Weak Cryptographic Hash: Hardcoded Salt

ABSTRACT

Hardcoded salt 會削弱系統安全性，一旦出現安全問題將無法輕易修正。

EXPLANATION

采用硬編碼處理 salt 絕非一個好方法。這不僅是因為所有項目開發人員都可以使用 hardcoded salt 來查看該 salt，而且還會使解決這一問題變得極其困難。一旦將該代碼投入生產，則無法輕易更改該 salt。如果攻擊者知道該 salt 的值，他們就可以計算出該應用程序的彩虹表以及更輕松地反轉散列值。


例 1：下列代碼使用了 hardcoded salt：

    ...
crypt(password, "ms");
    ...

該代碼可以正常運行，但是任何有該代碼權限的人都能得到這個 salt。一旦程序發布，將無法回頭更改名為 "ms" 的 salt。心懷不軌的雇員可以利用他們對這一信息的訪問權限來破壞系統。

REFERENCES

[1] Standards Mapping - OWASP Top 10 2010 - (OWASP 2010) A7 Insecure Cryptographic Storage

[2] Standards Mapping - OWASP Top 10 2007 - (OWASP 2007) A8 Insecure Cryptographic Storage

[3] Standards Mapping - OWASP Top 10 2004 - (OWASP 2004) A8 Insecure Storage

[4] Standards Mapping - Security Technical Implementation Guide Version 3 - (STIG 3) APP3150.1 CAT II

[5] Standards Mapping - Security Technical Implementation Guide Version 3.4 - (STIG 3.4) APP3150.1 CAT II

[6] Standards Mapping - Common Weakness Enumeration - (CWE) CWE ID 326

[7] Standards Mapping - Web Application Security Consortium 24 + 2 - (WASC 24 + 2) Information Leakage

[8] Standards Mapping - FIPS200 - (FISMA) MP

[9] Standards Mapping - SANS Top 25 2011 - (SANS Top 25 2011) Porous Defenses - CWE ID 759

[10] Standards Mapping - Payment Card Industry Data Security Standard Version 1.2 - (PCI 1.2) Requirement 6.3.1.3, Requirement 6.5.8

[11] Standards Mapping - Payment Card Industry Data Security Standard Version 2.0 - (PCI 2.0) Requirement 6.5.3

[12] Standards Mapping - Payment Card Industry Data Security Standard Version 1.1 - (PCI 1.1) Requirement 6.5.8

97av