49 lines
1.3 KiB
Go
49 lines
1.3 KiB
Go
package crypto
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import (
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"crypto/sha256"
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"crypto/sha512"
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"encoding/base64"
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"errors"
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"fmt"
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"hash"
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jose "github.com/go-jose/go-jose/v4"
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)
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var ErrUnsupportedAlgorithm = errors.New("unsupported signing algorithm")
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func GetHashAlgorithm(sigAlgorithm jose.SignatureAlgorithm) (hash.Hash, error) {
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switch sigAlgorithm {
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case jose.RS256, jose.ES256, jose.PS256:
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return sha256.New(), nil
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case jose.RS384, jose.ES384, jose.PS384:
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return sha512.New384(), nil
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case jose.RS512, jose.ES512, jose.PS512:
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return sha512.New(), nil
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// There is no published spec for this yet, but we have confirmation it will get published.
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// There is consensus here: https://bitbucket.org/openid/connect/issues/1125/_hash-algorithm-for-eddsa-id-tokens
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// Currently Go and go-jose only supports the ed25519 curve key for EdDSA, so we can safely assume sha512 here.
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// It is unlikely ed448 will ever be supported: https://github.com/golang/go/issues/29390
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case jose.EdDSA:
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return sha512.New(), nil
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default:
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return nil, fmt.Errorf("%w: %q", ErrUnsupportedAlgorithm, sigAlgorithm)
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}
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}
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func HashString(hash hash.Hash, s string, firstHalf bool) string {
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if hash == nil {
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return s
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}
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//nolint:errcheck
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hash.Write([]byte(s))
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size := hash.Size()
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if firstHalf {
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size = size / 2
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}
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sum := hash.Sum(nil)[:size]
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return base64.RawURLEncoding.EncodeToString(sum)
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}
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