go-srp | Automatically exported from code.google.com/p/go-srp

In order to authenticate and derive session keys, verifiers must be stored in a non-volatile medium on the server. The verifiers are generated once when a "user" is created on the server. The Client is the entity where the user enters their password and wishes to be authenticated with a SRP server. The communication between client and server can happen in clear text - SRP is immune to man in the middle attacks. The client and server need to agree a-priori on the number of bits to be used for the common "safe prime". It is acceptable to use 2048 or 4096 for this value. Each verifier can have a different number of safe prime bits - but it must be recorded along with the verifier. Every authentication attempt must use the same bit-size for the safe prime previously recorded for that verifier. Note that Ih is the hashed identity string for username.