1FETCH-CRL(8) System Manager's Manual FETCH-CRL(8)
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6 fetch-crl - retrieve certificate revocation lists
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9 fetch-crl [-c config] [-v[v..]] [-q] [-h] [-l infopath] [-o outputpath]
10 [-s statepath] [-a agingtolerance] [-T httptimeout] [-r randomwait] [-p paral‐
11 lelism] [--formats openssl|pem|der|nss] ..
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14 The fetch-crl utility will retrieve certificate revocation lists (CRLs)
15 for a set of installed trust anchors, based on crl_url files or IGTF-
16 style info files. It will install these for use with OpenSSL, NSS or
17 third-party tools.
18 It works based on a list of trust anchors, for each of which one or
20 more CRLs should be installed in a CRL store. And for each of these
21 CRLs, one or more URLs can be specified from which the specific CRL can
22 be retrieved. There are several supported formats for CRL stores:
23 openssl
25 has a directory in which hash. i files are stored, one CRL per
26 file, and all CRLs for the trust anchors whose subject distin‐
27 guished name hashes to hash are read and evaluated for each cer‐
28 tificate issues by the CAs whose subject name hash matches hash
29 OpenSSL in version 1 changes its subject name hashing algorithm,
31 though, so that for one trust anchor two hashes could be used,
32 depending on the specific OpenSSL version at hand. If OpenSSL
33 version 1 or higher is used by fetch-crl and the default mode is
34 used, each CRL is written out twice, once for each possible hash
35 value. This mode in controlled by the opensslmode = { dual |
36 single } configuration option in the configuration file.
37 pem writes out the CRL in PEM (RFC 1421) format.
39 der writes out the CRL in binary under distinguished encoding rules
41 nss will use the crlutil from the Mozilla NSS tools to add or
43 replace a CRL in the NSS cert8.db database.
44 Each CRLs can be retrieved from one of several URLs. These URLs are
47 listed by default in the trust anchor meta-data: the .info file or the
48 .crl_url file, as shipped with the trust anchor. In the crl_url file,
49 there is one URL per line; in the .info file, the crl_url attribute is
50 a semi-colon separated list of URLs. These URLs are then tried in order
51 to retrieve a fresh CRL. Once data has been successfully retrieved,
52 this data is used as the CRL if it passes verification, signature
53 checking and expiration checks. Http, https, ftp and file URLs are sup‐
54 ported. If data for a CRL has been downloaded but this data fails any
55 of the subsequent checks (signature validation, freshness), the CRL
56 data is discarded and NO further URLs are tried for this CRL!
57 URLs can be pre-pended or post-pended to the default list via the con‐
59 figuration file. This can be used to prefer a local mirror repository
60 over any URLs shipped by the trust anchor provider, without the need to
61 modify the trust anchor metadata. By post-pending a URL, a 'last-
62 resort' download location can be added in case the CA provided URLs
63 cannot be used. The pre- and post-pended URLS are subject to token
64 expansion of the tokens @ALIAS@, @ANCHORNAME@, and @R@, where R is the
65 sequence number of the CRL on a per-trust anchor basis.
66 Retrieved CRLs may be PEM (RFC1421) or DER encoded. They are automati‐
68 cally converted as needed by fetch-crl, using the OpenSSL command-line
69 tool.
70 Retrieving a CRL without having an accompanying CA root certificate in
72 an OpenSSL-accessible form (like @ALIAS@.0 or @ANCHORNAME@.@R@ will
73 result in a verification failures. The CA lookup directory and patterns
74 can be configured via the configuration file
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78 In paths and name templates, tokens are expanded to allow a single pat‐
79 tern to be used for all trust anchors. The nametemplate_*, catemplate,
80 prepend_url, and postpend_url configuration settings are subject to
81 token expansion.
82 The following tokens are recognised
84 @ALIAS@
86 The alias name of the trust anchor as defined in the info file.
87 If there is no info file and the meta-data is retrieved from
88 crl_url files, then the alias is set to the basename (excluding
89 the .crl_url suffix) of the filename of the trust anchor.
90 @ANCHORNAME@
92 The file name of the trust anchor, without any .info or .url_crl
93 suffix.
94 @R@ The CRL sequence number, counting from 0. Note that most trust
96 anchors only have a single CRL, with sequence number "0".
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100 -h --help
101 Show help text.
102 -l --infodir metadata-directory
104 The script will search this directory for files with the suffix
105 '.info' or '.crl_url'. Note: the CRL files to download must be
106 in either PEM or DER format.
107 -o --out outputDirectory
110 Directory where to put the downloaded and processed CRLs. The
111 directory to be used as argument for this option is typically
112 /etc/grid-security/certificates Default: infodir (meta-data
113 directory)
114 -a --agingtolerance hours
117 The maximum age of the locally downloaded CRL before download
118 failures trigger actual error messages. This error message sup‐
119 pression mechanism only works if the CRL has been downloaded at
120 least once and either the crl_url files are named after the hash
121 of the CRL issuer name, or a state directory is used to preserve
122 state across invocations.
123 Default: 24 hour aging tolerance
125 -q --quiet
127 Quiet mode (do not print information messages)
128 -r --randomwait s
131 Wait up to s seconds before starting the retrieval process(es).
132 -p --parallelism n
135 Do the retrieval for several trust anchors in parallel, with up
136 to n processes doing retrievals. At most n downloads will be
137 active at any one time. Multiple CRLs for the same trust anchor
138 are still downloaded sequentially.
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142 Please see http://www.nikhef.nl/grid/gridwiki/index.php/FetchCRL3 for a
143 description of the configuation options. The default location of the
144 configuration file is /etc/fetch-crl.conf.
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148 Defaults can be set in the fetch-crl system configuration file
149 /etc/fetch-crl.conf.
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153 openssl(1), http://www.nikhef.nl/grid/gridwiki/index.php/FetchCRL3
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157 Exit status is normally 0; if an error occurs, exit status is 1 and
158 diagnostics will be written to standard error.
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162 Licensed under the Apache License, Version 2.0 (the "License");
163 http://www.apache.org/licenses/LICENSE-2.0
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168 Although fetch-crl3 will install multiple CRLs in the CRL stores
169 (called '.r0', '.r1', or labelled appropriately in an NSS store), if
170 the number of CRLs decreases the left-overs are not automatically
171 removed. So if the number of CRLs for a particular CA does down from n
172 to n-1, the file '.rn' must be removed manually.
173Trust Anchor Utilities local FETCH-CRL(8)