Inconsistence usage of type KeySizes in AesGcm (size in byte vs. size in bit)

[dhcgn]

In AesGcm.cs the properties NonceByteSizes and TagByteSizes represents the size in Byte.

runtime/src/libraries/System.Security.Cryptography.Algorithms/src/System/Security/Cryptography/AesGcm.cs

Lines 11 to 13 in 4f9ae42

	private const int NonceSize = 12;
	public static KeySizes NonceByteSizes { get; } = new KeySizes(NonceSize, NonceSize, 1);
	public static KeySizes TagByteSizes { get; } = new KeySizes(12, 16, 1);

But the used type KeySizes represent valid key sizes in Bit.

<summary>Specifies the maximum key size in bits.</summary>
<value>The maximum key size in bits.</value>

see https://github.com/dotnet/dotnet-api-docs/blob/01e31683fa1feea031c94a1243b01d8ee0255a6d/xml/System.Security.Cryptography/KeySizes.xml#L135

In the namespace System.Security.Cryptography properties like "Size" vary between amount of bit and bytes. In this case the documentation is not consistent with the name of the property, ByteSizes to Specifies the maximum key size in bits.

I hope this description meets your quality standards for new issues.

[vcsjones]

I see. The properties of KeySizes are documented as returned values in bits while AesGcm and AesCcm use it to represent octets.

The properties on AesGcm and AesCcm have "Byte" in their name, perhaps to try and be super clear they really are bytes.

If anything were to be changed, I think the only thing that can realistically be done is relax the documentation of KeySizes properties to not specify bits / bytes and add documentation in the members the use KeySizes.

/cc @bartonjs @krwq

[krwq]

Yes agreed, since we already shipped like that I guess the only reasonable option is to update the docs and consider adding second API which returns values in Bits 🙄