/usr/man/cat.1/openssl-pkeyutl.1(/usr/man/cat.1/openssl-pkeyutl.1)

PKEYUTL(1)                   OpenSSL                   PKEYUTL(1)

NAME

     openssl-pkeyutl, 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.

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PKEYUTL(1)                   OpenSSL                   PKEYUTL(1)

     -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

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PKEYUTL(1)                   OpenSSL                   PKEYUTL(1)

     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.

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PKEYUTL(1)                   OpenSSL                   PKEYUTL(1)

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)

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See also pkeyutl(1)