chore: README

README.md

@@ -10,7 +10,91 @@ SwiftSRP
 
 ### About
 
-...
+Implementation of the Secure Remote Password protocol (SRP) - RFC 5054 for Swift.
+
+**Supported Hash Algorithms:**
+
+ - SHA-1
+ - SHA-224
+ - SHA-256
+ - SHA-384
+ - SHA-512
+
+**Supported Group Parameters:**
+
+ - 1024 bits
+ - 1536 bits
+ - 2048 bits
+ - 3072 bits
+ - 4096 bits
+ - 6144 bits
+ - 8192 bits
+
+### Example Usage
+
+```swift
+
+import Foundation
+import SwiftSRP
+
+// Server storage
+var salt:     Data!
+var verifier: Data!
+
+/* Registration */
+// Create a SRP client for an identity, with a given hash algorithm and group type
+let client = SRPClient( identity: account.identity, hashAlgorithm: .SHA256, groupType: .NG2048 )
+
+// User registers with a password
+client.setPassword( string: account.password )
+
+// Client generates a salt
+client.salt = SRPRandom.bytes( count: 16 )
+
+// Client -> Server:
+// Server receives salt and verifier from Client
+// Client can then discard them
+salt     = client.salt
+verifier = client.v.bytes( endianness: .bigEndian )
+
+/* Authentication */
+let client = SRPClient( identity: account.identity, hashAlgorithm: .SHA256, groupType: .NG2048 )
+let server = SRPServer( identity: account.identity, hashAlgorithm: .SHA256, groupType: .NG2048 )
+
+// Server has stored salt and verifier during registration (see above)
+server.v    = SRPBigNum( data: verifier, endianness: .bigEndian )
+server.salt = salt
+
+// Client -> Server:
+// Server receives A from Client
+server.A = client.A
+
+// Server -> Client:
+// Client receives B and salt from Server
+client.B    = server.B
+client.salt = server.salt
+
+// User inputs a wrong password
+client.setPassword( string: "salad" )
+
+// Client and Server will not have matching M1 and M2, meaning the authentication failed
+AssertFalse( client.M1 == server.M1 )
+AssertFalse( client.M2 == server.M2 )
+
+// User inputs the correct password
+client.setPassword( string: account.password )
+
+// With the correct password, Client and Server will have matching M1 and M2, meaning the authentication was successful
+AssertTrue( client.M1 == server.M1 )
+AssertTrue( client.M2 == server.M2 )
+
+```
+
+Requirements
+------------
+
+This project requires OpenSSL.  
+A pre-built version of BoringSSL is provided for macOS in the `Submodules/SRPXX/Submodules/BoringSSL/lib` directory.
 
 License
 -------