EC(1) OpenSSL EC(1) NNAAMMEE openssl-ec, ec - EC key processing SSYYNNOOPPSSIISS ooppeennssssll eecc [--iinnffoorrmm PPEEMM||DDEERR] [--oouuttffoorrmm PPEEMM||DDEERR] [--iinn ffiilleennaammee] [--ppaassssiinn aarrgg] [--oouutt ffiilleennaammee] [--ppaassssoouutt aarrgg] [--ddeess] [--ddeess33] [--iiddeeaa] [--tteexxtt] [--nnoooouutt] [--ppaarraamm__oouutt] [--ppuubbiinn] [--ppuubboouutt] [--ccoonnvv__ffoorrmm aarrgg] [--ppaarraamm__eenncc aarrgg] [--eennggiinnee iidd] DDEESSCCRRIIPPTTIIOONN The eecc command processes EC keys. They can be converted between various forms and their components printed out. NNoottee OpenSSL uses the private key format specified in 'SEC 1: Elliptic Curve Cryptography' (http://www.secg.org/). To convert a OpenSSL EC private key into the PKCS#8 private key format use the ppkkccss88 command. CCOOMMMMAANNDD OOPPTTIIOONNSS --iinnffoorrmm DDEERR||PPEEMM This specifies the input format. The DDEERR option with a private key uses an ASN.1 DER encoded SEC1 private key. When used with a public key it uses the SubjectPublicKeyInfo structure as specified in RFC 3280. The PPEEMM form is the default format: it consists of the DDEERR format base64 encoded with additional header and footer lines. In the case of a private key PKCS#8 format is also accepted. --oouuttffoorrmm DDEERR||PPEEMM This specifies the output format, the options have the same meaning as the --iinnffoorrmm option. --iinn ffiilleennaammee This specifies the input filename to read a key from or standard input if this option is not specified. If the key is encrypted a pass phrase will be prompted for. --ppaassssiinn aarrgg the input file 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). --oouutt ffiilleennaammee This specifies the output filename to write a key to or standard output by is not specified. If any encryption options are set then a pass phrase will be prompted for. The output filename should nnoott be the same as the input filename. --ppaassssoouutt aarrgg the output file password source. For more information about the format of aarrgg see the PPAASSSS PPHHRRAASSEE AARRGGUUMMEENNTTSS section in _o_p_e_n_s_s_l(1). --ddeess||--ddeess33||--iiddeeaa These options encrypt the private key with the DES, triple DES, IDEA or any other cipher supported by OpenSSL before outputting it. A pass phrase is prompted for. If none of these options is speci- fied the key is written in plain text. This means that using the eecc utility to read in an encrypted key with no encryption option can be used to remove the pass phrase from a key, or by setting the encryption options it can be use to add or change the pass phrase. These options can only be used with PEM format output files. --tteexxtt prints out the public, private key components and parameters. --nnoooouutt this option prevents output of the encoded version of the key. --mmoodduulluuss this option prints out the value of the public key component of the key. --ppuubbiinn by default a private key is read from the input file: with this option a public key is read instead. --ppuubboouutt by default a private key is output. With this option a public key will be output instead. This option is automatically set if the input is a public key. --ccoonnvv__ffoorrmm This specifies how the points on the elliptic curve are converted into octet strings. Possible values are: ccoommpprreesssseedd (the default value), uunnccoommpprreesssseedd and hhyybbrriidd. For more information regarding the point conversion forms please read the X9.62 standard. NNoottee Due to patent issues the ccoommpprreesssseedd option is disabled by default for binary curves and can be enabled by defining the preprocessor macro OOPPEENNSSSSLL__EECC__BBIINN__PPTT__CCOOMMPP at compile time. --ppaarraamm__eenncc aarrgg This specifies how the elliptic curve parameters are encoded. Pos- sible value are: nnaammeedd__ccuurrvvee, i.e. the ec parameters are specified by a OID, or eexxpplliicciitt where the ec parameters are explicitly given (see RFC 3279 for the definition of the EC parameters structures). The default value is nnaammeedd__ccuurrvvee. NNoottee the iimmpplliicciittllyyCCAA alterna- tive ,as specified in RFC 3279, is currently not implemented in OpenSSL. --eennggiinnee iidd specifying an engine (by its unique iidd string) will cause eecc 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. NNOOTTEESS The PEM private key format uses the header and footer lines: -----BEGIN EC PRIVATE KEY----- -----END EC PRIVATE KEY----- The PEM public key format uses the header and footer lines: -----BEGIN PUBLIC KEY----- -----END PUBLIC KEY----- EEXXAAMMPPLLEESS To encrypt a private key using triple DES: openssl ec -in key.pem -des3 -out keyout.pem To convert a private key from PEM to DER format: openssl ec -in key.pem -outform DER -out keyout.der To print out the components of a private key to standard output: openssl ec -in key.pem -text -noout To just output the public part of a private key: openssl ec -in key.pem -pubout -out pubkey.pem To change the parameters encoding to eexxpplliicciitt: openssl ec -in key.pem -param_enc explicit -out keyout.pem To change the point conversion form to ccoommpprreesssseedd: openssl ec -in key.pem -conv_form compressed -out keyout.pem SSEEEE AALLSSOO _e_c_p_a_r_a_m(1), _d_s_a(1), _r_s_a(1) HHIISSTTOORRYY The ec command was first introduced in OpenSSL 0.9.8. AAUUTTHHOORR Nils Larsch for the OpenSSL project (http://www.openssl.org). 1.0.2u 2019-12-20 EC(1)