genpkey.pod 5.3 KB

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  1. =pod
  2. =head1 NAME
  3. genpkey - generate a private key
  4. =head1 SYNOPSIS
  5. B<openssl> B<genpkey>
  6. [B<-out filename>]
  7. [B<-outform PEM|DER>]
  8. [B<-pass arg>]
  9. [B<-cipher>]
  10. [B<-engine id>]
  11. [B<-paramfile file>]
  12. [B<-algorithm alg>]
  13. [B<-pkeyopt opt:value>]
  14. [B<-genparam>]
  15. [B<-text>]
  16. =head1 DESCRIPTION
  17. The B<genpkey> command generates a private key.
  18. =head1 OPTIONS
  19. =over 4
  20. =item B<-out filename>
  21. the output filename. If this argument is not specified then standard output is
  22. used.
  23. =item B<-outform DER|PEM>
  24. This specifies the output format DER or PEM.
  25. =item B<-pass arg>
  26. the output file password source. For more information about the format of B<arg>
  27. see the B<PASS PHRASE ARGUMENTS> section in L<openssl(1)|openssl(1)>.
  28. =item B<-cipher>
  29. This option encrypts the private key with the supplied cipher. Any algorithm
  30. name accepted by EVP_get_cipherbyname() is acceptable such as B<des3>.
  31. =item B<-engine id>
  32. specifying an engine (by its unique B<id> string) will cause B<genpkey>
  33. to attempt to obtain a functional reference to the specified engine,
  34. thus initialising it if needed. The engine will then be set as the default
  35. for all available algorithms. If used this option should precede all other
  36. options.
  37. =item B<-algorithm alg>
  38. public key algorithm to use such as RSA, DSA or DH. If used this option must
  39. precede any B<-pkeyopt> options. The options B<-paramfile> and B<-algorithm>
  40. are mutually exclusive.
  41. =item B<-pkeyopt opt:value>
  42. set the public key algorithm option B<opt> to B<value>. The precise set of
  43. options supported depends on the public key algorithm used and its
  44. implementation. See B<KEY GENERATION OPTIONS> below for more details.
  45. =item B<-genparam>
  46. generate a set of parameters instead of a private key. If used this option must
  47. precede and B<-algorithm>, B<-paramfile> or B<-pkeyopt> options.
  48. =item B<-paramfile filename>
  49. Some public key algorithms generate a private key based on a set of parameters.
  50. They can be supplied using this option. If this option is used the public key
  51. algorithm used is determined by the parameters. If used this option must
  52. precede and B<-pkeyopt> options. The options B<-paramfile> and B<-algorithm>
  53. are mutually exclusive.
  54. =item B<-text>
  55. Print an (unencrypted) text representation of private and public keys and
  56. parameters along with the PEM or DER structure.
  57. =back
  58. =head1 KEY GENERATION OPTIONS
  59. The options supported by each algorith and indeed each implementation of an
  60. algorithm can vary. The options for the OpenSSL implementations are detailed
  61. below.
  62. =head1 RSA KEY GENERATION OPTIONS
  63. =over 4
  64. =item B<rsa_keygen_bits:numbits>
  65. The number of bits in the generated key. If not specified 1024 is used.
  66. =item B<rsa_keygen_pubexp:value>
  67. The RSA public exponent value. This can be a large decimal or
  68. hexadecimal value if preceded by B<0x>. Default value is 65537.
  69. =back
  70. =head1 DSA PARAMETER GENERATION OPTIONS
  71. =over 4
  72. =item B<dsa_paramgen_bits:numbits>
  73. The number of bits in the generated parameters. If not specified 1024 is used.
  74. =head1 DH PARAMETER GENERATION OPTIONS
  75. =over 4
  76. =item B<dh_paramgen_prime_len:numbits>
  77. The number of bits in the prime parameter B<p>.
  78. =item B<dh_paramgen_generator:value>
  79. The value to use for the generator B<g>.
  80. =back
  81. =head1 EC PARAMETER GENERATION OPTIONS
  82. =over 4
  83. =item B<ec_paramgen_curve:curve>
  84. the EC curve to use.
  85. =back
  86. =head1 GOST2001 KEY GENERATION AND PARAMETER OPTIONS
  87. Gost 2001 support is not enabled by default. To enable this algorithm,
  88. one should load the ccgost engine in the OpenSSL configuration file.
  89. See README.gost file in the engines/ccgost directiry of the source
  90. distribution for more details.
  91. Use of a parameter file for the GOST R 34.10 algorithm is optional.
  92. Parameters can be specified during key generation directly as well as
  93. during generation of parameter file.
  94. =over 4
  95. =item B<paramset:name>
  96. Specifies GOST R 34.10-2001 parameter set according to RFC 4357.
  97. Parameter set can be specified using abbreviated name, object short name or
  98. numeric OID. Following parameter sets are supported:
  99. paramset OID Usage
  100. A 1.2.643.2.2.35.1 Signature
  101. B 1.2.643.2.2.35.2 Signature
  102. C 1.2.643.2.2.35.3 Signature
  103. XA 1.2.643.2.2.36.0 Key exchange
  104. XB 1.2.643.2.2.36.1 Key exchange
  105. test 1.2.643.2.2.35.0 Test purposes
  106. =back
  107. =head1 NOTES
  108. The use of the genpkey program is encouraged over the algorithm specific
  109. utilities because additional algorithm options and ENGINE provided algorithms
  110. can be used.
  111. =head1 EXAMPLES
  112. Generate an RSA private key using default parameters:
  113. openssl genpkey -algorithm RSA -out key.pem
  114. Encrypt output private key using 128 bit AES and the passphrase "hello":
  115. openssl genpkey -algorithm RSA -out key.pem -aes-128-cbc -pass pass:hello
  116. Generate a 2048 bit RSA key using 3 as the public exponent:
  117. openssl genpkey -algorithm RSA -out key.pem -pkeyopt rsa_keygen_bits:2048 \
  118. -pkeyopt rsa_keygen_pubexp:3
  119. Generate 1024 bit DSA parameters:
  120. openssl genpkey -genparam -algorithm DSA -out dsap.pem \
  121. -pkeyopt dsa_paramgen_bits:1024
  122. Generate DSA key from parameters:
  123. openssl genpkey -paramfile dsap.pem -out dsakey.pem
  124. Generate 1024 bit DH parameters:
  125. openssl genpkey -genparam -algorithm DH -out dhp.pem \
  126. -pkeyopt dh_paramgen_prime_len:1024
  127. Generate DH key from parameters:
  128. openssl genpkey -paramfile dhp.pem -out dhkey.pem
  129. =cut