openssl-pkey, pkey - public or private key processing tool
openssl pkey [-inform PEM|DER] [-outform PEM|DER] [-in filename] [-passin arg] [-out filename] [-passout arg] [-cipher] [-text] [-text_pub] [-noout] [-pubin] [-pubout] [-engine id]
The pkey command processes public or private keys. They can be converted between various forms and their components printed out.
- -inform DER|PEM
This specifies the input format DER or PEM.
- -outform DER|PEM
This specifies the output format, the options have the same meaning as the -inform option.
- -in filename
This specifies the input filename to read a key from or standard input if this option is not specified. If the key is encrypted a pass phrase will be prompted for.
- -passin arg
the input file password source. For more information about the format of arg see the PASS PHRASE ARGUMENTS section in openssl.
- -out filename
This specifies the output filename to write a key to or standard output if this option is not specified. If any encryption options are set then a pass phrase will be prompted for. The output filename should not be the same as the input filename.
- -passout password
the output file password source. For more information about the format of arg see the PASS PHRASE ARGUMENTS section in openssl.
These options encrypt the private key with the supplied cipher. Any algorithm name accepted by EVP_get_cipherbyname() is acceptable such as des3.
prints out the various public or private key components in plain text in addition to the encoded version.
print out only public key components even if a private key is being processed.
do not output the encoded version of the key.
by default a private key is read from the input file: with this option a public key is read instead.
by default a private key is output: with this option a public key will be output instead. This option is automatically set if the input is a public key.
- -engine id
specifying an engine (by its unique id string) will cause pkey to attempt to obtain a functional reference to the specified engine, thus initialising it if needed. The engine will then be set as the default for all available algorithms.
To remove the pass phrase on an RSA private key:
openssl pkey -in key.pem -out keyout.pem
To encrypt a private key using triple DES:
openssl pkey -in key.pem -des3 -out keyout.pem
To convert a private key from PEM to DER format:
openssl pkey -in key.pem -outform DER -out keyout.der
To print out the components of a private key to standard output:
openssl pkey -in key.pem -text -noout
To print out the public components of a private key to standard output:
openssl pkey -in key.pem -text_pub -noout
To just output the public part of a private key:
openssl pkey -in key.pem -pubout -out pubkey.pem