XML signature - 签署 KeyInfo 元素的原因
XML signature - reasons to sign KeyInfo element
根据 XML Signature Specification (3.2.2 "Signature Validation")，KeyInfo 元素可能被签名：
"Note, KeyInfo (or some transformed version thereof) may be signed via a Reference element."
Here 我们可以看到一个带有这种签名的 xml 的例子。
是否有理由自行签署证书？
它消除了哪些安全风险？
查看有关 XAdES 中属性 signingCertificate 的澄清部分。 ETSI XAdES 建立在 XMLDSig 之上，以建立长期有效的高级签名的要求
当 ds:KeyInfo 不存在或不包含用于签名的证书时，signingCertificate 是强制性的，并且具有相同的目的
7.2.2 The SigningCertificate element
In many real life environments users will be able to get from different CAs or even from the same CA, different certificates containing the same public key for different names. The prime advantage is that a user can use the same private key for different purposes. Multiple use of the private key is an advantage when a smart card is used to protect the private key, since the storage of a smart card is always limited. When several CAs are involved, each different certificate may contain a different identity, e.g. as a national or as an employee from a company. Thus when a private key is used for various purposes, the certificate is needed to clarify the context in which the private key was used when generating the signature. Where there is the possibility of multiple uses of private keys it is necessary for the signer to indicate to the verifier the precise certificate to be used.
Many current schemes simply add the certificate after the signed data and thus are subject to various substitution attacks. An example of a substitution attack is a "bad" CA that would issue a certificate to someone with the public key of someone else. If the certificate from the signer was simply appended to the signature and thus not protected by the signature, any one could substitute one certificate by another and the message would appear to be signed by some one else. In order to counter this kind of attack, the identifier of the certificate has to be protected by the digital signature from the signer.
根据 XML Signature Specification (3.2.2 "Signature Validation")，KeyInfo 元素可能被签名：
"Note, KeyInfo (or some transformed version thereof) may be signed via a Reference element."
Here 我们可以看到一个带有这种签名的 xml 的例子。
是否有理由自行签署证书？
它消除了哪些安全风险？
查看有关 XAdES 中属性 signingCertificate 的澄清部分。 ETSI XAdES 建立在 XMLDSig 之上，以建立长期有效的高级签名的要求
ds:KeyInfo 不存在或不包含用于签名的证书时，signingCertificate 是强制性的，并且具有相同的目的
7.2.2 The SigningCertificate element
In many real life environments users will be able to get from different CAs or even from the same CA, different certificates containing the same public key for different names. The prime advantage is that a user can use the same private key for different purposes. Multiple use of the private key is an advantage when a smart card is used to protect the private key, since the storage of a smart card is always limited. When several CAs are involved, each different certificate may contain a different identity, e.g. as a national or as an employee from a company. Thus when a private key is used for various purposes, the certificate is needed to clarify the context in which the private key was used when generating the signature. Where there is the possibility of multiple uses of private keys it is necessary for the signer to indicate to the verifier the precise certificate to be used.
Many current schemes simply add the certificate after the signed data and thus are subject to various substitution attacks. An example of a substitution attack is a "bad" CA that would issue a certificate to someone with the public key of someone else. If the certificate from the signer was simply appended to the signature and thus not protected by the signature, any one could substitute one certificate by another and the message would appear to be signed by some one else. In order to counter this kind of attack, the identifier of the certificate has to be protected by the digital signature from the signer.