GetCiphertextLengthCfb()

int System.Security.Cryptography.SymmetricAlgorithm.GetCiphertextLengthCfb ( int plaintextLength, PaddingMode paddingMode = PaddingMode::None, int feedbackSizeInBits = 8 )

inlineinherited

Definition at line 297 of file SymmetricAlgorithm.cs.

    {
        if (plaintextLength < 0)
        {
            throw new ArgumentOutOfRangeException("plaintextLength", System.SR.ArgumentOutOfRange_NeedNonNegNum);
        }
        if (feedbackSizeInBits <= 0)
        {
            throw new ArgumentOutOfRangeException("feedbackSizeInBits", System.SR.ArgumentOutOfRange_NeedPosNum);
        }
        if (((uint)feedbackSizeInBits & 7u) != 0)
        {
            throw new ArgumentException(System.SR.Argument_BitsMustBeWholeBytes, "feedbackSizeInBits");
        }
        int num = feedbackSizeInBits >> 3;
        int result;
        int num2 = Math.DivRem(plaintextLength, num, out result) * num;
        switch (paddingMode)
        {
        case PaddingMode.None:
            if (result != 0)
            {
                throw new ArgumentException(System.SR.Cryptography_MatchFeedbackSize, "plaintextLength");
            }
            goto IL_0083;
        case PaddingMode.Zeros:
            if (result == 0)
            {
                goto IL_0083;
            }
            goto case PaddingMode.PKCS7;
        case PaddingMode.PKCS7:
        case PaddingMode.ANSIX923:
        case PaddingMode.ISO10126:
            if (int.MaxValue - num2 < num)
            {
                throw new ArgumentOutOfRangeException("plaintextLength", System.SR.Cryptography_PlaintextTooLarge);
            }
            return num2 + num;
        default:
            {
                throw new ArgumentOutOfRangeException("paddingMode", System.SR.Cryptography_InvalidPaddingMode);
            }
            IL_0083:
            return plaintextLength;
        }
    }

References System.SR.Argument_BitsMustBeWholeBytes, System.SR.ArgumentOutOfRange_NeedNonNegNum, System.SR.ArgumentOutOfRange_NeedPosNum, System.SR.Cryptography_InvalidPaddingMode, System.SR.Cryptography_MatchFeedbackSize, System.SR.Cryptography_PlaintextTooLarge, and System.Math.DivRem().

Referenced by System.Security.Cryptography.SymmetricAlgorithm.EncryptCfb().