open-vault/vendor/github.com/dgrijalva/jwt-go/v4/hmac.go
Lauren Voswinkel 7189a67a33
Adding snowflake as a bundled database secrets plugin (#10603)
* Adding snowflake as a bundled database secrets plugin

* Add snowflake-database-plugin to expected bundled plugins

* Add snowflake plugin name to the mockBuiltinRegistry
2021-01-07 09:30:24 -08:00

98 lines
2.4 KiB
Go

package jwt
import (
"crypto"
"crypto/hmac"
"errors"
)
// SigningMethodHMAC implements the HMAC-SHA family of signing methods
// Expects key type of []byte for both signing and validation
type SigningMethodHMAC struct {
Name string
Hash crypto.Hash
}
// Specific instances for HS256 and company
var (
SigningMethodHS256 *SigningMethodHMAC
SigningMethodHS384 *SigningMethodHMAC
SigningMethodHS512 *SigningMethodHMAC
ErrSignatureInvalid = errors.New("signature is invalid")
)
func init() {
// HS256
SigningMethodHS256 = &SigningMethodHMAC{"HS256", crypto.SHA256}
RegisterSigningMethod(SigningMethodHS256.Alg(), func() SigningMethod {
return SigningMethodHS256
})
// HS384
SigningMethodHS384 = &SigningMethodHMAC{"HS384", crypto.SHA384}
RegisterSigningMethod(SigningMethodHS384.Alg(), func() SigningMethod {
return SigningMethodHS384
})
// HS512
SigningMethodHS512 = &SigningMethodHMAC{"HS512", crypto.SHA512}
RegisterSigningMethod(SigningMethodHS512.Alg(), func() SigningMethod {
return SigningMethodHS512
})
}
// Alg implements SigningMethod
func (m *SigningMethodHMAC) Alg() string {
return m.Name
}
// Verify the signature of HSXXX tokens. Returns nil if the signature is valid.
func (m *SigningMethodHMAC) Verify(signingString, signature string, key interface{}) error {
// Verify the key is the right type
keyBytes, ok := key.([]byte)
if !ok {
return NewInvalidKeyTypeError("[]byte", key)
}
// Decode signature, for comparison
sig, err := DecodeSegment(signature)
if err != nil {
return err
}
// Can we use the specified hashing method?
if !m.Hash.Available() {
return ErrHashUnavailable
}
// This signing method is symmetric, so we validate the signature
// by reproducing the signature from the signing string and key, then
// comparing that against the provided signature.
hasher := hmac.New(m.Hash.New, keyBytes)
hasher.Write([]byte(signingString))
if !hmac.Equal(sig, hasher.Sum(nil)) {
return ErrSignatureInvalid
}
// No validation errors. Signature is good.
return nil
}
// Sign implements the Sign method from SigningMethod
// Key must be []byte
func (m *SigningMethodHMAC) Sign(signingString string, key interface{}) (string, error) {
keyBytes, ok := key.([]byte)
if !ok {
return "", NewInvalidKeyTypeError("[]byte", key)
}
if !m.Hash.Available() {
return "", ErrHashUnavailable
}
hasher := hmac.New(m.Hash.New, keyBytes)
hasher.Write([]byte(signingString))
return EncodeSegment(hasher.Sum(nil)), nil
}