Answered: Problem with SignedData.Decode when verify is done with sign -outform pem using openssl

Hello,

There is only slight but important difference between OpenSSL's der and pem formats. The DER file only contains binary ASN.1 data. The PEM file contain the same data, but Base-64 encoded, with a header and a footer. Rebex SignedData and EnvelopedData are currently unable to parse this - we'll add support for it to one of the next releases.

In the meantime, you can work around the issue by converting a PEM string loaded from a PEM file to DER data:

public static byte[] DecodeBase64(string text, out string typeName, out string info)
{
    if (!text.StartsWith("-----BEGIN ", StringComparison.Ordinal))
        throw new FormatException("Invalid header.");

    text = text.Replace("\r", "").TrimEnd('\0').Trim();

    int p = text.IndexOf('\n', 11, 64);
    if (p < 8)
        throw new FormatException("Invalid header length.");

    string type = text.Substring(11, p - 11);
    type = type.TrimEnd();

    if (!type.EndsWith("-----", StringComparison.Ordinal))
        throw new FormatException("Invalid header length.");

    typeName = type.Substring(0, type.Length - 5);

    string end = "-----END " + typeName + "-----";
    if (!text.EndsWith(end, StringComparison.Ordinal))
        throw new FormatException("Invalid footer.");

    for (int i = 0; i < text.Length; i++)
    {
        int c = text[i];
        if (c == '\n' || c == '\t')
            continue;

        if (c < 32 || c > 127)
            throw new FormatException(StringUtil.Format("Invalid character {0} at position {1}.", c, i));
    }

    text = text.Substring(end.Length + 2, text.Length - 2 - 2 * end.Length);

    int e = text.IndexOf("\n\n", StringComparison.Ordinal);
    if (e > 0)
    {
        info = text.Substring(0, e).Trim();
        text = text.Substring(e + 2);
    }
    else
    {
        info = null;
    }

    return Convert.FromBase64String(text);
}