Make password hashing parameters configurable

cmd/accountserver/main.go

@@ -3,11 +3,13 @@ package main
 import (
 	"errors"
 	"flag"
+	"fmt"
 	"io/ioutil"
 	"log"
 	"strings"
 
 	"git.autistici.org/ai3/accountserver"
+	"git.autistici.org/ai3/go-common/pwhash"
 	"git.autistici.org/ai3/go-common/serverutil"
 	"gopkg.in/yaml.v2"
 
@@ -30,6 +32,10 @@ type config struct {
 	} `yaml:"ldap"`
 	AccountServerConfig accountserver.Config     `yaml:",inline"`
 	ServerConfig        *serverutil.ServerConfig `yaml:"http_server"`
+	PwHash              struct {
+		Algo   string         `yaml:"algo"`
+		Params map[string]int `yaml:"params"`
+	} `yaml:"pwhash"`
 }
 
 func (c *config) validate() error {
@@ -54,6 +60,45 @@ func (c *config) validate() error {
 	return nil
 }
 
+func (c *config) getPasswordHash() (h pwhash.PasswordHash, err error) {
+	switch c.PwHash.Algo {
+	case "":
+		// Just use the defaults.
+		h = pwhash.DefaultEncryptAlgorithm
+	case "argon2":
+		pTime := 1
+		if i, ok := c.PwHash.Params["time"]; ok {
+			pTime = i
+		}
+		pMem := 4
+		if i, ok := c.PwHash.Params["mem"]; ok {
+			pMem = i
+		}
+		pThreads := 4
+		if i, ok := c.PwHash.Params["threads"]; ok {
+			pThreads = i
+		}
+		h = pwhash.NewArgon2WithParams(uint32(pTime), uint32(pMem), uint8(pThreads))
+	case "scrypt":
+		pN := 16384
+		if i, ok := c.PwHash.Params["n"]; ok {
+			pN = i
+		}
+		pR := 8
+		if i, ok := c.PwHash.Params["r"]; ok {
+			pR = i
+		}
+		pP := 1
+		if i, ok := c.PwHash.Params["p"]; ok {
+			pP = i
+		}
+		h = pwhash.NewScryptWithParams(pN, pR, pP)
+	default:
+		err = fmt.Errorf("unknown pwhash algo '%s'", c.PwHash.Algo)
+	}
+	return
+}
+
 func loadConfig(path string) (*config, error) {
 	// Read YAML config.
 	data, err := ioutil.ReadFile(path)
@@ -93,6 +138,12 @@ func main() {
 		log.Fatal(err)
 	}
 
+	h, err := config.getPasswordHash()
+	if err != nil {
+		log.Fatal(err)
+	}
+	accountserver.DefaultPasswordHash = h
+
 	bindPw, err := getBindPw(config)
 	if err != nil {
 		log.Fatal(err)

types.go

@@ -16,6 +16,13 @@ const (
 	UserStatusInactive = "inactive"
 )
 
+// The password hashing algorithm to use when updating credentials.
+var DefaultPasswordHash pwhash.PasswordHash
+
+func init() {
+	DefaultPasswordHash = pwhash.DefaultEncryptAlgorithm
+}
+
 // User information, public: includes data *about* credentials, but
 // not the credentials themselves. Every user has a unique
 // identifier, which may be an email address.
@@ -216,7 +223,7 @@ func (u *RawUser) setPrimaryPassword(ctx context.Context, tx TX, unlockPassword,
 		}
 	}
 
-	enc := pwhash.Encrypt(password)
+	enc := DefaultPasswordHash.Encrypt(password)
 	u.Password = enc
 	return tx.SetUserPassword(ctx, &u.User, enc)
 }
@@ -235,7 +242,7 @@ func (u *RawUser) setAccountRecoveryHint(ctx context.Context, tx TX, unlockPassw
 		}
 	}
 
-	enc := pwhash.Encrypt(response)
+	enc := DefaultPasswordHash.Encrypt(response)
 	u.RecoveryPassword = enc
 	return tx.SetAccountRecoveryHint(ctx, &u.User, hint, enc)
 }
@@ -285,7 +292,7 @@ func (u *RawUser) resetPassword(ctx context.Context, tx TX, password string) err
 		}
 	}
 
-	enc := pwhash.Encrypt(password)
+	enc := DefaultPasswordHash.Encrypt(password)
 	return tx.SetUserPassword(ctx, &u.User, enc)
 }
 
@@ -302,7 +309,7 @@ func (u *RawUser) addApplicationSpecificPassword(ctx context.Context, tx TX, unl
 		}
 	}
 
-	enc := pwhash.Encrypt(password)
+	enc := DefaultPasswordHash.Encrypt(password)
 	return tx.SetApplicationSpecificPassword(ctx, &u.User, asp, enc)
 }
 

vendor/git.autistici.org/ai3/go-common/pwhash/password.go

+// Package pwhash provides a simple interface to hashed passwords with
+// support for multiple hashing algorithms.
+//
+// The format is the well-known dollar-separated field string,
+// extended with optional algorithm-specific parameters:
+//
+//     $id[$params...]$salt$encrypted
+//
+// We extend 'id' beyond the values supported by the libc crypt(3)
+// function with the following hashing algorithms:
+//
+// Scrypt (id '$s$'), in which case the parameters are N, R and P.
+//
+// Argon2 (id '$a2$'), with parameters time, memory and threads. To
+// tune Argon2 parameters, you can run the benchmarks in this package:
+// the parameterized benchmarks are named with
+// time/memory(MB)/threads. For nicer results:
+//
+//     go test -bench=Argon2 -run=none . 2>&1 | \
+//         awk '/^Bench/ {ops=1000000000 / $3; print $1 " " ops " ops/sec"}'
+//
 package pwhash
 
 import (

vendor/golang.org/x/crypto/blake2b/blake2b.go

@@ -75,19 +75,19 @@ func Sum256(data []byte) [Size256]byte {
 }
 
 // New512 returns a new hash.Hash computing the BLAKE2b-512 checksum. A non-nil
-// key turns the hash into a MAC. The key must between zero and 64 bytes long.
+// key turns the hash into a MAC. The key must be between zero and 64 bytes long.
 func New512(key []byte) (hash.Hash, error) { return newDigest(Size, key) }
 
 // New384 returns a new hash.Hash computing the BLAKE2b-384 checksum. A non-nil
-// key turns the hash into a MAC. The key must between zero and 64 bytes long.
+// key turns the hash into a MAC. The key must be between zero and 64 bytes long.
 func New384(key []byte) (hash.Hash, error) { return newDigest(Size384, key) }
 
 // New256 returns a new hash.Hash computing the BLAKE2b-256 checksum. A non-nil
-// key turns the hash into a MAC. The key must between zero and 64 bytes long.
+// key turns the hash into a MAC. The key must be between zero and 64 bytes long.
 func New256(key []byte) (hash.Hash, error) { return newDigest(Size256, key) }
 
 // New returns a new hash.Hash computing the BLAKE2b checksum with a custom length.
-// A non-nil key turns the hash into a MAC. The key must between zero and 64 bytes long.
+// A non-nil key turns the hash into a MAC. The key must be between zero and 64 bytes long.
 // The hash size can be a value between 1 and 64 but it is highly recommended to use
 // values equal or greater than:
 // - 32 if BLAKE2b is used as a hash function (The key is zero bytes long).

vendor/golang.org/x/crypto/blake2b/blake2x.go

@@ -29,7 +29,7 @@ type XOF interface {
 }
 
 // OutputLengthUnknown can be used as the size argument to NewXOF to indicate
-// the the length of the output is not known in advance.
+// the length of the output is not known in advance.
 const OutputLengthUnknown = 0
 
 // magicUnknownOutputLength is a magic value for the output size that indicates

vendor/golang.org/x/crypto/scrypt/scrypt.go

@@ -29,7 +29,7 @@ func blockXOR(dst, src []uint32, n int) {
 }
 
 // salsaXOR applies Salsa20/8 to the XOR of 16 numbers from tmp and in,
-// and puts the result into both both tmp and out.
+// and puts the result into both tmp and out.
 func salsaXOR(tmp *[16]uint32, in, out []uint32) {
 	w0 := tmp[0] ^ in[0]
 	w1 := tmp[1] ^ in[1]

vendor/vendor.json

@@ -27,10 +27,10 @@
 			"revisionTime": "2019-03-27T08:48:39Z"
 		},
 		{
-			"checksumSHA1": "mfFIqmwojDqQdJvjLI3y7YCQ+2c=",
+			"checksumSHA1": "JcfbQfBD7HTqjhFYT1gBjbThSI4=",
 			"path": "git.autistici.org/ai3/go-common/pwhash",
-			"revision": "1f95fcdd58ebf63d338f05ceae29d2de811a2d2f",
-			"revisionTime": "2018-11-18T16:11:30Z"
+			"revision": "b4364e842290fdecd412056674b471af77663757",
+			"revisionTime": "2019-04-03T06:59:52Z"
 		},
 		{
 			"checksumSHA1": "TKGUNmKxj7KH3qhwiCh/6quUnwc=",
@@ -402,40 +402,40 @@
 		{
 			"checksumSHA1": "FwW3Vv4jW0Nv7V2SZC7x/Huj5M4=",
 			"path": "golang.org/x/crypto/argon2",
-			"revision": "e84da0312774c21d64ee2317962ef669b27ffb41",
-			"revisionTime": "2018-10-24T13:26:30Z"
+			"revision": "a5d413f7728c81fb97d96a2b722368945f651e78",
+			"revisionTime": "2019-03-25T14:57:12Z"
 		},
 		{
-			"checksumSHA1": "ejjxT0+wDWWncfh0Rt3lSH4IbXQ=",
+			"checksumSHA1": "eaK7NuGdfEVypOnqYniZSuF2S6s=",
 			"path": "golang.org/x/crypto/blake2b",
-			"revision": "e84da0312774c21d64ee2317962ef669b27ffb41",
-			"revisionTime": "2018-10-24T13:26:30Z"
+			"revision": "a5d413f7728c81fb97d96a2b722368945f651e78",
+			"revisionTime": "2019-03-25T14:57:12Z"
 		},
 		{
 			"checksumSHA1": "2LpxYGSf068307b7bhAuVjvzLLc=",
 			"origin": "git.autistici.org/id/go-sso/vendor/golang.org/x/crypto/ed25519",
 			"path": "golang.org/x/crypto/ed25519",
-			"revision": "bb8238eef0a55b1020e35a05c95f4247e7a35090",
-			"revisionTime": "2018-10-31T07:04:43Z"
+			"revision": "347348a99d9c23c8b3c9884176492d4b7d74037e",
+			"revisionTime": "2019-03-18T20:43:40Z"
 		},
 		{
 			"checksumSHA1": "0JTAFXPkankmWcZGQJGScLDiaN8=",
 			"origin": "git.autistici.org/id/go-sso/vendor/golang.org/x/crypto/ed25519/internal/edwards25519",
 			"path": "golang.org/x/crypto/ed25519/internal/edwards25519",
-			"revision": "bb8238eef0a55b1020e35a05c95f4247e7a35090",
-			"revisionTime": "2018-10-31T07:04:43Z"
+			"revision": "347348a99d9c23c8b3c9884176492d4b7d74037e",
+			"revisionTime": "2019-03-18T20:43:40Z"
 		},
 		{
 			"checksumSHA1": "1MGpGDQqnUoRpv7VEcQrXOBydXE=",
 			"path": "golang.org/x/crypto/pbkdf2",
-			"revision": "e84da0312774c21d64ee2317962ef669b27ffb41",
-			"revisionTime": "2018-10-24T13:26:30Z"
+			"revision": "a5d413f7728c81fb97d96a2b722368945f651e78",
+			"revisionTime": "2019-03-25T14:57:12Z"
 		},
 		{
-			"checksumSHA1": "sx1nQShs40UKtcJZNJuvYtGesaI=",
+			"checksumSHA1": "q+Rqy6Spw6qDSj75TGEZF7nzoFM=",
 			"path": "golang.org/x/crypto/scrypt",
-			"revision": "e84da0312774c21d64ee2317962ef669b27ffb41",
-			"revisionTime": "2018-10-24T13:26:30Z"
+			"revision": "a5d413f7728c81fb97d96a2b722368945f651e78",
+			"revisionTime": "2019-03-25T14:57:12Z"
 		},
 		{
 			"checksumSHA1": "/yo2FIWZX5FozwxE8ZZol2ekbxE=",