PKEYUTL(1) OpenSSL PKEYUTL(1) NNAAMMEE openssl-pkeyutl, pkeyutl - public key algorithm utility SSYYNNOOPPSSIISS ooppeennssssll ppkkeeyyuuttll [--iinn ffiillee] [--oouutt ffiillee] [--ssiiggffiillee ffiillee] [--iinnkkeeyy ffiillee] [--kkeeyyffoorrmm PPEEMM||DDEERR] [--ppaassssiinn aarrgg] [--ppeeeerrkkeeyy ffiillee] [--ppeeeerrffoorrmm PPEEMM||DDEERR] [--ppuubbiinn] [--cceerrttiinn] [--rreevv] [--ssiiggnn] [--vveerriiffyy] [--vveerriiffyyrreeccoovveerr] [--eennccrryypptt] [--ddeeccrryypptt] [--ddeerriivvee] [--ppkkeeyyoopptt oopptt::vvaalluuee] [--hheexxdduummpp] [--aassnn11ppaarrssee] [--eennggiinnee iidd] DDEESSCCRRIIPPTTIIOONN The ppkkeeyyuuttll command can be used to perform public key operations using any supported algorithm. CCOOMMMMAANNDD OOPPTTIIOONNSS --iinn ffiilleennaammee This specifies the input filename to read data from or standard input if this option is not specified. --oouutt ffiilleennaammee specifies the output filename to write to or standard output by default. --iinnkkeeyy ffiillee the input key file, by default it should be a private key. --kkeeyyffoorrmm PPEEMM||DDEERR the key format PEM, DER or ENGINE. --ppaassssiinn aarrgg the input key password source. For more information about the for- mat of aarrgg see the PPAASSSS PPHHRRAASSEE AARRGGUUMMEENNTTSS section in _o_p_e_n_s_s_l(1). --ppeeeerrkkeeyy ffiillee the peer key file, used by key derivation (agreement) operations. --ppeeeerrffoorrmm PPEEMM||DDEERR the peer key format PEM, DER or ENGINE. --eennggiinnee iidd specifying an engine (by its unique iidd string) will cause ppkkeeyyuuttll 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. --ppuubbiinn the input file is a public key. --cceerrttiinn the input is a certificate containing a public key. --rreevv reverse the order of the input buffer. This is useful for some libraries (such as CryptoAPI) which represent the buffer in little endian format. --ssiiggnn sign the input data and output the signed result. This requires a private key. --vveerriiffyy verify the input data against the signature file and indicate if the verification succeeded or failed. --vveerriiffyyrreeccoovveerr verify the input data and output the recovered data. --eennccrryypptt encrypt the input data using a public key. --ddeeccrryypptt decrypt the input data using a private key. --ddeerriivvee derive a shared secret using the peer key. --hheexxdduummpp hex dump the output data. --aassnn11ppaarrssee asn1parse the output data, this is useful when combined with the --vveerriiffyyrreeccoovveerr option when an ASN1 structure is signed. NNOOTTEESS The operations and options supported vary according to the key algo- rithm and its implementation. The OpenSSL operations and options are indicated below. Unless otherwise mentioned all algorithms support the ddiiggeesstt::aallgg option which specifies the digest in use for sign, verify and verifyrecover operations. The value aallgg should represent a digest name as used in the _E_V_P___g_e_t___d_i_g_e_s_t_b_y_n_a_m_e_(_) function for example sshhaa11. This value is used only for sanity-checking the lengths of data passed in to the ppkkeeyyuuttll and for creating the structures that make up the signature (e.g. DDiiggeessttIInnffoo 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 algo- rithm. 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 sshhaa11 the input should be 20 bytes long binary encoding of SHA-1 hash function output. RRSSAA AALLGGOORRIITTHHMM The RSA algorithm supports encrypt, decrypt, sign, verify and verifyre- cover operations in general. Some padding modes only support some of these operations however. -rrssaa__ppaaddddiinngg__mmooddee::mmooddee This sets the RSA padding mode. Acceptable values for mmooddee are ppkkccss11 for PKCS#1 padding, ssssllvv2233 for SSLv23 padding, nnoonnee for no padding, ooaaeepp for OOAAEEPP mode, xx993311 for X9.31 mode and ppssss for PSS. In PKCS#1 padding if the message digest is not set then the sup- plied data is signed or verified directly instead of using a DDiiggeessttIInnffoo structure. If a digest is set then the a DDiiggeessttIInnffoo structure is used and its the length must correspond to the digest type. For ooeeaapp mode only encryption and decryption is supported. For xx993311 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 ppssss mode only sign and verify are supported and the digest type must be specified. rrssaa__ppssss__ssaallttlleenn::lleenn For ppssss mode only this option specifies the salt length. Two spe- cial values are supported: -1 sets the salt length to the digest length. When signing -2 sets the salt length to the maximum permis- sible value. When verifying -2 causes the salt length to be auto- matically determined based on the PPSSSS block structure. DDSSAA AALLGGOORRIITTHHMM The DSA algorithm supports signing and verification operations only. Currently there are no additional options other than ddiiggeesstt. Only the SHA1 digest can be used and this digest is assumed by default. DDHH AALLGGOORRIITTHHMM The DH algorithm only supports the derivation operation and no addi- tional options. EECC AALLGGOORRIITTHHMM 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 ddiiggeesstt. Only the SHA1 digest can be used and this digest is assumed by default. EEXXAAMMPPLLEESS 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 SSEEEE AALLSSOO _g_e_n_p_k_e_y(1), _p_k_e_y(1), _r_s_a_u_t_l(1) _d_g_s_t(1), _r_s_a(1), _g_e_n_r_s_a(1) 1.0.2u 2019-12-20 PKEYUTL(1)