FromPolicy get all verifiers from VerificationPolicy.

ErrAlgorithmInvalid is returned the hash algorithm is not supported.

ErrDecodeKey is returned when the key cannot be decoded.

ErrEmptyKey is returned when the key doesn't contain data or keyRef.

ErrEmptyPublicKeys is returned when no public keys are founded.

ErrEmptySecretData is returned secret data is empty.

ErrFailedLoadKeyFile is returned the key file cannot be read.

ErrK8sSpecificationInvalid is returned when kubernetes specification format is invalid.

ErrLoadVerifier is returned when verifier cannot be loaded from the key.

ErrMultipleSecretData is returned secret contains multiple data.

ErrSecretNotFound is returned when the secret is not found.