f

common/src/pwdf.cpp

@@ -0,0 +1,55 @@
+#include <array>
+#include "fflerror.hpp"
+#include "pwdf.hpp"
+
+int pwdf::strength(const char *s)
+{
+    fflassert(s);
+
+    int length = 0;
+    int digits = 0;
+    int lowers = 0;
+    int uppers = 0;
+    int specials = 0;
+
+    std::array<uint8_t, 256> counts{};
+    for(; s[length] != '\0'; ++length){
+        if     (s[length] >= '0' && s[length] <= '9') ++digits;
+        else if(s[length] >= 'a' && s[length] <= 'z') ++lowers;
+        else if(s[length] >= 'A' && s[length] <= 'Z') ++uppers;
+        else if(s[length] == '!' || s[length] == '@' || s[length] == '#' ||
+                s[length] == '$' || s[length] == '%' || s[length] == '^' ||
+                s[length] == '&' || s[length] == '*' || s[length] == '(' ||
+                s[length] == ')' || s[length] == '-' || s[length] == '+') ++specials;
+
+        counts[s[length]]++;
+        if(length >= 255){
+            break;
+        }
+    }
+
+    if(length < 8 || digits == 0 || lowers == 0 || uppers == 0 || specials == 0){
+        return pwdf::INVALID;
+    }
+
+    const auto unichars = std::count_if(counts.begin(), counts.end(), [](const auto &x)
+    {
+        return x > 0;
+    });
+
+    if(unichars * 2 < length){
+        return pwdf::WEAK;
+    }
+
+    int score = 0;
+
+    if(length   >= 12) score++;
+    if(uppers   >=  2) score++;
+    if(specials >=  2) score++;
+
+    if(unichars * 4 >= length * 3) score++;
+
+    if     (score >= 4) return pwdf::STRONG;
+    else if(score >= 2) return pwdf::MODERATE;
+    else                return pwdf::WEAK;
+}

common/src/pwdf.hpp

@@ -0,0 +1,21 @@
+#pragma once
+namespace pwdf
+{
+    // A valid password should satisfy the following conditions:
+    //
+    //    It contains at least one digit.
+    //    It contains at least one lowercase character.
+    //    It contains at least one uppercase character.
+    //    It contains at least one special character, the special characters are: !@#$%^&*()-+
+    //    Its length is at least 8.
+
+    enum
+    {
+        INVALID  = 0,
+        WEAK     = 1,
+        MODERATE = 2,
+        STRONG   = 3,
+    };
+
+    int strength(const char *);
+}