Can I view a raw DER binary file? - x509

so I am learning X.509 certificates and I got a certificate from a random site with openssl, now it is in PEM format, and for example when I open the PEM in a text viewer, I can see it in it's pure PEM view, and I know how to decode it in openssl to see what it actually says.
But when I convert it into a DER format with this
openssl x509 -in cert.pem -out cert.der -outform DER
I get a DER file and when I view it in a text editor I don't get the binary view.
Is there a way to see the binary view of DER?
Thank you in advance,
Dubbed_Kiwi

Use the following:
openssl x509 -inform der -in CERTIFICATE.der -text -noout

Related

OpenSSL RSA public key digest

I'm trying to calculate the hash over a public key on both iOS (Swift) and macOS (terminal & OpenSSL), but both platforms export the key in a slightly different format.
My Swift code extracts the sequence containing both the modulus and exponent (according to Apple this is the PKCS#1 container).
let export = SecKeyCopyExternalRepresentation(publicKey, nil)! as Data
let hash = SHA256.hash(data: export)
// SHA256 digest: 57fc8238c609045b7c0b546f58d5f797ebec4e39eff481459edfb67bd850834d
print(hash)
Now when I do similar things with the terminal I get a different output.
openssl rsa -pubin -outform DER | openssl dgst -sha256
# writing RSA key
# 0ee9c99ef4ca3316e90dde23925bc9a670fa309d6f4663bb5d42050b5089b086
The latter one is cause by OpenSSL wrapping the output in a fuller structured ASN.1 container.
SEQUENCE (ASN.1 container)
SEQUENCE
OID (RSA algorithm)
NULL
BITSTRING
SEQUENCE (iOS container)
INTEGER (Modulus)
INTEGER (Exponent)
How can I use OpenSSL to export the key into only the sequence iOS expects, so the has will be the same for both commands?
It turns out OpenSSL has an undocumented parameter -RSAPublicKey_out that outputs the same data that SecKeyCopyExternalRepresentation does.
openssl rsa -pubin -RSAPublicKey_out -outform DER | openssl dgst -sha256
This provides the same digest for both iOS and macOS

How to use OPENSSL to sign an email message and CURL to send it?

I would like to know how to sign it with an email digital certificate and then use CURL to send this signed email message.
Below is an example of a simple TEXT/PLAIN email message that I would like to sign.
Content-Type: text/plain; charset="utf-8"
Content-Transfer-Encoding: 7bit
MIME-Version: 1.0 (Created with SublimeText 3)
Date: Fri, 01 Jan 2021 23:59:59 -0700
Message-ID: <aade2ef2-960f-4e0d-94e4-d100f5270d28#initech.com>
Subject: TPS Report #1001
From: "Michael # Initech" <michael#initech.com>
To: "Peter # Initech" <peter#initech.com>
User-Agent: CURL/7.75.0
Good morning.
This is a message in plain text format.
It contains no inline images or attachments.
Each line is no more than 76 characters in length.
Please reach out if you have any questions.
Thank you,
Michael Bolton
SENIOR DEVELOPER
michael#initech.com
P | 801.555.1234
I place the entire message in a file called singlepart--text-plain.eml and then I use CURL to send it.
curl --verbose -ssl smtps://secure.email.com:465 --login-options AUTH=PLAIN --user michael#initech.com:Letmein --mail-from michael#initech.com --mail-rcpt peter#initech.com --mail-rcpt-allowfails --upload-file singlepart--text-plain.eml
Bam. That is all it takes.
Now the following link describes how to sign mime messages with OPENSSL.
https://www.misterpki.com/openssl-smime/
openssl smime -sign -in singlepart--text-plain.eml -text -out signed-singlepart--text-plain.eml -signer michael-digital-signature.pem
RFC 8551 Section 3.5, 3.5.1 & 3.5.2 shows limited examples on how to structure the message and my question is how to correctly do this.
https://www.rfc-editor.org/rfc/rfc8551#section-3.5
What I don't know is, what am I signing?
The entire content?
Just the literal body of the message?
Is this supposed to be a multipart message containing the body of text unchanged and a digital signature as a base64 attachment?
Or is it supposed to contain modified/signed text within a single part just like text/plain?
As you know, RFC documents are not for the faint of heart.
Only the message body is signed. That is everything after the blank line that comes after the headers.
Headers cannot be included because they can be changed (existing ones modified, or new ones added) by mail servers and mail clients on their way to the recipient.
However, there are approaches to include some important headers (like To and Subject) by copying them to the body, but they're not widely supported (yet?).
openssl smime knows how to handle the S/MIME message correctly, so its input is the complete message (singlepart--text-plain.eml in your example).
Here's a load of useful openssl smime examples which I've copied from the page http://openssl.cs.utah.edu/docs/apps/smime.html which, much to my regret, seems to be gone:
Create a cleartext signed message:
openssl smime -sign -in message.txt -text -out mail.msg \
-signer mycert.pem
Create an opaque signed message:
openssl smime -sign -in message.txt -text -out mail.msg -nodetach \
-signer mycert.pem
Create a signed message, include some additional certificates and read the private key from another file:
openssl smime -sign -in in.txt -text -out mail.msg \
-signer mycert.pem -inkey mykey.pem -certfile mycerts.pem
Create a signed message with two signers:
openssl smime -sign -in message.txt -text -out mail.msg \
-signer mycert.pem -signer othercert.pem
Send a signed message under Unix directly to sendmail, including headers:
openssl smime -sign -in in.txt -text -signer mycert.pem \
-from steve#openssl.org -to someone#somewhere \
-subject "Signed message" | sendmail someone#somewhere
Verify a message and extract the signer's certificate if successful:
openssl smime -verify -in mail.msg -signer user.pem -out signedtext.txt
Send encrypted mail using triple DES:
openssl smime -encrypt -in in.txt -from steve#openssl.org \
-to someone#somewhere -subject "Encrypted message" \
-des3 user.pem -out mail.msg
Sign and encrypt mail:
openssl smime -sign -in ml.txt -signer my.pem -text \
| openssl smime -encrypt -out mail.msg \
-from steve#openssl.org -to someone#somewhere \
-subject "Signed and Encrypted message" -des3 user.pem
Note: the encryption command does not include the -text option because the message being encrypted already has MIME headers.
Decrypt mail:
openssl smime -decrypt -in mail.msg -recip mycert.pem -inkey key.pem
The output from Netscape form signing is a PKCS#7 structure with the detached signature format. You can use this program to verify the signature by line wrapping the base64 encoded structure and surrounding it with:
-----BEGIN PKCS7-----
-----END PKCS7-----
and using the command:
openssl smime -verify -inform PEM -in signature.pem -content content.txt
Alternatively you can base64 decode the signature and use:
openssl smime -verify -inform DER -in signature.der -content content.txt
Create an encrypted message using 128 bit Camellia:
openssl smime -encrypt -in plain.txt -camellia128 -out mail.msg cert.pem
Add a signer to an existing message:
openssl smime -resign -in mail.msg -signer newsign.pem -out mail2.msg
This is a recap starting from the main purpose of the question.
RFC-2311 - Section 3.4.3.3 Sample multipart/signed Message - I simply could not get this implementation to work with openssl. For some reason, it corrupts the message.
Content-Type: multipart/signed;
protocol="application/pkcs7-signature";
micalg=sha1; boundary=boundary42
--boundary42
Content-Type: text/plain
This is a clear-signed message.
--boundary42
Content-Type: application/pkcs7-signature; name=smime.p7s
Content-Transfer-Encoding: base64
Content-Disposition: attachment; filename=smime.p7s
ghyHhHUujhJhjH77n8HHGTrfvbnj756tbB9HG4VQpfyF467GhIGfHfYT6
4VQpfyF467GhIGfHfYT6jH77n8HHGghyHhHUujhJh756tbB9HGTrfvbnj
n8HHGTrfvhJhjH776tbB9HG4VQbnj7567GhIGfHfYT6ghyHhHUujpfyF4
7GhIGfHfYT64VQbnj756
--boundary42--
RFC-2311 - Section 3.4.2 Signing Using application/pkcs7-mime and SignedData - This implementation is veritably working in Outlook365 that I have tested.
I believe the reason signed-data works best is, if the entire contents are encoded to base64, it's less likely to be messed with during the email transfer process.
It takes your plain text message and embeds your digital signature into it creating an smime.p7m attachment that contains both. This is the file that contains all of it in base64 format.
S/MIME email clients will automatically verify, decode and display to you as plain text again. It works great!
Content-Type: application/pkcs7-mime; smime-type=signed-data;
name=smime.p7m
Content-Transfer-Encoding: base64
Content-Disposition: attachment; filename=smime.p7m
567GhIGfHfYT6ghyHhHUujpfyF4f8HHGTrfvhJhjH776tbB9HG4VQbnj7
77n8HHGT9HG4VQpfyF467GhIGfHfYT6rfvbnj756tbBghyHhHUujhJhjH
HUujhJh4VQpfyF467GhIGfHfYGTrfvbnjT6jH7756tbB9H7n8HHGghyHh
6YT64V0GhIGfHfQbnj75
Step 1. Generate a Certificate Signing Request and Private Key for the email address you want with openssl. Copy Private Key to openssl\bin directory.
Step 2. Use Certificate Signing Request to obtain a DigiCert S/MIME Class 1 Certificate (DV) from https://www.sslstore.com
Step 3. Download certificate files to disk and look for My_CA_Bundle.ca-bundle file. Copy this file to openssl\bin directory.
Optional Step. Create PKCS #12 from the 3 files My_Private.key My_Certificate.crt My_CA_Bundle.ca-bundle if you feel like importing this certificate into Windows Certificate Manager.
openssl pkcs12 -export -out My_Digital_Signature_Bundle.p12 -inkey My_Private.key -in My_Certificate.crt -certfile My_CA_Bundle.ca-bundle
Signing the plain text message
Step 1. Create a text file called text-message.eml, add the string This is an opaque-signed message. and copy it to openssl\bin directory. This file is the literal plain text message you want to sign. No headers. Just your message.
Now we are going to use the 3 files My_Private.key My_Certificate.crt My_CA_Bundle.ca-bundle to sign a plain text message which will then be output to signed-message.eml file.
openssl smime -sign -in text-message.eml -inkey My_Private.key -signer My_Certificate.crt -certfile My_CA_Bundle.ca-bundle -nodetach -text -out signed-message.eml -to "<admin#example.com>" -from "<client#example.com>" -subject "A Digitally Signed Message"
In the above openssl command, you see the -nodetach which creates a .p7m base64 fusion of the message and the signature into one blob.
signed-message.eml
What used to be just This is an opaque-signed message. has now transformed into:
To: <client#example.com>
From: <admin#example.com>
Subject: A Digitally Signed Message
MIME-Version: 1.0
Content-Disposition: attachment; filename="smime.p7m"
Content-Type: application/x-pkcs7-mime; smime-type=signed-data; name="smime.p7m"
Content-Transfer-Encoding: base64
MIISuwYJKoZIhvcNAQcCoIISrDCCEqgCAQExDzANBglghkgBZQMEAgEFADBKBgkq
hkiG9w0BBwGgPQQ7Q29udGVudC1UeXBlOiB0ZXh0L3BsYWluDQoNClRoaXMgaXMg
YSBjbGVhci1zaWduZWQgbWVzc2FnZS6ggg+1MIIGTjCCBTagAwIBAgIQBK55YGZm
kBq5xX+mbFvczTANBgkqhkiG9w0BAQsFADBlMQswCQYDVQQGEwJVUzEVMBMGA1UE
ChMMRGlnaUNlcnQgSW5jMRkwFwYDVQQLExB3d3cuZGlnaWNlcnQuY29tMSQwIgYD
VQQDExtEaWdpQ2VydCBBc3N1cmVkIElEIFJvb3QgQ0EwHhcNMTMxMTA1MTIwMDAw
WhcNMjg...
From this point forward, the plain text message is embedded in the base64 content together with public certificates. Even the slightest alteration to this base64 message will invalidate the entire message and fail verification. That means nothing; no extra words, no spaces, no dots. At all. Period.
Verify Digitally Signed Message with openssl
The final step is to verify the recently digitally signed message.
openssl smime -verify -in signed-message.eml -CAfile My_CA_Bundle.ca-bundle -binary -signer signer-certificate-extracted.crt -out signed-content-extracted.txt
openssl only needs the public My_CA_Bundle.ca-bundle file to do this verification. If successful, openssl will output the signer-certificate-extracted.crt and lastly the signed-content-extracted.txt that was digitally signed; the message intact, if you would.
The screenshot below illustrates a successful digital signature verification.
Send digitally signed email with CURL
curl --verbose -ssl smtps://secure.email.com:465 --login-options AUTH=PLAIN --user admin#example.com:Letmein --mail-from admin#example.com --mail-rcpt client#example.com --mail-rcpt-allowfails --upload-file signed-message.eml

Is there a way to export a .der certificate to .bin file?

I have a x509 .der certificate that I need to concatenate to a .bin package. The problem is that if I use
cat mycert.der >> package.bin
some of the characters in the certificate are changed. Is there a way to export the certificate in a .bin file using openssl or something? I am using Windows powershell to run commands.
The redirection operator in PowerShell (> or >>) messes up your binary data, because it applies some encoding based on $OutputEncoding. Piping between Get-Content and Set-/Add-Content does not modify your data.
So you can use
Get-Content mycert.der -Raw | Add-Content package.bin -NoNewline
to append your certificate to your binary as binary data. You need -Raw so that PowerShell will preserve any CR/LF bytes and you need -NoNewline to prevent PowerShell from adding an own CR/LF at the end.
maybe because of windows powershell cat replaces line ending \n into \r\n, can you try to copy file instead
otherwise to convert certificates
from man openssl and man x509
...
Convert a certificate from PEM to DER format:
openssl x509 -in cert.pem -inform PEM -out cert.der -outform DER
Convert a certificate to a certificate request:
openssl x509 -x509toreq -in cert.pem -out req.pem -signkey key.pem
Convert a certificate request into a self signed certificate using extensions for a CA:
openssl x509 -req -in careq.pem -extfile openssl.cnf -extensions v3_ca \
-signkey key.pem -out cacert.pem
...

Generate public/private keys AND sign them with Crypt::OpenSSL::RSA in Perl

I am used to generate keys with OpenSSL via shell, this way:
my $ssk="a29bRwoA73xZGeBc";
openssl req -new -newkey rsa:2048 -nodes -keyout "/etc/ssl/$ssk.key" -out "/etc/ssl/$ssk.csr"
openssl x509 -req -days 365 -in "/etc/ssl/$ssk.csr" -signkey "/etc/ssl/$ssk.key" -out "/etc/ssl/$ssk.crt"
Now I need to perform this action via PERL, but I have no idea if the below code can at least implement the 1st line:
my $ssk="a29bRwoA73xZGeBc";
# I didn't use Crypt::OpenSSL::Random, as I didn't found where it comes to action
use Crypt::OpenSSL::RSA;
my $rsa=Crypt::OpenSSL::RSA->generate_key(2048);
my $rsa_pub=Crypt::OpenSSL::RSA->new_public_key($rsa->get_public_key_x509_string());
my $rsa_prv=Crypt::OpenSSL::RSA->new_private_key($rsa->get_private_key_string());
my $cipher=$rsa->encrypt($rsa_pub);
my $plain=$rsa->encrypt($cipher);
my $sigt=$rsa_prv->sign($plain); # This seems to be part of the 2nd line in shell code, but maybe I am wrong.
unless($rsa->verify($plain,$sigt)) { die "Failed to create keys"; }
# Here is the issue:
&SaveFile("/etc/ssl/$ssk.key",$plain,0400); # Is it correct?
&SaveFile("/etc/ssl/$ssk.csr",$cipher,0400); # How about this?
# How do I proceed to implement the 2nd line in the shell code?
Note that the part of Crypt::OpenSSL::Random and saving to key files is not docmented...
Thanks a lot

Is it possible to sign my data using SSH private key in perl? [closed]

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I am new to perl so this might be very basic, but i am finding no way around this problem. I am trying to sign my data which has to be send over https connection using my ssh private key(id_rsa). I am not able to do so using perl and i am at it for days. Please someone show me a possible way to do so. If any more info is needed please ask me. Thanks in advance
My code as asked is
#!/usr/bin/perl
use File::Slurp qw(read_file);
use Crypt::OpenSSL::RSA;
use MIME::Base64 qw( decode_base64 encode_base64 );
my $keystring = read_file( 'id_rsa' );
my $privatekey = Crypt::OpenSSL::RSA->new_private_key($keystring);
$privatekey->use_pkcs1_padding();
my $datatosign = "hello";
my $signature = $privatekey->sign($datatosign);
my $base64 = encode_base64($signature);
print "$base64";
The error coming on running it is RSA.xs:178: OpenSSL error: unsupported encryption at test.pl line 7.
NOTE: As discussed in the comments, I am using a passphrase protected id_rsa.
So, leaving out the perl, and just doing this by hand with openssl
Checking the key:
ssh-keygen -t rsa -f test_id
openssl rsa -in test_id -check
RSA key ok
So we do have a 'valid' RSA private key there, which we should be able to use for encrpyting.
Generating a comparison key
However if you use openssl to generate a key pair
openssl genrsa -out openssl_gen_rsa
openssl rsa -in openssl_gen_rsa -pubout -out openssl_gen_rsa.out
Looks like the command you need is:
openssl rsautl -inkey test_id -in test_file.txt -encrypt -out test_file.enc
(That encrypts with the private key, so you'd decrypt with the public key - that's actually pretty similar to signing - normally you wouldn't do this).
The problem is - if you compare your generated -public- keys they don't match. test_id.pub looks like (Yes, this is the real one, and no, I did only use it for testing!)
ssh-rsa AAAAB3NzaC1yc2EAAAADAQABAAABAQDKfjRD+Gb5EE+SgOy7eoT0siQaAqfSY7KI2wkdrdygnJ+ccW/uMCtCVPhpz00u3EW2Gz1WI DteLKppjvUem1lKb8Tt2EWBQGyFOYKp44r3AJZgTcxLeDdqSUoiPsjWf1aUqy2Z1fBgtG+QOa7bpA8km6CbsORYX/TVg4B6vvdkkH K8WcmzBBF3rGsTCM3VXPp56bPoMCbwCsXvIjejmq+JdGHyxUmCxe1PrPyvmoYX3OUqpFBYIjeLWGDI9EXS6jA/r7viIAxdllvulPg IJ+4mdYzKN+T1ME0X0c+ZdFTMdeUnB9/TZmJr1j8Q/4SQm+3J9CiwtVXKxdkDsDObkcDp root#raspberrypi
Where my generated key file looks like:
-----BEGIN PUBLIC KEY-----
MIGfMA0GCSqGSIb3DQEBAQUAA4GNADCBiQKBgQDG8i33AuEp1wqbJgkEsnOmQim3
QT76B/oxsVGfJEDX3h4A6CD+ypBbfhhIn0GlfHanYvcGlpOJIlk3fzspbZNeoPJS
T4a0zQ0z8uJkugl8utyl9WR4tpgBRmzXZ42T/f4QSNqjDxUidRp5zPnXs9aRDtWb
XptswiGL3eVHMpbSnwIDAQAB
-----END PUBLIC KEY-----
I can use my generated pair (encrypting using public key, decrypting using private):
openssl rsautl -inkey openssl_gen_rsa.out -pubin -in test_file.txt -encrypt -out test_file.enc2
openssl rsautl -inkey openssl_gen_rsa -in test_file.enc2 -decrypt
This works.
Turning your OpenSSH private key into an RSA public key
So if we run your ssh private key through openssl:
openssl rsa -in test_id -pubout -out test_id.openssl.pub
We get:
-----BEGIN PUBLIC KEY-----
MIIBIjANBgkqhkiG9w0BAQEFAAOCAQ8AMIIBCgKCAQEAyn40Q/hm+RBPkoDsu3qE
9LIkGgKn0mOyiNsJHa3coJyfnHFv7jArQlT4ac9NLtxFths9ViA7XiyqaY71HptZ
Sm/E7dhFgUBshTmCqeOK9wCWYE3MS3g3aklKIj7I1n9WlKstmdXwYLRvkDmu26QP
JJugm7DkWF/01YOAer73ZJByvFnJswQRd6xrEwjN1Vz6eemz6DAm8ArF7yI3o5qv
iXRh8sVJgsXtT6z8r5qGF9zlKqRQWCI3i1hgyPRF0uowP6+74iAMXZZb7pT4CCfu
JnWMyjfk9TBNF9HPmXRUzHXlJwff02Zia9Y/EP+EkJvtyfQosLVVysXZA7Azm5HA
6QIDAQAB
-----END PUBLIC KEY-----
Which isn't even a remotely similar encoding to the id_rsa.pub file - and I think therefore why you have this problem.
openssl rsautl -inkey test_id.openssl.pub -pubin -in test_file.txt -encrypt -out test_file.openssl.pub.enc
Now works, and you can decrypt it using your test_id private key:
openssl rsautl -inkey test_id -in test_file.openssl.pub.enc -decrypt
So yes - for some reason the public key generated by ssh-keygen isn't the same format as openssl is expecting, so it's not going to work.
using an openssh key to verify
Anyway, back to your original example - using the private key to generate a signature:
openssl rsautl -sign -inkey test_id -in test_file.txt -out test_file.sig
openssl rsautl -verify -in test_file.sig -inkey test_id.openssl.pub -pubin
But the verify step won't work using the generated ssh key.
So does this answer your question as to whether it's possible? I'm afraid I don't know how the ssh public key differs from a 'normal' rsa public key.
I suspect your code therefore doesn't even need to be as complicated as it - I don't think you need to pkcs pad your key file.
E.g.
#!/usr/bin/perl
use strict;
use warnings;
use File::Slurp qw(read_file);
use Crypt::OpenSSL::RSA;
use MIME::Base64 qw( decode_base64 encode_base64 );
my $keystring = read_file ('test_id');
my $privatekey = Crypt::OpenSSL::RSA->new_private_key($keystring);
my $datatosign = "hello";
my $signature = $privatekey->sign($datatosign);
my $base64 = encode_base64($signature);
print "Signature:\n";
print "$base64";
my $public_key_text = $privatekey-> get_public_key_string();
print "Public Key:\n";
print $public_key_text;
my $rsa_pub = Crypt::OpenSSL::RSA->new_public_key ( $public_key_text );
print "Signed correctly\n" if ($rsa_pub->verify($datatosign, decode_base64($base64)));
This seems to work. (note lack of pkcs padding line).
Encrypted private key (passphrase)
Following from comments:
If your id_rsa has a passphrase set you'll have something like this:
-----BEGIN RSA PRIVATE KEY-----
Proc-Type: 4,ENCRYPTED
DEK-Info: AES-128-CBC,B44716076DD8B7D2B5E909BB8F70B48B
You can decrypt this by hand using openssl again:
openssl rsa -in test_id.enc
Enter pass phrase for test_id.enc:
Or:
openssl rsa -in test_id.enc -passin pass:testpass
I'm less sure how you do this using Crypt::OpenSSL::RSA - there doesn't seem to be any option to specify a passphrase to a private key.
I think you therefore need to use Crypt::CBC to decrypt the private key first. I can't test this, because I've got a load of dependencies to install.
A bit of googling suggests that you might be able to use Crypt::PK::RSA instead.
And as an alernative - use IPC::Open2 and start an openssl process to do the things without using libraries at all.
e.g.
my $keystring = `openssl rsa -passin pass:testpass -in test_id.enc`;
Not very nice, but it'll work. (and test it does actually work)