1 files changed, 296 insertions, 0 deletions
diff --git a/Godeps/_workspace/src/github.com/awslabs/aws-sdk-go/internal/signer/v4/v4.go b/Godeps/_workspace/src/github.com/awslabs/aws-sdk-go/internal/signer/v4/v4.go
new file mode 100644
index 000000000..d331475f4
--- /dev/null
+++ b/Godeps/_workspace/src/github.com/awslabs/aws-sdk-go/internal/signer/v4/v4.go
@@ -0,0 +1,296 @@
+package v4
+
+import (
+	"crypto/hmac"
+	"crypto/sha256"
+	"encoding/hex"
+	"fmt"
+	"io"
+	"net/http"
+	"net/url"
+	"sort"
+	"strconv"
+	"strings"
+	"time"
+
+	"github.com/awslabs/aws-sdk-go/aws"
+)
+
+const (
+	authHeaderPrefix = "AWS4-HMAC-SHA256"
+	timeFormat       = "20060102T150405Z"
+	shortTimeFormat  = "20060102"
+)
+
+var ignoredHeaders = map[string]bool{
+	"Authorization":  true,
+	"Content-Type":   true,
+	"Content-Length": true,
+	"User-Agent":     true,
+}
+
+type signer struct {
+	Request         *http.Request
+	Time            time.Time
+	ExpireTime      time.Duration
+	ServiceName     string
+	Region          string
+	AccessKeyID     string
+	SecretAccessKey string
+	SessionToken    string
+	Query           url.Values
+	Body            io.ReadSeeker
+	Debug           uint
+	Logger          io.Writer
+
+	isPresign          bool
+	formattedTime      string
+	formattedShortTime string
+
+	signedHeaders    string
+	canonicalHeaders string
+	canonicalString  string
+	credentialString string
+	stringToSign     string
+	signature        string
+	authorization    string
+}
+
+// Sign requests with signature version 4.
+func Sign(req *aws.Request) {
+	creds, err := req.Service.Config.Credentials.Credentials()
+	if err != nil {
+		req.Error = err
+		return
+	}
+
+	s := signer{
+		Request:         req.HTTPRequest,
+		Time:            req.Time,
+		ExpireTime:      req.ExpireTime,
+		Query:           req.HTTPRequest.URL.Query(),
+		Body:            req.Body,
+		ServiceName:     req.Service.ServiceName,
+		Region:          req.Service.Config.Region,
+		AccessKeyID:     creds.AccessKeyID,
+		SecretAccessKey: creds.SecretAccessKey,
+		SessionToken:    creds.SessionToken,
+		Debug:           req.Service.Config.LogLevel,
+		Logger:          req.Service.Config.Logger,
+	}
+	s.sign()
+	return
+}
+
+func (v4 *signer) sign() {
+	if v4.ExpireTime != 0 {
+		v4.isPresign = true
+	}
+
+	if v4.isPresign {
+		v4.Query.Set("X-Amz-Algorithm", authHeaderPrefix)
+		if v4.SessionToken != "" {
+			v4.Query.Set("X-Amz-Security-Token", v4.SessionToken)
+		} else {
+			v4.Query.Del("X-Amz-Security-Token")
+		}
+	} else if v4.SessionToken != "" {
+		v4.Request.Header.Set("X-Amz-Security-Token", v4.SessionToken)
+	}
+
+	v4.build()
+
+	if v4.Debug > 0 {
+		out := v4.Logger
+		fmt.Fprintf(out, "---[ CANONICAL STRING  ]-----------------------------\n")
+		fmt.Fprintln(out, v4.canonicalString)
+		fmt.Fprintf(out, "---[ STRING TO SIGN ]--------------------------------\n")
+		fmt.Fprintln(out, v4.stringToSign)
+		fmt.Fprintf(out, "---[ SIGNED URL ]--------------------------------\n")
+		fmt.Fprintln(out, v4.Request.URL)
+		fmt.Fprintf(out, "-----------------------------------------------------\n")
+	}
+}
+
+func (v4 *signer) build() {
+	v4.buildTime()             // no depends
+	v4.buildCredentialString() // no depends
+	if v4.isPresign {
+		v4.buildQuery() // no depends
+	}
+	v4.buildCanonicalHeaders() // depends on cred string
+	v4.buildCanonicalString()  // depends on canon headers / signed headers
+	v4.buildStringToSign()     // depends on canon string
+	v4.buildSignature()        // depends on string to sign
+
+	if v4.isPresign {
+		v4.Request.URL.RawQuery += "&X-Amz-Signature=" + v4.signature
+	} else {
+		parts := []string{
+			authHeaderPrefix + " Credential=" + v4.AccessKeyID + "/" + v4.credentialString,
+			"SignedHeaders=" + v4.signedHeaders,
+			"Signature=" + v4.signature,
+		}
+		v4.Request.Header.Set("Authorization", strings.Join(parts, ", "))
+	}
+}
+
+func (v4 *signer) buildTime() {
+	v4.formattedTime = v4.Time.UTC().Format(timeFormat)
+	v4.formattedShortTime = v4.Time.UTC().Format(shortTimeFormat)
+
+	if v4.isPresign {
+		duration := int64(v4.ExpireTime / time.Second)
+		v4.Query.Set("X-Amz-Date", v4.formattedTime)
+		v4.Query.Set("X-Amz-Expires", strconv.FormatInt(duration, 10))
+	} else {
+		v4.Request.Header.Set("X-Amz-Date", v4.formattedTime)
+	}
+}
+
+func (v4 *signer) buildCredentialString() {
+	v4.credentialString = strings.Join([]string{
+		v4.formattedShortTime,
+		v4.Region,
+		v4.ServiceName,
+		"aws4_request",
+	}, "/")
+
+	if v4.isPresign {
+		v4.Query.Set("X-Amz-Credential", v4.AccessKeyID+"/"+v4.credentialString)
+	}
+}
+
+func (v4 *signer) buildQuery() {
+	for k, h := range v4.Request.Header {
+		if strings.HasPrefix(http.CanonicalHeaderKey(k), "X-Amz-") {
+			continue // never hoist x-amz-* headers, they must be signed
+		}
+		if _, ok := ignoredHeaders[http.CanonicalHeaderKey(k)]; ok {
+			continue // never hoist ignored headers
+		}
+
+		v4.Request.Header.Del(k)
+		v4.Query.Del(k)
+		for _, v := range h {
+			v4.Query.Add(k, v)
+		}
+	}
+}
+
+func (v4 *signer) buildCanonicalHeaders() {
+	headers := make([]string, 0)
+	headers = append(headers, "host")
+	for k, _ := range v4.Request.Header {
+		if _, ok := ignoredHeaders[http.CanonicalHeaderKey(k)]; ok {
+			continue // ignored header
+		}
+		headers = append(headers, strings.ToLower(k))
+	}
+	sort.Strings(headers)
+
+	v4.signedHeaders = strings.Join(headers, ";")
+
+	if v4.isPresign {
+		v4.Query.Set("X-Amz-SignedHeaders", v4.signedHeaders)
+	}
+
+	headerValues := make([]string, len(headers))
+	for i, k := range headers {
+		if k == "host" {
+			headerValues[i] = "host:" + v4.Request.URL.Host
+		} else {
+			headerValues[i] = k + ":" +
+				strings.Join(v4.Request.Header[http.CanonicalHeaderKey(k)], ",")
+		}
+	}
+
+	v4.canonicalHeaders = strings.Join(headerValues, "\n")
+}
+
+func (v4 *signer) buildCanonicalString() {
+	v4.Request.URL.RawQuery = v4.Query.Encode()
+	uri := v4.Request.URL.Opaque
+	if uri != "" {
+		uri = "/" + strings.Join(strings.Split(uri, "/")[3:], "/")
+	} else {
+		uri = v4.Request.URL.Path
+	}
+	if uri == "" {
+		uri = "/"
+	}
+
+	v4.canonicalString = strings.Join([]string{
+		v4.Request.Method,
+		uri,
+		v4.Request.URL.RawQuery,
+		v4.canonicalHeaders + "\n",
+		v4.signedHeaders,
+		v4.bodyDigest(),
+	}, "\n")
+}
+
+func (v4 *signer) buildStringToSign() {
+	v4.stringToSign = strings.Join([]string{
+		authHeaderPrefix,
+		v4.formattedTime,
+		v4.credentialString,
+		hex.EncodeToString(makeSha256([]byte(v4.canonicalString))),
+	}, "\n")
+}
+
+func (v4 *signer) buildSignature() {
+	secret := v4.SecretAccessKey
+	date := makeHmac([]byte("AWS4"+secret), []byte(v4.formattedShortTime))
+	region := makeHmac(date, []byte(v4.Region))
+	service := makeHmac(region, []byte(v4.ServiceName))
+	credentials := makeHmac(service, []byte("aws4_request"))
+	signature := makeHmac(credentials, []byte(v4.stringToSign))
+	v4.signature = hex.EncodeToString(signature)
+}
+
+func (v4 *signer) bodyDigest() string {
+	hash := v4.Request.Header.Get("X-Amz-Content-Sha256")
+	if hash == "" {
+		if v4.isPresign && v4.ServiceName == "s3" {
+			hash = "UNSIGNED-PAYLOAD"
+		} else if v4.Body == nil {
+			hash = hex.EncodeToString(makeSha256([]byte{}))
+		} else {
+			hash = hex.EncodeToString(makeSha256Reader(v4.Body))
+		}
+		v4.Request.Header.Add("X-Amz-Content-Sha256", hash)
+	}
+	return hash
+}
+
+func makeHmac(key []byte, data []byte) []byte {
+	hash := hmac.New(sha256.New, key)
+	hash.Write(data)
+	return hash.Sum(nil)
+}
+
+func makeSha256(data []byte) []byte {
+	hash := sha256.New()
+	hash.Write(data)
+	return hash.Sum(nil)
+}
+
+func makeSha256Reader(reader io.ReadSeeker) []byte {
+	packet := make([]byte, 4096)
+	hash := sha256.New()
+
+	reader.Seek(0, 0)
+	for {
+		n, err := reader.Read(packet)
+		if n > 0 {
+			hash.Write(packet[0:n])
+		}
+		if err == io.EOF || n == 0 {
+			break
+		}
+	}
+	reader.Seek(0, 0)
+
+	return hash.Sum(nil)
+}