Specifies the login/username to use when connecting to a proxy server.

A Long value. If successful, 0 is returned, otherwise error as specified here. 

long Sftp_GetProxyLogin(void *Sftp, char *Buffer, int *Bufsize);
long Sftp_SetProxyLogin(void *Sftp, char *newVal);

The ProxyLogin function syntax has these parts:

This function specifies the Login (username) to use when connecting to a remote server through a proxy server. As some proxy servers require authorization for access, the ProxyLogin and ProxyPassword properties enable the user to specify their logon name and password for the proxy server.

Among all of the supported proxies, only Socks 4, Socks 5, ProxyWEBStandard and ProxyWEBNtlmAuth protocols support authorization of this type.

The Bufsize variable should contain the maximum data length that can be stored in the Buffer variable. If you set Bufsize = 0, then the function will return with error ERROR_INSUFFICIENT_BUFFER and Bufsize will contain the required buffer size.