根据您提供的文件内容，keybox.xml 文件包含以下主要信息：

1. Keybox数量 ([NumberOfKeyboxes](file:///d%3A/010F200/svn/ProduceToolMfc/FtSmartPos/FtSmartPos/ToolBydMes/httpclient/e%3A%5CGoogleKey%5CLinux_AttestationKeyboxPack_Tool%5CLinux_AttestationKeyboxPack_Tool%5Ckb.xml#3%2C3-3%2C3)) - 指定文件中包含的密钥盒数量。
2. 设备ID ([DeviceID](file:///d%3A/010F200/svn/ProduceToolMfc/FtSmartPos/FtSmartPos/ToolBydMes/httpclient/e%3A%5CGoogleKey%5CLinux_AttestationKeyboxPack_Tool%5CLinux_AttestationKeyboxPack_Tool%5Ckb.xml#4%2C10-4%2C10)) - 每个密钥盒有一个与之关联的设备ID。
3. 算法 ([algorithm](file:///d%3A/010F200/svn/ProduceToolMfc/FtSmartPos/FtSmartPos/ToolBydMes/httpclient/e%3A%5CGoogleKey%5CLinux_AttestationKeyboxPack_Tool%5CLinux_AttestationKeyboxPack_Tool%5Ckb.xml#5%2C8-5%2C8)) - 每个密钥盒指定使用的加密算法，例如 [ecdsa](file:///d%3A/010F200/svn/ProduceToolMfc/FtSmartPos/FtSmartPos/ToolBydMes/httpclient/e%3A%5CGoogleKey%5CLinux_AttestationKeyboxPack_Tool%5CLinux_AttestationKeyboxPack_Tool%5Ckb.xml#5%2C19-5%2C19) (ECDSA即ECC) 或 [rsa](file:///d%3A/010F200/svn/ProduceToolMfc/FtSmartPos/FtSmartPos/ToolBydMes/httpclient/e%3A%5CGoogleKey%5CLinux_AttestationKeyboxPack_Tool%5CLinux_AttestationKeyboxPack_Tool%5Ckb.xml#84%2C19-84%2C19) (RSA)。
4. 私钥 ([PrivateKey](file:///d%3A/010F200/svn/ProduceToolMfc/FtSmartPos/FtSmartPos/ToolBydMes/httpclient/e%3A%5CGoogleKey%5CLinux_AttestationKeyboxPack_Tool%5CLinux_AttestationKeyboxPack_Tool%5Ckb.xml#6%2C5-6%2C5)) - 每个密钥盒包含一个私钥，格式通常为PEM。
5. 证书链 ([CertificateChain](file:///d%3A/010F200/svn/ProduceToolMfc/FtSmartPos/FtSmartPos/ToolBydMes/httpclient/e%3A%5CGoogleKey%5CLinux_AttestationKeyboxPack_Tool%5CLinux_AttestationKeyboxPack_Tool%5Ckb.xml#12%2C5-12%2C5)) - 包括一个或多个证书，每个密钥盒可能包含多个证书，用于验证密钥的合法性。

具体到您的文件，结构如下：

<?xml version="1.0"?>
<AndroidAttestation>
    <NumberOfKeyboxes>1</NumberOfKeyboxes>
    <Keybox DeviceID="0">
        <Key algorithm="ecdsa">
            <PrivateKey format="pem">
                -----BEGIN EC PRIVATE KEY-----
                ...
                -----END EC PRIVATE KEY-----
            </PrivateKey>
            <CertificateChain>
                <NumberOfCertificates>3</NumberOfCertificates>
                <Certificate format="pem">
                    -----BEGIN CERTIFICATE-----
                    ...
                    -----END CERTIFICATE-----
                </Certificate>
                ...
            </CertificateChain>
        </Key>
        <Key algorithm="rsa">
            <PrivateKey format="pem">
                -----BEGIN RSA PRIVATE KEY-----
                ...
                -----END RSA PRIVATE KEY-----
            </PrivateKey>
            <CertificateChain>
                <NumberOfCertificates>3</NumberOfCertificates>
                <Certificate format="pem">
                    -----BEGIN CERTIFICATE-----
                    ...
                    -----END CERTIFICATE-----
                </Certificate>
                ...
            </CertificateChain>
        </Key>
    </Keybox>
</AndroidAttestation>

每个Key元素代表一个密钥盒，包含使用的算法、私钥和证书链。每个证书链可以包含多个证书，用于建立信任链。