公钥:"MIGfMA0GCSqGSIb3DQEBAQUAA4GNADCBiQKBgQC-LWbJvb1nU1guxNEdl9QvVafrahSHOSn1ahHheHveMsCxG_tGU4wRJGOPbfXavvvAUcDqWB56piKidrfT2c5t5hAR8l5ov1Q_d-NJrMVSvx5xOiQ_N8YwbyUOIcgCbccqbVZk2M2uE4Bb3JR7wn8hCCm-RhCIKEt0QKDNNKv6CQIDAQAB"
FromBase64String会直接报错{"输入的不是有效的 Base-64 字符串,因为它包含非 Base-64 字符、两个以上的填充字符,或者填充字符间包含非法字符。"}
key = key.Replace('-', '+').Replace('_', '/');