private static byte[] sshBufferReadBlock(ByteArrayInputStream in) throws IOException {
		int len = sshBufferReadUInt32(in);
		if (len <= 0 || len > in.available()) {
			throw new IOException("insufficient data");
		}
		return in.readNBytes(len);
	}
Read block of data from SSH-encoded buffer.
(modeled after org.bouncycastle.crypto.util.SSHBuffer.readBlock())
@param in data input stream
@return byte array
@throws IOException if IO error occurs reading input stream or inadequate 
bytes are available.
Ghidra/Features/GhidraServer/src/main/java/ghidra/server/security/SSHAuthenticationModule.java