Test framework for LibGit2 credential callback

base/libgit2/callbacks.jl

@@ -261,3 +261,56 @@ mirror_cb() = cfunction(mirror_callback, Cint, (Ptr{Ptr{Void}}, Ptr{Void}, Cstri
 credentials_cb() = cfunction(credentials_callback, Cint, (Ptr{Ptr{Void}}, Cstring, Cstring, Cuint, Ptr{Void}))
 "C function pointer for `fetchhead_foreach_callback`"
 fetchhead_foreach_cb() = cfunction(fetchhead_foreach_callback, Cint, (Cstring, Cstring, Ptr{GitHash}, Cuint, Ptr{Void}))
+
+"""
+Emulates the LibGit2 credential loop to allows testing of the credential_callback function
+without having to authenticate against a real server.
+"""
+function credential_loop(
+        valid_credential::AbstractCredentials,
+        url::AbstractString,
+        user::AbstractString,
+        allowed_types::UInt32)
+    cb = credentials_cb()
+    libgitcred_ptr_ptr = Ref{Ptr{Void}}(C_NULL)
+    cache = CachedCredentials()
+    payload_ptr = Ref(Nullable{AbstractCredentials}(cache))
+
+    # Number of times credentials were authenticated against. With the real LibGit2
+    # credential loop this would be how many times we sent credentials to the remote.
+    num_authentications = 0
+
+    # Emulate how LibGit2 uses the credential callback by repeatedly calling the function
+    # until we find valid credentials or an exception is raised.
+    err = Cint(0)
+    while err == 0
+        err = ccall(cb, Cint, (Ptr{Ptr{Void}}, Cstring, Cstring, Cuint, Ptr{Void}),
+            libgitcred_ptr_ptr, url, isempty(user) ? C_NULL : user, allowed_types, pointer_from_objref(payload_ptr))
+        num_authentications += 1
+
+        # Check if the callback provided us with valid credentials
+        if length(cache.cred) == 1 && first(values(cache.cred)) == valid_credential
+            break
+        end
+
+        if num_authentications > 50
+            error("Credential callback seems to be caught in an infinite loop")
+        end
+    end
+
+    return err, num_authentications
+end
+
+function credential_loop(
+        valid_credential::UserPasswordCredentials,
+        url::AbstractString,
+        user::AbstractString="")
+    credential_loop(valid_credential, url, user, 0x000001)
+end
+
+function credential_loop(
+        valid_credential::SSHCredentials,
+        url::AbstractString,
+        user::AbstractString="")
+    credential_loop(valid_credential, url, user, 0x000046)
+end

base/libgit2/types.jl

@@ -670,32 +670,46 @@ function securezero!(cred::UserPasswordCredentials)
     return cred
 end
 
+function Base.:(==)(a::UserPasswordCredentials, b::UserPasswordCredentials)
+    a.user == b.user && a.pass == b.pass
+end
+
 "SSH credentials type"
 mutable struct SSHCredentials <: AbstractCredentials
     user::String
     pass::String
-    pubkey::String
     prvkey::String
+    pubkey::String
     usesshagent::String  # used for ssh-agent authentication
     prompt_if_incorrect::Bool    # Whether to allow interactive prompting if the credentials are incorrect
     count::Int
-
-    function SSHCredentials(u::AbstractString,p::AbstractString,prompt_if_incorrect::Bool=false)
-        c = new(u,p,"","","Y",prompt_if_incorrect,3)
+    function SSHCredentials(u::AbstractString,p::AbstractString,prvkey::AbstractString,pubkey::AbstractString,prompt_if_incorrect::Bool=false)
+        c = new(u,p,prvkey,pubkey,"Y",prompt_if_incorrect,3)
         finalizer(c, securezero!)
         return c
     end
-    SSHCredentials(prompt_if_incorrect::Bool=false) = SSHCredentials("","",prompt_if_incorrect)
+    SSHCredentials(u::AbstractString,p::AbstractString,prompt_if_incorrect::Bool=false) = SSHCredentials(u,p,prompt_if_incorrect)
+    SSHCredentials(prompt_if_incorrect::Bool=false) = SSHCredentials("","","","",prompt_if_incorrect)
 end
+
 function securezero!(cred::SSHCredentials)
     securezero!(cred.user)
     securezero!(cred.pass)
-    securezero!(cred.pubkey)
     securezero!(cred.prvkey)
+    securezero!(cred.pubkey)
     cred.count = 0
     return cred
 end
 
+function Base.:(==)(a::SSHCredentials, b::SSHCredentials)
+    return (
+        a.user == b.user &&
+        a.pass == b.pass &&
+        a.prvkey == b.prvkey &&
+        a.pubkey == b.pubkey
+    )
+end
+
 "Credentials that support caching"
 mutable struct CachedCredentials <: AbstractCredentials
     cred::Dict{String,AbstractCredentials}