1RSA(1) OpenSSL RSA(1)
2
6 openssl-rsa, rsa - RSA key processing tool
7
9 openssl rsa [-help] [-inform PEM|NET|DER] [-outform PEM|NET|DER] [-in
10 filename] [-passin arg] [-out filename] [-passout arg] [-aes128]
11 [-aes192] [-aes256] [-aria128] [-aria192] [-aria256] [-camellia128]
12 [-camellia192] [-camellia256] [-des] [-des3] [-idea] [-text] [-noout]
13 [-modulus] [-check] [-pubin] [-pubout] [-RSAPublicKey_in]
14 [-RSAPublicKey_out] [-engine id]
15
17 The rsa command processes RSA keys. They can be converted between
18 various forms and their components printed out. Note this command uses
19 the traditional SSLeay compatible format for private key encryption:
20 newer applications should use the more secure PKCS#8 format using the
21 pkcs8 utility.
22
24 -help
25 Print out a usage message.
26 -inform DER|NET|PEM
28 This specifies the input format. The DER option uses an ASN1 DER
29 encoded form compatible with the PKCS#1 RSAPrivateKey or
30 SubjectPublicKeyInfo format. The PEM form is the default format:
31 it consists of the DER format base64 encoded with additional header
32 and footer lines. On input PKCS#8 format private keys are also
33 accepted. The NET form is a format is described in the NOTES
34 section.
35 -outform DER|NET|PEM
37 This specifies the output format, the options have the same meaning
38 and default as the -inform option.
39 -in filename
41 This specifies the input filename to read a key from or standard
42 input if this option is not specified. If the key is encrypted a
43 pass phrase will be prompted for.
44 -passin arg
46 The input file password source. For more information about the
47 format of arg see the PASS PHRASE ARGUMENTS section in openssl(1).
48 -out filename
50 This specifies the output filename to write a key to or standard
51 output if this option is not specified. If any encryption options
52 are set then a pass phrase will be prompted for. The output
53 filename should not be the same as the input filename.
54 -passout password
56 The output file password source. For more information about the
57 format of arg see the PASS PHRASE ARGUMENTS section in openssl(1).
58 -aes128, -aes192, -aes256, -aria128, -aria192, -aria256, -camellia128,
60 -camellia192, -camellia256, -des, -des3, -idea
61 These options encrypt the private key with the specified cipher
62 before outputting it. A pass phrase is prompted for. If none of
63 these options is specified the key is written in plain text. This
64 means that using the rsa utility to read in an encrypted key with
65 no encryption option can be used to remove the pass phrase from a
66 key, or by setting the encryption options it can be use to add or
67 change the pass phrase. These options can only be used with PEM
68 format output files.
69 -text
71 Prints out the various public or private key components in plain
72 text in addition to the encoded version.
73 -noout
75 This option prevents output of the encoded version of the key.
76 -modulus
78 This option prints out the value of the modulus of the key.
79 -check
81 This option checks the consistency of an RSA private key.
82 -pubin
84 By default a private key is read from the input file: with this
85 option a public key is read instead.
86 -pubout
88 By default a private key is output: with this option a public key
89 will be output instead. This option is automatically set if the
90 input is a public key.
91 -RSAPublicKey_in, -RSAPublicKey_out
93 Like -pubin and -pubout except RSAPublicKey format is used instead.
94 -engine id
96 Specifying an engine (by its unique id string) will cause rsa to
97 attempt to obtain a functional reference to the specified engine,
98 thus initialising it if needed. The engine will then be set as the
99 default for all available algorithms.
100
102 The PEM private key format uses the header and footer lines:
103 -----BEGIN RSA PRIVATE KEY-----
105 -----END RSA PRIVATE KEY-----
106 The PEM public key format uses the header and footer lines:
108 -----BEGIN PUBLIC KEY-----
110 -----END PUBLIC KEY-----
111 The PEM RSAPublicKey format uses the header and footer lines:
113 -----BEGIN RSA PUBLIC KEY-----
115 -----END RSA PUBLIC KEY-----
116 The NET form is a format compatible with older Netscape servers and
118 Microsoft IIS .key files, this uses unsalted RC4 for its encryption.
119 It is not very secure and so should only be used when necessary.
120 Some newer version of IIS have additional data in the exported .key
122 files. To use these with the utility, view the file with a binary
123 editor and look for the string "private-key", then trace back to the
124 byte sequence 0x30, 0x82 (this is an ASN1 SEQUENCE). Copy all the data
125 from this point onwards to another file and use that as the input to
126 the rsa utility with the -inform NET option.
127
129 To remove the pass phrase on an RSA private key:
130 openssl rsa -in key.pem -out keyout.pem
132 To encrypt a private key using triple DES:
134 openssl rsa -in key.pem -des3 -out keyout.pem
136 To convert a private key from PEM to DER format:
138 openssl rsa -in key.pem -outform DER -out keyout.der
140 To print out the components of a private key to standard output:
142 openssl rsa -in key.pem -text -noout
144 To just output the public part of a private key:
146 openssl rsa -in key.pem -pubout -out pubkey.pem
148 Output the public part of a private key in RSAPublicKey format:
150 openssl rsa -in key.pem -RSAPublicKey_out -out pubkey.pem
152
154 The command line password arguments don't currently work with NET
155 format.
156 There should be an option that automatically handles .key files,
158 without having to manually edit them.
159
161 pkcs8(1), dsa(1), genrsa(1), gendsa(1)
162
164 Copyright 2000-2018 The OpenSSL Project Authors. All Rights Reserved.
165 Licensed under the OpenSSL license (the "License"). You may not use
167 this file except in compliance with the License. You can obtain a copy
168 in the file LICENSE in the source distribution or at
169 <https://www.openssl.org/source/license.html>.
1701.1.1 2018-09-11 RSA(1)