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Updated: Wednesday, February 9, 2022

pkeyutl (1openssl)


pkeyutl - public key algorithm utility


openssl pkeyutl [-in file] [-out file] [-sigfile file] [-inkey file]
[-keyform PEM|DER] [-passin arg] [-peerkey file] [-peerform PEM|DER]
[-pubin] [-certin] [-rev] [-sign] [-verify] [-verifyrecover] [-encrypt]
[-decrypt] [-derive] [-pkeyopt opt:value] [-hexdump] [-asn1parse]
[-engine id]


PKEYUTL(1openssl)                   OpenSSL                  PKEYUTL(1openssl)

       openssl-pkeyutl, pkeyutl - public key algorithm utility

       openssl pkeyutl [-in file] [-out file] [-sigfile file] [-inkey file]
       [-keyform PEM|DER] [-passin arg] [-peerkey file] [-peerform PEM|DER]
       [-pubin] [-certin] [-rev] [-sign] [-verify] [-verifyrecover] [-encrypt]
       [-decrypt] [-derive] [-pkeyopt opt:value] [-hexdump] [-asn1parse]
       [-engine id]

       The pkeyutl command can be used to perform public key operations using
       any supported algorithm.

       -in filename
           This specifies the input filename to read data from or standard
           input if this option is not specified.

       -out filename
           specifies the output filename to write to or standard output by

       -inkey file
           the input key file, by default it should be a private key.

       -keyform PEM|DER
           the key format PEM, DER or ENGINE.

       -passin arg
           the input key password source. For more information about the
           format of arg see the PASS PHRASE ARGUMENTS section in openssl(1).

       -peerkey file
           the peer key file, used by key derivation (agreement) operations.

       -peerform PEM|DER
           the peer key format PEM, DER or ENGINE.

       -engine id
           specifying an engine (by its unique id string) will cause pkeyutl
           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.

           the input file is a public key.

           the input is a certificate containing a public key.

           reverse the order of the input buffer. This is useful for some
           libraries (such as CryptoAPI) which represent the buffer in little
           endian format.

           sign the input data and output the signed result. This requires a
           private key.

           verify the input data against the signature file and indicate if
           the verification succeeded or failed.

           verify the input data and output the recovered data.

           encrypt the input data using a public key.

           decrypt the input data using a private key.

           derive a shared secret using the peer key.

           hex dump the output data.

           asn1parse the output data, this is useful when combined with the
           -verifyrecover option when an ASN1 structure is signed.

       See attributes(7) for descriptions of the following attributes:

       |Availability   | library/security/openssl |
       |Stability      | Pass-through uncommitted |

       The operations and options supported vary according to the key
       algorithm and its implementation. The OpenSSL operations and options
       are indicated below.

       Unless otherwise mentioned all algorithms support the digest:alg option
       which specifies the digest in use for sign, verify and verifyrecover
       operations.  The value alg should represent a digest name as used in
       the EVP_get_digestbyname() function for example sha1.  This value is
       used only for sanity-checking the lengths of data passed in to the
       pkeyutl and for creating the structures that make up the signature
       (e.g. DigestInfo in RSASSA PKCS#1 v1.5 signatures).  In case of RSA,
       ECDSA and DSA signatures, this utility will not perform hashing on
       input data but rather use the data directly as input of signature
       algorithm. Depending on key type, signature type and mode of padding,
       the maximum acceptable lengths of input data differ. In general, with
       RSA the signed data can't be longer than the key modulus, in case of
       ECDSA and DSA the data shouldn't be longer than field size, otherwise
       it will be silently truncated to field size.

       In other words, if the value of digest is sha1 the input should be 20
       bytes long binary encoding of SHA-1 hash function output.

       Source code for open source software components in Oracle Solaris can
       be found at https://www.oracle.com/downloads/opensource/solaris-source-

       This software was built from source available at
       https://github.com/oracle/solaris-userland.  The original community
       source was downloaded from

       Further information about this software can be found on the open source
       community website at https://www.openssl.org/.

       The RSA algorithm supports encrypt, decrypt, sign, verify and
       verifyrecover operations in general. Some padding modes only support
       some of these operations however.

           This sets the RSA padding mode. Acceptable values for mode are
           pkcs1 for PKCS#1 padding, sslv23 for SSLv23 padding, none for no
           padding, oaep for OAEP mode, x931 for X9.31 mode and pss for PSS.

           In PKCS#1 padding if the message digest is not set then the
           supplied data is signed or verified directly instead of using a
           DigestInfo structure. If a digest is set then the a DigestInfo
           structure is used and its the length must correspond to the digest

           For oeap mode only encryption and decryption is supported.

           For x931 if the digest type is set it is used to format the block
           data otherwise the first byte is used to specify the X9.31 digest
           ID. Sign, verify and verifyrecover are can be performed in this

           For pss mode only sign and verify are supported and the digest type
           must be specified.

           For pss mode only this option specifies the salt length. Two
           special values are supported: -1 sets the salt length to the digest
           length. When signing -2 sets the salt length to the maximum
           permissible value. When verifying -2 causes the salt length to be
           automatically determined based on the PSS block structure.

       The DSA algorithm supports signing and verification operations only.
       Currently there are no additional options other than digest. Only the
       SHA1 digest can be used and this digest is assumed by default.

       The DH algorithm only supports the derivation operation and no
       additional options.

       The EC algorithm supports sign, verify and derive operations. The sign
       and verify operations use ECDSA and derive uses ECDH. Currently there
       are no additional options other than digest. Only the SHA1 digest can
       be used and this digest is assumed by default.

       Sign some data using a private key:

        openssl pkeyutl -sign -in file -inkey key.pem -out sig

       Recover the signed data (e.g. if an RSA key is used):

        openssl pkeyutl -verifyrecover -in sig -inkey key.pem

       Verify the signature (e.g. a DSA key):

        openssl pkeyutl -verify -in file -sigfile sig -inkey key.pem

       Sign data using a message digest value (this is currently only valid
       for RSA):

        openssl pkeyutl -sign -in file -inkey key.pem -out sig -pkeyopt digest:sha256

       Derive a shared secret value:

        openssl pkeyutl -derive -inkey key.pem -peerkey pubkey.pem -out secret

       genpkey(1), pkey(1), rsautl(1) dgst(1), rsa(1), genrsa(1)

1.0.2za                           2021-08-24                 PKEYUTL(1openssl)