opensslCMD

#Convert PFX Windows Cert to Linux Public/Private Key and Chain
openssl pkcs12 -in ./cert.pfx -clcerts -nokeys -out public.crt
openssl pkcs12 -in ./cert.pfx -nocerts -nodes -out private.rsa
cat public.crt ca-bundle.crt >> bundle.crt

openssl pkcs12 -in file.pfx -nocerts -out privateKey.pem
openssl pkcs12 -in file.pfx -clcerts -nokeys -out publicCert.cer
openssl rsa -in privateKey.pem -out privateKey_nopasswd.pem


openssl pkcs12 -in file.pfx -nocerts -out file.pem -nodes
openssl pkcs12 -in file.pfx -clcerts -nokeys -out file.cert

#Creating the certs from pfx
openssl pkcs12 -nocerts -in ssl.pfx -out ssl.key -nodes

openssl pkcs12 -nokeys -clcerts -in ssl.pfx -out ssl.cer -nodes

openssl pkcs12 -nokeys -cacerts -in ssl.pfx  -out ssl.crt -nodes

#Checking the certs

openssl x509 -noout -modulus -in ssl.cer | openssl md5
openssl rsa -noout -modulus -in ssl.key | openssl md5


#To read a certificate file:
openssl x509 -inform PEM -in servercert.pem -text

#To read a private key file:
openssl rsa -noout -text -in serverkey.pem

#To read a CSR request:
openssl req -noout -text -in serverreq.pem

#To view CER/DER (binary) files:
openssl x509 -noout -text -in exported.crt -inform DER

#To read a CRL PEM file
openssl crl -inform PEM -in crl.pem -text

#To convert pem files to pfx files:
openssl pkcs12 -export -in clientcert.pem -inkey clientkey.pem -out bbva_cert.pfx

#To convert pfx files to pem files:
openssl pkcs12 -nocerts -in "trader certificate.pfx" -out clientkey.pem #(outputs the key)
openssl pkcs12 -clcerts -nokeys -in "trader certificate.pfx" -out clientcert.pem #(outputs the cert)
openssl rsa -in key.pem -out newkey.pem #remove the pem passphrase

#To convert CER/DER (binary) files to the .PEM format used by the SCS:
openssl x509 -inform DER -in cert.cer -out rootcacert.pem

#To convert CRL DER files into CRL for PEM
openssl crl -inform DER -in site_name.crt -outform PEM -out site_name.pem

#To make a test SSL connection and download the server certificate
openssl s_client -connect remote.host:443

#To make a test SSL connection using a client certificate
openssl s_client -cert clientcert.pem -key clientkey.pem -connect remote.host:443

General OpenSSL Commands

These commands allow you to generate CSRs, Certificates, Private Keys and do other miscellaneous tasks.

Generate a new private key and Certificate Signing Request
openssl req -out CSR.csr -new -newkey rsa:2048 -nodes -keyout privateKey.key
Generate a self-signed certificate (see How to Create and Install an Apache Self Signed Certificate for more info)
openssl req -x509 -nodes -days 365 -newkey rsa:2048 -keyout privateKey.key -out certificate.crt
Generate a certificate signing request (CSR) for an existing private key
openssl req -out CSR.csr -key privateKey.key -new
Generate a certificate signing request based on an existing certificate
openssl x509 -x509toreq -in certificate.crt -out CSR.csr -signkey privateKey.key
Remove a passphrase from a private key
openssl rsa -in privateKey.pem -out newPrivateKey.pem
Checking Using OpenSSL

If you need to check the information within a Certificate, CSR or Private Key, use these commands. You can also check CSRs and check certificates using our online tools.

Check a Certificate Signing Request (CSR)
openssl req -text -noout -verify -in CSR.csr
Check a private key
openssl rsa -in privateKey.key -check
Check a certificate
openssl x509 -in certificate.crt -text -noout
Check a PKCS#12 file (.pfx or .p12)
openssl pkcs12 -info -in keyStore.p12
Debugging Using OpenSSL

If you are receiving an error that the private doesn't match the certificate or that a certificate that you installed to a site is not trusted, try one of these commands. If you are trying to verify that an SSL certificate is installed correctly, be sure to check out the SSL Checker.

Check an MD5 hash of the public key to ensure that it matches with what is in a CSR or private key
openssl x509 -noout -modulus -in certificate.crt | openssl md5
openssl rsa -noout -modulus -in privateKey.key | openssl md5
openssl req -noout -modulus -in CSR.csr | openssl md5
Check an SSL connection. All the certificates (including Intermediates) should be displayed
openssl s_client -connect www.paypal.com:443
Converting Using OpenSSL

These commands allow you to convert certificates and keys to different formats to make them compatible with specific types of servers or software. For example, you can convert a normal PEM file that would work with Apache to a PFX (PKCS#12) file and use it with Tomcat or IIS. Use our SSL Converter to convert certificates without messing with OpenSSL.

Convert a DER file (.crt .cer .der) to PEM
openssl x509 -inform der -in certificate.cer -out certificate.pem
Convert a PEM file to DER
openssl x509 -outform der -in certificate.pem -out certificate.der
Convert a PKCS#12 file (.pfx .p12) containing a private key and certificates to PEM
openssl pkcs12 -in keyStore.pfx -out keyStore.pem -nodes
You can add -nocerts to only output the private key or add -nokeys to only output the certificates.

Convert a PEM certificate file and a private key to PKCS#12 (.pfx .p12)
openssl pkcs12 -export -out certificate.pfx -inkey privateKey.key -in certificate.crt -certfile CACert.crt


I. Convert PEM files
PEM to DER
openssl x509 -outform der -in certificate.pem -out certificate.der
PEM to P7B
openssl crl2pkcs7 -nocrl -certfile certificate.cer -out certificate.p7b -certfile CACert.cer
PEM to PFX
openssl pkcs12 -export -out certificate.pfx -inkey privateKey.key -in certificate.crt -certfile CACert.crt

II. Convert P7B files
P7B to PEM
openssl pkcs7 -print_certs -in certificate.p7b -out certificate.cer
P7B to PFX
openssl pkcs7 -print_certs -in certificate.p7b -out certificate.cer
openssl pkcs12 -export -in certificate.cer -inkey privateKey.key -out certificate.pfx -certfile CACert.cer

III. Convert PFX files
PFX to PEM
openssl pkcs12 -in certificate.pfx -out certificate.cer -nodes konwersja poprze OpenSSL

IV. Convert DER files
DER to PEM
openssl x509 -inform der -in certificate.cer -out certificate.pem

KEY Gen

    $ openssl genrsa 2048 > mfapola.key

CSR Gen

    $ openssl req -new -key mfapola.key > mfapola.csr
    $ openssl req -nodes -newkey rsa:2048 -sha1 -keyout mydomain.key -out mydomain.csr

Sign CRT

    $ openssl x509 -req -days 3650 -signkey mfapola.key < mfapola.csr > mfapola.crt

Change type SSL cert from pkcs12(.pfx) to CER(PEM)

    $ conv to pkcs12 from cer/crt
    $ openssl pkcs12 -export -out test.pfx -inkey mfapola.key -in mfapola.crt

Other

    $ openssl x509 -noout -text -in
    $ openssl x509 -noout -issuer -subject -dates -modulus -in
    $ openssl req -noout -text -in
    $ openssl req -noout -subject -modulus -in
    $ openssl rsa -noout -text -in
    $ openssl rsa -noout -modulus -in




For symmetic encryption, you can use the following:

To encrypt:
openssl aes-256-cbc -salt -a -e -in plaintext.txt -out encrypted.txt

To decrypt:
openssl aes-256-cbc -salt -a -d -in encrypted.txt -out plaintext.txt


For Asymmetric encryption you must first generate your private key and extract the public key.

openssl genrsa -aes256 -out private.key 8912
openssl -in private.key -pubout -out public.key

To encrypt:
openssl rsautl -encrypt -pubin -inkey public.key -in plaintext.txt -out encrypted.txt

To decrypt:
openssl rsautl -decrypt -inkey private.key -in encrypted.txt -out plaintext.txt

Source: http://bsdsupport.org/2007/01/q-how-do-i-use-openssl-to-encrypt-files/

=============================================================================================================

You can't directly encrypt a large file using rsautl. instead, do something like the following:

Generate a key using openssl rand, eg. openssl rand 32 -out keyfile
Encrypt the key file using openssl rsautl
Encrypt the data using openssl enc, using the generated key from step 1.
Package the encrypted key file with the encrypted data. the recipient will need to decrypt the key with their private key, then decrypt the data with the resulting key.

Ultimate solution for safe and high secured encode anyone file in OpenSSL and command-line:

You should have ready some X.509 certificate for encrypt files in PEM format.

NOTE: You can generated a X.509 certificate using:

Private key generation (encrypted private key):
openssl genrsa -aes256 -out private.pem 8912
openssl -in private.pem -pubout -out public.pem

With unecrypted private key:
openssl req -x509 -nodes -days 100000 -newkey rsa:8912 -keyout private_key.pem -out certificate.pem

With encrypted private key:
openssl req -x509 -days 100000 -newkey rsa:8912 -keyout private_key.pem -out certificate.pem

With existing encrypted (unecrypted) private key:
openssl req -x509 -new -days 100000 -key private_key.pem -out certificate.pem

To encrypt:
openssl smime -encrypt -binary -aes-256-cbc -in plainfile.zip -out encrypted.zip.enc -outform PEM yourSslCertificate.pem
openssl smime -encrypt -binary -aes-256-cbc -in plainfile.zip -out encrypted.zip.enc -outform DER yourSslCertificate.pem

For text files:
openssl smime -encrypt -aes-256-cbc -in input.txt -out output.txt -outform DER yourSslCertificate.pem
openssl smime -encrypt -aes-256-cbc -in input.txt -out output.txt -outform PEM yourSslCertificate.pem

What is what:

smime - ssl command for S/MIME utility (smime(1))
-encrypt - chosen method for file process
-binary - use safe file process. Normally the input message is converted to "canonical" format as required by the S/MIME specification, this switch disable it. It is necessary for all binary files (like a images, sounds, ZIP archives).
-aes-256-cbc - chosen cipher AES in 256 bit for encryption (strong). If not specified 40 bit RC2 is used (very weak). (Supported ciphers)
-in plainfile.zip - input file name
-out encrypted.zip.enc - output file name
-outform DER - encode output file as binary. If is not specified, file is encoded by base64 and file size will be increased by 30%.
yourSslCertificate.pem - file name of your certificate's. That should be in PEM format.
That command can very effectively a strongly encrypt any file regardless of its size or format.

To decrypt:

openssl smime -decrypt -binary -in encrypted.zip.enc -inform DER -out decrypted.zip -inkey private.key -passin pass:your_password
openssl smime -decrypt -binary -in encrypted.zip.enc -inform PEM -out decrypted.zip -inkey private.key -passin pass:your_password

For text files:
openssl smime -decrypt -in encrypted_input.txt -inform DER -out decrypted_input.zip -inkey private.key -passin pass:your_password
openssl smime -decrypt -in encrypted_input.txt -inform PEM -out decrypted_input.zip -inkey private.key -passin pass:your_password

What is what:

-inform DER - same as -outform above
-inkey private.key - file name of your private key. That should be in PEM format and can be encrypted by password.
-passin pass:your_password - your password for private key encrypt. (http://www.openssl.org/docs/apps/openssl.html#PASS_PHRASE_ARGUMENTS)

Generating public key from private key:
openssl rsa -in private_key.pem -pubout > public_key.pem

Creating a signed digest of a file:
openssl dgst -sha512 -sign private_key.pem -out digest.sha512 file.txt

Verify a signed digest:
openssl dgst -sha512 -verify public_key.pem -signature digest.sha512 file.txt

Source: http://stackoverflow.com/questions/7143514/how-to-encrypt-a-large-file-in-openssl-using-public-key
http://www.madboa.com/geek/openssl/
http://stackoverflow.com/questions/5140425/openssl-command-line-to-verify-the-signature