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SSL_CTX_load_verify_locations(3)
NAME
  SSL_CTX_load_verify_locations - Set default locations for trusted CA
  certificates

SYNOPSIS
  #include <openssl/ssl.h>

  int SSL_CTX_load_verify_locations(
	  SSL_CTX *ctx,
	  const char *CAfile,
	  const char *CApath );

DESCRIPTION
  The SSL_CTX_load_verify_locations() function specifies the locations for
  ctx, at which CA certificates for verification purposes are located. The
  certificates available via CAfile and CApath are trusted.

NOTES
  If CAfile is not NULL, it points to a file of CA certificates in PEM
  format. The file can contain several CA certificates identified by the
  following sequences:

	-----BEGIN CERTIFICATE-----
	... (CA certificate in base64 encoding) ...
	-----END CERTIFICATE-----

  Text is allowed before, between, and after the certificates. It can be
  used, for example, to describe the certificates.

  The CAfile is processed on execution of the SSL_CTX_load_verify_locations()
  function.

  If CApath is not NULL, it points to a directory containing CA certificates
  in PEM format. The files each contain one CA certificate.  The files are
  looked up by the CA subject name hash value, which must be available.	 If
  more than one CA certificate with the same name hash value exist, the
  extension must be different (e.g. 9d66eef0.0, 9d66eef0.1 etc). The search
  is performed in the ordering of the extension number, regardless of other
  properties of the certificates. Use the c_rehash utility to create the
  necessary links.

  The certificates in CApath are only looked up when required, such as when
  building the certificate chain or when actually performing the verification
  of a peer certificate.

  When looking up CA certificates, the OpenSSL library will first search the
  certificates in CAfile, then those in CApath. Certificate matching is done
  based on the subject name, the key identifier (if present), and the serial
  number as taken from the certificate to be verified. If these data do not
  match, the next certificate will be tried.  If a first certificate matching
  the parameters is found, the verification process will be performed; no
  other certificates for the same parameters will be searched in case of
  failure.

  In server mode, when requesting a client certificate, the server must send
  the list of CAs from which it will accept client certificates. This listis
  not influenced by the contents of CAfile or CApath and must explicitly be
  set using the SSL_CTX_set_client_CA_list() family of functions.

  When building its own certificate chain, an OpenSSL client/server will try
  to fill in missing certificates from CAfile/CApath, if the certificate
  chain was not explicitly specified. (See SSL_CTX_add_extra_chain_cert() and
  SSL_CTX_use_certificate().)

RESTRICTIONS
  If several CA certificates matching the name, key identifier, and serial
  number condition are available, only the first one will be examined. This
  may lead to unexpected results if the same CA certificate is available with
  different expiration dates. If a "certificate expired" verification error
  occurs, no other certificate will be searched. Do no mix expired
  certificates with valid certificates.

RETURN VALUES
  The following return values can occur:

  0	  The operation failed because CAfile and CApath are NULL or the
	  processing at one of the locations specified failed. Check the
	  error stack to find out the reason.

  1	  The operation succeeded.

EXAMPLES
  Generate a CA certificate file with descriptive text from the CA
  certificates ca1.pem ca2.pem ca3.pem:

	#!/bin/sh
	rm CAfile.pem
	for i in ca1.pem ca2.pem ca3.pem ; do
	  openssl x509 -in $i -text >> CAfile.pem
	done

  Prepare the directory /some/where/certs containing several CA certificates
  for use as CApath:

	cd /some/where/certs
	c_rehash .

SEE ALSO
  Functions: ssl(3), SSL_CTX_set_client_CA_list(3),
  SSL_get_client_CA_list(3), SSL_CTX_use_certificate(3),
  SSL_CTX_add_extra_chain_cert(3), SSL_CTX_set_cert_store(3)

Index for Section 3

Alphabetical listing for S

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