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.
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):
