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pkcs8(1) - pkcs8 - PKCS#8 format private key conversion tool - man 1 pkcs8

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PKCS8(1)                            OpenSSL                           PKCS8(1)

       pkcs8 - PKCS#8 format private key conversion tool

       openssl pkcs8 [-topk8] [-inform PEM|DER] [-outform PEM|DER] [-in file-
       name] [-passin arg] [-out filename] [-passout arg] [-noiter] [-nocrypt]
       [-nooct] [-embed] [-nsdb] [-v2 alg] [-v1 alg] [-engine id]

       The pkcs8 command processes private keys in(1,8) PKCS#8 format. It can han-
       dle both unencrypted PKCS#8 PrivateKeyInfo format and EncryptedPri-
       vateKeyInfo format with a variety of PKCS#5 (v1.5 and v2.0) and PKCS#12

           Normally a PKCS#8 private key is expected on input and a tradi-
           tional format private key will be written. With the -topk8 option
           the situation is reversed: it reads a traditional format private
           key and writes a PKCS#8 format key.

       -inform DER|PEM
           This specifies the input format. If a PKCS#8 format key is expected
           on input then either a DER or PEM encoded version(1,3,5) of a PKCS#8 key
           will be expected. Otherwise the DER or PEM format of the tradi-
           tional format private key is used.

       -outform DER|PEM
           This specifies the output format, the options have the same meaning
           as the -inform option.

       -in filename
           This specifies the input filename to read(2,n,1 builtins) a key from or standard
           input if(3,n) this option is not specified. If the key is encrypted a
           pass phrase will be prompted for.

       -passin arg
           the input file(1,n) password source. For more information about the for-
           mat of arg see the PASS PHRASE ARGUMENTS section in(1,8) openssl(1).

       -out filename
           This specifies the output filename to write(1,2) a key to or standard
           output by default. If any encryption options are set(7,n,1 builtins) then a pass
           phrase will be prompted for. The output filename should not be the
           same as the input filename.

       -passout arg
           the output file(1,n) password source. For more information about the
           format of arg see the PASS PHRASE ARGUMENTS section in(1,8) openssl(1).

           PKCS#8 keys generated or input are normally PKCS#8 EncryptedPri-
           vateKeyInfo structures using an appropriate password based encryp-
           tion algorithm. With this option an unencrypted PrivateKeyInfo
           structure is expected or output.  This option does not encrypt pri-
           vate keys at all and should only be used when absolutely necessary.
           Certain software such as some versions of Java code signing soft-
           ware used unencrypted private keys.

           This option generates RSA private keys in(1,8) a broken format that some
           software uses. Specifically the private key should be enclosed in(1,8) a
           OCTET STRING but some software just includes the structure itself
           without the surrounding OCTET STRING.

           This option generates DSA keys in(1,8) a broken format. The DSA parame-
           ters are embedded inside the PrivateKey structure. In this form the
           OCTET STRING contains an ASN1 SEQUENCE consisting of two struc-
           tures: a SEQUENCE containing the parameters and an ASN1 INTEGER
           containing the private key.

           This option generates DSA keys in(1,8) a broken format compatible with
           Netscape private key databases. The PrivateKey contains a SEQUENCE
           consisting of the public and private keys respectively.

       -v2 alg
           This option enables the use of PKCS#5 v2.0 algorithms. Normally
           PKCS#8 private keys are encrypted with the password based encryp-
           tion algorithm called pbeWithMD5AndDES-CBC this uses 56 bit DES
           encryption but it was the strongest encryption algorithm supported
           in(1,8) PKCS#5 v1.5. Using the -v2 option PKCS#5 v2.0 algorithms are
           used which can use any encryption algorithm such as 168 bit triple
           DES or 128 bit RC2 however not many implementations support PKCS#5
           v2.0 yet. If you are just using private keys with OpenSSL then this
           doesn't matter.

           The alg argument is the encryption algorithm to use, valid values
           include des, des3 and rc2. It is recommended that des3 is used.

       -v1 alg
           This option specifies a PKCS#5 v1.5 or PKCS#12 algorithm to use. A
           complete list of possible algorithms is included below.

       -engine id
           specifying an engine (by it's unique id string(3,n)) will cause req to
           attempt to obtain a functional reference to the specified engine,
           thus initialising it if(3,n) needed. The engine will then be set(7,n,1 builtins) as the
           default for all available algorithms.

       The encrypted form of a PEM encode PKCS#8 files uses the following
       headers and footers:


       The unencrypted form uses:

        -----BEGIN PRIVATE KEY-----
        -----END PRIVATE KEY-----

       Private keys encrypted using PKCS#5 v2.0 algorithms and high iteration
       counts are more secure that those encrypted using the traditional
       SSLeay compatible formats. So if(3,n) additional security is considered
       important the keys should be converted.

       The default encryption is only 56 bits because this is the encryption
       that most current implementations of PKCS#8 will support.

       Some software may use PKCS#12 password based encryption algorithms with
       PKCS#8 format private keys: these are handled automatically but there
       is no option to produce them.

       It is possible to write(1,2) out DER encoded encrypted private keys in(1,8)
       PKCS#8 format because the encryption details are included at an ASN1
       level whereas the traditional format includes them at a PEM level.

PKCS#5 v1.5 and PKCS#12 algorithms.
       Various algorithms can be used with the -v1 command line option,
       including PKCS#5 v1.5 and PKCS#12. These are described in(1,8) more detail

           These algorithms were included in(1,8) the original PKCS#5 v1.5 specifi-
           cation.  They only offer 56 bits of protection since they both use

       PBE-SHA1-RC2-64 PBE-MD2-RC2-64 PBE-MD5-RC2-64 PBE-SHA1-DES
           These algorithms are not mentioned in(1,8) the original PKCS#5 v1.5
           specification but they use the same key derivation algorithm and
           are supported by some software. They are mentioned in(1,8) PKCS#5 v2.0.
           They use either 64 bit RC2 or 56 bit DES.

       PBE-SHA1-RC2-128 PBE-SHA1-RC2-40
           These algorithms use the PKCS#12 password based encryption algo-
           rithm and allow strong encryption algorithms like triple DES or 128
           bit RC2 to be used.

       Convert a private from traditional to PKCS#5 v2.0 format using triple

        openssl pkcs8 -in key.pem -topk8 -v2 des3 -out enckey.pem

       Convert a private key to PKCS#8 using a PKCS#5 1.5 compatible algorithm

        openssl pkcs8 -in key.pem -topk8 -out enckey.pem

       Convert a private key to PKCS#8 using a PKCS#12 compatible algorithm

        openssl pkcs8 -in key.pem -topk8 -out enckey.pem -v1 PBE-SHA1-3DES

       Read a DER unencrypted PKCS#8 format private key:

        openssl pkcs8 -inform DER -nocrypt -in key.der -out key.pem

       Convert a private key from any PKCS#8 format to traditional format:

        openssl pkcs8 -in pk8.pem -out key.pem

       Test vectors from this PKCS#5 v2.0 implementation were posted to the
       pkcs-tng mailing list using triple DES, DES and RC2 with high iteration
       counts, several people confirmed that they could decrypt the private
       keys produced and Therefore it can be assumed that the PKCS#5 v2.0
       implementation is reasonably accurate at least as far as these algo-
       rithms are concerned.

       The format of PKCS#8 DSA (and other) private keys is not well docu-
       mented: it is hidden away in(1,8) PKCS#11 v2.01, section 11.9. OpenSSL's
       default DSA PKCS#8 private key format complies with this standard.

       There should be an option that prints out the encryption algorithm in(1,8)
       use and other details such as the iteration count.

       PKCS#8 using triple DES and PKCS#5 v2.0 should be the default private
       key format for OpenSSL: for compatibility several of the utilities use
       the old format at present.

       dsa(1,3)(1), rsa(1,3)(1), genrsa(1), gendsa(1)

0.9.7d                            2003-01-30                          PKCS8(1)

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