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PKEYUTL(1)                          OpenSSL                         PKEYUTL(1)

NAME
       pkeyutl - public key algorithm utility
SYNOPSIS
       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]
DESCRIPTION
       The pkeyutl command can be used to perform public key operations using
       any supported algorithm.
COMMAND OPTIONS
       -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
           default.
       -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.
       -pubin
           the input file is a public key.
       -certin
           the input is a certificate containing a public key.
       -rev
           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
           sign the input data and output the signed result. This requires a
           private key.
       -verify
           verify the input data against the signature file and indicate if
           the verification succeeded or failed.
       -verifyrecover
           verify the input data and output the recovered data.
       -encrypt
           encrypt the input data using a public key.
       -decrypt
           decrypt the input data using a private key.
       -derive
           derive a shared secret using the peer key.
       -hexdump
           hex dump the output data.
       -asn1parse
           asn1parse the output data, this is useful when combined with the
           -verifyrecover option when an ASN1 structure is signed.
NOTES
       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.
RSA ALGORITHM
       The RSA algorithm supports encrypt, decrypt, sign, verify and
       verifyrecover operations in general. Some padding modes only support
       some of these operations however.
       -rsa_padding_mode:mode
           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
           type.
           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
           mode.
           For pss mode only sign and verify are supported and the digest type
           must be specified.
       rsa_pss_saltlen:len
           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.
DSA ALGORITHM
       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.
DH ALGORITHM
       The DH algorithm only supports the derivation operation and no
       additional options.
EC ALGORITHM
       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.
EXAMPLES
       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
SEE ALSO
       genpkey(1), pkey(1), rsautl(1) dgst(1), rsa(1), genrsa(1)

1.0.2k                            2017-01-26                        PKEYUTL(1)