-help

Print out a usage message.

-in

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

-out

specifies the output filename to write to or standard output by default.

-sigfile

Signature file, required for verify operations only

-inkey

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

-keyform

the key format PEM, DER or ENGINE. Default is PEM.

-passin

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

-peerkey

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

-peerform

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) whichrepresent 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.

-kdf

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. SeeEVP_PKEY_CTX_set_hkdf_md(3) and EVP_PKEY_CTX_set_tls1_prf_md(3) for the supported string parameters ofeach algorithm.

-kdflen

Set the output length for KDF.

-pkeyopt

Public key options specified as opt:value. See NOTES below for more details.

-hexdump

hex dump the output data.

-asn1parse

asn1parse the output data, this is useful when combined with the -verifyrecover option when an ASN1structure is signed.

-engine

specifying an engine (by its unique id string) will cause pkeyutl to attempt to obtain a functionalreference to the specified engine, thus initialising it if needed. The engine will then be set as thedefault for all available algorithms.

-engine_impl

When used with the -engine option, it specifies to also use engine id for crypto operations.NOTESThe operations and options supported vary according to the key algorithm and its implementation. The OpenSSLoperations and options are indicated below.Unless otherwise mentioned all algorithms support the digest:alg option which specifies the digest in use forsign, verify and verifyrecover operations. The value alg should represent a digest name as used in theEVP_get_digestbyname() function for example sha1. This value is used only for sanity-checking the lengths ofdata passed in to the pkeyutl and for creating the structures that make up the signature (e.g. DigestInfo inRSASSA PKCS#1 v1.5 signatures). In case of RSA, ECDSA and DSA signatures, this utility will not performhashing 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 RSAthe signed data can't be longer than the key modulus, in case of ECDSA and DSA the data shouldn't be longerthan 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 hashfunction output.RSA ALGORITHMThe 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 aresupported:rsa_padding_mode:modeThis sets the RSA padding mode. Acceptable values for mode are pkcs1 for PKCS#1 padding, sslv23 for SSLv23padding, 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 directlyinstead of using a DigestInfo structure. If a digest is set then the a DigestInfo structure is used andits 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 tospecify 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:lenFor pss mode only this option specifies the salt length. Two special values are supported: -1 sets thesalt 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 ALGORITHMThe DSA algorithm supports signing and verification operations only. Currently there are no additional optionsother than digest. Only the SHA1 digest can be used and this digest is assumed by default.DH ALGORITHMThe DH algorithm only supports the derivation operation and no additional options.EC ALGORITHMThe EC algorithm supports sign, verify and derive operations. The sign and verify operations use ECDSA andderive uses ECDH. Currently there are no additional options other than digest. Only the SHA1 digest can beused and this digest is assumed by default.X25519 ALGORITHMThe X25519 algorithm supports key derivation only. Currently there are no additional options.EXAMPLESSign some data using a private key:openssl pkeyutl -sign -in file -inkey key.pem -out sigRecover the signed data (e.g. if an RSA key is used):openssl pkeyutl -verifyrecover -in sig -inkey key.pemVerify the signature (e.g. a DSA key):openssl pkeyutl -verify -in file -sigfile sig -inkey key.pemSign 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:sha256Derive a shared secret value:openssl pkeyutl -derive -inkey key.pem -peerkey pubkey.pem -out secretHexdump 48 bytes of TLS1 PRF using digest SHA256 and shared secret and seed consisting of the single byte0xFF:openssl pkeyutl -kdf TLS1-PRF -kdflen 48 -pkeyopt md:SHA256 \