如何从 SecCertificate 中提取或比较 kSecPropertyKeyValue

Question

需要解析和比较证书值，但其中一些返回为 Data，不解析为字符串。大多数属性以数字或字符串形式返回，但 kSecPropertyKeyValue 是 CFData 的数组。需要这个来显示与 Keychain Access 类似的证书信息。

import Foundation
import Security

let query: [CFString: Any] = [
    kSecClass: kSecClassCertificate,
    kSecReturnAttributes: kCFBooleanTrue,
    kSecReturnRef: kCFBooleanTrue,
    kSecReturnData: kCFBooleanTrue,
    kSecMatchLimit: kSecMatchLimitAll
]

var result: AnyObject?
SecItemCopyMatching(query as CFDictionary, &result)
let certs: [SecCertificate] = (result as? [[CFString: Any]])?.map({ [=10=][kSecValueRef] as! SecCertificate }) ?? []

for cert in certs {
    if let values: [CFString:Any] = (SecCertificateCopyValues(cert, [kSecOIDExtendedKeyUsage] as CFArray, nil) as? [CFString:Any])?[kSecOIDExtendedKeyUsage] as? [CFString:Any] {

        // Expect to find `kSecOIDExtendedUseCodeSigning` value or something else
        // meaningful. How do I do that?

        print(
            "type:", values[kSecPropertyKeyType]!,
            "||| data values:", values[kSecPropertyKeyValue] as! [Data],
            "||| cString:", (values[kSecPropertyKeyValue] as! [CFData]).map({ String(cString: CFDataGetBytePtr([=10=])) }),
            "||| string:", (values[kSecPropertyKeyValue] as! [Data]).map({ String(data: [=10=], encoding: .utf8) })
        )
    }
}

在操场上粘贴，打印：

type: array ||| data values: [8 bytes] ||| cString: ["+\u{06}\u{01}\u{05}\u{05}\u{07}\u{03}\u{04}"] ||| string: [Optional("+\u{06}\u{01}\u{05}\u{05}\u{07}\u{03}\u{04}")]
type: array ||| data values: [9 bytes] ||| cString: ["*�H��cd\u{04}\t"] ||| string: [nil]

有些看起来像 unicode 转义，有些看起来像无效字符串。任何帮助表示赞赏。

Answer 1

显然 OID 值没有可读的字符串表示形式，而是常量，可以在 google/der-ascii.

中找到

比如上面+\u{06}\u{01}\u{05}\u{05}\u{07}\u{03}\u{04}的输出匹配0x2b, 0x06, 0x01, 0x05, 0x05, 0x07, 0x03, 0x04，也就是email protection（+是0x2b字节）。

如何从 SecCertificate 中提取或比较 kSecPropertyKeyValue

How to extract or compare kSecPropertyKeyValue from SecCertificate

security

certificate

keychain

swift