1X509_LOOKUP_HASH_DIR(3ossl)         OpenSSL        X509_LOOKUP_HASH_DIR(3ossl)
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NAME

6       X509_LOOKUP_hash_dir, X509_LOOKUP_file, X509_LOOKUP_store,
7       X509_load_cert_file_ex, X509_load_cert_file, X509_load_crl_file,
8       X509_load_cert_crl_file_ex, X509_load_cert_crl_file - Default OpenSSL
9       certificate lookup methods
10

SYNOPSIS

12        #include <openssl/x509_vfy.h>
13
14        X509_LOOKUP_METHOD *X509_LOOKUP_hash_dir(void);
15        X509_LOOKUP_METHOD *X509_LOOKUP_file(void);
16        X509_LOOKUP_METHOD *X509_LOOKUP_store(void);
17
18        int X509_load_cert_file_ex(X509_LOOKUP *ctx, const char *file, int type,
19                                   OSSL_LIB_CTX *libctx, const char *propq);
20        int X509_load_cert_file(X509_LOOKUP *ctx, const char *file, int type);
21        int X509_load_crl_file(X509_LOOKUP *ctx, const char *file, int type);
22        int X509_load_cert_crl_file_ex(X509_LOOKUP *ctx, const char *file, int type,
23                                       OSSL_LIB_CTX *libctx, const char *propq);
24        int X509_load_cert_crl_file(X509_LOOKUP *ctx, const char *file, int type);
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DESCRIPTION

27       X509_LOOKUP_hash_dir and X509_LOOKUP_file are two certificate lookup
28       methods to use with X509_STORE, provided by OpenSSL library.
29
30       Users of the library typically do not need to create instances of these
31       methods manually, they would be created automatically by
32       X509_STORE_load_locations(3) or SSL_CTX_load_verify_locations(3)
33       functions.
34
35       Internally loading of certificates and CRLs is implemented via
36       functions X509_load_cert_crl_file, X509_load_cert_file and
37       X509_load_crl_file. These functions support parameter type, which can
38       be one of constants FILETYPE_PEM, FILETYPE_ASN1 and FILETYPE_DEFAULT.
39       They load certificates and/or CRLs from specified file into memory
40       cache of X509_STORE objects which given ctx parameter is associated
41       with.
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43       Functions X509_load_cert_file and X509_load_crl_file can load both PEM
44       and DER formats depending of type value. Because DER format cannot
45       contain more than one certificate or CRL object (while PEM can contain
46       several concatenated PEM objects) X509_load_cert_crl_file with
47       FILETYPE_ASN1 is equivalent to X509_load_cert_file.
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49       Constant FILETYPE_DEFAULT with NULL filename causes these functions to
50       load default certificate store file (see
51       X509_STORE_set_default_paths(3).
52
53       Functions return number of objects loaded from file or 0 in case of
54       error.
55
56       Both methods support adding several certificate locations into one
57       X509_STORE.
58
59       This page documents certificate store formats used by these methods and
60       caching policy.
61
62   File Method
63       The X509_LOOKUP_file method loads all the certificates or CRLs present
64       in a file into memory at the time the file is added as a lookup source.
65
66       File format is ASCII text which contains concatenated PEM certificates
67       and CRLs.
68
69       This method should be used by applications which work with a small set
70       of CAs.
71
72   Hashed Directory Method
73       X509_LOOKUP_hash_dir is a more advanced method, which loads
74       certificates and CRLs on demand, and caches them in memory once they
75       are loaded. As of OpenSSL 1.0.0, it also checks for newer CRLs upon
76       each lookup, so that newer CRLs are as soon as they appear in the
77       directory.
78
79       The directory should contain one certificate or CRL per file in PEM
80       format, with a filename of the form hash.N for a certificate, or
81       hash.rN for a CRL.  The hash is the value returned by the
82       X509_NAME_hash_ex(3) function applied to the subject name for
83       certificates or issuer name for CRLs.  The hash can also be obtained
84       via the -hash option of the openssl-x509(1) or openssl-crl(1) commands.
85
86       The .N or .rN suffix is a sequence number that starts at zero, and is
87       incremented consecutively for each certificate or CRL with the same
88       hash value.  Gaps in the sequence numbers are not supported, it is
89       assumed that there are no more objects with the same hash beyond the
90       first missing number in the sequence.
91
92       Sequence numbers make it possible for the directory to contain multiple
93       certificates with same subject name hash value.  For example, it is
94       possible to have in the store several certificates with same subject or
95       several CRLs with same issuer (and, for example, different validity
96       period).
97
98       When checking for new CRLs once one CRL for given hash value is loaded,
99       hash_dir lookup method checks only for certificates with sequence
100       number greater than that of the already cached CRL.
101
102       Note that the hash algorithm used for subject name hashing changed in
103       OpenSSL 1.0.0, and all certificate stores have to be rehashed when
104       moving from OpenSSL 0.9.8 to 1.0.0.
105
106       OpenSSL includes a openssl-rehash(1) utility which creates symlinks
107       with hashed names for all files with .pem suffix in a given directory.
108
109   OSSL_STORE Method
110       X509_LOOKUP_store is a method that allows access to any store of
111       certificates and CRLs through any loader supported by ossl_store(7).
112       It works with the help of URIs, which can be direct references to
113       certificates or CRLs, but can also be references to catalogues of such
114       objects (that behave like directories).
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116       This method overlaps the "File Method" and "Hashed Directory Method"
117       because of the 'file:' scheme loader.  It does no caching of its own,
118       but can use a caching ossl_store(7) loader, and therefore depends on
119       the loader's capability.
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RETURN VALUES

122       X509_LOOKUP_hash_dir(), X509_LOOKUP_file() and X509_LOOKUP_store()
123       always return a valid X509_LOOKUP_METHOD structure.
124
125       X509_load_cert_file(), X509_load_crl_file() and
126       X509_load_cert_crl_file() return the number of loaded objects or 0 on
127       error.
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SEE ALSO

130       PEM_read_PrivateKey(3), X509_STORE_load_locations(3),
131       SSL_CTX_load_verify_locations(3), X509_LOOKUP_meth_new(3),
132       ossl_store(7)
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HISTORY

135       The functions X509_load_cert_file_ex(), X509_load_cert_crl_file_ex()
136       and X509_LOOKUP_store() were added in OpenSSL 3.0.
137
139       Copyright 2015-2021 The OpenSSL Project Authors. All Rights Reserved.
140
141       Licensed under the Apache License 2.0 (the "License").  You may not use
142       this file except in compliance with the License.  You can obtain a copy
143       in the file LICENSE in the source distribution or at
144       <https://www.openssl.org/source/license.html>.
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1483.0.5                             2022-07-05       X509_LOOKUP_HASH_DIR(3ossl)
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