Decrypt encrypted RSA Private Key on the Browser side - cryptography

I have an encrypted private RSA key:
-----BEGIN RSA PRIVATE KEY-----
Proc-Type: 4,ENCRYPTED
DEK-Info: AES-256-CBC,B92E0E3A7B... // <--- IV here.
...
-----END RSA PRIVATE KEY-----
I need to decrypt it via a passphrase, basically I need the equivalent of
openssl rsa -in <encrypted_private.key> -out <decrypted_private.key>
on the browser side with an Angular based client, using webcrypto and pkijs.


So for anyone who will in the future maybe face the same issue like I did:
PKI.js is providing an examples folder in their repo:
OpenSSLPrivateKeyEncryption
In there you will find a method called decrypt.
With the code I were able to decrypt my AES-CBC Private key.

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unable to load certificates with openssl to convert to pxf [duplicate]

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I need a hash-name for file for posting in Stunnel's CApath directory. I have got some certs in this directory and they are working well. Also, I have a server sert and server key:
cert = c:\Program Files (x86)\stunnel\server_cert.pem
key = c:\Program> Files (x86)\stunnel\private\server_key.pem
When I try to calculate a hash of my new cert, I get an error:
/etc/pki/tls/misc/c_hash cert.pem
unable to load certificate 140603809879880:error:0906D06C:PEM
routines:PEM_read_bio:no start line:pem_lib.c:703:Expecting: TRUSTED CERTIFICATE
As I understand I must sign my cert, but I don't understand how I can do that.
Please, provide the solution.
P.S.:
The message
unable to load certificate 140603809879880:error:0906D06C:PEM
routines:PEM_read_bio:no start line:pem_lib.c:703:Expecting: TRUSTED CERTIFICATE:
posted when I made c_hash for cert.pem This is not server_cert.pem, this is Root_CA and it is content something like
-----BEGIN CERTIFICATE-----
...6UXBNSDVg5rSx60=..
-----END CERTIFICATE-----
When I write
openssl x509 -noout -text -in cert.pem
In console panel I see this info:
Certificate:
Data:
Version: 3 (0x2)
Serial Number: 1 (0x1)
Signature Algorithm: sha1WithRSAEncryption
Issuer: C=BE, ST=BB, L=BB, O=BANKSYS NV, OU=SCY, CN=TEST Root CA
Validity
Not Before: May 31 08:06:40 2005 GMT
Not After : May 31 08:06:40 2020 GMT
Subject: C=BE, ST=BB, L=BB, O=BB NV, OU=SCY, CN=TEST Root CA
Subject Public Key Info:
Public Key Algorithm: rsaEncryption
Public-Key: (2048 bit)
Modulus:
00:82:c8:58:1e:e5:7a:b2:63:a6:15:bd:f9:bb:1f:
............
Exponent: 65537 (0x10001)
X509v3 extensions:
X509v3 Basic Constraints: critical
CA:TRUE
X509v3 Key Usage: critical
Certificate Sign, CRL Sign
X509v3 Subject Key Identifier:
76:70:AB:92:9B:B1:26:CE:9E:93:D8:77:4F:78:0D:B8:D4:6C:DA:C6
Signature Algorithm: sha1WithRSAEncryption
2c:7e:bd:3f:da:48:a4:df:8d:7c:96:58:f7:87:bd:e7:16:24:
...............

Since you are on Windows, make sure that your certificate in Windows "compatible", most importantly that it doesn't have ^M in the end of each line
If you open it it will look like this:
-----BEGIN CERTIFICATE-----^M
MIIDITCCAoqgAwIBAgIQL9+89q6RUm0PmqPfQDQ+mjANBgkqhkiG9w0BAQUFADBM^M
To solve "this" open it with Write or Notepad++ and have it convert it to Windows "style"
Try to run openssl x509 -text -inform DER -in server_cert.pem and see what the output is, it is unlikely that a private/secret key would be untrusted, trust only is needed if you exported the key from a keystore, did you?

Another possible cause of this is trying to use the ;x509; module on something that is not X.509.
The server certificate is X.509 format, but the private key is RSA.
So:
openssl rsa -noout -text -in privkey.pem
openssl x509 -noout -text -in servercert.pem

My mistake was simply using the CSR file instead of the CERT file.

My situation was a little different. The solution was to strip the .pem from everything outside of the CERTIFICATE and PRIVATE KEY sections and to invert the order which they appeared.
After converting from pfx to pem file, the certificate looked like this:
Bag Attributes
localKeyID: ...
issuer=...
-----BEGIN CERTIFICATE-----
...
-----END CERTIFICATE-----
Bag Attributes
more garbage...
-----BEGIN PRIVATE KEY-----
...
-----END PRIVATE KEY-----
After correcting the file, it was just:
-----BEGIN PRIVATE KEY-----
...
-----END PRIVATE KEY-----
-----BEGIN CERTIFICATE-----
...
-----END CERTIFICATE-----

I had the same issue using Windows, got if fixed by opening it in Notepad++ and changing the encoding from "UCS-2 LE BOM" to "UTF-8".

Change encoding in notepad++ UTF-8 with BOM. That is how it worked for me

You can get this misleading error if you naively try to do this:
[clear] -> Private Key Encrypt -> [encrypted] -> Public Key Decrypt -> [clear]
Encrypting data using a private key is not allowed by design.
You can see from the command line options for open ssl that the only options to encrypt -> decrypt go in one direction public -> private.
-encrypt encrypt with public key
-decrypt decrypt with private key
The other direction is intentionally prevented because public keys basically "can be guessed." So, encrypting with a private key means the only thing you gain is verifying the author has access to the private key.
The private key encrypt -> public key decrypt direction is called "signing" to differentiate it from being a technique that can actually secure data.
-sign sign with private key
-verify verify with public key
Note: my description is a simplification for clarity. Read this answer for more information.

Finding PKCS version while having the SSL certificate and the public and private keys

I'm new to PKI and need to know something. I'm not even sure if my question makes sense so excuse me in advance. If we have the SSL certificate and the public and private keys, can we find which version of PKCS is used ? Like PKCS#1 RSASSA-PKCS1-V1_5 or another ?
Thank you!

Usually you should have some text/base64 encoded PEM files. In those files you can see the type by the ----BEGIN line in the private key file.
-----BEGIN RSA PRIVATE KEY----- means you have an RSA private key in PKCS#1 format.
-----BEGIN PRIVATE KEY----- means you have an RSA private key in PKCS#8 format.
For all the formats see https://tls.mbed.org/kb/cryptography/asn1-key-structures-in-der-and-pem

How to get RSA key from -----BEGIN CERTIFICATE----- from.crt and .pem file?

I'm having .crt and .pem file with
-----BEGIN CERTIFICATE-----
MIIFSDCCBDCg........................................
-----END CERTIFICATE-----
and I want RSA key from this file.
anyone is having any idea that how we can do that.
I have used below command one by one
openssl rsa -in XXX.crt -out input1.der -outform DER
openssl rsa -in input1.der -inform DER -out key.pem -outform PEM
But, It gives error:
unable to load Private Key 140331982231200:error:0906D06C:PEM
routines:PEM_read_bio:no start line:pem_lib.c:703:Expecting: ANY
PRIVATE KEY
and I have also used different command but it give above error.

-----BEGIN CERTIFICATE-----
MIIFSDCCBDCg........................................
-----END CERTIFICATE-----
This is a certificate in pem format which is a wrapper over public key. A Certificate is supposed to be public and can be distributed, but private key (as the name suggest) is supposed to be kept secret. So a certificate can never contain a private key.
You mentioned, you have a ´.pem´ file too. What is it's content? Does it start with -----BEGIN RSA PRIVATE KEY-----. If yes, it would be your private key.
The command you are trying:
openssl rsa
It expects a private key in input, but you are supplying it a certificate. Hence the error.

You can't get a private key from a certificate, because the private key isn't in the certificate, and you can't get it from a PEM file unless the PEM file contains it, which ain't necessarily so,

How do I identify if my certificate contains private key?

According to the answer to this server-fault question almost all certificate file formats can contain private key alongside public key, as such how can I identify whether a certificate contains private key?
This is important because I do not want to unknowingly send the private key to the remote client.

Following the structure of the link:
.csr. Only public keys in pem or der format
.pem. keys and/or certificates. Look for -----BEGIN PRIVATE KEY---- or -----BEGIN RSA PRIVATE KEY----- or -----BEGIN ENCRYPTED PRIVATE KEY-----
.key keys in pem format
.pkcs12 .pfx .p12 keys and/or certificates. List keys with openssl pkcs12 -info -nocerts -in keystore.p12
.jks keys and/or certificates. Java specific format.
.der pem content without base64 encoding. Look for KEY in openssl x509 -inform DER -in cert.der
.cert .cer .crt keys and/or certificates. Content can be pem or der
.p7b. Only certificates
.crl. No keys

one PEM file with private key and certificate into JKS

I have a JKS keystore in client application and I have been given one PEM file containing both private key and certificate to use for SOAP signature. PEM file looks like this:
-----BEGIN RSA PRIVATE KEY-----
...
-----END RSA PRIVATE KEY-----
-----BEGIN CERTIFICATE-----
...
-----END CERTIFICATE-----
First question is how to import correctly this PEM to JKS?
Second question: given private key isn't password protected, it's possible to add a password to it before importing it to JKS keystore?
Thanks!

If you prefer a GUI solution I would take Portecle. This simple key store management tool allows to create a JKS and then import cert and private key.
I am not sure if you can import cert and key from the same combined PEM file as you have it but may be the command "Import Key pair" of Portecle works with such a file.
If not you can simply split the PEM file directly after the -----END RSA PRIVATE KEY----- line into two PEM files and import them separately.
After importing, when you save the JKS Portecle will ask you for a password.