Destructible Passwords in a Silverlight E-Commerce Application

I have a business requirement that calls for an end user to be able to login to a开发者_开发问答n e-commerce system with a one-time use password, purchase a course, and then never be able to login again. At the moment the company that is allowing their employees, my client's students, is going to generate that password for them and send me a list of the passwords they are generating.

I do not like the concept but I have yet to come up with a better one that will work for all parties. If something happens mid-purchase they have to go back to the company to get new login credentials.

The ability to purchase a course cannot be open to the public, it has to be through the e-commerce portal, and for the moment there is only one company participating but there will be more in the future. I am seeing this as a total maintenance nightmare.

My question is has anyone run across this before, if you wouldn't mind sharing tell me how you solved it, or point me in a direction that will give me some insight. I have googled the concept to death and have not come up with any bright ideas.

You can't resolve the "problem during purchase" issue yourself - They need to modify their service so that the password is destroyed when the transaction completes.

No matter what you do with regards to the password, once the user is logged in, the password is disabled on their servers. After that, you have no control.

They should either:

• Cancel password on transaction completion
• Provide you with an API/Web service to allow you to request a new key.

I have the answer for this one and document it here for my own personal OCD completion purposes. I created a login form that allows for a two part key; username is based on company name plus internal company ID(not a guid), paired with a password that is cryptic key, ex: @SCD6-, plus employee id generated by the company. The rub is I don't know what the employee ID is, and only use it because it should be unique although it doesn't matter if it is not, once the user logs in once completes the only marginally secure process then checks out the login is invalid and can never be used again, unless manually unlocked (in case of a duplicate employeeID at some time in the future, which is unlikely). The username and key is emailed to the employees of the target company, which is generated by the target company.If I do have the employeeID in the system which is 50/50 then I can pre-fill the forms out.

The only thing this lock protects is a process and not secure information so I am not too worried about security and it's only real purpose is to keep John Q, from stumbling onto the process and paying money that my client would need to refund later. If it were a secure data process I would not use this method.