remove unused dep in go.mod, addresses #4

vendor/gopkg.in/hlandau/passlib.v1/hash/argon2/raw/argon2.go

@@ -0,0 +1,186 @@
+// Package raw provides a raw implementation of the modular-crypt-wrapped Argon2i primitive.
+package raw
+
+import (
+	"encoding/base64"
+	"fmt"
+	"golang.org/x/crypto/argon2"
+	"strconv"
+	"strings"
+)
+
+// The current recommended time value for interactive logins.
+const RecommendedTime uint32 = 4
+
+// The current recommended memory for interactive logins.
+const RecommendedMemory uint32 = 32 * 1024
+
+// The current recommended number of threads for interactive logins.
+const RecommendedThreads uint8 = 4
+
+// Wrapper for golang.org/x/crypto/argon2 implementing a sensible
+// hashing interface.
+//
+// password should be a UTF-8 plaintext password.
+// salt should be a random salt value in binary form.
+//
+// Time, memory, and threads are parameters to argon2.
+//
+// Returns an argon2 encoded hash.
+func Argon2(password string, salt []byte, time, memory uint32, threads uint8) string {
+	passwordb := []byte(password)
+
+	hash := argon2.Key(passwordb, salt, time, memory, threads, 32)
+
+	hstr := base64.RawStdEncoding.EncodeToString(hash)
+	sstr := base64.RawStdEncoding.EncodeToString(salt)
+
+	return fmt.Sprintf("$argon2i$v=%d$m=%d,t=%d,p=%d$%s$%s", argon2.Version, memory, time, threads, sstr, hstr)
+}
+
+// Indicates that a password hash or stub is invalid.
+var ErrInvalidStub = fmt.Errorf("invalid argon2 password stub")
+
+// Indicates that a key-value pair in the configuration part is malformed.
+var ErrInvalidKeyValuePair = fmt.Errorf("invalid argon2 key-value pair")
+
+// Indicates that the version part had the wrong number of parameters.
+var ErrParseVersion = fmt.Errorf("version section has wrong number of parameters")
+
+// Indicates that the hash config part had the wrong number of parameters.
+var ErrParseConfig = fmt.Errorf("hash config section has wrong number of parameters")
+
+// Indicates that the version parameter ("v") was missing in the version part,
+// even though it is required.
+var ErrMissingVersion = fmt.Errorf("version parameter (v) is missing")
+
+// Indicates that the memory parameter ("m") was mossing in the hash config
+// part, even though it is required.
+var ErrMissingMemory = fmt.Errorf("memory parameter (m) is missing")
+
+// Indicates that the time parameter ("t") was mossing in the hash config part,
+// even though it is required.
+var ErrMissingTime = fmt.Errorf("time parameter (t) is missing")
+
+// Indicates that the parallelism parameter ("p") was mossing in the hash config
+// part, even though it is required.
+var ErrMissingParallelism = fmt.Errorf("parallelism parameter (p) is missing")
+
+// Parses an argon2 encoded hash.
+//
+// The format is as follows:
+//
+//   $argon2i$v=version$m=memory,t=time,p=threads$salt$hash   // hash
+//   $argon2i$v=version$m=memory,t=time,p=threads$salt        // stub
+//
+func Parse(stub string) (salt, hash []byte, version int, time, memory uint32, parallelism uint8, err error) {
+	if len(stub) < 26 || !strings.HasPrefix(stub, "$argon2i$") {
+		err = ErrInvalidStub
+		return
+	}
+
+	// $argon2i$  v=version$m=memory,t=time,p=threads$salt-base64$hash-base64
+	parts := strings.Split(stub[9:], "$")
+
+	// version-params$hash-config-params$salt[$hash]
+	if len(parts) < 3 || len(parts) > 4 {
+		err = ErrInvalidStub
+		return
+	}
+
+	// Parse the first configuration part, the version parameters.
+	versionParams, err := parseKeyValuePair(parts[0])
+	if err != nil {
+		return
+	}
+
+	// Must be exactly one parameter in the version part.
+	if len(versionParams) != 1 {
+		err = ErrParseVersion
+		return
+	}
+
+	// It must be "v".
+	val, ok := versionParams["v"]
+	if !ok {
+		err = ErrMissingVersion
+		return
+	}
+
+	version = int(val)
+
+	// Parse the second configuration part, the hash config parameters.
+	hashParams, err := parseKeyValuePair(parts[1])
+	if err != nil {
+		return
+	}
+
+	// It must have exactly three parameters.
+	if len(hashParams) != 3 {
+		err = ErrParseConfig
+		return
+	}
+
+	// Memory parameter.
+	val, ok = hashParams["m"]
+	if !ok {
+		err = ErrMissingMemory
+		return
+	}
+
+	memory = uint32(val)
+
+	// Time parameter.
+	val, ok = hashParams["t"]
+	if !ok {
+		err = ErrMissingTime
+		return
+	}
+
+	time = uint32(val)
+
+	// Parallelism parameter.
+	val, ok = hashParams["p"]
+	if !ok {
+		err = ErrMissingParallelism
+		return
+	}
+
+	parallelism = uint8(val)
+
+	// Decode salt.
+	salt, err = base64.RawStdEncoding.DecodeString(parts[2])
+	if err != nil {
+		return
+	}
+
+	// Decode hash if present.
+	if len(parts) >= 4 {
+		hash, err = base64.RawStdEncoding.DecodeString(parts[3])
+	}
+
+	return
+}
+
+func parseKeyValuePair(pairs string) (result map[string]uint64, err error) {
+	result = map[string]uint64{}
+
+	parameterParts := strings.Split(pairs, ",")
+
+	for _, parameter := range parameterParts {
+		parts := strings.SplitN(parameter, "=", 2)
+		if len(parts) != 2 {
+			err = ErrInvalidKeyValuePair
+			return
+		}
+
+		parsedi, err := strconv.ParseUint(parts[1], 10, 32)
+		if err != nil {
+			return result, err
+		}
+
+		result[parts[0]] = parsedi
+	}
+
+	return result, nil
+}