Presentation on theme: "About PKI Certificates Dartmouth College PKI Lab."— Presentation transcript:
About PKI Certificates Dartmouth College PKI Lab
X.509 Certificate Defined A type that binds an entity's distinguished name to a public key with a digital signature. This type is defined in the Internet X.509 Public Key Infrastructure (PKIX) Certificate and CRL Profile. This type also contains the distinguished name of the certificate issuer (the signer), an issuer-specific serial number, the issuer's signature algorithm identifier, a validity period, and extensions also defined in that document.
X.509 Certificate Defined 2 Data associated with a private key and containing a public key that provides information about: Identities of the issuer and subject Certificate validity dates and CRL location Certificate intended uses Serial number Other certificate information
X.509 Certificate Format version serialNumber signature issuer validity subject subjectPublicKeyInfo issuerUniqueIdentifier subjectUniqueIdentifier Extensions Certificate information is contained in ASN.1 structures.
Certificate Encodings DER is a binary encoding of the X.509 ASN.1 structures. PEM is the base 64 encoded version of DER. (For situations where binary format won’t work.) Text is a human-readable version of the ASN.1 structures.
Text Example Certificate: Data: Version: v3 Serial Number: 0x401 Signature Algorithm: SHA1withRSA Issuer: CN=Dartmouth CertAuth1,O=Dartmouth College,C=US,DC=dartmouth,DC=edu Validity: Not Before: Friday, October 24, :08:58 AM EDT America/New_York Not After: Friday, October 24, :08:58 PM EDT America/New_York Subject: J. Franklin,O=Dartmouth College,C=US,DC=dartmouth,DC=edu Subject Public Key Info: Algorithm: RSA Public Key: Exponent: Public Key Modulus: (1024 bits) : AD:97:B1:BF:B4:F8:43:6A:13:08:2E:D7:94:AD:86:FE: 3B:88:A2:7C:F4:ED:5C:8B:44:CB:75:B5:58:A0:55:7D: DB:00:F2:91:7E:BC:FA:6D:99:D0:D4:81:88:CF:A6:42: A8:C3:93:C7:3A:51:29:C0:BF:00:D9:52:D3:15:2B:90: 94:F6:47:FD:FE:18:82:5E:65:71:6C:52:E0:B2:A6:E9: 54:43:F3:73:CD:D2:19:0D:DF:4B:BD:0F:B8:57:AE:D3: 43:1D:4D:12:3A:FA:D8:6D:C1:31:7F:9F:B6:5F:18:57: 36:5C:64:CA:5C:C9:F0:A8:28:7C:71:B3:8F:EC:7E:4D Extensions: Identifier: Netscape Certificate Type Critical: no Certificate Usage: SSL Client Secure Identifier: Key Usage: Critical: yes Key Usage: Digital Signature Non Repudiation Key Encipherment Identifier: CertificatePolicies
Certificate Viewer Example
Certificate Revocation List (CRL) Defined A type that contains information about certificates whose validity an issuer has prematurely revoked. The information consists of an issuer name, the time of issue, the next scheduled time of issue, a list of certificate serial numbers and their associated revocation times, and extensions. The CRL is signed by the issuer.
Certificate Revocation List (CRL) Defined 2 A secured list of no longer trusted certificates provided by a Certificate Authority so applications can reject otherwise valid certificates that are compromised or otherwise invalid before their validity period expires. Issued periodically or as needed. Checked by applications at certificate verification time. OCSP protocol provides an alternative which can be an online service.
CRL Format version signature issuer thisUpdate nextUpdate revokedCertificates crlEntryExtensions crlExtensions
CRL Example 2
Certificate Viewers Windows (invoked from IE, desktop, other applications) Mozilla/Thunderbird (invoked from Preferences in Mozilla or Account Options in Thunderbird) Other applications Demos of Certificate Viewers (add hyperlinks as available) Windows Mozilla