1PKEYUTL(1)                          OpenSSL                         PKEYUTL(1)
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4

NAME

6       openssl-pkeyutl, pkeyutl - public key algorithm utility
7

SYNOPSIS

9       openssl pkeyutl [-help] [-in file] [-out file] [-sigfile file] [-inkey
10       file] [-keyform PEM|DER|ENGINE] [-passin arg] [-peerkey file]
11       [-peerform PEM|DER|ENGINE] [-pubin] [-certin] [-rev] [-sign] [-verify]
12       [-verifyrecover] [-encrypt] [-decrypt] [-derive] [-kdf algorithm]
13       [-kdflen length] [-pkeyopt opt:value] [-hexdump] [-asn1parse] [-rand
14       file...]  [-writerand file] [-engine id] [-engine_impl]
15

DESCRIPTION

17       The pkeyutl command can be used to perform low-level public key
18       operations using any supported algorithm.
19

OPTIONS

21       -help
22           Print out a usage message.
23
24       -in filename
25           This specifies the input filename to read data from or standard
26           input if this option is not specified.
27
28       -out filename
29           Specifies the output filename to write to or standard output by
30           default.
31
32       -sigfile file
33           Signature file, required for verify operations only
34
35       -inkey file
36           The input key file, by default it should be a private key.
37
38       -keyform PEM|DER|ENGINE
39           The key format PEM, DER or ENGINE. Default is PEM.
40
41       -passin arg
42           The input key password source. For more information about the
43           format of arg see "Pass Phrase Options" in openssl(1).
44
45       -peerkey file
46           The peer key file, used by key derivation (agreement) operations.
47
48       -peerform PEM|DER|ENGINE
49           The peer key format PEM, DER or ENGINE. Default is PEM.
50
51       -pubin
52           The input file is a public key.
53
54       -certin
55           The input is a certificate containing a public key.
56
57       -rev
58           Reverse the order of the input buffer. This is useful for some
59           libraries (such as CryptoAPI) which represent the buffer in little
60           endian format.
61
62       -sign
63           Sign the input data (which must be a hash) and output the signed
64           result. This requires a private key.
65
66       -verify
67           Verify the input data (which must be a hash) against the signature
68           file and indicate if the verification succeeded or failed.
69
70       -verifyrecover
71           Verify the input data (which must be a hash) and output the
72           recovered data.
73
74       -encrypt
75           Encrypt the input data using a public key.
76
77       -decrypt
78           Decrypt the input data using a private key.
79
80       -derive
81           Derive a shared secret using the peer key.
82
83       -kdf algorithm
84           Use key derivation function algorithm.  The supported algorithms
85           are at present TLS1-PRF and HKDF.  Note: additional parameters and
86           the KDF output length will normally have to be set for this to
87           work.  See EVP_PKEY_CTX_set_hkdf_md(3) and
88           EVP_PKEY_CTX_set_tls1_prf_md(3) for the supported string parameters
89           of each algorithm.
90
91       -kdflen length
92           Set the output length for KDF.
93
94       -pkeyopt opt:value
95           Public key options specified as opt:value. See NOTES below for more
96           details.
97
98       -hexdump
99           hex dump the output data.
100
101       -asn1parse
102           Parse the ASN.1 output data, this is useful when combined with the
103           -verifyrecover option when an ASN1 structure is signed.
104
105       -rand file...
106           A file or files containing random data used to seed the random
107           number generator.  Multiple files can be specified separated by an
108           OS-dependent character.  The separator is ; for MS-Windows, , for
109           OpenVMS, and : for all others.
110
111       [-writerand file]
112           Writes random data to the specified file upon exit.  This can be
113           used with a subsequent -rand flag.
114
115       -engine id
116           Specifying an engine (by its unique id string) will cause pkeyutl
117           to attempt to obtain a functional reference to the specified
118           engine, thus initialising it if needed. The engine will then be set
119           as the default for all available algorithms.
120
121       -engine_impl
122           When used with the -engine option, it specifies to also use engine
123           id for crypto operations.
124

NOTES

126       The operations and options supported vary according to the key
127       algorithm and its implementation. The OpenSSL operations and options
128       are indicated below.
129
130       Unless otherwise mentioned all algorithms support the digest:alg option
131       which specifies the digest in use for sign, verify and verifyrecover
132       operations.  The value alg should represent a digest name as used in
133       the EVP_get_digestbyname() function for example sha1. This value is not
134       used to hash the input data. It is used (by some algorithms) for
135       sanity-checking the lengths of data passed in to the pkeyutl and for
136       creating the structures that make up the signature (e.g. DigestInfo in
137       RSASSA PKCS#1 v1.5 signatures).
138
139       This utility does not hash the input data but rather it will use the
140       data directly as input to the signature algorithm. Depending on the key
141       type, signature type, and mode of padding, the maximum acceptable
142       lengths of input data differ. The signed data can't be longer than the
143       key modulus with RSA. In case of ECDSA and DSA the data shouldn't be
144       longer than the field size, otherwise it will be silently truncated to
145       the field size. In any event the input size must not be larger than the
146       largest supported digest size.
147
148       In other words, if the value of digest is sha1 the input should be the
149       20 bytes long binary encoding of the SHA-1 hash function output.
150
151       The Ed25519 and Ed448 signature algorithms are not supported by this
152       utility.  They accept non-hashed input, but this utility can only be
153       used to sign hashed input.
154

RSA ALGORITHM

156       The RSA algorithm generally supports the encrypt, decrypt, sign, verify
157       and verifyrecover operations. However, some padding modes support only
158       a subset of these operations. The following additional pkeyopt values
159       are supported:
160
161       rsa_padding_mode:mode
162           This sets the RSA padding mode. Acceptable values for mode are
163           pkcs1 for PKCS#1 padding, sslv23 for SSLv23 padding, none for no
164           padding, oaep for OAEP mode, x931 for X9.31 mode and pss for PSS.
165
166           In PKCS#1 padding if the message digest is not set then the
167           supplied data is signed or verified directly instead of using a
168           DigestInfo structure. If a digest is set then the a DigestInfo
169           structure is used and its the length must correspond to the digest
170           type.
171
172           For oaep mode only encryption and decryption is supported.
173
174           For x931 if the digest type is set it is used to format the block
175           data otherwise the first byte is used to specify the X9.31 digest
176           ID. Sign, verify and verifyrecover are can be performed in this
177           mode.
178
179           For pss mode only sign and verify are supported and the digest type
180           must be specified.
181
182       rsa_pss_saltlen:len
183           For pss mode only this option specifies the salt length. Three
184           special values are supported: "digest" sets the salt length to the
185           digest length, "max" sets the salt length to the maximum
186           permissible value. When verifying "auto" causes the salt length to
187           be automatically determined based on the PSS block structure.
188
189       rsa_mgf1_md:digest
190           For PSS and OAEP padding sets the MGF1 digest. If the MGF1 digest
191           is not explicitly set in PSS mode then the signing digest is used.
192

RSA-PSS ALGORITHM

194       The RSA-PSS algorithm is a restricted version of the RSA algorithm
195       which only supports the sign and verify operations with PSS padding.
196       The following additional pkeyopt values are supported:
197
198       rsa_padding_mode:mode, rsa_pss_saltlen:len, rsa_mgf1_md:digest
199           These have the same meaning as the RSA algorithm with some
200           additional restrictions. The padding mode can only be set to pss
201           which is the default value.
202
203           If the key has parameter restrictions than the digest, MGF1 digest
204           and salt length are set to the values specified in the parameters.
205           The digest and MG cannot be changed and the salt length cannot be
206           set to a value less than the minimum restriction.
207

DSA ALGORITHM

209       The DSA algorithm supports signing and verification operations only.
210       Currently there are no additional -pkeyopt options other than digest.
211       The SHA1 digest is assumed by default.
212

DH ALGORITHM

214       The DH algorithm only supports the derivation operation and no
215       additional -pkeyopt options.
216

EC ALGORITHM

218       The EC algorithm supports sign, verify and derive operations. The sign
219       and verify operations use ECDSA and derive uses ECDH. SHA1 is assumed
220       by default for the -pkeyopt digest option.
221

X25519 and X448 ALGORITHMS

223       The X25519 and X448 algorithms support key derivation only. Currently
224       there are no additional options.
225

EXAMPLES

227       Sign some data using a private key:
228
229        openssl pkeyutl -sign -in file -inkey key.pem -out sig
230
231       Recover the signed data (e.g. if an RSA key is used):
232
233        openssl pkeyutl -verifyrecover -in sig -inkey key.pem
234
235       Verify the signature (e.g. a DSA key):
236
237        openssl pkeyutl -verify -in file -sigfile sig -inkey key.pem
238
239       Sign data using a message digest value (this is currently only valid
240       for RSA):
241
242        openssl pkeyutl -sign -in file -inkey key.pem -out sig -pkeyopt digest:sha256
243
244       Derive a shared secret value:
245
246        openssl pkeyutl -derive -inkey key.pem -peerkey pubkey.pem -out secret
247
248       Hexdump 48 bytes of TLS1 PRF using digest SHA256 and shared secret and
249       seed consisting of the single byte 0xFF:
250
251        openssl pkeyutl -kdf TLS1-PRF -kdflen 48 -pkeyopt md:SHA256 \
252           -pkeyopt hexsecret:ff -pkeyopt hexseed:ff -hexdump
253

SEE ALSO

255       genpkey(1), pkey(1), rsautl(1) dgst(1), rsa(1), genrsa(1),
256       EVP_PKEY_CTX_set_hkdf_md(3), EVP_PKEY_CTX_set_tls1_prf_md(3)
257
259       Copyright 2006-2021 The OpenSSL Project Authors. All Rights Reserved.
260
261       Licensed under the OpenSSL license (the "License").  You may not use
262       this file except in compliance with the License.  You can obtain a copy
263       in the file LICENSE in the source distribution or at
264       <https://www.openssl.org/source/license.html>.
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2681.1.1l                            2021-09-15                        PKEYUTL(1)
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