diff options
Diffstat (limited to 'vendor/golang.org/x/crypto/ssh/certs.go')
-rw-r--r-- | vendor/golang.org/x/crypto/ssh/certs.go | 519 |
1 files changed, 0 insertions, 519 deletions
diff --git a/vendor/golang.org/x/crypto/ssh/certs.go b/vendor/golang.org/x/crypto/ssh/certs.go deleted file mode 100644 index b1f0220..0000000 --- a/vendor/golang.org/x/crypto/ssh/certs.go +++ /dev/null @@ -1,519 +0,0 @@ -// Copyright 2012 The Go Authors. All rights reserved. -// Use of this source code is governed by a BSD-style -// license that can be found in the LICENSE file. - -package ssh - -import ( - "bytes" - "errors" - "fmt" - "io" - "net" - "sort" - "time" -) - -// These constants from [PROTOCOL.certkeys] represent the algorithm names -// for certificate types supported by this package. -const ( - CertAlgoRSAv01 = "ssh-rsa-cert-v01@openssh.com" - CertAlgoDSAv01 = "ssh-dss-cert-v01@openssh.com" - CertAlgoECDSA256v01 = "ecdsa-sha2-nistp256-cert-v01@openssh.com" - CertAlgoECDSA384v01 = "ecdsa-sha2-nistp384-cert-v01@openssh.com" - CertAlgoECDSA521v01 = "ecdsa-sha2-nistp521-cert-v01@openssh.com" - CertAlgoED25519v01 = "ssh-ed25519-cert-v01@openssh.com" -) - -// Certificate types distinguish between host and user -// certificates. The values can be set in the CertType field of -// Certificate. -const ( - UserCert = 1 - HostCert = 2 -) - -// Signature represents a cryptographic signature. -type Signature struct { - Format string - Blob []byte -} - -// CertTimeInfinity can be used for OpenSSHCertV01.ValidBefore to indicate that -// a certificate does not expire. -const CertTimeInfinity = 1<<64 - 1 - -// An Certificate represents an OpenSSH certificate as defined in -// [PROTOCOL.certkeys]?rev=1.8. -type Certificate struct { - Nonce []byte - Key PublicKey - Serial uint64 - CertType uint32 - KeyId string - ValidPrincipals []string - ValidAfter uint64 - ValidBefore uint64 - Permissions - Reserved []byte - SignatureKey PublicKey - Signature *Signature -} - -// genericCertData holds the key-independent part of the certificate data. -// Overall, certificates contain an nonce, public key fields and -// key-independent fields. -type genericCertData struct { - Serial uint64 - CertType uint32 - KeyId string - ValidPrincipals []byte - ValidAfter uint64 - ValidBefore uint64 - CriticalOptions []byte - Extensions []byte - Reserved []byte - SignatureKey []byte - Signature []byte -} - -func marshalStringList(namelist []string) []byte { - var to []byte - for _, name := range namelist { - s := struct{ N string }{name} - to = append(to, Marshal(&s)...) - } - return to -} - -type optionsTuple struct { - Key string - Value []byte -} - -type optionsTupleValue struct { - Value string -} - -// serialize a map of critical options or extensions -// issue #10569 - per [PROTOCOL.certkeys] and SSH implementation, -// we need two length prefixes for a non-empty string value -func marshalTuples(tups map[string]string) []byte { - keys := make([]string, 0, len(tups)) - for key := range tups { - keys = append(keys, key) - } - sort.Strings(keys) - - var ret []byte - for _, key := range keys { - s := optionsTuple{Key: key} - if value := tups[key]; len(value) > 0 { - s.Value = Marshal(&optionsTupleValue{value}) - } - ret = append(ret, Marshal(&s)...) - } - return ret -} - -// issue #10569 - per [PROTOCOL.certkeys] and SSH implementation, -// we need two length prefixes for a non-empty option value -func parseTuples(in []byte) (map[string]string, error) { - tups := map[string]string{} - var lastKey string - var haveLastKey bool - - for len(in) > 0 { - var key, val, extra []byte - var ok bool - - if key, in, ok = parseString(in); !ok { - return nil, errShortRead - } - keyStr := string(key) - // according to [PROTOCOL.certkeys], the names must be in - // lexical order. - if haveLastKey && keyStr <= lastKey { - return nil, fmt.Errorf("ssh: certificate options are not in lexical order") - } - lastKey, haveLastKey = keyStr, true - // the next field is a data field, which if non-empty has a string embedded - if val, in, ok = parseString(in); !ok { - return nil, errShortRead - } - if len(val) > 0 { - val, extra, ok = parseString(val) - if !ok { - return nil, errShortRead - } - if len(extra) > 0 { - return nil, fmt.Errorf("ssh: unexpected trailing data after certificate option value") - } - tups[keyStr] = string(val) - } else { - tups[keyStr] = "" - } - } - return tups, nil -} - -func parseCert(in []byte, privAlgo string) (*Certificate, error) { - nonce, rest, ok := parseString(in) - if !ok { - return nil, errShortRead - } - - key, rest, err := parsePubKey(rest, privAlgo) - if err != nil { - return nil, err - } - - var g genericCertData - if err := Unmarshal(rest, &g); err != nil { - return nil, err - } - - c := &Certificate{ - Nonce: nonce, - Key: key, - Serial: g.Serial, - CertType: g.CertType, - KeyId: g.KeyId, - ValidAfter: g.ValidAfter, - ValidBefore: g.ValidBefore, - } - - for principals := g.ValidPrincipals; len(principals) > 0; { - principal, rest, ok := parseString(principals) - if !ok { - return nil, errShortRead - } - c.ValidPrincipals = append(c.ValidPrincipals, string(principal)) - principals = rest - } - - c.CriticalOptions, err = parseTuples(g.CriticalOptions) - if err != nil { - return nil, err - } - c.Extensions, err = parseTuples(g.Extensions) - if err != nil { - return nil, err - } - c.Reserved = g.Reserved - k, err := ParsePublicKey(g.SignatureKey) - if err != nil { - return nil, err - } - - c.SignatureKey = k - c.Signature, rest, ok = parseSignatureBody(g.Signature) - if !ok || len(rest) > 0 { - return nil, errors.New("ssh: signature parse error") - } - - return c, nil -} - -type openSSHCertSigner struct { - pub *Certificate - signer Signer -} - -// NewCertSigner returns a Signer that signs with the given Certificate, whose -// private key is held by signer. It returns an error if the public key in cert -// doesn't match the key used by signer. -func NewCertSigner(cert *Certificate, signer Signer) (Signer, error) { - if bytes.Compare(cert.Key.Marshal(), signer.PublicKey().Marshal()) != 0 { - return nil, errors.New("ssh: signer and cert have different public key") - } - - return &openSSHCertSigner{cert, signer}, nil -} - -func (s *openSSHCertSigner) Sign(rand io.Reader, data []byte) (*Signature, error) { - return s.signer.Sign(rand, data) -} - -func (s *openSSHCertSigner) PublicKey() PublicKey { - return s.pub -} - -const sourceAddressCriticalOption = "source-address" - -// CertChecker does the work of verifying a certificate. Its methods -// can be plugged into ClientConfig.HostKeyCallback and -// ServerConfig.PublicKeyCallback. For the CertChecker to work, -// minimally, the IsAuthority callback should be set. -type CertChecker struct { - // SupportedCriticalOptions lists the CriticalOptions that the - // server application layer understands. These are only used - // for user certificates. - SupportedCriticalOptions []string - - // IsUserAuthority should return true if the key is recognized as an - // authority for the given user certificate. This allows for - // certificates to be signed by other certificates. This must be set - // if this CertChecker will be checking user certificates. - IsUserAuthority func(auth PublicKey) bool - - // IsHostAuthority should report whether the key is recognized as - // an authority for this host. This allows for certificates to be - // signed by other keys, and for those other keys to only be valid - // signers for particular hostnames. This must be set if this - // CertChecker will be checking host certificates. - IsHostAuthority func(auth PublicKey, address string) bool - - // Clock is used for verifying time stamps. If nil, time.Now - // is used. - Clock func() time.Time - - // UserKeyFallback is called when CertChecker.Authenticate encounters a - // public key that is not a certificate. It must implement validation - // of user keys or else, if nil, all such keys are rejected. - UserKeyFallback func(conn ConnMetadata, key PublicKey) (*Permissions, error) - - // HostKeyFallback is called when CertChecker.CheckHostKey encounters a - // public key that is not a certificate. It must implement host key - // validation or else, if nil, all such keys are rejected. - HostKeyFallback HostKeyCallback - - // IsRevoked is called for each certificate so that revocation checking - // can be implemented. It should return true if the given certificate - // is revoked and false otherwise. If nil, no certificates are - // considered to have been revoked. - IsRevoked func(cert *Certificate) bool -} - -// CheckHostKey checks a host key certificate. This method can be -// plugged into ClientConfig.HostKeyCallback. -func (c *CertChecker) CheckHostKey(addr string, remote net.Addr, key PublicKey) error { - cert, ok := key.(*Certificate) - if !ok { - if c.HostKeyFallback != nil { - return c.HostKeyFallback(addr, remote, key) - } - return errors.New("ssh: non-certificate host key") - } - if cert.CertType != HostCert { - return fmt.Errorf("ssh: certificate presented as a host key has type %d", cert.CertType) - } - if !c.IsHostAuthority(cert.SignatureKey, addr) { - return fmt.Errorf("ssh: no authorities for hostname: %v", addr) - } - - hostname, _, err := net.SplitHostPort(addr) - if err != nil { - return err - } - - // Pass hostname only as principal for host certificates (consistent with OpenSSH) - return c.CheckCert(hostname, cert) -} - -// Authenticate checks a user certificate. Authenticate can be used as -// a value for ServerConfig.PublicKeyCallback. -func (c *CertChecker) Authenticate(conn ConnMetadata, pubKey PublicKey) (*Permissions, error) { - cert, ok := pubKey.(*Certificate) - if !ok { - if c.UserKeyFallback != nil { - return c.UserKeyFallback(conn, pubKey) - } - return nil, errors.New("ssh: normal key pairs not accepted") - } - - if cert.CertType != UserCert { - return nil, fmt.Errorf("ssh: cert has type %d", cert.CertType) - } - if !c.IsUserAuthority(cert.SignatureKey) { - return nil, fmt.Errorf("ssh: certificate signed by unrecognized authority") - } - - if err := c.CheckCert(conn.User(), cert); err != nil { - return nil, err - } - - return &cert.Permissions, nil -} - -// CheckCert checks CriticalOptions, ValidPrincipals, revocation, timestamp and -// the signature of the certificate. -func (c *CertChecker) CheckCert(principal string, cert *Certificate) error { - if c.IsRevoked != nil && c.IsRevoked(cert) { - return fmt.Errorf("ssh: certicate serial %d revoked", cert.Serial) - } - - for opt, _ := range cert.CriticalOptions { - // sourceAddressCriticalOption will be enforced by - // serverAuthenticate - if opt == sourceAddressCriticalOption { - continue - } - - found := false - for _, supp := range c.SupportedCriticalOptions { - if supp == opt { - found = true - break - } - } - if !found { - return fmt.Errorf("ssh: unsupported critical option %q in certificate", opt) - } - } - - if len(cert.ValidPrincipals) > 0 { - // By default, certs are valid for all users/hosts. - found := false - for _, p := range cert.ValidPrincipals { - if p == principal { - found = true - break - } - } - if !found { - return fmt.Errorf("ssh: principal %q not in the set of valid principals for given certificate: %q", principal, cert.ValidPrincipals) - } - } - - clock := c.Clock - if clock == nil { - clock = time.Now - } - - unixNow := clock().Unix() - if after := int64(cert.ValidAfter); after < 0 || unixNow < int64(cert.ValidAfter) { - return fmt.Errorf("ssh: cert is not yet valid") - } - if before := int64(cert.ValidBefore); cert.ValidBefore != uint64(CertTimeInfinity) && (unixNow >= before || before < 0) { - return fmt.Errorf("ssh: cert has expired") - } - if err := cert.SignatureKey.Verify(cert.bytesForSigning(), cert.Signature); err != nil { - return fmt.Errorf("ssh: certificate signature does not verify") - } - - return nil -} - -// SignCert sets c.SignatureKey to the authority's public key and stores a -// Signature, by authority, in the certificate. -func (c *Certificate) SignCert(rand io.Reader, authority Signer) error { - c.Nonce = make([]byte, 32) - if _, err := io.ReadFull(rand, c.Nonce); err != nil { - return err - } - c.SignatureKey = authority.PublicKey() - - sig, err := authority.Sign(rand, c.bytesForSigning()) - if err != nil { - return err - } - c.Signature = sig - return nil -} - -var certAlgoNames = map[string]string{ - KeyAlgoRSA: CertAlgoRSAv01, - KeyAlgoDSA: CertAlgoDSAv01, - KeyAlgoECDSA256: CertAlgoECDSA256v01, - KeyAlgoECDSA384: CertAlgoECDSA384v01, - KeyAlgoECDSA521: CertAlgoECDSA521v01, - KeyAlgoED25519: CertAlgoED25519v01, -} - -// certToPrivAlgo returns the underlying algorithm for a certificate algorithm. -// Panics if a non-certificate algorithm is passed. -func certToPrivAlgo(algo string) string { - for privAlgo, pubAlgo := range certAlgoNames { - if pubAlgo == algo { - return privAlgo - } - } - panic("unknown cert algorithm") -} - -func (cert *Certificate) bytesForSigning() []byte { - c2 := *cert - c2.Signature = nil - out := c2.Marshal() - // Drop trailing signature length. - return out[:len(out)-4] -} - -// Marshal serializes c into OpenSSH's wire format. It is part of the -// PublicKey interface. -func (c *Certificate) Marshal() []byte { - generic := genericCertData{ - Serial: c.Serial, - CertType: c.CertType, - KeyId: c.KeyId, - ValidPrincipals: marshalStringList(c.ValidPrincipals), - ValidAfter: uint64(c.ValidAfter), - ValidBefore: uint64(c.ValidBefore), - CriticalOptions: marshalTuples(c.CriticalOptions), - Extensions: marshalTuples(c.Extensions), - Reserved: c.Reserved, - SignatureKey: c.SignatureKey.Marshal(), - } - if c.Signature != nil { - generic.Signature = Marshal(c.Signature) - } - genericBytes := Marshal(&generic) - keyBytes := c.Key.Marshal() - _, keyBytes, _ = parseString(keyBytes) - prefix := Marshal(&struct { - Name string - Nonce []byte - Key []byte `ssh:"rest"` - }{c.Type(), c.Nonce, keyBytes}) - - result := make([]byte, 0, len(prefix)+len(genericBytes)) - result = append(result, prefix...) - result = append(result, genericBytes...) - return result -} - -// Type returns the key name. It is part of the PublicKey interface. -func (c *Certificate) Type() string { - algo, ok := certAlgoNames[c.Key.Type()] - if !ok { - panic("unknown cert key type " + c.Key.Type()) - } - return algo -} - -// Verify verifies a signature against the certificate's public -// key. It is part of the PublicKey interface. -func (c *Certificate) Verify(data []byte, sig *Signature) error { - return c.Key.Verify(data, sig) -} - -func parseSignatureBody(in []byte) (out *Signature, rest []byte, ok bool) { - format, in, ok := parseString(in) - if !ok { - return - } - - out = &Signature{ - Format: string(format), - } - - if out.Blob, in, ok = parseString(in); !ok { - return - } - - return out, in, ok -} - -func parseSignature(in []byte) (out *Signature, rest []byte, ok bool) { - sigBytes, rest, ok := parseString(in) - if !ok { - return - } - - out, trailing, ok := parseSignatureBody(sigBytes) - if !ok || len(trailing) > 0 { - return nil, nil, false - } - return -} |