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In the standardized algorithm, the following steps are performed for each certificate in the path, starting from the trust anchor. If any check fails on any certificate, the algorithm terminates and path validation fails. (This is an explanatory summary of the scope of the algorithm, not a rigorous
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is present in the relying party's web browser. In a bridged PKI, a certificate chain starting with a user at
Company A might lead to Company A's CA certificate, then to a bridge CA, then to company B's CA certificate, then to company B's trust anchor, which a relying party at company B could trust.
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to make an informed trust decision when presented with any certificate that is not already explicitly trusted. For example, in a hierarchical PKI, a certificate chain starting with a web server certificate might lead to a small CA, then to an intermediate CA, then to a large CA whose
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Policy constraints and basic constraints are checked, to ensure that any explicit policy requirements are not violated and that the certificate is a CA certificate, respectively. This step is crucial in preventing some
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If this procedure reaches the last certificate in the chain, with no name constraint or policy violations or any other error condition, then the certificate path validation algorithm terminates successfully.
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Name constraints are checked, to make sure the subject name is within the permitted subtrees list of all previous CA certificates and not within the excluded subtrees list of any previous CA certificate;
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are checked against the permissible OIDs as of the previous certificate, including any policy mapping equivalencies asserted by the previous certificate;
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certificates, given a certificate path. (Path discovery, the actual construction of a path, is not covered.) The algorithm takes the following inputs:
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The path length is checked to ensure that it does not exceed any maximum path length asserted in this or a previous certificate;
35:(PKI). A path starts with the Subject certificate and proceeds through a number of intermediate certificates up to a trusted
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The issuer name is checked to ensure that it equals the subject name of the previous certificate in the path;
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The key usage extension is checked to ensure that is allowed to sign certificates; and
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Indicators whether policy mapping is allowed and how/when/whether the "any" policy
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The current date/time is checked against the validity period of the certificate;
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182:(May 2008), chapter 6., a standardized path validation algorithm for
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object identifiers (OIDs) acceptable to the relying party (or any);
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Any other critical extensions are recognized and processed.
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defines a standardized path validation algorithm for
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The public key algorithm and parameters are checked;
87:The trust anchor of the certificate path; and
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200:New Tricks For Defeating SSL In Practice
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21:certification path validation algorithm
16:Test for a valid public key certificate
99:reproduction of the detailed steps.)
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46:Path validation is necessary for a
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39:, typically issued by a trusted
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206:DC Briefings 2009 conference.
27:which verifies that a given
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225:Delegated Path Validation
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33:public key infrastructure
220:Delegated Path Discovery
240:Cryptographic protocols
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31:is valid under a given
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82:certificate policy
196:Moxie Marlinspike
111:revocation status
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