1 /**

     2 @page Security_intro_certificates Certificates

     3 

     4 A @ref certificate binds a public key to a certain individual/entity. This is usually done using @ref digital_signature "digital signatures": if a 

     5 @ref certificate bearing a public key and an individual's name is signed with a key pair which you already trust, then you can 

     6 rest assure that the public key in the @ref certificate really does belong to the individual named in the @ref certificate.

     7 

     8 Different standards using public key cryptography employ different models for using certificates to establish trust. 

     9 Such a model, encompassing data structures, rules for their use, and users of them, may be referred to as a 

    10 @ref PKI "Public Key Infrastructure" (PKI). @ref SSL, @ref TLS and @ref SMIME "S/MIME" all use @ref X509 "X.509" v.3 certificates, and a 

    11 hierarchical @ref PKI in which users are certified by @ref CA "Certification Authorities" (CAs). 

    12 

    13 All data which appear in the interface between the Symbian OS and the rest of the world need a transport encoding, and it 

    14 is in this form that they are sent and received. The transport encoding for @ref X509 "X.509" data structures is @ref DER encoded

    15 @ref ASN "ASN.1".

    16 

    17 @section certification_authorities Certification Authorities

    18 

    19 @ref CA "Certification Authorities" (CAs) are trusted third parties which perform the following functions in the @ref PKIX public 

    20 key infrastructure:

    21 

    22 @li provide trusted 'root' certificates to users (@ref EE "End Entities"), by supplying them with the @ref CA's public key 

    23 @li certifying End Entities: checking that they are who they say they are, and generating certificates for them. The 

    24 certified End Entity is the \b subject of the @ref certificate: the @ref CA is the \b issuer

    25 @li supporting @ref certificate revocation and revocation checking: if an End Entity suspects that their key has been 

    26 compromised, they contact the Certification Authority which issued it. @ref CA "CA"s publish lists of revoked certificates 

    27 (known as @ref CRL "Certificate Revocation Lists") at regular intervals, which End Entities can use to check that 

    28 certificates sent to them have not been revoked 

    29 @li publishing certificates: the most likely place for this is an LDAP directory, since @ref X509_certificate "X.509 certificates" identify 

    30 their subjects and issuers by describing a path through an X.500 directory 

    31 

    32 

    33 */