The data structure of SSL certificates usually follows the X.509 certificate standard, which defines the fields and data organization methods contained in certificates. The following is the general data structure of SSL certificate:

Certificate version: indicates the X.509 version number of the certificate.

Serial number: The serial number that uniquely identifies the certificate.

Signature algorithm ID: ID indicating the algorithm used to sign the certificate.

Issuer: the identification information of the certification authority (CA), including the name of the CA and its unique identifier.

Validity period: the validity period of the certificate, including the start date and end date of the certificate.

Subject: Identification information of the entity to which the certificate belongs, usually the name of the certificate applicant (server or client) and other identification information.

Public key: the public key of the certificate holder, which is used for encryption and key agreement.

Extended field: optional extended field, which contains some additional information, such as subject replacement name, key usage, extended key usage, etc.

Signature algorithm: the algorithm used to sign certificates.

Signature value: the result of the certificate authority signing the contents of the certificate with its private key.