vendor: add cfssl dependency

vendor/github.com/cloudflare/cfssl/config/config.go

@@ -0,0 +1,563 @@
+// Package config contains the configuration logic for CFSSL.
+package config
+
+import (
+	"crypto/x509"
+	"encoding/asn1"
+	"encoding/json"
+	"errors"
+	"fmt"
+	"io/ioutil"
+	"regexp"
+	"strconv"
+	"strings"
+	"time"
+
+	"github.com/cloudflare/cfssl/auth"
+	cferr "github.com/cloudflare/cfssl/errors"
+	"github.com/cloudflare/cfssl/helpers"
+	"github.com/cloudflare/cfssl/log"
+	ocspConfig "github.com/cloudflare/cfssl/ocsp/config"
+)
+
+// A CSRWhitelist stores booleans for fields in the CSR. If a CSRWhitelist is
+// not present in a SigningProfile, all of these fields may be copied from the
+// CSR into the signed certificate. If a CSRWhitelist *is* present in a
+// SigningProfile, only those fields with a `true` value in the CSRWhitelist may
+// be copied from the CSR to the signed certificate. Note that some of these
+// fields, like Subject, can be provided or partially provided through the API.
+// Since API clients are expected to be trusted, but CSRs are not, fields
+// provided through the API are not subject to whitelisting through this
+// mechanism.
+type CSRWhitelist struct {
+	Subject, PublicKeyAlgorithm, PublicKey, SignatureAlgorithm bool
+	DNSNames, IPAddresses, EmailAddresses                      bool
+}
+
+// OID is our own version of asn1's ObjectIdentifier, so we can define a custom
+// JSON marshal / unmarshal.
+type OID asn1.ObjectIdentifier
+
+// CertificatePolicy represents the ASN.1 PolicyInformation structure from
+// https://tools.ietf.org/html/rfc3280.html#page-106.
+// Valid values of Type are "id-qt-unotice" and "id-qt-cps"
+type CertificatePolicy struct {
+	ID         OID
+	Qualifiers []CertificatePolicyQualifier
+}
+
+// CertificatePolicyQualifier represents a single qualifier from an ASN.1
+// PolicyInformation structure.
+type CertificatePolicyQualifier struct {
+	Type  string
+	Value string
+}
+
+// AuthRemote is an authenticated remote signer.
+type AuthRemote struct {
+	RemoteName  string `json:"remote"`
+	AuthKeyName string `json:"auth_key"`
+}
+
+// A SigningProfile stores information that the CA needs to store
+// signature policy.
+type SigningProfile struct {
+	Usage               []string   `json:"usages"`
+	IssuerURL           []string   `json:"issuer_urls"`
+	OCSP                string     `json:"ocsp_url"`
+	CRL                 string     `json:"crl_url"`
+	CA                  bool       `json:"is_ca"`
+	OCSPNoCheck         bool       `json:"ocsp_no_check"`
+	ExpiryString        string     `json:"expiry"`
+	BackdateString      string     `json:"backdate"`
+	AuthKeyName         string     `json:"auth_key"`
+	RemoteName          string     `json:"remote"`
+	NotBefore           time.Time  `json:"not_before"`
+	NotAfter            time.Time  `json:"not_after"`
+	NameWhitelistString string     `json:"name_whitelist"`
+	AuthRemote          AuthRemote `json:"auth_remote"`
+	CTLogServers        []string   `json:"ct_log_servers"`
+	AllowedExtensions   []OID      `json:"allowed_extensions"`
+	CertStore           string     `json:"cert_store"`
+
+	Policies                    []CertificatePolicy
+	Expiry                      time.Duration
+	Backdate                    time.Duration
+	Provider                    auth.Provider
+	RemoteProvider              auth.Provider
+	RemoteServer                string
+	CSRWhitelist                *CSRWhitelist
+	NameWhitelist               *regexp.Regexp
+	ExtensionWhitelist          map[string]bool
+	ClientProvidesSerialNumbers bool
+}
+
+// UnmarshalJSON unmarshals a JSON string into an OID.
+func (oid *OID) UnmarshalJSON(data []byte) (err error) {
+	if data[0] != '"' || data[len(data)-1] != '"' {
+		return errors.New("OID JSON string not wrapped in quotes." + string(data))
+	}
+	data = data[1 : len(data)-1]
+	parsedOid, err := parseObjectIdentifier(string(data))
+	if err != nil {
+		return err
+	}
+	*oid = OID(parsedOid)
+	return
+}
+
+// MarshalJSON marshals an oid into a JSON string.
+func (oid OID) MarshalJSON() ([]byte, error) {
+	return []byte(fmt.Sprintf(`"%v"`, asn1.ObjectIdentifier(oid))), nil
+}
+
+func parseObjectIdentifier(oidString string) (oid asn1.ObjectIdentifier, err error) {
+	validOID, err := regexp.MatchString("\\d(\\.\\d+)*", oidString)
+	if err != nil {
+		return
+	}
+	if !validOID {
+		err = errors.New("Invalid OID")
+		return
+	}
+
+	segments := strings.Split(oidString, ".")
+	oid = make(asn1.ObjectIdentifier, len(segments))
+	for i, intString := range segments {
+		oid[i], err = strconv.Atoi(intString)
+		if err != nil {
+			return
+		}
+	}
+	return
+}
+
+const timeFormat = "2006-01-02T15:04:05"
+
+// populate is used to fill in the fields that are not in JSON
+//
+// First, the ExpiryString parameter is needed to parse
+// expiration timestamps from JSON. The JSON decoder is not able to
+// decode a string time duration to a time.Duration, so this is called
+// when loading the configuration to properly parse and fill out the
+// Expiry parameter.
+// This function is also used to create references to the auth key
+// and default remote for the profile.
+// It returns true if ExpiryString is a valid representation of a
+// time.Duration, and the AuthKeyString and RemoteName point to
+// valid objects. It returns false otherwise.
+func (p *SigningProfile) populate(cfg *Config) error {
+	if p == nil {
+		return cferr.Wrap(cferr.PolicyError, cferr.InvalidPolicy, errors.New("can't parse nil profile"))
+	}
+
+	var err error
+	if p.RemoteName == "" && p.AuthRemote.RemoteName == "" {
+		log.Debugf("parse expiry in profile")
+		if p.ExpiryString == "" {
+			return cferr.Wrap(cferr.PolicyError, cferr.InvalidPolicy, errors.New("empty expiry string"))
+		}
+
+		dur, err := time.ParseDuration(p.ExpiryString)
+		if err != nil {
+			return cferr.Wrap(cferr.PolicyError, cferr.InvalidPolicy, err)
+		}
+
+		log.Debugf("expiry is valid")
+		p.Expiry = dur
+
+		if p.BackdateString != "" {
+			dur, err = time.ParseDuration(p.BackdateString)
+			if err != nil {
+				return cferr.Wrap(cferr.PolicyError, cferr.InvalidPolicy, err)
+			}
+
+			p.Backdate = dur
+		}
+
+		if !p.NotBefore.IsZero() && !p.NotAfter.IsZero() && p.NotAfter.Before(p.NotBefore) {
+			return cferr.Wrap(cferr.PolicyError, cferr.InvalidPolicy, err)
+		}
+
+		if len(p.Policies) > 0 {
+			for _, policy := range p.Policies {
+				for _, qualifier := range policy.Qualifiers {
+					if qualifier.Type != "" && qualifier.Type != "id-qt-unotice" && qualifier.Type != "id-qt-cps" {
+						return cferr.Wrap(cferr.PolicyError, cferr.InvalidPolicy,
+							errors.New("invalid policy qualifier type"))
+					}
+				}
+			}
+		}
+	} else if p.RemoteName != "" {
+		log.Debug("match remote in profile to remotes section")
+		if p.AuthRemote.RemoteName != "" {
+			log.Error("profile has both a remote and an auth remote specified")
+			return cferr.New(cferr.PolicyError, cferr.InvalidPolicy)
+		}
+		if remote := cfg.Remotes[p.RemoteName]; remote != "" {
+			if err := p.updateRemote(remote); err != nil {
+				return err
+			}
+		} else {
+			return cferr.Wrap(cferr.PolicyError, cferr.InvalidPolicy,
+				errors.New("failed to find remote in remotes section"))
+		}
+	} else {
+		log.Debug("match auth remote in profile to remotes section")
+		if remote := cfg.Remotes[p.AuthRemote.RemoteName]; remote != "" {
+			if err := p.updateRemote(remote); err != nil {
+				return err
+			}
+		} else {
+			return cferr.Wrap(cferr.PolicyError, cferr.InvalidPolicy,
+				errors.New("failed to find remote in remotes section"))
+		}
+	}
+
+	if p.AuthKeyName != "" {
+		log.Debug("match auth key in profile to auth_keys section")
+		if key, ok := cfg.AuthKeys[p.AuthKeyName]; ok == true {
+			if key.Type == "standard" {
+				p.Provider, err = auth.New(key.Key, nil)
+				if err != nil {
+					log.Debugf("failed to create new standard auth provider: %v", err)
+					return cferr.Wrap(cferr.PolicyError, cferr.InvalidPolicy,
+						errors.New("failed to create new standard auth provider"))
+				}
+			} else {
+				log.Debugf("unknown authentication type %v", key.Type)
+				return cferr.Wrap(cferr.PolicyError, cferr.InvalidPolicy,
+					errors.New("unknown authentication type"))
+			}
+		} else {
+			return cferr.Wrap(cferr.PolicyError, cferr.InvalidPolicy,
+				errors.New("failed to find auth_key in auth_keys section"))
+		}
+	}
+
+	if p.AuthRemote.AuthKeyName != "" {
+		log.Debug("match auth remote key in profile to auth_keys section")
+		if key, ok := cfg.AuthKeys[p.AuthRemote.AuthKeyName]; ok == true {
+			if key.Type == "standard" {
+				p.RemoteProvider, err = auth.New(key.Key, nil)
+				if err != nil {
+					log.Debugf("failed to create new standard auth provider: %v", err)
+					return cferr.Wrap(cferr.PolicyError, cferr.InvalidPolicy,
+						errors.New("failed to create new standard auth provider"))
+				}
+			} else {
+				log.Debugf("unknown authentication type %v", key.Type)
+				return cferr.Wrap(cferr.PolicyError, cferr.InvalidPolicy,
+					errors.New("unknown authentication type"))
+			}
+		} else {
+			return cferr.Wrap(cferr.PolicyError, cferr.InvalidPolicy,
+				errors.New("failed to find auth_remote's auth_key in auth_keys section"))
+		}
+	}
+
+	if p.NameWhitelistString != "" {
+		log.Debug("compiling whitelist regular expression")
+		rule, err := regexp.Compile(p.NameWhitelistString)
+		if err != nil {
+			return cferr.Wrap(cferr.PolicyError, cferr.InvalidPolicy,
+				errors.New("failed to compile name whitelist section"))
+		}
+		p.NameWhitelist = rule
+	}
+
+	p.ExtensionWhitelist = map[string]bool{}
+	for _, oid := range p.AllowedExtensions {
+		p.ExtensionWhitelist[asn1.ObjectIdentifier(oid).String()] = true
+	}
+
+	return nil
+}
+
+// updateRemote takes a signing profile and initializes the remote server object
+// to the hostname:port combination sent by remote.
+func (p *SigningProfile) updateRemote(remote string) error {
+	if remote != "" {
+		p.RemoteServer = remote
+	}
+	return nil
+}
+
+// OverrideRemotes takes a signing configuration and updates the remote server object
+// to the hostname:port combination sent by remote
+func (p *Signing) OverrideRemotes(remote string) error {
+	if remote != "" {
+		var err error
+		for _, profile := range p.Profiles {
+			err = profile.updateRemote(remote)
+			if err != nil {
+				return err
+			}
+		}
+		err = p.Default.updateRemote(remote)
+		if err != nil {
+			return err
+		}
+	}
+	return nil
+}
+
+// NeedsRemoteSigner returns true if one of the profiles has a remote set
+func (p *Signing) NeedsRemoteSigner() bool {
+	for _, profile := range p.Profiles {
+		if profile.RemoteServer != "" {
+			return true
+		}
+	}
+
+	if p.Default.RemoteServer != "" {
+		return true
+	}
+
+	return false
+}
+
+// NeedsLocalSigner returns true if one of the profiles doe not have a remote set
+func (p *Signing) NeedsLocalSigner() bool {
+	for _, profile := range p.Profiles {
+		if profile.RemoteServer == "" {
+			return true
+		}
+	}
+
+	if p.Default.RemoteServer == "" {
+		return true
+	}
+
+	return false
+}
+
+// Usages parses the list of key uses in the profile, translating them
+// to a list of X.509 key usages and extended key usages.  The unknown
+// uses are collected into a slice that is also returned.
+func (p *SigningProfile) Usages() (ku x509.KeyUsage, eku []x509.ExtKeyUsage, unk []string) {
+	for _, keyUse := range p.Usage {
+		if kuse, ok := KeyUsage[keyUse]; ok {
+			ku |= kuse
+		} else if ekuse, ok := ExtKeyUsage[keyUse]; ok {
+			eku = append(eku, ekuse)
+		} else {
+			unk = append(unk, keyUse)
+		}
+	}
+	return
+}
+
+// A valid profile must be a valid local profile or a valid remote profile.
+// A valid local profile has defined at least key usages to be used, and a
+// valid local default profile has defined at least a default expiration.
+// A valid remote profile (default or not) has remote signer initialized.
+// In addition, a remote profile must has a valid auth provider if auth
+// key defined.
+func (p *SigningProfile) validProfile(isDefault bool) bool {
+	if p == nil {
+		return false
+	}
+
+	if p.RemoteName != "" {
+		log.Debugf("validate remote profile")
+
+		if p.RemoteServer == "" {
+			log.Debugf("invalid remote profile: no remote signer specified")
+			return false
+		}
+
+		if p.AuthKeyName != "" && p.Provider == nil {
+			log.Debugf("invalid remote profile: auth key name is defined but no auth provider is set")
+			return false
+		}
+
+		if p.AuthRemote.RemoteName != "" {
+			log.Debugf("invalid remote profile: auth remote is also specified")
+		}
+	} else if p.AuthRemote.RemoteName != "" {
+		log.Debugf("validate auth remote profile")
+		if p.RemoteServer == "" {
+			log.Debugf("invalid auth remote profile: no remote signer specified")
+			return false
+		}
+
+		if p.AuthRemote.AuthKeyName == "" || p.RemoteProvider == nil {
+			log.Debugf("invalid auth remote profile: no auth key is defined")
+			return false
+		}
+	} else {
+		log.Debugf("validate local profile")
+		if !isDefault {
+			if len(p.Usage) == 0 {
+				log.Debugf("invalid local profile: no usages specified")
+				return false
+			} else if _, _, unk := p.Usages(); len(unk) == len(p.Usage) {
+				log.Debugf("invalid local profile: no valid usages")
+				return false
+			}
+		} else {
+			if p.Expiry == 0 {
+				log.Debugf("invalid local profile: no expiry set")
+				return false
+			}
+		}
+	}
+
+	log.Debugf("profile is valid")
+	return true
+}
+
+// Signing codifies the signature configuration policy for a CA.
+type Signing struct {
+	Profiles map[string]*SigningProfile `json:"profiles"`
+	Default  *SigningProfile            `json:"default"`
+}
+
+// Config stores configuration information for the CA.
+type Config struct {
+	Signing  *Signing           `json:"signing"`
+	OCSP     *ocspConfig.Config `json:"ocsp"`
+	AuthKeys map[string]AuthKey `json:"auth_keys,omitempty"`
+	Remotes  map[string]string  `json:"remotes,omitempty"`
+}
+
+// Valid ensures that Config is a valid configuration. It should be
+// called immediately after parsing a configuration file.
+func (c *Config) Valid() bool {
+	return c.Signing.Valid()
+}
+
+// Valid checks the signature policies, ensuring they are valid
+// policies. A policy is valid if it has defined at least key usages
+// to be used, and a valid default profile has defined at least a
+// default expiration.
+func (p *Signing) Valid() bool {
+	if p == nil {
+		return false
+	}
+
+	log.Debugf("validating configuration")
+	if !p.Default.validProfile(true) {
+		log.Debugf("default profile is invalid")
+		return false
+	}
+
+	for _, sp := range p.Profiles {
+		if !sp.validProfile(false) {
+			log.Debugf("invalid profile")
+			return false
+		}
+	}
+	return true
+}
+
+// KeyUsage contains a mapping of string names to key usages.
+var KeyUsage = map[string]x509.KeyUsage{
+	"signing":             x509.KeyUsageDigitalSignature,
+	"digital signature":   x509.KeyUsageDigitalSignature,
+	"content committment": x509.KeyUsageContentCommitment,
+	"key encipherment":    x509.KeyUsageKeyEncipherment,
+	"key agreement":       x509.KeyUsageKeyAgreement,
+	"data encipherment":   x509.KeyUsageDataEncipherment,
+	"cert sign":           x509.KeyUsageCertSign,
+	"crl sign":            x509.KeyUsageCRLSign,
+	"encipher only":       x509.KeyUsageEncipherOnly,
+	"decipher only":       x509.KeyUsageDecipherOnly,
+}
+
+// ExtKeyUsage contains a mapping of string names to extended key
+// usages.
+var ExtKeyUsage = map[string]x509.ExtKeyUsage{
+	"any":              x509.ExtKeyUsageAny,
+	"server auth":      x509.ExtKeyUsageServerAuth,
+	"client auth":      x509.ExtKeyUsageClientAuth,
+	"code signing":     x509.ExtKeyUsageCodeSigning,
+	"email protection": x509.ExtKeyUsageEmailProtection,
+	"s/mime":           x509.ExtKeyUsageEmailProtection,
+	"ipsec end system": x509.ExtKeyUsageIPSECEndSystem,
+	"ipsec tunnel":     x509.ExtKeyUsageIPSECTunnel,
+	"ipsec user":       x509.ExtKeyUsageIPSECUser,
+	"timestamping":     x509.ExtKeyUsageTimeStamping,
+	"ocsp signing":     x509.ExtKeyUsageOCSPSigning,
+	"microsoft sgc":    x509.ExtKeyUsageMicrosoftServerGatedCrypto,
+	"netscape sgc":     x509.ExtKeyUsageNetscapeServerGatedCrypto,
+}
+
+// An AuthKey contains an entry for a key used for authentication.
+type AuthKey struct {
+	// Type contains information needed to select the appropriate
+	// constructor. For example, "standard" for HMAC-SHA-256,
+	// "standard-ip" for HMAC-SHA-256 incorporating the client's
+	// IP.
+	Type string `json:"type"`
+	// Key contains the key information, such as a hex-encoded
+	// HMAC key.
+	Key string `json:"key"`
+}
+
+// DefaultConfig returns a default configuration specifying basic key
+// usage and a 1 year expiration time. The key usages chosen are
+// signing, key encipherment, client auth and server auth.
+func DefaultConfig() *SigningProfile {
+	d := helpers.OneYear
+	return &SigningProfile{
+		Usage:        []string{"signing", "key encipherment", "server auth", "client auth"},
+		Expiry:       d,
+		ExpiryString: "8760h",
+	}
+}
+
+// LoadFile attempts to load the configuration file stored at the path
+// and returns the configuration. On error, it returns nil.
+func LoadFile(path string) (*Config, error) {
+	log.Debugf("loading configuration file from %s", path)
+	if path == "" {
+		return nil, cferr.Wrap(cferr.PolicyError, cferr.InvalidPolicy, errors.New("invalid path"))
+	}
+
+	body, err := ioutil.ReadFile(path)
+	if err != nil {
+		return nil, cferr.Wrap(cferr.PolicyError, cferr.InvalidPolicy, errors.New("could not read configuration file"))
+	}
+
+	return LoadConfig(body)
+}
+
+// LoadConfig attempts to load the configuration from a byte slice.
+// On error, it returns nil.
+func LoadConfig(config []byte) (*Config, error) {
+	var cfg = &Config{}
+	err := json.Unmarshal(config, &cfg)
+	if err != nil {
+		return nil, cferr.Wrap(cferr.PolicyError, cferr.InvalidPolicy,
+			errors.New("failed to unmarshal configuration: "+err.Error()))
+	}
+
+	if cfg.Signing == nil {
+		return nil, errors.New("No \"signing\" field present")
+	}
+
+	if cfg.Signing.Default == nil {
+		log.Debugf("no default given: using default config")
+		cfg.Signing.Default = DefaultConfig()
+	} else {
+		if err := cfg.Signing.Default.populate(cfg); err != nil {
+			return nil, err
+		}
+	}
+
+	for k := range cfg.Signing.Profiles {
+		if err := cfg.Signing.Profiles[k].populate(cfg); err != nil {
+			return nil, err
+		}
+	}
+
+	if !cfg.Valid() {
+		return nil, cferr.Wrap(cferr.PolicyError, cferr.InvalidPolicy, errors.New("invalid configuration"))
+	}
+
+	log.Debugf("configuration ok")
+	return cfg, nil
+}