as you add rules and masks, things grow quickly.
+In fact, just a single long mask on its own is often infeasible.
+Generally, you don't want to run against rockyou and a huge collection of rules (or even just one complex one).
+It's better to either use rockyou with a simple rule or have a limited wordlist and a large collection of rules.
+If you're brute forcing, generally you don't want a huge mask.
+If you're hybrid brute forcing, you also don't want a huge wordlist with tons of different masks.
+Again, you want to pick a limited word list and a collection of simple masks.
+One weird gotcha, though, is that hashcat will produce a "base" list of candidates on the CPU
+that then gets blown up into more candidates with an amplifier on the GPU.
+If, after this amplification, the candidate list is too short, the GPU's parallelization can't be taken advantage of.
+For instance, in a hybrid attack with a small wordlist and large list of masks, but some of the masks are very short.
+Each mask in the list will generate a separate candidate list via amplification on the GPU.
+For the short masks, this candidate list will be very short.  This causes a HUGE bottleneck where the GPU can't parallelize.
+Fortunately, hashcat will print out a warning when this happens to let you know.
+It can be somewhat mitigated by tweaking your lists or by running STDOUT/STDIN mode.
+This will generate the candidates as one big batch and pipe them into the main hashcat instance.
+Since we're effectively combining the different amplified candidate lists into one,
+we have a better chance of have a long enough candidate list for the GPU to be properly utilized.
+The main downside is that the main hashcat instance has no idea how long our keyspace is and can't estimate the run time.
+https://hashcat.net/faq/morework
+
+Getting Hardware to Work
+Hashcat uses opencl most of the time.  It can use CUDA directly as well.
+We need to set up all of the drivers and opencl implementations to get it to use our hardware.
+Even if we wanted to run on the CPU, we would need the opencl implementation that uses it.
+Usually the CPU implementation would be through pocl (portable computing language).
+$ apt install pocl-opencl-icd
+There are mesa implementations for opencl, but they're kind of shit.
+$ apt install mesa-opencl-icd
+You can access CUDA through opencl, but it may still need CUDA libraries installed
+A better option would be to have hashcat use CUDA directly since you'll be installing the libraries anyways.
+https://developer.nvidia.com/cuda-downloads
+And make sure hashcat is selecting the direct implementation instead of opencl.
+On AMD, there is the ROCM API which is similar to CUDA.
+With hashcat, we need an opencl implementation to ROCM.
+https://rocmdocs.amd.com/en/latest/Installation_Guide/Installation-Guide.html
+As it turns out, ROCM is only supported on dedicated GPUs.
+There doesn't seem to be a proper solution for APUs.  There is a 3rd party implementation of ROCM for APUs here:
+https://apt.bruhnspace.com/
+But I couldn't get it working.
+
diff --git a/docs/nix/iptables.txt b/docs/nix/iptables.txt
new file mode 100644
index 0000000..41912a7
--- /dev/null
+++ b/docs/nix/iptables.txt
@@ -0,0 +1,147 @@
+iptables is a configuration utility for the Linux kernel's firewall
+
+useful one-liners:
+iptables -t filter -L -v
+iptables -t filter -F
+iptables -t filter -F INPUT
+iptables -t filter -P INPUT DROP
+iptables -t filter -A INPUT -s 8.8.8.8 -j DROP
+iptables -t filter -A INPUT -p tcp --dport 80 -j DROP
+iptables -t filter -A FORWARD -p tcp --dport 22 -j REJECT --reject-with tcp-reset
+iptables -t nat -A POSTROUTING -o wlan0 -j MASQUERADE
+iptables -t nat -A POSTROUTING -p tcp --sport 1337 -j MASQUERADE --to-ports 1024-30000
+iptables -t nat -A PREROUTING -p tcp --dport 80 -j REDIRECT --to-ports 8080
+iptables -t nat -D POSTROUTING 1
+
+useful options:
+-t <table>                              -- chooses a table to operate on
+-L                                      -- print the contents of the selected table
+-v                                      -- verbose mode (can give more 'v's for more verbosity)
+-F [<chain>]                            -- flush/clear the contents of the selected table or a chain in that table
+-A <chain>                              -- append a new rule to the selected chain in the selected table
+-I <chain> <index>                      -- insert a rule at specified index in the selected chain in the selected table
+-D <chain> <index>                      -- delete a rule at specified index in the selected chain in the selected table
+-R <chain> <index>                      -- replace a rule at specified index in the selected chain in the selected table
+-P <chain> <target>                     -- change the default policy of the selected chain in the selected table
+-p <protocol>                           -- match on protocol (ICMP,TCP,UDP)
+-i <interface>                          -- match on incoming interface
+-s <address>[/mask]                     -- match on source address
+--sport <port>[:<port>]                 -- match on source port(s) (only works with -p)
+-o <interface>                          -- match on outgoing interface
+-d <address>[/mask]                     -- match on destination address
+--dport <port>[:<port>]                 -- match on destination port(s) (only works with -p)
+--to-source <address>[:<port>[-<port>]][-<address>]       -- for SNAT target. Sets the source address(es)
+--to-destination <address>[:<port>[-<port>]][-<address>]  -- for DNAT target. Sets the destination address(es)
+--to-ports <port>[-<port>]              -- for the MASQUERADE and REDIRECT targets. Sets the port(s) of a packet.
+--reject-with <response>                -- for the REJECT target. Return an error after dropping a packet.
+
+It operates on "rules" which are a set of criteria to match a packet by and a "target" which decides what to do with the packet.
+The rules are organized into predefined "chains" which apply at different parts of the packet's journey through the system's routing.
+The rules in a chain are evaluated and potentially applied in the sequence they were added to the chain.
+The chains are organized into "tables" which are mostly just an organization construct.
+Each chain also has a default policy that applies if the packet makes it all the way through the chain (no rule applied).
+
+There are 5 main tables:
+-raw configures packets to be exempt from connection tracking
+-mangle is used for specialized packet alterations
+-security is used for Mandatory Access Control rules
+-nat is used for Network Address Translation
+-filter is the default table which does the stuff you usually think of when thinking about firewalls
+
+For the most part, you'll only ever care about the filter and nat tables.
+Each table has a predefined list of chains which apply at different times as the packet is routed.
+Technically you can jump into a user-defined chain as a target for a rule as well.
+These cannot have default policies. If every rule in one fails to match, the packet goes back to the calling chain.
+A flowchart from the Arch wiki presents a simplified overview of this:
+
+                               XXXXXXXXXXXXXXXXXX
+                             XXX     Network    XXX
+                               XXXXXXXXXXXXXXXXXX
+                                       +
+                                       |
+                                       v
+ +-------------+              +------------------+
+ |table: filter| <---+        | table: nat       |
+ |chain: INPUT |     |        | chain: PREROUTING|
+ +-----+-------+     |        +--------+---------+
+       |             |                 |
+       v             |                 v
+ [local process]     |           ****************          +--------------+
+       |             +---------+ Routing decision +------> |table: filter |
+       v                         ****************          |chain: FORWARD|
+****************                                           +------+-------+
+Routing decision                                                  |
+****************                                                  |
+       |                                                          |
+       v                        ****************                  |
++-------------+       +------>  Routing decision  <---------------+
+|table: nat   |       |         ****************
+|chain: OUTPUT|       |               +
++-----+-------+       |               |
+      |               |               v
+      v               |      +-------------------+
++--------------+      |      | table: nat        |
+|table: filter | +----+      | chain: POSTROUTING|
+|chain: OUTPUT |             +--------+----------+
++--------------+                      |
+                                      v
+                               XXXXXXXXXXXXXXXXXX
+                             XXX    Network     XXX
+                               XXXXXXXXXXXXXXXXXX
+
+or you can look at a more detailed version:
+https://www.frozentux.net/iptables-tutorial/chunkyhtml/images/tables_traverse.jpg
+The first routing decision has to do with whether the packet's destination is the local machine or elsewhere.
+The other routing decisions have to do with deciding which interface to send the packet to.
+
+filter chains:
+-INPUT
+-FORWARD
+-OUTPUT
+
+nat chains:
+-PREROUTING
+-INPUT
+-OUTPUT
+-POSTROUTING
+
+At a high level,
+PREROUTING is packets coming in from a network,
+POSTROUTING is packets going out to a network,
+FORWARD is packets coming from a network out onto a network,
+INPUT is packets coming in to a local process,
+OUTPUT is packets coming out from a local process
+
+If you're using the PREROUTING, POSTROUTING, or FORWARD chains, you are probably trying to forward packets from a network onto a network.
+If this is the case, you need to enable ip forwarding in the kernel
+$ sudo su
+$ echo "1" > /proc/sys/net/ipv4/ip_forward
+
+
+A rule's predicate has several conditions that must be met by a packet for it to apply.
+For some chains, certain conditions don't make sense and aren't allowed to be set.
+For instance, it doesn't make sense to predicate a nat PREROUTING rule on the output interface when that hasn't been decided yet.
+
+Most rules are predicated on
+-packet protocol (ICMP,TCP,UDP)
+-input interface
+-source host
+-source port
+-output interface
+-destination host
+-destination port
+
+Each rule has a target that will apply if the packet matches the rule's predicate.
+These can be a user defined chain, or a built-in target.
+
+There are quite a few built-in targets, but the vast majority of the time you will be using:
+-ACCEPT (stop traversing the current chain and pass the packet to the next chain)
+-DROP (stop traversing all chains entirely and drop the packet dead)
+-REJECT (same as drop except send back an error specified with --reject-with)
+-RETURN (if in a subchain, go back to the superior chain. if in a main chain, use the chain default policy)
+-MASQUERADE (forward incoming packets back out, but change the source address to our outgoing interface's. can also specify a new source port for the packet with --to-ports only valid in nat POSTROUTING)
+-REDIRECT (forward incoming packets to our own host. can also specify a new destination port for the packet with --to-ports only valid in nat PREROUTING and OUTPUT)
+-SNAT (forward incoming packets back out, but change the source address to the specified address(s) via --to-source)
+-DNAT (forward incoming packets back out, but change the destination address to the specified address(s) via --to-destination)
+
+note: for nat rules, only the first packet of a connection is actually mached through the table. the rest of the connection is automatically handled the same (or inverse for responses)
diff --git a/docs/nix/proxychains.txt b/docs/nix/proxychains.txt
new file mode 100644
index 0000000..3ed6b60
--- /dev/null
+++ b/docs/nix/proxychains.txt
@@ -0,0 +1,10 @@
+proxychains is a tool that allows us to issue commands over a proxy
+
+Configure your proxy setup in /etc/proxychains.conf
+e.g.
+#/etc/proxychains.conf
+socks5 172.15.18.117 1080
+
+From there we can actually use the proxy with the proxychains command.
+$ proxychains nmap -A -p- 127.0.0.1
+$ proxychains wget http://127.0.0.1:8000
diff --git a/docs/pwn/one_gadget.txt b/docs/pwn/one_gadget.txt
new file mode 100644
index 0000000..d9a4ff1
--- /dev/null
+++ b/docs/pwn/one_gadget.txt
@@ -0,0 +1,57 @@
+https://github.com/david942j/one_gadget
+$ gem install one_gadget
+
+Find libc for the target through dependencies or leaking libc version remotely
+$ ldd <target>
+https://libc.blukat.me
+https://libc.rip
+
+Give this libc binary to one_gadget
+$ one_gadget <path_to_libc>
+
+This will print out multiple offsets that, if jumped into, will call execve("/bin/sh")
+These options will also have a list of requirements for them to work.
+
+Example:
+$ one_gadget /lib/x86_64-linux-gnu/libc.so.6 
+0xe6c7e execve("/bin/sh", r15, r12)
+constraints:
+  [r15] == NULL || r15 == NULL
+  [r12] == NULL || r12 == NULL
+
+0xe6c81 execve("/bin/sh", r15, rdx)
+constraints:
+  [r15] == NULL || r15 == NULL
+  [rdx] == NULL || rdx == NULL
+
+0xe6c84 execve("/bin/sh", rsi, rdx)
+constraints:
+  [rsi] == NULL || rsi == NULL
+  [rdx] == NULL || rdx == NULL
+
+By setting the requisite registers to the correct values
+and jumping to the corresponding offset, you will get a shell.
+
+For situations where you can overwrite a GOT address, but not leak libc,
+you may want to overwrite just the last couple bytes of an address to
+a libc function that is close to the one-gadget.  This gives a good chance
+of jumping into your one-gadget.
+You can list one-gadgets that are close to a libc function with
+$ one_gadget <path_to_libc> -n <comma separated list of regular expression libc functions>
+
+You can also give the target binary to "-n" and it will consider the entire GOT
+$ one_gadget <path_to_libc> -n <path_to_target>
+
+By default, one_gadget only shows gadgets with high probability,
+but by setting "-l 1", it will show all found gadgets.
+
+By giving a bash script string, one_gadget can call your script with all found gadgets as an argument.
+The following would call 'echo <gadget offset>' for each found one-gadget
+$ one_gadget <path_to_libc> -s 'echo'
+
+This isn't particularly useful with sploit currently since you can't give cli arguments to the script right now.
+
+Some boilerplate for calling and consuming the output of one_gadget from within Python:
+def one_gadget(filename):
+  return [int(i) for i in subprocess.check_output(['one_gadget', '--raw', filename]).decode().split(' ')]
+one_gadget('/lib/x86_64-linux-gnu/libc.so.6')
diff --git a/docs/re/ptrace_not_permitted.txt b/docs/re/ptrace_not_permitted.txt
new file mode 100644
index 0000000..07ca568
--- /dev/null
+++ b/docs/re/ptrace_not_permitted.txt
@@ -0,0 +1,22 @@
+If you are seeing errors from your debugger such as
+strace: (PTRACE_ATTACH): operation not permitted
+ptrace: operation not permitted
+ptrace_attach: operation not permitted
+etc.
+
+This is likely because of a linux kernel hardening setting.
+/proc/sys/kernel/yama/ptrace_scope
+This setting prevents a process from running ptrace on a non-child process.
+Even with this on, a can still ptrace another process if it is a child.
+Debuggers like gdb and radare2 use ptrace when you attach via PID.
+
+You can turn this off
+$ sudo su
+$ echo 0 > /proc/sys/kernel/yama/ptrace_scope
+
+Turning this off is global, though.
+Instead, set the capabilities of just your debugger to override this setting.
+
+$ sudo setcap CAP_SYS_PTRACE=+eip /usr/bin/gdb
+$ sudo setcap CAP_SYS_PTRACE=+eip /usr/bin/radare2
+
diff --git a/docs/re/radare2_cheatsheet.txt b/docs/re/radare2_cheatsheet.txt
new file mode 100644
index 0000000..7c30b89
--- /dev/null
+++ b/docs/re/radare2_cheatsheet.txt
@@ -0,0 +1,88 @@
+r2 command cheatsheet
+
+https://github.com/radareorg/radare2
+https://book.rada.re
+
+#Install
+git clone https://github.com/radareorg/radare2.git
+./sys/install.sh
+
+#Uninstall
+sudo make uninstall
+sudo make purge
+
+#Run Command From Shell Without Opening r2 Prompt
+r2 -q -c "<r2 command>" <target>
+
+#Generic
+? <expr>            expression evaluation/conversions
+!<command>          run shell command from inside r2
+s <addr>            seek to address
+
+#Useful Operators
+<command1>;<command2>               do command2 after command1
+"<command>"                         don't parse r2 operators in the command
+<command> `<inner command>`         run inner command and use its output in outer command
+<command> ~<word>                   grep output of command for lines matching word
+<command> @ <address>               temporarily seek to address and run command
+<command> @@ <flag>*                run command on every flag matching flag*
+<command> @@f                       run command on all functions
+<command> @@f:<func>                run command on all functions matching name
+<command> @@s:<from> <to> <step>    run command on each offset from->to incrementing by step
+
+#Info and Analysis
+i                   print file info (including binary info; e.g. rabin -I or checksec)
+ia                  print binary info, imported symbols, and exported symbols
+il                  print linked libraries
+iS                  print sections (with permissions)
+is                  print symbols
+ic                  print classes
+afl                 print functions
+ie                  print entry points
+iM                  print main's address
+iz                  print strings in data section
+izz                 print strings in whole binary
+aaa                 analyze all
+fs                  list flagspaces
+fs <flagspace>      set current flagspace
+f                   print current flagspace
+axt [<addr>]        show references to this address
+axf [<addr>]        show references from this address
+
+#Searching
+/ <string>              search for string
+/i <string>             case-insensitive search for string
+/e /<string>/<options>  regex search for string
+/R <opcodes>            search for opcodes
+/R/ <opcodes>           regex search for opcodes
+/v <value>              search for value
+/V <min> <max>          search for value in range
+/x <hex>                search for hex string
+
+#Print Address Contents
+pdf         print function disassembled
+pdc         print function in c-like pseudo-code
+pv          print value
+px          print hexdump
+ps          print string
+psz         print zero-terminated string
+
+#Tracking Things
+afn <func> [<addr>]         rename function at address
+afvn <arg> [<old_name>]     rename variable or function argument
+
+#Visual Mode
+V                       enter visual mode
+VV                      enter visual graph mode
+:                       open r2 cli
+p                       next screen
+P                       previous screen
+g <address>             seek to address 
+[tag next to call]      seek to tag (in visual mode)
+o[tag next to call]     seek to tag (in visual graph mode)
+x                       xrefs to
+X                       xrefs from
+m<key>                  mark offset (in visual mode)
+'<key>                  seek to marked offset (in visual mode)
+u                       undo seek
+U                       redo seek
diff --git a/docs/re/rep_prefix.txt b/docs/re/rep_prefix.txt
new file mode 100644
index 0000000..23e0cec
--- /dev/null
+++ b/docs/re/rep_prefix.txt
@@ -0,0 +1,18 @@
+The "rep" prefix on a string instruction repeats that string instruction for CX block loads.
+e.g.
+STOS is "Store String"
+It will store the value in AX at the address in RDI
+(technically, STOSB, STOSW, STOD, and STOSQ use AL, AX, EAX, and RAX respectively)
+If RCX = 0x20, RDI = some buffer, and RAX = 0,
+
+`rep stosq`
+
+is equivalent to:
+
+```
+buf_ptr = buf
+for(i = 0x20; i != 0; i--)
+    *buf_ptr = 0;
+    buf_ptr++;
+```
+
diff --git a/docs/web/api-testing.txt b/docs/web/api-testing.txt
new file mode 100644
index 0000000..1c9f7b6
--- /dev/null
+++ b/docs/web/api-testing.txt
@@ -0,0 +1,7 @@
+REST/SOAP API Client
+(basically curl or burpsuite but hosted online)
+https://reqbin.com/
+
+HTTP Request Capture Server
+(host an endpoint that captures requests and let's you inspect them)
+https://hookbin.com/
diff --git a/docs/web/curl-cheatsheet.txt b/docs/web/curl-cheatsheet.txt
new file mode 100644
index 0000000..49dc4d5
--- /dev/null
+++ b/docs/web/curl-cheatsheet.txt
@@ -0,0 +1,89 @@
+curl common options cheatsheet
+
+#output control
+-v
+"verbose" mode which will print lots of other information including the actual headers in the request and response
+-o <file>
+output file to write the body of the response to
+
+#emulating a browser
+-b <cookiefile> -c <cookiefile>
+read and write cookies from the cookiefile
+-L
+follow redirects (3XX response codes)
+The RFC states that the request method shouldn't be modified for the new request,
+but for 301-303, most browsers will convert a POST into a GET
+--post301,--post302,--post303
+will maintain the request method on redirect
+
+#request header control
+-X <method>
+use the specified request method
+curl will infer this based on other flags and it is generally not needed
+also, it only changes the text in the request, so if other behavior is needed (e.g. HEAD), this won't be sufficient
+(-F,-d imply POST, -G forces GET, -I forces HEAD, -T forces PUT)
+-I
+performs a HEAD request
+(if used with -d, the data will be added as a query string)
+-G
+forces a GET request and appends any -d data as a query string
+-T <file>
+send the specified file with a PUT request
+-H <"Key: Value">
+set a request header
+--path-as-is
+prevents curl from squashing "/../" and "/./" in the path
+
+#sending data
+both the -d and -F families of flags send POST form data
+the -d family of flags uses Content-Type: application/x-www-form-urlencoded
+the -F family of flags uses Content-Type: multipart/form-data
+-d <data>
+sends the specified data in the body of the request
+multiple instances of the flag will append them with a '&' character separating them
+the special characters '=' and '@' have meaning as interpreted in the format section of this cheatsheet
+carriage returns and newlines are stripped
+--data-urlencode <data>
+same as -d except the content is urlencoded before sending it
+--data-binary <data>
+same as -d except newlines and carriage returns are preserved and there are no conversions
+--data-raw <data>
+same as --data-binary except there is no special interpretation of the @ character
+-F <name=content>
+sends data in key/value pairs similar to how a browser works when submitting a form
+content prefixed with '@' or '<' have meaning as interpreted in the format section of this cheatsheet
+--form-string <name=string>
+same as -F except '@', '<', and ';type=' are have no special meaning
+--raw
+disables all HTTP decoding of content and transfer encoding and passes them on unaltered
+
+#various formats for specifying data
+For the -d family of flags:
+-d <content>
+performs any special handling of the content and then passes it on
+-d <name=content>
+performs any special handling of the content part and then passes it on
+-d <=content>
+strips the leading '=', performs any special handling of the content, and then passes it on
+this is mostly useful if the data contains special characters that should be encoded rather than acted on by curl
+-d <@filename>
+performs any special handling of the contents of the file and then passes it on
+-d <name@filename>
+performs any special handling of the contents of the file, prepends it with "name=", and then passes it on
+
+For the -F family of flags:
+-F <name=content>
+sends the key/value pair "name=content" as a field of the form
+each key/value pair in the form should be specified with their own separate -F flag
+-F <name=<filename>
+same as a normal plain-text field except the content is read from the specified file
+-F <name=@filename>
+uploads the file as the content of a named field of a form
+the contents of the file are automatically handled the way a browser handles uploading files through a form
+-F <name=@filename;meta=data>
+by appending ';' after a filename, you can specify various metadata that controls the file upload
+for a comprehensive list, check the man page
+;type=image/png
+set the Content-Type of the file
+;filename=foo.bar
+give the filename of the uploaded file (otherwise curl automatically gives it as the original filename)