WIP: All the Client API work and dependencies rolled in to one monster PR

Makefile

@@ -11,7 +11,7 @@ ifneq ($(GITUNTRACKEDCHANGES),)
 GITCOMMIT := $(GITCOMMIT)-dirty
 endif
 CTIMEVAR=-X $(NOTARY_PKG)/version.GitCommit=$(GITCOMMIT) -X $(NOTARY_PKG)/version.NotaryVersion=$(NOTARY_VERSION)
-GO_LDFLAGS=-ldflags "-w $(CTIMEVAR)"
+GO_LDFLAGS=-ldflags "-s -w $(CTIMEVAR)"
 GO_LDFLAGS_STATIC=-ldflags "-w $(CTIMEVAR) -extldflags -static"
 GOOSES = darwin linux windows
 NOTARY_BUILDTAGS ?= pkcs11

auth/client/authchallenge.go

@@ -0,0 +1,222 @@
+package client
+
+import (
+	"net/http"
+	"net/url"
+	"strings"
+)
+
+// Challenge carries information from a WWW-Authenticate response header.
+// See RFC 2617.
+type Challenge struct {
+	// Scheme is the auth-scheme according to RFC 2617
+	Scheme string
+
+	// Parameters are the auth-params according to RFC 2617
+	Parameters map[string]string
+}
+
+// Manager manages the challenges for endpoints.
+// The challenges are pulled out of HTTP responses. Only
+// responses which expect challenges should be added to
+// the manager, since a non-unauthorized request will be
+// viewed as not requiring challenges.
+type Manager interface {
+	// GetChallenges returns the challenges for the given
+	// endpoint URL.
+	GetChallenges(endpoint url.URL) ([]Challenge, error)
+
+	// AddResponse adds the response to the challenge
+	// manager. The challenges will be parsed out of
+	// the WWW-Authenicate headers and added to the
+	// URL which was produced the response. If the
+	// response was authorized, any challenges for the
+	// endpoint will be cleared.
+	AddResponse(resp *http.Response) error
+}
+
+// NewSimpleManager returns an instance of
+// Manger which only maps endpoints to challenges
+// based on the responses which have been added the
+// manager. The simple manager will make no attempt to
+// perform requests on the endpoints or cache the responses
+// to a backend.
+//func NewSimpleManager() Manager {
+//	return &simpleManager{
+//		Challanges: make(map[string][]Challenge),
+//	}
+//}
+//
+//type simpleManager struct {
+//	sync.RWMutex
+//	Challanges map[string][]Challenge
+//}
+//
+//func normalizeURL(endpoint *url.URL) {
+//	endpoint.Host = strings.ToLower(endpoint.Host)
+//	endpoint.Host = canonicalAddr(endpoint)
+//}
+//
+//func (m *simpleManager) GetChallenges(endpoint url.URL) ([]Challenge, error) {
+//	normalizeURL(&endpoint)
+//
+//	m.RLock()
+//	defer m.RUnlock()
+//	challenges := m.Challanges[endpoint.String()]
+//	return challenges, nil
+//}
+//
+//func (m *simpleManager) AddResponse(resp *http.Response) error {
+//	challenges := ResponseChallenges(resp)
+//	if resp.Request == nil {
+//		return fmt.Errorf("missing request reference")
+//	}
+//	urlCopy := url.URL{
+//		Path:   resp.Request.URL.Path,
+//		Host:   resp.Request.URL.Host,
+//		Scheme: resp.Request.URL.Scheme,
+//	}
+//	normalizeURL(&urlCopy)
+//
+//	m.Lock()
+//	defer m.Unlock()
+//	m.Challanges[urlCopy.String()] = challenges
+//	return nil
+//}
+
+// Octet types from RFC 2616.
+type octetType byte
+
+var octetTypes [256]octetType
+
+const (
+	isToken octetType = 1 << iota
+	isSpace
+)
+
+func init() {
+	// OCTET      = <any 8-bit sequence of data>
+	// CHAR       = <any US-ASCII character (octets 0 - 127)>
+	// CTL        = <any US-ASCII control character (octets 0 - 31) and DEL (127)>
+	// CR         = <US-ASCII CR, carriage return (13)>
+	// LF         = <US-ASCII LF, linefeed (10)>
+	// SP         = <US-ASCII SP, space (32)>
+	// HT         = <US-ASCII HT, horizontal-tab (9)>
+	// <">        = <US-ASCII double-quote mark (34)>
+	// CRLF       = CR LF
+	// LWS        = [CRLF] 1*( SP | HT )
+	// TEXT       = <any OCTET except CTLs, but including LWS>
+	// separators = "(" | ")" | "<" | ">" | "@" | "," | ";" | ":" | "\" | <">
+	//              | "/" | "[" | "]" | "?" | "=" | "{" | "}" | SP | HT
+	// token      = 1*<any CHAR except CTLs or separators>
+	// qdtext     = <any TEXT except <">>
+
+	for c := 0; c < 256; c++ {
+		var t octetType
+		isCtl := c <= 31 || c == 127
+		isChar := 0 <= c && c <= 127
+		isSeparator := strings.IndexRune(" \t\"(),/:;<=>?@[]\\{}", rune(c)) >= 0
+		if strings.IndexRune(" \t\r\n", rune(c)) >= 0 {
+			t |= isSpace
+		}
+		if isChar && !isCtl && !isSeparator {
+			t |= isToken
+		}
+		octetTypes[c] = t
+	}
+}
+
+func ParseAuthHeader(header []string) []Challenge {
+	challenges := []Challenge{}
+	for _, h := range header {
+		v, p := parseValueAndParams(h)
+		if v != "" {
+			challenges = append(challenges, Challenge{Scheme: v, Parameters: p})
+		}
+	}
+	return challenges
+}
+
+func parseValueAndParams(header string) (value string, params map[string]string) {
+	params = make(map[string]string)
+	value, s := expectToken(header)
+	if value == "" {
+		return
+	}
+	value = strings.ToLower(value)
+	s = "," + skipSpace(s)
+	for strings.HasPrefix(s, ",") {
+		var pkey string
+		pkey, s = expectToken(skipSpace(s[1:]))
+		if pkey == "" {
+			return
+		}
+		if !strings.HasPrefix(s, "=") {
+			return
+		}
+		var pvalue string
+		pvalue, s = expectTokenOrQuoted(s[1:])
+		if pvalue == "" {
+			return
+		}
+		pkey = strings.ToLower(pkey)
+		params[pkey] = pvalue
+		s = skipSpace(s)
+	}
+	return
+}
+
+func skipSpace(s string) (rest string) {
+	i := 0
+	for ; i < len(s); i++ {
+		if octetTypes[s[i]]&isSpace == 0 {
+			break
+		}
+	}
+	return s[i:]
+}
+
+func expectToken(s string) (token, rest string) {
+	i := 0
+	for ; i < len(s); i++ {
+		if octetTypes[s[i]]&isToken == 0 {
+			break
+		}
+	}
+	return s[:i], s[i:]
+}
+
+func expectTokenOrQuoted(s string) (value string, rest string) {
+	if !strings.HasPrefix(s, "\"") {
+		return expectToken(s)
+	}
+	s = s[1:]
+	for i := 0; i < len(s); i++ {
+		switch s[i] {
+		case '"':
+			return s[:i], s[i+1:]
+		case '\\':
+			p := make([]byte, len(s)-1)
+			j := copy(p, s[:i])
+			escape := true
+			for i = i + 1; i < len(s); i++ {
+				b := s[i]
+				switch {
+				case escape:
+					escape = false
+					p[j] = b
+					j++
+				case b == '\\':
+					escape = true
+				case b == '"':
+					return string(p[:j]), s[i+1:]
+				default:
+					p[j] = b
+					j++
+				}
+			}
+			return "", ""
+		}
+	}
+	return "", ""
+}