Support loading credentials from io.Reader (#3)

Add the NewFromReader constructor and ReloadFromReader method for
*HtpasswdFile.

This makes it easier for users that receive credentials from sources
other than a file, because they don't have to create temporary files.

Signed-off-by: Peter Schultz <peter.schultz@classmarkets.com>

htpasswd.go

@@ -14,6 +14,7 @@ package htpasswd
 import (
 	"bufio"
 	"fmt"
+	"io"
 	"os"
 	"strings"
 	"sync"
@@ -83,6 +84,21 @@ func New(filename string, parsers []PasswdParser, bad BadLineHandler) (*Htpasswd
 	return &bf, nil
 }
 
+// NewFromReader is like new but reads from r instead of a named file. Calling
+// Reload on the returned HtpasswdFile will result in an error; use
+// ReloadFromReader instead.
+func NewFromReader(r io.Reader, parsers []PasswdParser, bad BadLineHandler) (*HtpasswdFile, error) {
+	bf := HtpasswdFile{
+		parsers: parsers,
+	}
+
+	if err := bf.ReloadFromReader(r, bad); err != nil {
+		return nil, err
+	}
+
+	return &bf, nil
+}
+
 // Match checks the username and password combination to see if it represents
 // a valid account from the htpassword file.
 func (bf *HtpasswdFile) Match(username, password string) bool {
@@ -111,11 +127,18 @@ func (bf *HtpasswdFile) Reload(bad BadLineHandler) error {
 	}
 	defer f.Close()
 
+	return bf.ReloadFromReader(f, bad)
+}
+
+// ReloadFromReader is like Reload but reads credentials from r instead of a named
+// file. If HtpasswdFile was created by New, it is okay to call Reload and
+// ReloadFromReader as desired.
+func (bf *HtpasswdFile) ReloadFromReader(r io.Reader, bad BadLineHandler) error {
 	// ... and a new map ...
 	newPasswdMap := passwdTable{}
 
 	// ... for each line ...
-	scanner := bufio.NewScanner(f)
+	scanner := bufio.NewScanner(r)
 	for scanner.Scan() {
 		line := scanner.Text()
 

htpasswd_test.go

@@ -3,6 +3,7 @@ package htpasswd
 import (
 	"io/ioutil"
 	"os"
+	"strings"
 	"testing"
 )
 
@@ -1420,6 +1421,26 @@ user198:$1$D89ubl/e$SdHoMvPduS1kS3KVqEw9W.
 user199:$1$D89ubl/e$1FQtoOElFQQCBL53IT2LL0
 user200:$1$D89ubl/e$xO3.z/20nsNEXnaWJdsfB/`
 
+func testSystemReader(t *testing.T, name string, contents string) {
+	r := strings.NewReader(contents)
+
+	htp, err := NewFromReader(r, DefaultSystems, nil)
+	if err != nil {
+		t.Fatalf("Failed to read htpasswd reader")
+	}
+
+	for _, u := range testUsers {
+		if good := htp.Match(u.username, u.password); !good {
+			t.Errorf("%s user %s, password %s failed to authenticate: %t", name, u.username, u.password, good)
+		}
+
+		notPass := u.password + "not"
+		if bad := htp.Match(u.username, notPass); bad {
+			t.Errorf("%s user %s, password %s erroneously authenticated: %t", name, u.username, notPass, bad)
+		}
+	}
+}
+
 func testSystem(t *testing.T, name string, contents string) {
 	f, err := ioutil.TempFile("", "??")
 	if err != nil {
@@ -1450,27 +1471,22 @@ func testSystem(t *testing.T, name string, contents string) {
 			t.Errorf("%s user %s, password %s erroneously authenticated: %t", name, u.username, notPass, bad)
 		}
 	}
-
 }
 
-func Test_PlainFile(t *testing.T) {
-	testSystem(t, "plain", textPlain)
-}
-func Test_ShaFile(t *testing.T) {
-	testSystem(t, "sha", textSha)
-}
-func Test_Apr1File(t *testing.T) {
-	testSystem(t, "md5", textApr1)
-}
+func Test_PlainReader(t *testing.T) { testSystemReader(t, "plain", textPlain) }
+func Test_PlainFile(t *testing.T)   { testSystem(t, "plain", textPlain) }
 
-func Test_Md5File(t *testing.T) {
-	testSystem(t, "md5", textMd5Crypt)
-}
+func Test_ShaReader(t *testing.T) { testSystemReader(t, "sha", textSha) }
+func Test_ShaFile(t *testing.T)   { testSystem(t, "sha", textSha) }
 
-func Test_BcryptFile(t *testing.T) {
-	testSystem(t, "bcrypt", textBcrypt)
-}
+func Test_Apr1Reader(t *testing.T) { testSystemReader(t, "md5", textApr1) }
+func Test_Apr1File(t *testing.T)   { testSystem(t, "md5", textApr1) }
 
-func Test_SshaFile(t *testing.T) {
-	testSystem(t, "ssha", textSsha)
-}
+func Test_Md5Reader(t *testing.T) { testSystemReader(t, "md5", textMd5Crypt) }
+func Test_Md5File(t *testing.T)   { testSystem(t, "md5", textMd5Crypt) }
+
+func Test_BcryptReader(t *testing.T) { testSystemReader(t, "bcrypt", textBcrypt) }
+func Test_BcryptFile(t *testing.T)   { testSystem(t, "bcrypt", textBcrypt) }
+
+func Test_SshaReader(t *testing.T) { testSystemReader(t, "ssha", textSsha) }
+func Test_SshaFile(t *testing.T)   { testSystem(t, "ssha", textSsha) }