複製的數字簽名_數字簽名的安全性

sha1和MD5算法的區別

sha-1與MD5的最大區別在於其摘要比MD5摘要長32B。對於強行攻擊，產生任何一個報文使之摘要等於給定報文摘要的難度：MD5是2128數量級的操作，sha-1是2160數量級的操作。產生具有相同摘要的兩個報文的難度：MD5是264是數量級的操作，sha-1是280數量級的操作。因而，sha-1對強行攻擊的強度更大。但由於sha-1的循環步驟比MD5多（80:64）且要處理的緩存大（160B:128B），sha-1的運行速度比MD5慢。

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數字簽名的複製

在百度中搜索一下數字簽名複製，你會發現，這樣的工具太多了……

而且，我下載了7款複製數字簽名的軟件，複製成功率竟然達到了56%！可怕！邪惡的我把Explorer.exe的數字簽名（微軟的官籤）給複製到了我用來測試的軟件上面。[時間戳也僞造上了]

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複製後出現的問題

當我正在沾沾自喜時，360老毛病又犯了，未經我允許，直接刪除┭┮﹏┭┮，而且，它提示：偵測到極危險的木馬（簽名不正常，創建可疑進程），已經徹底覆蓋。
崩潰……
可是，它怎麼能把微軟官籤當成“不正常的簽名”呢？好奇。

換做金山官籤試了一下，還是一樣。
但當我查看證書詳細信息時，發現了一些蛛絲馬跡。

呵呵，看出不正常的地方來了吧？7款複製數字簽名的軟件全部沒用！
再往下看：

我將Kingsoft的sha1證書導出爲.cer便於查看詳細信息。

x509 -inform der -in Kingsoft.cer -out Kingsoft.pem

導出完成。
查看詳細信息。

x509 -in Kingsoft.pem -noout -text

輸出：

OpenSSL> x509 -in Kingsoft.pem -noout -text
Certificate:
    Data:
        Version: 3 (0x2)
        Serial Number:
            02:e4:4d:7d:1d:38:ae:22:3b:27:a0:2b:ac:d7:9b:53
        Signature Algorithm: sha1WithRSAEncryption
        Issuer: C = US, O = DigiCert Inc, OU = www.digicert.com, CN = DigiCert Assured ID Code Signing CA-1
        Validity
            Not Before: Jan 20 00:00:00 2020 GMT
            Not After : Feb  4 12:00:00 2023 GMT
        Subject: C = CN, ST = Guangdong, L = Zhuhai, O = "Zhuhai Kingsoft Office Software Co., Ltd.", CN = "Zhuhai Kingsoft Office Software Co., Ltd."
        Subject Public Key Info:
            Public Key Algorithm: rsaEncryption
                RSA Public-Key: (2048 bit)
                Modulus:
                    00:ee:8b:7e:43:90:32:eb:45:75:59:be:c8:69:ca:
                    6a:2d:e9:6a:2d:a3:cc:4e:98:46:57:3c:e5:5b:5d:
                    e5:1e:cc:52:da:4e:0e:80:82:a0:1d:f8:98:18:fd:
                    82:2c:c4:56:38:e6:57:be:ac:06:f5:4e:6d:1f:26:
                    c4:1e:e5:38:5b:08:21:70:6b:04:8e:42:d0:05:3a:
                    c1:e1:57:c9:74:6f:69:86:89:40:ad:22:6a:77:ec:
                    94:44:e4:74:23:58:7b:c4:08:d3:43:64:d7:0d:e4:
                    2b:2c:75:ab:52:b2:58:f3:2d:7e:5e:7f:9a:2d:be:
                    4c:56:b7:67:35:45:16:60:f3:23:a5:91:04:70:0e:
                    99:5e:6c:9f:a5:1a:d3:37:80:fb:84:26:ff:38:cf:
                    c9:1b:ba:77:0d:a3:d8:db:73:82:94:84:09:f2:63:
                    5d:f8:bc:2f:c8:3b:15:94:c0:0e:53:19:aa:68:7f:
                    f5:64:d4:bd:e0:25:35:43:f1:83:7f:45:0c:9a:6f:
                    a8:37:db:ed:c9:8a:37:d2:f2:d5:f9:4d:7e:d4:7d:
                    4d:38:fb:1f:af:ec:ba:de:f6:f3:91:df:d6:ac:da:
                    80:a2:ac:92:08:24:e8:bf:b0:02:0e:a7:23:4c:b2:
                    10:c4:82:76:65:59:b1:45:8e:5e:3d:ab:00:d9:24:
                    51:37
                Exponent: 3 (0x3)
        X509v3 extensions:
            X509v3 Authority Key Identifier:
                keyid:7B:68:CE:29:AA:C0:17:BE:49:7A:E1:E5:3F:D6:A7:F7:45:8F:35:32

            X509v3 Subject Key Identifier:
                BF:6E:75:73:61:2C:35:9D:43:B4:DE:38:DE:D2:D8:85:4F:AC:9E:D7
            X509v3 Key Usage: critical
                Digital Signature
            X509v3 Extended Key Usage:
                Code Signing
            X509v3 CRL Distribution Points:

                Full Name:
                  URI:http://crl3.digicert.com/assured-cs-g1.crl

                Full Name:
                  URI:http://crl4.digicert.com/assured-cs-g1.crl

            X509v3 Certificate Policies:
                Policy: 2.16.840.1.114412.3.1
                  CPS: https://www.digicert.com/CPS
                Policy: 2.23.140.1.4.1

            Authority Information Access:
                OCSP - URI:http://ocsp.digicert.com
                CA Issuers - URI:http://cacerts.digicert.com/DigiCertAssuredIDCodeSigningCA-1.crt

            X509v3 Basic Constraints: critical
                CA:FALSE
    Signature Algorithm: sha1WithRSAEncryption
         39:b9:97:02:7e:cf:01:f0:c9:16:82:20:6d:76:bd:bb:aa:50:
         f2:91:6a:8b:c8:4d:b2:3d:3d:10:aa:bd:5b:36:12:cb:2e:73:
         b0:08:34:b7:69:80:cd:c9:ad:e5:67:18:0a:27:16:99:a7:ad:
         d2:ed:b4:d3:86:82:19:9e:ca:69:d1:37:21:d6:55:5c:1c:7f:
         64:9c:e9:6d:02:67:d4:83:1a:98:b6:41:b8:c6:88:a1:4b:81:
         17:90:eb:d6:67:5d:60:21:33:c1:8a:98:3a:4b:3c:53:14:9c:
         f3:8e:7d:a5:e2:57:0a:66:68:c6:9c:ab:c9:79:45:a0:d3:6b:
         56:c7:80:5c:d4:d5:8c:2c:13:90:b2:ce:7f:11:9a:72:8b:20:
         53:89:04:8e:45:c7:a5:97:06:b5:75:d1:49:d0:99:a2:72:f2:
         d3:5a:27:6c:15:84:b0:e1:de:78:21:8c:5e:4e:9f:3f:1e:f1:
         04:d4:04:44:61:7f:0a:49:9e:60:cf:4f:48:eb:da:9c:73:2a:
         81:f7:dd:92:84:e9:2c:51:3b:62:44:f4:42:84:e8:b6:48:16:
         5a:55:e2:e0:b9:c5:60:a8:82:66:f5:a4:da:e6:5c:05:94:68:
         03:31:50:78:ca:5f:93:41:90:94:10:88:ac:10:3d:bb:a6:51:
         b4:80:05:06

複製的證書：

OpenSSL> x509 -in Kingsoft_copy.pem -noout -text
Certificate:
    Data:
        Version: 3 (0x2)
        Serial Number:
            02:e4:4d:7d:1d:38:ae:22:3b:27:a0:2b:ac:d7:9b:53
        Signature Algorithm: sha1WithRSAEncryption
        Issuer: C = US, O = DigiCert Inc, OU = www.digicert.com, CN = DigiCert Assured ID Code Signing CA-1
        Validity
            Not Before: Jan 20 00:00:00 2020 GMT
            Not After : Feb  4 12:00:00 2023 GMT
        Subject: C = CN, ST = Guangdong, L = Zhuhai, O = "Zhuhai Kingsoft Office Software Co., Ltd.", CN = "Zhuhai Kingsoft Office Software Co., Ltd."
        Subject Public Key Info:
            Public Key Algorithm: rsaEncryption
                RSA Public-Key: (2048 bit)
                Modulus:
                    00:ee:8b:7e:43:90:32:eb:45:75:59:be:c8:69:ca:
                    6a:2d:e9:6a:2d:a3:cc:4e:98:46:57:3c:e5:5b:5d:
                    e5:1e:cc:52:da:4e:0e:80:82:a0:1d:f8:98:18:fd:
                    82:2c:c4:56:38:e6:57:be:ac:06:f5:4e:6d:1f:26:
                    c4:1e:e5:38:5b:08:21:70:6b:04:8e:42:d0:05:3a:
                    c1:e1:57:c9:74:6f:69:86:89:40:ad:22:6a:77:ec:
                    94:44:e4:74:23:58:7b:c4:08:d3:43:64:d7:0d:e4:
                    2b:2c:75:ab:52:b2:58:f3:2d:7e:5e:7f:9a:2d:be:
                    4c:56:b7:67:35:45:16:60:f3:23:a5:91:04:70:0e:
                    99:5e:6c:9f:a5:1a:d3:37:80:fb:84:26:ff:38:cf:
                    c9:1b:ba:77:0d:a3:d8:db:73:82:94:84:09:f2:63:
                    5d:f8:bc:2f:c8:3b:15:94:c0:0e:53:19:aa:68:7f:
                    f5:64:d4:bd:e0:25:35:43:f1:83:7f:45:0c:9a:6f:
                    a8:37:db:ed:c9:8a:37:d2:f2:d5:f9:4d:7e:d4:7d:
                    4d:38:fb:1f:af:ec:ba:de:f6:f3:91:df:d6:ac:da:
                    80:a2:ac:92:08:24:e8:bf:b0:02:0e:a7:23:4c:b2:
                    10:c4:82:76:65:59:b1:45:8e:5e:3d:ab:00:d9:24:
                    51:37
                Exponent: 3 (0x3)
        X509v3 extensions:
            X509v3 Authority Key Identifier:
                keyid:7B:68:CE:29:AA:C0:17:BE:49:7A:E1:E5:3F:D6:A7:F7:45:8F:35:32

            X509v3 Subject Key Identifier:
                BF:6E:75:73:61:2C:35:9D:43:B4:DE:38:DE:D2:D8:85:4F:AC:9E:D7
            X509v3 Key Usage: critical
                Digital Signature
            X509v3 Extended Key Usage:
                Code Signing
            X509v3 CRL Distribution Points:

                Full Name:
                  URI:http://crl3.digicert.com/assured-cs-g1.crl

                Full Name:
                  URI:http://crl4.digicert.com/assured-cs-g1.crl

            X509v3 Certificate Policies:
                Policy: 2.16.840.1.114412.3.1
                  CPS: https://www.digicert.com/CPS
                Policy: 2.23.140.1.4.1

            Authority Information Access:
                OCSP - URI:http://ocsp.digicert.com
                CA Issuers - URI:http://cacerts.digicert.com/DigiCertAssuredIDCodeSigningCA-1.crt

            X509v3 Basic Constraints: critical
                CA:FALSE
    Signature Algorithm: sha1WithRSAEncryption
         39:b9:97:02:7e:cf:01:f0:c9:16:82:20:6d:76:bd:bb:aa:50:
         f2:91:6a:8b:c8:4d:b2:3d:3d:10:aa:bd:5b:36:12:cb:2e:73:
         b0:08:34:b7:69:80:cd:c9:ad:e5:67:18:0a:27:16:99:a7:ad:
         d2:ed:b4:d3:86:82:19:9e:ca:69:d1:37:21:d6:55:5c:1c:7f:
         64:9c:e9:6d:02:67:d4:83:1a:98:b6:41:b8:c6:88:a1:4b:81:
         17:90:eb:d6:67:5d:60:21:33:c1:8a:98:3a:4b:3c:53:14:9c:
         f3:8e:7d:a5:e2:57:0a:66:68:c6:9c:ab:c9:79:45:a0:d3:6b:
         56:c7:80:5c:d4:d5:8c:2c:13:90:b2:ce:7f:11:9a:72:8b:20:
         53:89:04:8e:45:c7:a5:97:06:b5:75:d1:49:d0:99:a2:72:f2:
         d3:5a:27:6c:15:84:b0:e1:de:78:21:8c:5e:4e:9f:3f:1e:f1:
         04:d4:04:44:61:7f:0a:49:9e:60:cf:4f:48:eb:da:9c:73:2a:
         81:f7:dd:92:84:e9:2c:51:3b:62:44:f4:42:84:e8:b6:48:16:
         5a:55:e2:e0:b9:c5:60:a8:82:66:f5:a4:da:e6:5c:05:94:68:
         03:31:50:78:ca:5f:93:41:90:94:10:88:ac:10:3d:bb:a6:51:
         b4:80:05:06

呵呵，證書一模一樣。
Windows是怎麼識別的呢？
複製數字簽名的原理：
複製證書，然後將軟件的數字簽名導向證書[假冒僞劣產品]，沒有經過加密。
數字簽名安全性真不是吹的。

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兩個賬號幾個月以來第一次用Markdown，佈局有問題請在評論區發表建議哈。
這行文字只是用來 證明這篇文章是用 Markdown 編輯器 撰寫的。
注：本文所用的數字簽名只是爲了示範，沒有任何針對性。