Improve password hash handling

This adds support for more hash algorithms. Also a stored password will
be updated to SSHA512 upon a successful bind. It will also automatically
hash a cleartext password if the `userpassword` field is modified with
a cleartext one.

Hashes supported:
* SSHA
* SSHA256
* SSHA512

5 files changed, 94 insertions, 58 deletions

diff --git a/go.mod b/go.mod
index a7ce11d..410153e 100644
--- a/go.mod
+++ b/go.mod
@@ -3,9 +3,9 @@ module bottin
 go 1.13
 
 require (
-	github.com/go-ldap/ldap/v3 v3.3.0
 	github.com/google/uuid v1.1.1
 	github.com/hashicorp/consul/api v1.3.0
+	github.com/jsimonetti/pwscheme v0.0.0-20220125093853-4d9895f5db73
 	github.com/sirupsen/logrus v1.4.2
 	golang.org/x/crypto v0.0.0-20200604202706-70a84ac30bf9 // indirect
 )
diff --git a/go.sum b/go.sum
index 8954334..c1ba571 100644
--- a/go.sum
+++ b/go.sum
@@ -1,5 +1,3 @@
-github.com/Azure/go-ntlmssp v0.0.0-20200615164410-66371956d46c h1:/IBSNwUN8+eKzUzbJPqhK839ygXJ82sde8x3ogr6R28=
-github.com/Azure/go-ntlmssp v0.0.0-20200615164410-66371956d46c/go.mod h1:chxPXzSsl7ZWRAuOIE23GDNzjWuZquvFlgA8xmpunjU=
 github.com/armon/circbuf v0.0.0-20150827004946-bbbad097214e/go.mod h1:3U/XgcO3hCbHZ8TKRvWD2dDTCfh9M9ya+I9JpbB7O8o=
 github.com/armon/go-metrics v0.0.0-20180917152333-f0300d1749da h1:8GUt8eRujhVEGZFFEjBj46YV4rDjvGrNxb0KMWYkL2I=
 github.com/armon/go-metrics v0.0.0-20180917152333-f0300d1749da/go.mod h1:Q73ZrmVTwzkszR9V5SSuryQ31EELlFMUz1kKyl939pY=
@@ -9,11 +7,6 @@ github.com/davecgh/go-spew v1.1.0/go.mod h1:J7Y8YcW2NihsgmVo/mv3lAwl/skON4iLHjSs
 github.com/davecgh/go-spew v1.1.1 h1:vj9j/u1bqnvCEfJOwUhtlOARqs3+rkHYY13jYWTU97c=
 github.com/davecgh/go-spew v1.1.1/go.mod h1:J7Y8YcW2NihsgmVo/mv3lAwl/skON4iLHjSsI+c5H38=
 github.com/fatih/color v1.7.0/go.mod h1:Zm6kSWBoL9eyXnKyktHP6abPY2pDugNf5KwzbycvMj4=
-github.com/go-asn1-ber/asn1-ber v1.5.1 h1:pDbRAunXzIUXfx4CB2QJFv5IuPiuoW+sWvr/Us009o8=
-github.com/go-asn1-ber/asn1-ber v1.5.1/go.mod h1:hEBeB/ic+5LoWskz+yKT7vGhhPYkProFKoKdwZRWMe0=
-github.com/go-ldap/ldap v2.5.1+incompatible h1:Opaoft5zMW8IU/VRULB0eGMBQ9P5buRvCW6sFTRmMn8=
-github.com/go-ldap/ldap/v3 v3.3.0 h1:lwx+SJpgOHd8tG6SumBQZXCmNX51zM8B1cfxJ5gv4tQ=
-github.com/go-ldap/ldap/v3 v3.3.0/go.mod h1:iYS1MdmrmceOJ1QOTnRXrIs7i3kloqtmGQjRvjKpyMg=
 github.com/google/btree v0.0.0-20180813153112-4030bb1f1f0c h1:964Od4U6p2jUkFxvCydnIczKteheJEzHRToSGK3Bnlw=
 github.com/google/btree v0.0.0-20180813153112-4030bb1f1f0c/go.mod h1:lNA+9X1NB3Zf8V7Ke586lFgjr2dZNuvo3lPJSGZ5JPQ=
 github.com/google/uuid v1.1.1 h1:Gkbcsh/GbpXz7lPftLA3P6TYMwjCLYm83jiFQZF/3gY=
@@ -49,6 +42,8 @@ github.com/hashicorp/memberlist v0.1.3 h1:EmmoJme1matNzb+hMpDuR/0sbJSUisxyqBGG67
 github.com/hashicorp/memberlist v0.1.3/go.mod h1:ajVTdAv/9Im8oMAAj5G31PhhMCZJV2pPBoIllUwCN7I=
 github.com/hashicorp/serf v0.8.2 h1:YZ7UKsJv+hKjqGVUUbtE3HNj79Eln2oQ75tniF6iPt0=
 github.com/hashicorp/serf v0.8.2/go.mod h1:6hOLApaqBFA1NXqRQAsxw9QxuDEvNxSQRwA/JwenrHc=
+github.com/jsimonetti/pwscheme v0.0.0-20220125093853-4d9895f5db73 h1:ZhC4QngptYaGx53+ph1RjxcH8fkCozBaY+935TNX4i8=
+github.com/jsimonetti/pwscheme v0.0.0-20220125093853-4d9895f5db73/go.mod h1:t0Q9JvoMTfTYdAWIk2MF69iz+Qpdk9D+PgVu6fVmaDI=
 github.com/konsorten/go-windows-terminal-sequences v1.0.1 h1:mweAR1A6xJ3oS2pRaGiHgQ4OO8tzTaLawm8vnODuwDk=
 github.com/konsorten/go-windows-terminal-sequences v1.0.1/go.mod h1:T0+1ngSBFLxvqU3pZ+m/2kptfBszLMUkC4ZK/EgS/cQ=
 github.com/mattn/go-colorable v0.0.9/go.mod h1:9vuHe8Xs5qXnSaW/c/ABM9alt+Vo+STaOChaDxuIBZU=
@@ -88,6 +83,7 @@ golang.org/x/crypto v0.0.0-20200604202706-70a84ac30bf9 h1:vEg9joUBmeBcK9iSJftGNf
 golang.org/x/crypto v0.0.0-20200604202706-70a84ac30bf9/go.mod h1:LzIPMQfyMNhhGPhUkYOs5KpL4U8rLKemX1yGLhDgUto=
 golang.org/x/net v0.0.0-20181023162649-9b4f9f5ad519/go.mod h1:mL1N/T3taQHkDXs73rZJwtUhF3w3ftmwwsq0BUmARs4=
 golang.org/x/net v0.0.0-20181201002055-351d144fa1fc/go.mod h1:mL1N/T3taQHkDXs73rZJwtUhF3w3ftmwwsq0BUmARs4=
+golang.org/x/net v0.0.0-20190404232315-eb5bcb51f2a3 h1:0GoQqolDA55aaLxZyTzK/Y2ePZzZTUrRacwib7cNsYQ=
 golang.org/x/net v0.0.0-20190404232315-eb5bcb51f2a3/go.mod h1:t9HGtf8HONx5eT2rtn7q6eTqICYqUVnKs3thJo3Qplg=
 golang.org/x/sync v0.0.0-20181221193216-37e7f081c4d4 h1:YUO/7uOKsKeq9UokNS62b8FYywz3ker1l1vDZRCRefw=
 golang.org/x/sync v0.0.0-20181221193216-37e7f081c4d4/go.mod h1:RxMgew5VJxzue5/jJTE5uejpjVlOe/izrB70Jof72aM=
diff --git a/main.go b/main.go
index 4e5abce..2b37803 100644
--- a/main.go
+++ b/main.go
@@ -12,8 +12,8 @@ import (
 	"os/signal"
 	"syscall"
 
-	ldap "bottin/ldapserver"
 	message "bottin/goldap"
+	ldap "bottin/ldapserver"
 
 	consul "github.com/hashicorp/consul/api"
 	log "github.com/sirupsen/logrus"
@@ -320,7 +320,6 @@ func (server *Server) init() error {
 		return err
 	}
 
-
 	admin_pass_str, environnement_variable_exist := os.LookupEnv("BOTTIN_DEFAULT_ADMIN_PW")
 	if !environnement_variable_exist {
 		admin_pass := make([]byte, 8)
@@ -329,11 +328,15 @@ func (server *Server) init() error {
 			return err
 		}
 		admin_pass_str = base64.RawURLEncoding.EncodeToString(admin_pass)
-	 } else {
+	} else {
 		server.logger.Debug("BOTTIN_DEFAULT_ADMIN_PW environment variable is set, using it for admin's password")
 	}
 
-	admin_pass_hash := SSHAEncode([]byte(admin_pass_str))
+	admin_pass_hash, err := SSHAEncode(admin_pass_str)
+	if err != nil {
+		server.logger.Error("can't create admin password")
+		panic(err)
+	}
 
 	admin_dn := "cn=admin," + server.config.Suffix
 	admin_attributes := Entry{
@@ -434,8 +437,8 @@ func (server *Server) handleBindInternal(state *State, r *message.BindRequest) (
 	}
 
 	for _, hash := range passwd {
-		valid := SSHAMatches(hash, []byte(r.AuthenticationSimple()))
-		if valid {
+		valid, err := SSHAMatches(hash, string(r.AuthenticationSimple()))
+		if valid && err == nil {
 			groups, err := server.getAttribute(string(r.Name()), ATTR_MEMBEROF)
 			if err != nil {
 				return ldap.LDAPResultOperationsError, err
@@ -444,8 +447,32 @@ func (server *Server) handleBindInternal(state *State, r *message.BindRequest) (
 				user:   string(r.Name()),
 				groups: groups,
 			}
+
+			updatePasswordHash(string(r.AuthenticationSimple()), hash, server, string(r.Name()))
+
 			return ldap.LDAPResultSuccess, nil
+		} else {
+			return ldap.LDAPResultInvalidCredentials, fmt.Errorf("can't authenticate: %w", err)
 		}
 	}
 	return ldap.LDAPResultInvalidCredentials, fmt.Errorf("No password match")
 }
+
+// Update the hash if it's not already SSHA512
+func updatePasswordHash(password string, currentHash string, server *Server, dn string) {
+	hashType, err := determineHashType(currentHash)
+	if err != nil {
+		server.logger.Errorf("can't determine hash type of password")
+		return
+	}
+	if hashType != SSHA512 {
+		reencodedPassword, err := SSHAEncode(password)
+		if err != nil {
+			server.logger.Errorf("can't encode password")
+			return
+		}
+		server.putAttributes(dn, Entry{
+			ATTR_USERPASSWORD: []string{reencodedPassword},
+		})
+	}
+}
diff --git a/ssha.go b/ssha.go
index 15b8e1d..202ce12 100644
--- a/ssha.go
+++ b/ssha.go
@@ -1,59 +1,53 @@
 package main
 
 import (
-	"bytes"
-	"crypto/rand"
-	"crypto/sha1"
-	"encoding/base64"
-	"fmt"
-	"strings"
-
-	log "github.com/sirupsen/logrus"
+	"errors"
+
+	"github.com/jsimonetti/pwscheme/ssha"
+	"github.com/jsimonetti/pwscheme/ssha256"
+	"github.com/jsimonetti/pwscheme/ssha512"
+)
+
+const (
+	SSHA    = "{SSHA}"
+	SSHA256 = "{SSHA256}"
+	SSHA512 = "{SSHA512}"
 )
 
-// Encode encodes the []byte of raw password
-func SSHAEncode(rawPassPhrase []byte) string {
-	hash := makeSSHAHash(rawPassPhrase, makeSalt())
-	b64 := base64.StdEncoding.EncodeToString(hash)
-	return fmt.Sprintf("{ssha}%s", b64)
+// Encode encodes the string to ssha512
+func SSHAEncode(rawPassPhrase string) (string, error) {
+	return ssha512.Generate(rawPassPhrase, 16)
 }
 
 // Matches matches the encoded password and the raw password
-func SSHAMatches(encodedPassPhrase string, rawPassPhrase []byte) bool {
-	if !strings.EqualFold(encodedPassPhrase[:6], "{ssha}") {
-		return false
-	}
-
-	bhash, err := base64.StdEncoding.DecodeString(encodedPassPhrase[6:])
+func SSHAMatches(encodedPassPhrase string, rawPassPhrase string) (bool, error) {
+	hashType, err := determineHashType(encodedPassPhrase)
 	if err != nil {
-		return false
+		return false, errors.New("invalid password hash stored")
 	}
-	salt := bhash[20:]
-
-	newssha := makeSSHAHash(rawPassPhrase, salt)
 
-	if bytes.Compare(newssha, bhash) != 0 {
-		return false
+	switch hashType {
+	case SSHA:
+		return ssha.Validate(rawPassPhrase, encodedPassPhrase)
+	case SSHA256:
+		return ssha256.Validate(rawPassPhrase, encodedPassPhrase)
+	case SSHA512:
+		return ssha512.Validate(rawPassPhrase, encodedPassPhrase)
 	}
-	return true
-}
 
-// makeSalt make a 32 byte array containing random bytes.
-func makeSalt() []byte {
-	sbytes := make([]byte, 32)
-	_, err := rand.Read(sbytes)
-	if err != nil {
-		log.Panicf("Could not read random bytes: %s", err)
-	}
-	return sbytes
+	return false, errors.New("no matching hash type found")
 }
 
-// makeSSHAHash make hasing using SHA-1 with salt. This is not the final output though. You need to append {SSHA} string with base64 of this hash.
-func makeSSHAHash(passphrase, salt []byte) []byte {
-	sha := sha1.New()
-	sha.Write(passphrase)
-	sha.Write(salt)
+func determineHashType(hash string) (string, error) {
+	if len(hash) >= 7 && string(hash[0:6]) == SSHA {
+		return SSHA, nil
+	}
+	if len(hash) >= 10 && string(hash[0:9]) == SSHA256 {
+		return SSHA256, nil
+	}
+	if len(hash) >= 10 && string(hash[0:9]) == SSHA512 {
+		return SSHA512, nil
+	}
 
-	h := sha.Sum(nil)
-	return append(h, salt...)
+	return "", errors.New("no valid hash found")
 }
diff --git a/write.go b/write.go
index 2dd42c6..55ab5e0 100644
--- a/write.go
+++ b/write.go
@@ -7,8 +7,9 @@ import (
 
 	ldap "bottin/ldapserver"
 
-	consul "github.com/hashicorp/consul/api"
 	message "bottin/goldap"
+
+	consul "github.com/hashicorp/consul/api"
 )
 
 // Generic item modification function --------
@@ -38,7 +39,7 @@ func (server *Server) putAttributes(dn string, attrs Entry) error {
 
 	// Retreieve previously existing attributes, which we will use to delete
 	// entries with the wrong case
-	previous_pairs, _, err := server.kv.List(prefix + "/attribute=", &server.readOpts)
+	previous_pairs, _, err := server.kv.List(prefix+"/attribute=", &server.readOpts)
 	if err != nil {
 		return err
 	}
@@ -65,6 +66,24 @@ func (server *Server) putAttributes(dn string, attrs Entry) error {
 			}
 		}
 
+		// if the password is not yet hashed we hash it
+		if k == ATTR_USERPASSWORD {
+			tmpValues := []string{}
+			for _, pw := range values {
+				_, err := determineHashType(pw)
+				if err != nil {
+					encodedPassword, err := SSHAEncode(pw)
+					if err != nil {
+						return err
+					}
+					tmpValues = append(tmpValues, encodedPassword)
+				} else {
+					tmpValues = append(tmpValues, pw)
+				}
+			}
+			values = tmpValues
+		}
+
 		// If we have zero values, delete associated k/v pair
 		// Otherwise, write new values
 		if len(values) == 0 {