Add Support for Manta Object Storage as a Gateway (#5025)

Manta is an Object Storage by [Joyent](https://www.joyent.com/)

This PR adds initial support for Manta. It is intended as non-production 
ready so that feedback can be obtained.

vendor/github.com/joyent/triton-go/authentication/dummy.go

@@ -0,0 +1,72 @@
+package authentication
+
+// DON'T USE THIS OUTSIDE TESTING ~ This key was only created to use for
+// internal unit testing. It should never be used for acceptance testing either.
+//
+// This is just a randomly generated key pair.
+var Dummy = struct {
+	Fingerprint string
+	PrivateKey  []byte
+	PublicKey   []byte
+	Signer      Signer
+}{
+	"9f:d6:65:fc:d6:60:dc:d0:4e:db:2d:75:f7:92:8c:31",
+	[]byte(`-----BEGIN RSA PRIVATE KEY-----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=
+-----END RSA PRIVATE KEY-----`),
+	[]byte(`ssh-rsa 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 test-dummy-20171002140848`),
+	nil,
+}
+
+func init() {
+	testSigner, _ := NewTestSigner()
+	Dummy.Signer = testSigner
+}

vendor/github.com/joyent/triton-go/authentication/ecdsa_signature.go

@@ -0,0 +1,66 @@
+package authentication
+
+import (
+	"encoding/asn1"
+	"encoding/base64"
+	"fmt"
+	"math/big"
+
+	"github.com/hashicorp/errwrap"
+	"golang.org/x/crypto/ssh"
+)
+
+type ecdsaSignature struct {
+	hashAlgorithm string
+	R             *big.Int
+	S             *big.Int
+}
+
+func (s *ecdsaSignature) SignatureType() string {
+	return fmt.Sprintf("ecdsa-%s", s.hashAlgorithm)
+}
+
+func (s *ecdsaSignature) String() string {
+	toEncode := struct {
+		R *big.Int
+		S *big.Int
+	}{
+		R: s.R,
+		S: s.S,
+	}
+
+	signatureBytes, err := asn1.Marshal(toEncode)
+	if err != nil {
+		panic(fmt.Sprintf("Error marshaling signature: %s", err))
+	}
+
+	return base64.StdEncoding.EncodeToString(signatureBytes)
+}
+
+func newECDSASignature(signatureBlob []byte) (*ecdsaSignature, error) {
+	var ecSig struct {
+		R *big.Int
+		S *big.Int
+	}
+
+	if err := ssh.Unmarshal(signatureBlob, &ecSig); err != nil {
+		return nil, errwrap.Wrapf("Error unmarshaling signature: {{err}}", err)
+	}
+
+	rValue := ecSig.R.Bytes()
+	var hashAlgorithm string
+	switch len(rValue) {
+	case 31, 32:
+		hashAlgorithm = "sha256"
+	case 65, 66:
+		hashAlgorithm = "sha512"
+	default:
+		return nil, fmt.Errorf("Unsupported key length: %d", len(rValue))
+	}
+
+	return &ecdsaSignature{
+		hashAlgorithm: hashAlgorithm,
+		R:             ecSig.R,
+		S:             ecSig.S,
+	}, nil
+}

vendor/github.com/joyent/triton-go/authentication/private_key_signer.go

@@ -0,0 +1,106 @@
+package authentication
+
+import (
+	"crypto"
+	"crypto/rand"
+	"crypto/rsa"
+	"crypto/x509"
+	"encoding/base64"
+	"encoding/pem"
+	"errors"
+	"fmt"
+	"strings"
+
+	"github.com/hashicorp/errwrap"
+	"golang.org/x/crypto/ssh"
+)
+
+type PrivateKeySigner struct {
+	formattedKeyFingerprint string
+	keyFingerprint          string
+	algorithm               string
+	accountName             string
+	hashFunc                crypto.Hash
+
+	privateKey *rsa.PrivateKey
+}
+
+func NewPrivateKeySigner(keyFingerprint string, privateKeyMaterial []byte, accountName string) (*PrivateKeySigner, error) {
+	keyFingerprintMD5 := strings.Replace(keyFingerprint, ":", "", -1)
+
+	block, _ := pem.Decode(privateKeyMaterial)
+	if block == nil {
+		return nil, errors.New("Error PEM-decoding private key material: nil block received")
+	}
+
+	rsakey, err := x509.ParsePKCS1PrivateKey(block.Bytes)
+	if err != nil {
+		return nil, errwrap.Wrapf("Error parsing private key: {{err}}", err)
+	}
+
+	sshPublicKey, err := ssh.NewPublicKey(rsakey.Public())
+	if err != nil {
+		return nil, errwrap.Wrapf("Error parsing SSH key from private key: {{err}}", err)
+	}
+
+	matchKeyFingerprint := formatPublicKeyFingerprint(sshPublicKey, false)
+	displayKeyFingerprint := formatPublicKeyFingerprint(sshPublicKey, true)
+	if matchKeyFingerprint != keyFingerprintMD5 {
+		return nil, errors.New("Private key file does not match public key fingerprint")
+	}
+
+	signer := &PrivateKeySigner{
+		formattedKeyFingerprint: displayKeyFingerprint,
+		keyFingerprint:          keyFingerprint,
+		accountName:             accountName,
+
+		hashFunc:   crypto.SHA1,
+		privateKey: rsakey,
+	}
+
+	_, algorithm, err := signer.SignRaw("HelloWorld")
+	if err != nil {
+		return nil, fmt.Errorf("Cannot sign using ssh agent: %s", err)
+	}
+	signer.algorithm = algorithm
+
+	return signer, nil
+}
+
+func (s *PrivateKeySigner) Sign(dateHeader string) (string, error) {
+	const headerName = "date"
+
+	hash := s.hashFunc.New()
+	hash.Write([]byte(fmt.Sprintf("%s: %s", headerName, dateHeader)))
+	digest := hash.Sum(nil)
+
+	signed, err := rsa.SignPKCS1v15(rand.Reader, s.privateKey, s.hashFunc, digest)
+	if err != nil {
+		return "", errwrap.Wrapf("Error signing date header: {{err}}", err)
+	}
+	signedBase64 := base64.StdEncoding.EncodeToString(signed)
+
+	keyID := fmt.Sprintf("/%s/keys/%s", s.accountName, s.formattedKeyFingerprint)
+	return fmt.Sprintf(authorizationHeaderFormat, keyID, "rsa-sha1", headerName, signedBase64), nil
+}
+
+func (s *PrivateKeySigner) SignRaw(toSign string) (string, string, error) {
+	hash := s.hashFunc.New()
+	hash.Write([]byte(toSign))
+	digest := hash.Sum(nil)
+
+	signed, err := rsa.SignPKCS1v15(rand.Reader, s.privateKey, s.hashFunc, digest)
+	if err != nil {
+		return "", "", errwrap.Wrapf("Error signing date header: {{err}}", err)
+	}
+	signedBase64 := base64.StdEncoding.EncodeToString(signed)
+	return signedBase64, "rsa-sha1", nil
+}
+
+func (s *PrivateKeySigner) KeyFingerprint() string {
+	return s.formattedKeyFingerprint
+}
+
+func (s *PrivateKeySigner) DefaultAlgorithm() string {
+	return s.algorithm
+}

vendor/github.com/joyent/triton-go/authentication/rsa_signature.go

@@ -0,0 +1,25 @@
+package authentication
+
+import (
+	"encoding/base64"
+)
+
+type rsaSignature struct {
+	hashAlgorithm string
+	signature     []byte
+}
+
+func (s *rsaSignature) SignatureType() string {
+	return s.hashAlgorithm
+}
+
+func (s *rsaSignature) String() string {
+	return base64.StdEncoding.EncodeToString(s.signature)
+}
+
+func newRSASignature(signatureBlob []byte) (*rsaSignature, error) {
+	return &rsaSignature{
+		hashAlgorithm: "rsa-sha1",
+		signature:     signatureBlob,
+	}, nil
+}

vendor/github.com/joyent/triton-go/authentication/signature.go

@@ -0,0 +1,27 @@
+package authentication
+
+import (
+	"regexp"
+	"fmt"
+)
+
+type httpAuthSignature interface {
+	SignatureType() string
+	String() string
+}
+
+func keyFormatToKeyType(keyFormat string) (string, error) {
+	if keyFormat == "ssh-rsa" {
+		return "rsa", nil
+	}
+
+	if keyFormat == "ssh-ed25519" {
+		return "ed25519", nil
+	}
+
+	if regexp.MustCompile("^ecdsa-sha2-*").Match([]byte(keyFormat)) {
+		return "ecdsa", nil
+	}
+
+	return "", fmt.Errorf("Unknown key format: %s", keyFormat)
+}

vendor/github.com/joyent/triton-go/authentication/signer.go

@@ -0,0 +1,10 @@
+package authentication
+
+const authorizationHeaderFormat = `Signature keyId="%s",algorithm="%s",headers="%s",signature="%s"`
+
+type Signer interface {
+	DefaultAlgorithm() string
+	KeyFingerprint() string
+	Sign(dateHeader string) (string, error)
+	SignRaw(toSign string) (string, string, error)
+}

vendor/github.com/joyent/triton-go/authentication/ssh_agent_signer.go

@@ -0,0 +1,170 @@
+package authentication
+
+import (
+	"crypto/md5"
+	"crypto/sha256"
+	"encoding/base64"
+	"errors"
+	"fmt"
+	"net"
+	"os"
+	"strings"
+
+	"github.com/hashicorp/errwrap"
+	"golang.org/x/crypto/ssh"
+	"golang.org/x/crypto/ssh/agent"
+)
+
+var (
+	ErrUnsetEnvVar = errors.New("SSH_AUTH_SOCK is not set")
+)
+
+type SSHAgentSigner struct {
+	formattedKeyFingerprint string
+	keyFingerprint          string
+	algorithm               string
+	accountName             string
+	keyIdentifier           string
+
+	agent agent.Agent
+	key   ssh.PublicKey
+}
+
+func NewSSHAgentSigner(keyFingerprint, accountName string) (*SSHAgentSigner, error) {
+	sshAgentAddress, agentOk := os.LookupEnv("SSH_AUTH_SOCK")
+	if !agentOk {
+		return nil, ErrUnsetEnvVar
+	}
+
+	conn, err := net.Dial("unix", sshAgentAddress)
+	if err != nil {
+		return nil, errwrap.Wrapf("Error dialing SSH agent: {{err}}", err)
+	}
+
+	ag := agent.NewClient(conn)
+
+	signer := &SSHAgentSigner{
+		keyFingerprint: keyFingerprint,
+		accountName:    accountName,
+		agent:          ag,
+	}
+
+	matchingKey, err := signer.MatchKey()
+	if err != nil {
+		return nil, err
+	}
+	signer.key = matchingKey
+	signer.formattedKeyFingerprint = formatPublicKeyFingerprint(signer.key, true)
+	signer.keyIdentifier = fmt.Sprintf("/%s/keys/%s", signer.accountName, signer.formattedKeyFingerprint)
+
+	_, algorithm, err := signer.SignRaw("HelloWorld")
+	if err != nil {
+		return nil, fmt.Errorf("Cannot sign using ssh agent: %s", err)
+	}
+	signer.algorithm = algorithm
+
+	return signer, nil
+}
+
+func (s *SSHAgentSigner) MatchKey() (ssh.PublicKey, error) {
+	keys, err := s.agent.List()
+	if err != nil {
+		return nil, errwrap.Wrapf("Error listing keys in SSH Agent: %s", err)
+	}
+
+	keyFingerprintStripped := strings.TrimPrefix(s.keyFingerprint, "MD5:")
+	keyFingerprintStripped = strings.TrimPrefix(keyFingerprintStripped, "SHA256:")
+	keyFingerprintStripped = strings.Replace(keyFingerprintStripped, ":", "", -1)
+
+	var matchingKey ssh.PublicKey
+	for _, key := range keys {
+		keyMD5 := md5.New()
+		keyMD5.Write(key.Marshal())
+		finalizedMD5 := fmt.Sprintf("%x", keyMD5.Sum(nil))
+
+		keySHA256 := sha256.New()
+		keySHA256.Write(key.Marshal())
+		finalizedSHA256 := base64.RawStdEncoding.EncodeToString(keySHA256.Sum(nil))
+
+		if keyFingerprintStripped == finalizedMD5 || keyFingerprintStripped == finalizedSHA256 {
+			matchingKey = key
+		}
+	}
+
+	if matchingKey == nil {
+		return nil, fmt.Errorf("No key in the SSH Agent matches fingerprint: %s", s.keyFingerprint)
+	}
+
+	return matchingKey, nil
+}
+
+func (s *SSHAgentSigner) Sign(dateHeader string) (string, error) {
+	const headerName = "date"
+
+	signature, err := s.agent.Sign(s.key, []byte(fmt.Sprintf("%s: %s", headerName, dateHeader)))
+	if err != nil {
+		return "", errwrap.Wrapf("Error signing date header: {{err}}", err)
+	}
+
+	keyFormat, err := keyFormatToKeyType(signature.Format)
+	if err != nil {
+		return "", errwrap.Wrapf("Error reading signature: {{err}}", err)
+	}
+
+	var authSignature httpAuthSignature
+	switch keyFormat {
+	case "rsa":
+		authSignature, err = newRSASignature(signature.Blob)
+		if err != nil {
+			return "", errwrap.Wrapf("Error reading signature: {{err}}", err)
+		}
+	case "ecdsa":
+		authSignature, err = newECDSASignature(signature.Blob)
+		if err != nil {
+			return "", errwrap.Wrapf("Error reading signature: {{err}}", err)
+		}
+	default:
+		return "", fmt.Errorf("Unsupported algorithm from SSH agent: %s", signature.Format)
+	}
+
+	return fmt.Sprintf(authorizationHeaderFormat, s.keyIdentifier,
+		authSignature.SignatureType(), headerName, authSignature.String()), nil
+}
+
+func (s *SSHAgentSigner) SignRaw(toSign string) (string, string, error) {
+	signature, err := s.agent.Sign(s.key, []byte(toSign))
+	if err != nil {
+		return "", "", errwrap.Wrapf("Error signing string: {{err}}", err)
+	}
+
+	keyFormat, err := keyFormatToKeyType(signature.Format)
+	if err != nil {
+		return "", "", errwrap.Wrapf("Error reading signature: {{err}}", err)
+	}
+
+	var authSignature httpAuthSignature
+	switch keyFormat {
+	case "rsa":
+		authSignature, err = newRSASignature(signature.Blob)
+		if err != nil {
+			return "", "", errwrap.Wrapf("Error reading signature: {{err}}", err)
+		}
+	case "ecdsa":
+		authSignature, err = newECDSASignature(signature.Blob)
+		if err != nil {
+			return "", "", errwrap.Wrapf("Error reading signature: {{err}}", err)
+		}
+	default:
+		return "", "", fmt.Errorf("Unsupported algorithm from SSH agent: %s", signature.Format)
+	}
+
+	return authSignature.String(), authSignature.SignatureType(), nil
+}
+
+func (s *SSHAgentSigner) KeyFingerprint() string {
+	return s.formattedKeyFingerprint
+}
+
+func (s *SSHAgentSigner) DefaultAlgorithm() string {
+	return s.algorithm
+}

vendor/github.com/joyent/triton-go/authentication/test_signer.go

@@ -0,0 +1,27 @@
+package authentication
+
+// TestSigner represents an authentication key signer which we can use for
+// testing purposes only. This will largely be a stub to send through client
+// unit tests.
+type TestSigner struct{}
+
+// NewTestSigner constructs a new instance of test signer
+func NewTestSigner() (Signer, error) {
+	return &TestSigner{}, nil
+}
+
+func (s *TestSigner) DefaultAlgorithm() string {
+	return ""
+}
+
+func (s *TestSigner) KeyFingerprint() string {
+	return ""
+}
+
+func (s *TestSigner) Sign(dateHeader string) (string, error) {
+	return "", nil
+}
+
+func (s *TestSigner) SignRaw(toSign string) (string, string, error) {
+	return "", "", nil
+}

vendor/github.com/joyent/triton-go/authentication/util.go

@@ -0,0 +1,29 @@
+package authentication
+
+import (
+	"crypto/md5"
+	"fmt"
+	"strings"
+
+	"golang.org/x/crypto/ssh"
+)
+
+// formatPublicKeyFingerprint produces the MD5 fingerprint of the given SSH
+// public key. If display is true, the fingerprint is formatted with colons
+// between each byte, as per the output of OpenSSL.
+func formatPublicKeyFingerprint(key ssh.PublicKey, display bool) string {
+	publicKeyFingerprint := md5.New()
+	publicKeyFingerprint.Write(key.Marshal())
+	publicKeyFingerprintString := fmt.Sprintf("%x", publicKeyFingerprint.Sum(nil))
+
+	if !display {
+		return publicKeyFingerprintString
+	}
+
+	formatted := ""
+	for i := 0; i < len(publicKeyFingerprintString); i = i + 2 {
+		formatted = fmt.Sprintf("%s%s:", formatted, publicKeyFingerprintString[i:i+2])
+	}
+
+	return strings.TrimSuffix(formatted, ":")
+}