PKEYUTL
Section: OpenSSL (1)
Updated: 2017-05-25
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NAME
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.
- -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 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.
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)
Index
- NAME
-
- SYNOPSIS
-
- DESCRIPTION
-
- COMMAND OPTIONS
-
- NOTES
-
- RSA ALGORITHM
-
- DSA ALGORITHM
-
- DH ALGORITHM
-
- EC ALGORITHM
-
- EXAMPLES
-
- SEE ALSO
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