| =pod |
| {- OpenSSL::safe::output_do_not_edit_headers(); -} |
| |
| =head1 NAME |
| |
| openssl-pkcs8 - PKCS#8 format private key conversion command |
| |
| =head1 SYNOPSIS |
| |
| B<openssl> B<pkcs8> |
| [B<-help>] |
| [B<-topk8>] |
| [B<-inform> B<DER>|B<PEM>] |
| [B<-outform> B<DER>|B<PEM>] |
| [B<-in> I<filename>] |
| [B<-passin> I<arg>] |
| [B<-out> I<filename>] |
| [B<-passout> I<arg>] |
| [B<-iter> I<count>] |
| [B<-noiter>] |
| [B<-nocrypt>] |
| [B<-traditional>] |
| [B<-v2> I<alg>] |
| [B<-v2prf> I<alg>] |
| [B<-v1> I<alg>] |
| [B<-scrypt>] |
| [B<-scrypt_N> I<N>] |
| [B<-scrypt_r> I<r>] |
| [B<-scrypt_p> I<p>] |
| {- $OpenSSL::safe::opt_r_synopsis -} |
| {- $OpenSSL::safe::opt_engine_synopsis -}{- $OpenSSL::safe::opt_provider_synopsis -} |
| |
| =head1 DESCRIPTION |
| |
| This command processes private keys in PKCS#8 format. It can handle |
| both unencrypted PKCS#8 PrivateKeyInfo format and EncryptedPrivateKeyInfo |
| format with a variety of PKCS#5 (v1.5 and v2.0) and PKCS#12 algorithms. |
| |
| =head1 OPTIONS |
| |
| =over 4 |
| |
| =item B<-help> |
| |
| Print out a usage message. |
| |
| =item B<-topk8> |
| |
| Normally a PKCS#8 private key is expected on input and a private key will be |
| written to the output file. With the B<-topk8> option the situation is |
| reversed: it reads a private key and writes a PKCS#8 format key. |
| |
| =item B<-inform> B<DER>|B<PEM>, B<-outform> B<DER>|B<PEM> |
| |
| The input and formats; the default is B<PEM>. |
| See L<openssl-format-options(1)> for details. |
| |
| If a key is being converted from PKCS#8 form (i.e. the B<-topk8> option is |
| not used) then the input file must be in PKCS#8 format. An encrypted |
| key is expected unless B<-nocrypt> is included. |
| |
| If B<-topk8> is not used and B<PEM> mode is set the output file will be an |
| unencrypted private key in PKCS#8 format. If the B<-traditional> option is |
| used then a traditional format private key is written instead. |
| |
| If B<-topk8> is not used and B<DER> mode is set the output file will be an |
| unencrypted private key in traditional DER format. |
| |
| If B<-topk8> is used then any supported private key can be used for the input |
| file in a format specified by B<-inform>. The output file will be encrypted |
| PKCS#8 format using the specified encryption parameters unless B<-nocrypt> |
| is included. |
| |
| =item B<-traditional> |
| |
| When this option is present and B<-topk8> is not a traditional format private |
| key is written. |
| |
| =item B<-in> I<filename> |
| |
| 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. |
| |
| =item B<-passin> I<arg>, B<-passout> I<arg> |
| |
| The password source for the input and output file. |
| For more information about the format of B<arg> |
| see L<openssl-passphrase-options(1)>. |
| |
| =item B<-out> I<filename> |
| |
| This specifies the output filename to write a key to or standard output by |
| default. If any encryption options are set then a pass phrase will be |
| prompted for. The output filename should B<not> be the same as the input |
| filename. |
| |
| =item B<-iter> I<count> |
| |
| When creating new PKCS#8 containers, use a given number of iterations on |
| the password in deriving the encryption key for the PKCS#8 output. |
| High values increase the time required to brute-force a PKCS#8 container. |
| |
| =item B<-noiter> |
| |
| When creating new PKCS#8 containers, use 1 as iteration count. |
| |
| =item B<-nocrypt> |
| |
| PKCS#8 keys generated or input are normally PKCS#8 EncryptedPrivateKeyInfo |
| structures using an appropriate password based encryption algorithm. With |
| this option an unencrypted PrivateKeyInfo structure is expected or output. |
| This option does not encrypt private keys at all and should only be used |
| when absolutely necessary. Certain software such as some versions of Java |
| code signing software used unencrypted private keys. |
| |
| =item B<-v2> I<alg> |
| |
| This option sets the PKCS#5 v2.0 algorithm. |
| |
| The I<alg> argument is the encryption algorithm to use, valid values include |
| B<aes128>, B<aes256> and B<des3>. If this option isn't specified then B<aes256> |
| is used. |
| |
| =item B<-v2prf> I<alg> |
| |
| This option sets the PRF algorithm to use with PKCS#5 v2.0. A typical value |
| value would be B<hmacWithSHA256>. If this option isn't set then the default |
| for the cipher is used or B<hmacWithSHA256> if there is no default. |
| |
| Some implementations may not support custom PRF algorithms and may require |
| the B<hmacWithSHA1> option to work. |
| |
| =item B<-v1> I<alg> |
| |
| This option indicates a PKCS#5 v1.5 or PKCS#12 algorithm should be used. Some |
| older implementations may not support PKCS#5 v2.0 and may require this option. |
| If not specified PKCS#5 v2.0 form is used. |
| |
| =item B<-scrypt> |
| |
| Uses the B<scrypt> algorithm for private key encryption using default |
| parameters: currently N=16384, r=8 and p=1 and AES in CBC mode with a 256 bit |
| key. These parameters can be modified using the B<-scrypt_N>, B<-scrypt_r>, |
| B<-scrypt_p> and B<-v2> options. |
| |
| =item B<-scrypt_N> I<N>, B<-scrypt_r> I<r>, B<-scrypt_p> I<p> |
| |
| Sets the scrypt I<N>, I<r> or I<p> parameters. |
| |
| {- $OpenSSL::safe::opt_r_item -} |
| |
| {- $OpenSSL::safe::opt_engine_item -} |
| |
| {- $OpenSSL::safe::opt_provider_item -} |
| |
| =back |
| |
| =head1 NOTES |
| |
| By default, when converting a key to PKCS#8 format, PKCS#5 v2.0 using 256 bit |
| AES with HMAC and SHA256 is used. |
| |
| Some older implementations do not support PKCS#5 v2.0 format and require |
| the older PKCS#5 v1.5 form instead, possibly also requiring insecure weak |
| encryption algorithms such as 56 bit DES. |
| |
| 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 additional security is considered |
| important the keys should be converted. |
| |
| It is possible to write out DER encoded encrypted private keys in |
| PKCS#8 format because the encryption details are included at an ASN1 |
| level whereas the traditional format includes them at a PEM level. |
| |
| =head1 PKCS#5 V1.5 AND PKCS#12 ALGORITHMS |
| |
| Various algorithms can be used with the B<-v1> command line option, |
| including PKCS#5 v1.5 and PKCS#12. These are described in more detail |
| below. |
| |
| =over 4 |
| |
| =item B<PBE-MD2-DES PBE-MD5-DES> |
| |
| These algorithms were included in the original PKCS#5 v1.5 specification. |
| They only offer 56 bits of protection since they both use DES. |
| |
| =item B<PBE-SHA1-RC2-64>, B<PBE-MD2-RC2-64>, B<PBE-MD5-RC2-64>, B<PBE-SHA1-DES> |
| |
| These algorithms are not mentioned in 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 PKCS#5 v2.0. They use either 64 bit RC2 or |
| 56 bit DES. |
| |
| =item B<PBE-SHA1-RC4-128>, B<PBE-SHA1-RC4-40>, B<PBE-SHA1-3DES>, B<PBE-SHA1-2DES>, B<PBE-SHA1-RC2-128>, B<PBE-SHA1-RC2-40> |
| |
| These algorithms use the PKCS#12 password based encryption algorithm and |
| allow strong encryption algorithms like triple DES or 128 bit RC2 to be used. |
| |
| =back |
| |
| =head1 EXAMPLES |
| |
| Convert a private key to PKCS#8 format using default parameters (AES with |
| 256 bit key and B<hmacWithSHA256>): |
| |
| openssl pkcs8 -in key.pem -topk8 -out enckey.pem |
| |
| Convert a private key to PKCS#8 unencrypted format: |
| |
| openssl pkcs8 -in key.pem -topk8 -nocrypt -out enckey.pem |
| |
| Convert a private key to PKCS#5 v2.0 format using triple DES: |
| |
| openssl pkcs8 -in key.pem -topk8 -v2 des3 -out enckey.pem |
| |
| Convert a private key to PKCS#5 v2.0 format using AES with 256 bits in CBC |
| mode and B<hmacWithSHA512> PRF: |
| |
| openssl pkcs8 -in key.pem -topk8 -v2 aes-256-cbc -v2prf hmacWithSHA512 -out enckey.pem |
| |
| Convert a private key to PKCS#8 using a PKCS#5 1.5 compatible algorithm |
| (DES): |
| |
| openssl pkcs8 -in key.pem -topk8 -v1 PBE-MD5-DES -out enckey.pem |
| |
| Convert a private key to PKCS#8 using a PKCS#12 compatible algorithm |
| (3DES): |
| |
| 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 encrypted format to traditional format: |
| |
| openssl pkcs8 -in pk8.pem -traditional -out key.pem |
| |
| Convert a private key to PKCS#8 format, encrypting with AES-256 and with |
| one million iterations of the password: |
| |
| openssl pkcs8 -in key.pem -topk8 -v2 aes-256-cbc -iter 1000000 -out pk8.pem |
| |
| =head1 STANDARDS |
| |
| 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 |
| algorithms are concerned. |
| |
| The format of PKCS#8 DSA (and other) private keys is not well documented: |
| it is hidden away in PKCS#11 v2.01, section 11.9. OpenSSL's default DSA |
| PKCS#8 private key format complies with this standard. |
| |
| =head1 BUGS |
| |
| There should be an option that prints out the encryption algorithm |
| in use and other details such as the iteration count. |
| |
| =head1 SEE ALSO |
| |
| L<openssl(1)>, |
| L<openssl-dsa(1)>, |
| L<openssl-rsa(1)>, |
| L<openssl-genrsa(1)>, |
| L<openssl-gendsa(1)> |
| |
| =head1 HISTORY |
| |
| The B<-iter> option was added in OpenSSL 1.1.0. |
| |
| The B<-engine> option was deprecated in OpenSSL 3.0. |
| |
| =head1 COPYRIGHT |
| |
| Copyright 2000-2021 The OpenSSL Project Authors. All Rights Reserved. |
| |
| Licensed under the Apache License 2.0 (the "License"). You may not use |
| this file except in compliance with the License. You can obtain a copy |
| in the file LICENSE in the source distribution or at |
| L<https://www.openssl.org/source/license.html>. |
| |
| =cut |