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PKEYUTL(1) OpenSSL PKEYUTL(1)NAMEpkeyutl - public key algorithm utilityLIBRARYlibcrypto, -lcryptoSYNOPSISopensslpkeyutl[-infile] [-outfile] [-sigfilefile] [-inkeyfile] [-keyformPEM|DER] [-passinarg] [-peerkeyfile] [-peerformPEM|DER] [-pubin] [-certin] [-rev] [-sign] [-verify] [-verifyrecover] [-encrypt] [-decrypt] [-derive] [-pkeyoptopt:value] [-hexdump] [-asn1parse] [-engineid]DESCRIPTIONThepkeyutlcommand can be used to perform public key operations using any supported algorithm.COMMANDOPTIONS-infilenameThis specifies the input filename to read data from or standard input if this option is not specified.-outfilenamespecifies the output filename to write to or standard output by default.-inkeyfilethe input key file, by default it should be a private key.-keyformPEM|DERthe key format PEM, DER or ENGINE.-passinargthe input key password source. For more information about the format ofargsee thePASSPHRASEARGUMENTSsection in openssl(1).-peerkeyfilethe peer key file, used by key derivation (agreement) operations.-peerformPEM|DERthe peer key format PEM, DER or ENGINE.-engineidspecifying an engine (by its uniqueidstring) will causepkeyutlto 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.-pubinthe input file is a public key.-certinthe input is a certificate containing a public key.-revreverse the order of the input buffer. This is useful for some libraries (such as CryptoAPI) which represent the buffer in little endian format.-signsign the input data and output the signed result. This requires a private key.-verifyverify the input data against the signature file and indicate if the verification succeeded or failed.-verifyrecoververify the input data and output the recovered data.-encryptencrypt the input data using a public key.-decryptdecrypt the input data using a private key.-derivederive a shared secret using the peer key.-hexdumphex dump the output data.-asn1parseasn1parse the output data, this is useful when combined with the-verifyrecoveroption when an ASN1 structure is signed.NOTESThe 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 thedigest:algoption which specifies the digest in use for sign, verify and verifyrecover operations. The valuealgshould represent a digest name as used in the EVP_get_digestbyname() function for examplesha1. This value is used only for sanity-checking the lengths of data passed in to thepkeyutland for creating the structures that make up the signature (e.g.DigestInfoin 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 issha1the input should be 20 bytes long binary encoding of SHA-1 hash function output.RSAALGORITHMThe 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:modeThis sets the RSA padding mode. Acceptable values formodearepkcs1for PKCS#1 padding,sslv23for SSLv23 padding,nonefor no padding,oaepforOAEPmode,x931for X9.31 mode andpssfor PSS. In PKCS#1 padding if the message digest is not set then the supplied data is signed or verified directly instead of using aDigestInfostructure. If a digest is set then the aDigestInfostructure is used and its the length must correspond to the digest type. Foroeapmode only encryption and decryption is supported. Forx931if 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. Forpssmode only sign and verify are supported and the digest type must be specified.rsa_pss_saltlen:lenForpssmode 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 thePSSblock structure.DSAALGORITHMThe DSA algorithm supports signing and verification operations only. Currently there are no additional options other thandigest. Only the SHA1 digest can be used and this digest is assumed by default.DHALGORITHMThe DH algorithm only supports the derivation operation and no additional options.ECALGORITHMThe 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 thandigest. Only the SHA1 digest can be used and this digest is assumed by default.EXAMPLESSign 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 secretSEEALSOgenpkey(1), pkey(1), openssl_rsautl(1) openssl_dgst(1), openssl_rsa(1), openssl_genrsa(1) 1.0.2k 2016-10-14 PKEYUTL(1)