Add the sprig functions in the template engine

vendor/github.com/Masterminds/sprig/crypto.go

@@ -0,0 +1,148 @@
+package sprig
+
+import (
+	"bytes"
+	"crypto/dsa"
+	"crypto/ecdsa"
+	"crypto/elliptic"
+	"crypto/hmac"
+	"crypto/rand"
+	"crypto/rsa"
+	"crypto/sha256"
+	"crypto/x509"
+	"encoding/asn1"
+	"encoding/binary"
+	"encoding/hex"
+	"encoding/pem"
+	"fmt"
+	"math/big"
+
+	uuid "github.com/satori/go.uuid"
+	"golang.org/x/crypto/scrypt"
+)
+
+func sha256sum(input string) string {
+	hash := sha256.Sum256([]byte(input))
+	return hex.EncodeToString(hash[:])
+}
+
+// uuidv4 provides a safe and secure UUID v4 implementation
+func uuidv4() string {
+	return fmt.Sprintf("%s", uuid.NewV4())
+}
+
+var master_password_seed = "com.lyndir.masterpassword"
+
+var password_type_templates = map[string][][]byte{
+	"maximum": {[]byte("anoxxxxxxxxxxxxxxxxx"), []byte("axxxxxxxxxxxxxxxxxno")},
+	"long": {[]byte("CvcvnoCvcvCvcv"), []byte("CvcvCvcvnoCvcv"), []byte("CvcvCvcvCvcvno"), []byte("CvccnoCvcvCvcv"), []byte("CvccCvcvnoCvcv"),
+		[]byte("CvccCvcvCvcvno"), []byte("CvcvnoCvccCvcv"), []byte("CvcvCvccnoCvcv"), []byte("CvcvCvccCvcvno"), []byte("CvcvnoCvcvCvcc"),
+		[]byte("CvcvCvcvnoCvcc"), []byte("CvcvCvcvCvccno"), []byte("CvccnoCvccCvcv"), []byte("CvccCvccnoCvcv"), []byte("CvccCvccCvcvno"),
+		[]byte("CvcvnoCvccCvcc"), []byte("CvcvCvccnoCvcc"), []byte("CvcvCvccCvccno"), []byte("CvccnoCvcvCvcc"), []byte("CvccCvcvnoCvcc"),
+		[]byte("CvccCvcvCvccno")},
+	"medium": {[]byte("CvcnoCvc"), []byte("CvcCvcno")},
+	"short":  {[]byte("Cvcn")},
+	"basic":  {[]byte("aaanaaan"), []byte("aannaaan"), []byte("aaannaaa")},
+	"pin":    {[]byte("nnnn")},
+}
+
+var template_characters = map[byte]string{
+	'V': "AEIOU",
+	'C': "BCDFGHJKLMNPQRSTVWXYZ",
+	'v': "aeiou",
+	'c': "bcdfghjklmnpqrstvwxyz",
+	'A': "AEIOUBCDFGHJKLMNPQRSTVWXYZ",
+	'a': "AEIOUaeiouBCDFGHJKLMNPQRSTVWXYZbcdfghjklmnpqrstvwxyz",
+	'n': "0123456789",
+	'o': "@&%?,=[]_:-+*$#!'^~;()/.",
+	'x': "AEIOUaeiouBCDFGHJKLMNPQRSTVWXYZbcdfghjklmnpqrstvwxyz0123456789!@#$%^&*()",
+}
+
+func derivePassword(counter uint32, password_type, password, user, site string) string {
+	var templates = password_type_templates[password_type]
+	if templates == nil {
+		return fmt.Sprintf("cannot find password template %s", password_type)
+	}
+
+	var buffer bytes.Buffer
+	buffer.WriteString(master_password_seed)
+	binary.Write(&buffer, binary.BigEndian, uint32(len(user)))
+	buffer.WriteString(user)
+
+	salt := buffer.Bytes()
+	key, err := scrypt.Key([]byte(password), salt, 32768, 8, 2, 64)
+	if err != nil {
+		return fmt.Sprintf("failed to derive password: %s", err)
+	}
+
+	buffer.Truncate(len(master_password_seed))
+	binary.Write(&buffer, binary.BigEndian, uint32(len(site)))
+	buffer.WriteString(site)
+	binary.Write(&buffer, binary.BigEndian, counter)
+
+	var hmacv = hmac.New(sha256.New, key)
+	hmacv.Write(buffer.Bytes())
+	var seed = hmacv.Sum(nil)
+	var temp = templates[int(seed[0])%len(templates)]
+
+	buffer.Truncate(0)
+	for i, element := range temp {
+		pass_chars := template_characters[element]
+		pass_char := pass_chars[int(seed[i+1])%len(pass_chars)]
+		buffer.WriteByte(pass_char)
+	}
+
+	return buffer.String()
+}
+
+func generatePrivateKey(typ string) string {
+	var priv interface{}
+	var err error
+	switch typ {
+	case "", "rsa":
+		// good enough for government work
+		priv, err = rsa.GenerateKey(rand.Reader, 4096)
+	case "dsa":
+		key := new(dsa.PrivateKey)
+		// again, good enough for government work
+		if err = dsa.GenerateParameters(&key.Parameters, rand.Reader, dsa.L2048N256); err != nil {
+			return fmt.Sprintf("failed to generate dsa params: %s", err)
+		}
+		err = dsa.GenerateKey(key, rand.Reader)
+		priv = key
+	case "ecdsa":
+		// again, good enough for government work
+		priv, err = ecdsa.GenerateKey(elliptic.P256(), rand.Reader)
+	default:
+		return "Unknown type " + typ
+	}
+	if err != nil {
+		return fmt.Sprintf("failed to generate private key: %s", err)
+	}
+
+	return string(pem.EncodeToMemory(pemBlockForKey(priv)))
+}
+
+type DSAKeyFormat struct {
+	Version       int
+	P, Q, G, Y, X *big.Int
+}
+
+func pemBlockForKey(priv interface{}) *pem.Block {
+	switch k := priv.(type) {
+	case *rsa.PrivateKey:
+		return &pem.Block{Type: "RSA PRIVATE KEY", Bytes: x509.MarshalPKCS1PrivateKey(k)}
+	case *dsa.PrivateKey:
+		val := DSAKeyFormat{
+			P: k.P, Q: k.Q, G: k.G,
+			Y: k.Y, X: k.X,
+		}
+		bytes, _ := asn1.Marshal(val)
+		return &pem.Block{Type: "DSA PRIVATE KEY", Bytes: bytes}
+	case *ecdsa.PrivateKey:
+		b, _ := x509.MarshalECPrivateKey(k)
+		return &pem.Block{Type: "EC PRIVATE KEY", Bytes: b}
+	default:
+		return nil
+	}
+}