Ktor Client Digest Auth Missing "qop" and "end" tokens in "response" parameter. Not RFC2617 Compliant

Ktor Version and Engine Used (client or server and name) ktor-client-auth 1.2.5

Describe the bug

val client = HttpClient(Apache) {
    install(Auth) {
        digest {
            username = "user"
            password = "pass"
            realm = "realm"
       }
   }
}

Using this code does not properly handle Digest authentication. The reason why is located right here. The non-null qop should include the qop and the end variable in the token.

If you take a look at the RFC 2617 here, the request-digest states the following:

If the "qop" value is "auth" or "auth-int":

      request-digest  = <"> < KD ( H(A1),     unq(nonce-value)
                                          ":" nc-value
                                          ":" unq(cnonce-value)
                                          ":" unq(qop-value)
                                          ":" H(A2)
                                  ) <">

Notice the qop-value and H(A2) there. That’s what’s missing. Interestingly enough, it’s implemented correctly in the ktor server side code

It’s a simple enough fix and I’ve already forked and will work on a PR for this, but my VM is running out of memory trying to build the project so it may take a bit. But it really should be as simple as doing the following diff:

diff --git a/ktor-client/ktor-client-features/ktor-client-auth/common/src/io/ktor/client/features/auth/providers/DigestAuthProvider.kt b/ktor-client/ktor-client-features/ktor-client-auth/common/src/io/ktor/client/features/auth/providers/DigestAuthProvider.kt
index 6ed33248f..1a12248dc 100644
--- a/ktor-client/ktor-client-features/ktor-client-auth/common/src/io/ktor/client/features/auth/providers/DigestAuthProvider.kt
+++ b/ktor-client/ktor-client-features/ktor-client-auth/common/src/io/ktor/client/features/auth/providers/DigestAuthProvider.kt
@@ -83,7 +83,7 @@ class DigestAuthProvider(
 
         val start = hex(credential)
         val end = hex(makeDigest("$methodName:${url.encodedPath}"))
-        val tokenSequence = if (actualQop == null) listOf(start, nonce, end) else listOf(start, nonce, nonceCount, clientNonce)
+        val tokenSequence = if (actualQop == null) listOf(start, nonce, end) else listOf(start, nonce, nonceCount, clientNonce, actualQop, end)
         val token = makeDigest(tokenSequence.joinToString(":"))
 
         val auth = HttpAuthHeader.Parameterized(AuthScheme.Digest, linkedMapOf<String, String>().apply {

[cy6erGn0m]

Thank you for your investigation and detailed explanation

[e5l]

Merged.