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]
  [-rand file...] [-writerand file] [-engine id]
  [-engine_impl]
The pkeyutl command can be used to perform low-level public key
  operations using any supported algorithm.
  - -help
- Print out a usage message.
- -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.
- -sigfile file
- Signature file, required for verify operations only
- -inkey file
- The input key file, by default it should be a private key.
- -keyform PEM|DER|ENGINE
- The key format PEM, DER or ENGINE. Default is PEM.
- -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|ENGINE
- The peer key format PEM, DER or ENGINE. Default is PEM.
- -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 (which must be a hash) and output the signed result.
      This requires a private key.
- -verify
- Verify the input data (which must be a hash) against the signature file
      and indicate if the verification succeeded or failed.
- -verifyrecover
- Verify the input data (which must be a hash) 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.
- -kdf algorithm
- 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.
- -kdflen length
- Set the output length for KDF.
- -pkeyopt opt:value
- Public key options specified as opt:value. See NOTES below for more
      details.
- -hexdump
- hex dump the output data.
- -asn1parse
- Parse the ASN.1 output data, this is useful when combined with the
      -verifyrecover option when an ASN1 structure is signed.
- -rand file...
- A file or files containing random data used to seed the random number
      generator. Multiple files can be specified separated by an OS-dependent
      character. The separator is ; for MS-Windows, , for OpenVMS,
      and : for all others.
- [-writerand file]
- Writes random data to the specified file upon exit. This can be
      used with a subsequent -rand flag.
- -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.
- -engine_impl
- 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 not used to hash the input data. It is used (by
    some algorithms) 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).
This utility does not hash the input data but rather it will use
    the data directly as input to the signature algorithm. Depending on the key
    type, signature type, and mode of padding, the maximum acceptable lengths of
    input data differ. The signed data can't be longer than the key modulus with
    RSA. In case of ECDSA and DSA the data shouldn't be longer than the field
    size, otherwise it will be silently truncated to the field size. In any
    event the input size must not be larger than the largest supported digest
    size.
In other words, if the value of digest is sha1 the input
    should be the 20 bytes long binary encoding of the SHA-1 hash function
    output.
The Ed25519 and Ed448 signature algorithms are not supported by
    this utility. They accept non-hashed input, but this utility can only be
    used to sign hashed input.
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 are
  supported:
  - 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 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
        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. Three
      special values are supported: "digest" sets the salt length to
      the digest length, "max" sets the salt length to the maximum
      permissible value. When verifying "auto" causes the salt length
      to be automatically determined based on the PSS block
    structure.
- rsa_mgf1_md:digest
- For PSS and OAEP padding sets the MGF1 digest. If the MGF1 digest is not
      explicitly set in PSS mode then the signing digest is used.
The RSA-PSS algorithm is a restricted version of the RSA algorithm which only
  supports the sign and verify operations with PSS padding. The following
  additional pkeyopt values are supported:
  - rsa_padding_mode:mode, rsa_pss_saltlen:len,
    rsa_mgf1_md:digest
- These have the same meaning as the RSA algorithm with some
      additional restrictions. The padding mode can only be set to pss
      which is the default value.
    If the key has parameter restrictions than the digest, MGF1
        digest and salt length are set to the values specified in the
        parameters. The digest and MG cannot be changed and the salt length
        cannot be set to a value less than the minimum restriction. 
The DSA algorithm supports signing and verification operations only. Currently
  there are no additional -pkeyopt options other than digest. The
  SHA1 digest is assumed by default.
The DH algorithm only supports the derivation operation and no additional
  -pkeyopt options.
The EC algorithm supports sign, verify and derive operations. The sign and
  verify operations use ECDSA and derive uses ECDH. SHA1 is assumed by default
  for the -pkeyopt digest option.
The X25519 and X448 algorithms support 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 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
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), EVP_PKEY_CTX_set_hkdf_md(3),
  EVP_PKEY_CTX_set_tls1_prf_md(3)
Copyright 2006-2020 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
    <https://www.openssl.org/source/license.html>.