验证数字签名

验证数字签名包含两个部分：验证签名有效和验证证书可信。

签名有效代表文档未被篡改，证书可信代表签名者是可信任的。一般来说，签名有效且证书可信才代表一个签名验证通过。

验证数字签名关键代码如下：

swiftobjective-c

swift

if let url = URL(string: pdfPath) {
    let document = CPDFDocument(url: url)
    
    if let signatures = document?.signatures {
        // 遍历所有数字签名
        for signature in signatures {
          	signature.verifySignature(with: document)
            if let signer = signature.signers.first, let certificate = signer.certificates.first {
                var isSignVerified = true
                var isCertTrusted = true
                
                if !signer.isCertTrusted {
                    isCertTrusted = false
                }
                
                if !signer.isSignVerified {
                    isSignVerified = false
                }
                
                if isSignVerified && isCertTrusted {
                    //签名有效，证书受信任
                    //执行相应的操作
                } else if isSignVerified && !isCertTrusted {
                    //签名有效，但证书不受信任
                    //执行相应的操作
                } else if !isSignVerified && !isCertTrusted {
                    // 签名无效
                    // 执行相应的操作
                } else {
                    // 签名无效
                    // 执行相应的操作
                }
            }
        }
    }
}

objective-c

NSURL *url = [NSURL fileURLWithPath:@"file path"];

CPDFDocument *document = [[CPDFDocument alloc] initWithURL:url];

NSArray *signatures = [document signatures];

// 遍历所有数字签名
for (CPDFSignature *signature in signatures) {
  	[sign verifySignatureWithDocument:document];
    CPDFSigner *signer = signature.signers.firstObject;
    CPDFSignatureCertificate * cer = signer.certificates.firstObject;

    BOOL isSignVerified = YES;
    BOOL isCertTrusted = YES;
  
   if (!signer.isCertTrusted) {
        isCertTrusted = NO;
    }

    if (!signer.isSignVerified) {
        isSignVerified = NO;
    }
        
    if (isSignVerified && isCertTrusted) {
        //签名有效，证书受信任 
				//执行相应的操作
 
    } else if(isSignVerified && !isCertTrusted) {
        //签名有效，但证书不受信任 
				//执行相应的操作
    } else if(!isSignVerified && !isCertTrusted){
       
    } else {
       //签名无效 
			//执行相应的操作
    }
}

验证数字签名 ​

验证数字签名