PKEYUTL(1SSL) OpenSSL PKEYUTL(1SSL)
openssl-pkeyutl, pkeyutl - public key algorithm utility
openssl pkeyutl [-help] [-in file] [-out file] [-sigfile file] [-inkey
file] [-keyform PEM|DER|ENGINE] [-passin arg] [-peerkey file]
[-peerform PEM|DER|ENGINE] [-pubin] [-certin] [-rev] [-sign] [-verify]
[-verifyrecover] [-encrypt] [-decrypt] [-derive] [-kdf algorithm]
[-kdflen length] [-pkeyopt opt:value] [-hexdump] [-asn1parse] [-engine
The pkeyutl command can be used to perform public key operations using
any supported algorithm.
Print out a usage message.
This specifies the input filename to read data from or standard
input if this option is not specified.
specifies the output filename to write to or standard output by
Signature file, required for verify operations only
the input key file, by default it should be a private key.
the key format PEM, DER or ENGINE. Default is PEM.
the input key password source. For more information about the
format of arg see the PASS PHRASE ARGUMENTS section in openssl(1).
the peer key file, used by key derivation (agreement) operations.
the peer key format PEM, DER or ENGINE. Default is PEM.
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
sign the input data and output the signed result. This requires a
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.
Use key derivation function algorithm. The supported algorithms
are at present TLS1-PRF and HKDF. Note: additional parameters and
the KDF output length will normally have to be set for this to
work. See EVP_PKEY_CTX_set_hkdf_md(3) and
EVP_PKEY_CTX_set_tls1_prf_md(3) for the supported string parameters
of each algorithm.
Set the output length for KDF.
Public key options specified as opt:value. See NOTES below for more
hex dump the output data.
asn1parse the output data, this is useful when combined with the
-verifyrecover option when an ASN1 structure is signed.
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.
When used with the -engine option, it specifies to also use engine
id for crypto operations.
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.
The RSA algorithm generally supports the encrypt, decrypt, sign, verify
and verifyrecover operations. However, some padding modes support only
a subset of these operations. The following additional pkeyopt values
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 oaep 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
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.
The X25519 algorithm supports key derivation only. Currently there are
no additional options.
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
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
Hexdump 48 bytes of TLS1 PRF using digest SHA256 and shared secret and
seed consisting of the single byte 0xFF:
openssl pkeyutl -kdf TLS1-PRF -kdflen 48 -pkeyopt md:SHA256 \
-pkeyopt hexsecret:ff -pkeyopt hexseed:ff -hexdump
genpkey(1), pkey(1), rsautl(1)dgst(1), rsa(1), genrsa(1),
Copyright 2006-2016 The OpenSSL Project Authors. All Rights Reserved.
Licensed under the OpenSSL license (the "License"). You may not use
this file except in compliance with the License. You can obtain a copy
in the file LICENSE in the source distribution or at
1.1.0g 2017-11-04 PKEYUTL(1SSL)