Initial commit

specialpass.go

@@ -0,0 +1,194 @@
+package main
+
+import (
+	"code.google.com/p/gopass"
+	"flag"
+	"fmt"
+	"io"
+	"strings"
+	"crypto/sha512"
+)
+
+type PasswordRestrictions struct {
+	name          string
+	minLength     int
+	maxLength     int
+	alphaLowerMin int
+	alphaLowerMax int
+	alphaUpperMin int
+	alphaUpperMax int
+	numberMin     int
+	numberMax     int
+	specialMin    int
+	specialMax    int
+	allowedSpecial string
+}
+
+var siteName string
+
+const DEFAULT_SITE = "etrade"
+
+var sites []PasswordRestrictions = []PasswordRestrictions{
+	PasswordRestrictions{
+		name:          "etrade",
+		minLength:     6,
+		maxLength:     32,
+		alphaLowerMin: 0,
+		alphaLowerMax: 32,
+		alphaUpperMin: 0,
+		alphaUpperMax: 32,
+		numberMin:     1,
+		numberMax:     32,
+		specialMin:    0,
+		specialMax:    0},
+	PasswordRestrictions{
+		name:          "fidelity",
+		minLength:     6,
+		maxLength:     12,
+		alphaLowerMin: 0,
+		alphaLowerMax: 12,
+		alphaUpperMin: 0,
+		alphaUpperMax: 12,
+		numberMin:     0,
+		numberMax:     12,
+		specialMin:    0,
+		specialMax:    0},
+}
+
+func init() {
+	const site_usage = "Name of site for which to generate password"
+	flag.StringVar(&siteName, "siteName", DEFAULT_SITE, site_usage)
+	flag.StringVar(&siteName, "s", DEFAULT_SITE, site_usage+" (shorthand)")
+}
+
+func main() {
+	flag.Parse()
+
+	var restrictions *PasswordRestrictions
+	for _, v := range sites {
+		if strings.ToLower(siteName) == strings.ToLower(v.name) {
+			restrictions = &v
+			break
+		}
+	}
+
+	if restrictions == nil {
+		fmt.Println("Error: Site name not recognized, please use one of the following:")
+		for _, v := range sites {
+			fmt.Println("\t" + v.name)
+		}
+	}
+
+	oldPassword, err := gopass.GetPass("Enter Password: ")
+	if err != nil {
+		panic(err)
+	}
+
+	c := make(chan int)
+	go generateBytes(c, oldPassword, restrictions.name)
+
+	maxValue := 62 /*alphanumeric*/ + len(restrictions.allowedSpecial)
+
+	curAlphaLower := 0
+	curAlphaUpper := 0
+	curNumber := 0
+	curSpecial := 0
+	password := ""
+
+	lower := "abcdefghijklmnopqrstuvwxyz"
+	upper := "ABCDEFGHIJKLMNOPQRSTUVWXYZ"
+	numbers := "0123456789"
+
+	//build up the initial string, making sure we don't go over the max allowed for each type
+	for length := 0; length < restrictions.maxLength; length++ {
+		val := <- c % maxValue
+		switch {
+		case val >= 0 && val < 26:
+			if curAlphaLower + 1 <= restrictions.alphaLowerMax {
+				password += lower[val:val+1]
+				curAlphaLower++
+			}
+		case val >= 26 && val < 52:
+			if curAlphaUpper + 1 <= restrictions.alphaUpperMax {
+				password += upper[val-26:val-25]
+				curAlphaUpper++
+			}
+		case val >= 52 && val < 62:
+			if curNumber + 1 <= restrictions.numberMax {
+				password += numbers[val-52:val-51]
+				curNumber++
+			}
+		default:
+			if curSpecial + 1 <= restrictions.specialMax {
+				password += restrictions.allowedSpecial[val-62:val-61]
+				curSpecial++
+			}
+		}
+	}
+
+	//now, make sure we meet the minimum requirements. If we don't, start replacing items in the password
+	for {
+		removed := true
+		switch {
+		case curAlphaLower < restrictions.alphaLowerMin:
+			val := <- c % 26
+			password += lower[val:val+1]
+			curAlphaLower++
+		case curAlphaUpper < restrictions.alphaUpperMin:
+			val := <- c % 26
+			password += upper[val:val+1]
+			curAlphaUpper++
+		case curNumber < restrictions.numberMin:
+			val := <- c % 10
+			password += numbers[val:val+1]
+			curNumber++
+		case curSpecial < restrictions.specialMin:
+			val := <- c % len(restrictions.allowedSpecial)
+			password += restrictions.allowedSpecial[val:val+1]
+			curSpecial++
+		default:
+			removed = false
+		}
+		if !removed {
+			break
+		}
+
+		removedChar := password[:1]
+		password = password[1:]
+
+		switch{
+		case strings.Contains(lower, removedChar):
+			curAlphaLower--
+		case strings.Contains(upper, removedChar):
+			curAlphaUpper--
+		case strings.Contains(numbers, removedChar):
+			curNumber--
+		case strings.Contains(restrictions.allowedSpecial, removedChar):
+			curSpecial--
+		default:
+			panic("Unknown character made its way into the password")
+		}
+	}
+
+	//finally, (pseudo-)randomize the password ordering, one element at a time
+	for i := 0; i < restrictions.maxLength; i++ {
+		position := (<- c % (restrictions.maxLength - i)) + i
+		password = password[position:position+1] + password[0:position] + password[position+1:restrictions.maxLength]
+	}
+
+	fmt.Println("Generated password for " + restrictions.name + ": " + password)
+}
+
+func generateBytes(c chan int, password string, siteName string) {
+	h := sha512.New()
+	io.WriteString(h, password + strings.ToLower(siteName))
+	hashBytes := h.Sum(nil)
+
+	for {
+		for _, b := range hashBytes {
+			c <- int(b)
+		}
+		h.Write(hashBytes)
+		hashBytes = h.Sum(nil)
+	}
+}