diff options
Diffstat (limited to 'vendor/golang.org/x/crypto/ssh/certs.go')
| -rw-r--r-- | vendor/golang.org/x/crypto/ssh/certs.go | 26 |
1 files changed, 17 insertions, 9 deletions
diff --git a/vendor/golang.org/x/crypto/ssh/certs.go b/vendor/golang.org/x/crypto/ssh/certs.go index a3dc629c6..139fa31e1 100644 --- a/vendor/golang.org/x/crypto/ssh/certs.go +++ b/vendor/golang.org/x/crypto/ssh/certs.go @@ -233,7 +233,11 @@ func parseCert(in []byte, privAlgo string) (*Certificate, error) { if err != nil { return nil, err } - + // The Type() function is intended to return only certificate key types, but + // we use certKeyAlgoNames anyway for safety, to match [Certificate.Type]. + if _, ok := certKeyAlgoNames[k.Type()]; ok { + return nil, fmt.Errorf("ssh: the signature key type %q is invalid for certificates", k.Type()) + } c.SignatureKey = k c.Signature, rest, ok = parseSignatureBody(g.Signature) if !ok || len(rest) > 0 { @@ -301,16 +305,13 @@ type CertChecker struct { 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. + // authority for user certificate. 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. + // an authority for this host. 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 @@ -447,12 +448,19 @@ func (c *CertChecker) CheckCert(principal string, cert *Certificate) error { // SignCert signs the certificate with an authority, setting the Nonce, // SignatureKey, and Signature fields. If the authority implements the // MultiAlgorithmSigner interface the first algorithm in the list is used. This -// is useful if you want to sign with a specific algorithm. +// is useful if you want to sign with a specific algorithm. As specified in +// [SSH-CERTS], Section 2.1.1, authority can't be a [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 } + // The Type() function is intended to return only certificate key types, but + // we use certKeyAlgoNames anyway for safety, to match [Certificate.Type]. + if _, ok := certKeyAlgoNames[authority.PublicKey().Type()]; ok { + return fmt.Errorf("ssh: certificates cannot be used as authority (public key type %q)", + authority.PublicKey().Type()) + } c.SignatureKey = authority.PublicKey() if v, ok := authority.(MultiAlgorithmSigner); ok { |