initial public commit

pkg/model/util.go

@@ -0,0 +1,92 @@
+package model
+
+import (
+	"crypto/md5"
+	"crypto/rand"
+	"crypto/rsa"
+	"crypto/x509"
+	"encoding/pem"
+	"fmt"
+	"strings"
+	"unicode"
+
+	"code.google.com/p/go.crypto/ssh"
+	"code.google.com/p/go.text/unicode/norm"
+	"github.com/dchest/uniuri"
+)
+
+var (
+	lat = []*unicode.RangeTable{unicode.Letter, unicode.Number}
+	nop = []*unicode.RangeTable{unicode.Mark, unicode.Sk, unicode.Lm}
+)
+
+// helper function to create a Gravatar Hash
+// for the given Email address.
+func createGravatar(email string) string {
+	email = strings.ToLower(strings.TrimSpace(email))
+	hash := md5.New()
+	hash.Write([]byte(email))
+	return fmt.Sprintf("%x", hash.Sum(nil))
+}
+
+// helper function to create a Slug for the
+// given string of text.
+func createSlug(s string) string {
+	buf := make([]rune, 0, len(s))
+	dash := false
+	for _, r := range norm.NFKD.String(s) {
+		switch {
+		// unicode 'letters' like mandarin characters pass through
+		case unicode.IsOneOf(lat, r):
+			buf = append(buf, unicode.ToLower(r))
+			dash = true
+		case unicode.IsOneOf(nop, r):
+			// skip
+		case dash:
+			buf = append(buf, '-')
+			dash = false
+		}
+	}
+	if i := len(buf) - 1; i >= 0 && buf[i] == '-' {
+		buf = buf[:i]
+	}
+	return string(buf)
+}
+
+// helper function to create a random 40-byte
+// Token that is URL-friendly.
+func createToken() string {
+	return uniuri.NewLen(40)
+}
+
+// -----------------------------------------------------------------------------
+// SSH Functions
+
+const (
+	RSA_BITS     = 2048 // Default number of bits in an RSA key
+	RSA_BITS_MIN = 768  // Minimum number of bits in an RSA key
+)
+
+// helper function to generate an RSA Private Key.
+func generatePrivateKey() (*rsa.PrivateKey, error) {
+	return rsa.GenerateKey(rand.Reader, RSA_BITS)
+}
+
+// helper function that marshalls an RSA Public Key to an SSH
+// .authorized_keys format
+func marshalPublicKey(pubkey *rsa.PublicKey) string {
+	pk, err := ssh.NewPublicKey(pubkey)
+	if err != nil {
+		return ""
+	}
+
+	return string(ssh.MarshalAuthorizedKey(pk))
+}
+
+// helper function that marshalls an RSA Private Key to
+// a PEM encoded file.
+func marshalPrivateKey(privkey *rsa.PrivateKey) string {
+	privateKeyMarshaled := x509.MarshalPKCS1PrivateKey(privkey)
+	privateKeyPEM := pem.EncodeToMemory(&pem.Block{Type: "RSA PRIVATE KEY", Headers: nil, Bytes: privateKeyMarshaled})
+	return string(privateKeyPEM)
+}