decrypt file using pfx and password

I suspect he means he has a file secured by the public key - s/mime encoded.

openssl would decode that, if it is correctly formatted, but depending on how the file is encoded it might need a bit of scripting and ebcrypt.

I already imported it in windows, but I have no idea how to use it against the small encrypted txt file that I need to be decrypted.

openssl smime --decrypt [--inform ? ] -in 'message-file' -inkey 'pfx-file'
if smime... extra options may apply.   see 'openssl smime --help' for more options

if rsa enconding 'openssl rsa --help' or 'openssl rsautl --help'
if rsa encoded files....

Properties from the imported pfx file are

Version: V3

Signature algorithm: sha1RSA

Public key: RSA(1024Bits)

I found that there is a password file also.
I tried both in Windows and Linux

1.
openssl rsautl -in inputFileName -out outputFileName -inkey keyfile.pfx -decrypt -passin fileContainingPassword

Invalid password argument "fileContainingPassword"
Error getting password

2.
openssl rsautl -in inputFileName -out outputFileName -inkey keyfile.pfx -decrypt -passin passwordFromTheFile

Invalid password argument "passwordFromTheFile"

Am I using the right tool?

Also tried

openssl rsautl -in inputFileName -out outputFileName -inkey keyfile.pfx -decrypt -passin file:fileContainingPassword

unable to load Private Key

probably replace -inkey with -certin as a pfx contains a certificate. + public key; otherwise use -pubin for a public key.
(also check pkeyutl, it seems rsautl is replaced by it).

file:... is the right form for a passin.

I am not sure what you got..., the pfx seems to be a public key, is the other key  a private key?; you might need -decrypt with -pubin?
From the example: the way it meant to be used....
Encription:
openssl rsautl -encrypt -pubin -inkey publickey.pem -in plain.txt -out cipher.txt                  

Decryption:
openssl rsautl -decrypt -inkey privatekey.pem -in cipher.txt -out plainRcv.txt
- This will ask for a passphrase/password of the privatekey.pem if encrypted...., -passin should also work.

You can derive a public key from a private key, but not the other way around...:
openssl rsa -in privatekey.pem  -pubout -out publickey.pem
- This will ask for a passphrase/password of the privatekey.pem if encrypted...., -passin should also work.

I found that pfx file conains both private key and certificate and is password protected. I used

openssl pkcs12 -in pfxFile.pfx -out pemFile.pem

to derive a pem file. It asked for a password (I entered the pass I have for the pfx file) and after entering, before creating pem file asked for a pass phrase (I guess password to be used when decrypting), so I entered some word.  I used this pem file for decrypting

openssl rsautl -decrypt -inkey pemFile.pem -in encryptedFile.crp -out test.txt
Enter pass phrase for pemFile.pem:
RSA operation error
6421:error:0406506C:rsa routines:RSA_EAY_PRIVATE_DECRYPT:data greater than mod len:rsa_eay.c:512:

The 2nd passphrase is to protect the .pem file, if you press enter you would have an unprotected private key....
Ok, then your data is very probably bsae64 encoded...

using: openssl enc -a -d -in encryptedFile.crp -out encryptedFile.crp.bin
you can make this binary, and then decrypt the binary file.

openssl enc -a -d -in File.crp -out File.crp.bin


openssl rsautl -decrypt -inkey keyPem.pem -in File.crp.bin -out test.txt
Enter pass phrase for keyPem.pem:
RSA operation error
10154:error:0406506C:rsa routines:RSA_EAY_PRIVATE_DECRYPT:data greater than mod len:rsa_eay.c:512:

was the message bare to begin with....

no headers & foorters (lines above & below a line with ---'s and a BEGIN or END tag, including those tagged lines)

You will then have a blob of text that contains only readble text (digits, alphabetics (lower & uppercase) + reading signs (+-()/\ etc.)
the text will most probably end with a couple of == signs.

This blob is the one that needs to be decoded.

Before

openssl enc -a -d -in File.crp -out File.crp.bin

File had header and footer and the lines in between  were readable with ^M mark at the end of them

after

openssl enc -a -d -in File.crp -out File.crp.bin

It is completely unreadable

Tried to decode only lines that had ^M mark (lines that are readable), but same message "data greater than mod len:rsa_eay.c:512:".

on a linux system jou dont want the ^M character.., although I would expect them to be ignored.
The binary blob is expected to be unreadable... (it is compressed data, which is then encrypted using binary keys).

I found some references that this sometimes happens with messages that were created using pgp 9?

Then another thing, could this be a s/mime formatted mail, it has been asked before, but (silently?) ignored?
S/Mime looks almost like regular mime, but supports encrypted content.

Then the command would become:

openssl smime -decrypt -in File.crp -recip mycert.pem -inkey key.pem

The pem file I have is derived from pfx file, so I have only one. I think that both certificate and key are in it.
I tried openssl smime -decrypt -in File.crp -recip mycert.pem

I tried various combinations, but everytime I got
6397:error:2107A087:PKCS7 routines:SMIME_read_PKCS7:no content type:pk7_mime.c:296:

Windows imported PFX file into certificates without any problem and states that I have a key that corresponds to the certificate. I guess windows can reveal what type of information is stored in pfx file, so is there a way to find what kind of encryption is used and which tool should be used for decryption?

You don't need to look at the key, but at the encrypted file.
There should be hints about it's format...

IF there is stuff like this inside:

MIME-Version: 1.0
Content-Type: multipart/signed;
  protocol="application/x-pkcs7-signature";
  micalg=sha1;
  boundary="------------ms010504060809030906030009"

Later in the mail:
--------------ms010504060809030906030009
Content-Type: application/x-pkcs7-signature; name="smime.p7s"
Content-Transfer-Encoding: base64
Content-Disposition: attachment; filename="smime.p7s"
Content-Description: S/MIME Cryptographic Signature

indicating a signature. can also be encrypted content.
then it's s/mime

If there is no mentioning og content-type: multipart/signed... then you have another format
Here you can also see it is pkcs7 structured.

PGP headers are like:

-----BEGIN PGP SIGNED MESSAGE-----
blah blah
-----BEGIN PGP SIGNATURE-----
Version: PGP Desktop 9.0.6 (Build 6060)

blah
-----END PGP SIGNATURE-----

Other format do exist too... basically this tells you the tool to use for encryption...
PGP encrypted file cannot be decrypted with OPENSSL and vice versa, it's different technology.
Within both format there are sub formats....

There is nothing readable in the encrypted text. The file is intended for me to send to somebody as attachment by mail and is not encrypted mail message. Imported certificate in Windows states that it's intended purposes are  "Secure EmailI". I have public key, pfx file and file that contains the password for the pfx. The program that creates the encrypted file is installed on my computer and uses the files above for encryption. The data that is encrypted is created by me in the installed program. the problem is that now I have all the encrypted files created by me and I need original files that are ordinary text files.