libcli/auth: add support for AES/HMAC-SHA256 schannel session key support

metze

Signed-off-by: Günther Deschner <gd@samba.org>

diff --git a/libcli/auth/credentials.c b/libcli/auth/credentials.c
index 81304764a8c5a49aaa8f6bb43b242df0969ddc0b..dfbfdb356aa65abc3027f4581491a685a15d43f1 100644 (file)
--- a/libcli/auth/credentials.c
+++ b/libcli/auth/credentials.c
@@ -30,7 +30,17 @@ static void netlogon_creds_step_crypt(struct netlogon_creds_CredentialState *cre
                                      const struct netr_Credential *in,
                                      struct netr_Credential *out)
 {
-       des_crypt112(out->data, in->data, creds->session_key, 1);
+       if (creds->negotiate_flags & NETLOGON_NEG_SUPPORTS_AES) {
+               AES_KEY key;
+               uint8_t iv[AES_BLOCK_SIZE];
+
+               AES_set_encrypt_key(creds->session_key, 128, &key);
+               ZERO_STRUCT(iv);
+
+               aes_cfb8_encrypt(in->data, out->data, 8, &key, iv, AES_ENCRYPT);
+       } else {
+               des_crypt112(out->data, in->data, creds->session_key, 1);
+       }
 }
 
 /*
@@ -85,6 +95,34 @@ static void netlogon_creds_init_128bit(struct netlogon_creds_CredentialState *cr
        hmac_md5_final(creds->session_key, &ctx);
 }
 
+/*
+  initialise the credentials state for AES/HMAC-SHA256-style 128 bit session keys
+
+  this call is made after the netr_ServerReqChallenge call
+*/
+static void netlogon_creds_init_hmac_sha256(struct netlogon_creds_CredentialState *creds,
+                                           const struct netr_Credential *client_challenge,
+                                           const struct netr_Credential *server_challenge,
+                                           const struct samr_Password *machine_password)
+{
+       struct HMACSHA256Context ctx;
+       uint8_t digest[SHA256_DIGEST_LENGTH];
+
+       ZERO_STRUCT(creds->session_key);
+
+       hmac_sha256_init(machine_password->hash,
+                        sizeof(machine_password->hash),
+                        &ctx);
+       hmac_sha256_update(client_challenge->data, 8, &ctx);
+       hmac_sha256_update(server_challenge->data, 8, &ctx);
+       hmac_sha256_final(digest, &ctx);
+
+       memcpy(creds->session_key, digest, sizeof(creds->session_key));
+
+       ZERO_STRUCT(digest);
+       ZERO_STRUCT(ctx);
+}
+
 static void netlogon_creds_first_step(struct netlogon_creds_CredentialState *creds,
                                      const struct netr_Credential *client_challenge,
                                      const struct netr_Credential *server_challenge)
@@ -227,7 +265,12 @@ struct netlogon_creds_CredentialState *netlogon_creds_client_init(TALLOC_CTX *me
        dump_data_pw("Server chall", server_challenge->data, sizeof(server_challenge->data));
        dump_data_pw("Machine Pass", machine_password->hash, sizeof(machine_password->hash));
 
-       if (negotiate_flags & NETLOGON_NEG_128BIT) {
+       if (negotiate_flags & NETLOGON_NEG_SUPPORTS_AES) {
+               netlogon_creds_init_hmac_sha256(creds,
+                                               client_challenge,
+                                               server_challenge,
+                                               machine_password);
+       } else if (negotiate_flags & NETLOGON_NEG_STRONG_KEYS) {
                netlogon_creds_init_128bit(creds, client_challenge, server_challenge, machine_password);
        } else {
                netlogon_creds_init_64bit(creds, client_challenge, server_challenge, machine_password);
@@ -338,6 +381,10 @@ struct netlogon_creds_CredentialState *netlogon_creds_server_init(TALLOC_CTX *me
        creds->negotiate_flags = negotiate_flags;
        creds->secure_channel_type = secure_channel_type;
 
+       dump_data_pw("Client chall", client_challenge->data, sizeof(client_challenge->data));
+       dump_data_pw("Server chall", server_challenge->data, sizeof(server_challenge->data));
+       dump_data_pw("Machine Pass", machine_password->hash, sizeof(machine_password->hash));
+
        creds->computer_name = talloc_strdup(creds, client_computer_name);
        if (!creds->computer_name) {
                talloc_free(creds);
@@ -349,7 +396,12 @@ struct netlogon_creds_CredentialState *netlogon_creds_server_init(TALLOC_CTX *me
                return NULL;
        }
 
-       if (negotiate_flags & NETLOGON_NEG_128BIT) {
+       if (negotiate_flags & NETLOGON_NEG_SUPPORTS_AES) {
+               netlogon_creds_init_hmac_sha256(creds,
+                                               client_challenge,
+                                               server_challenge,
+                                               machine_password);
+       } else if (negotiate_flags & NETLOGON_NEG_STRONG_KEYS) {
                netlogon_creds_init_128bit(creds, client_challenge, server_challenge, 
                                           machine_password);
        } else {
@@ -359,6 +411,12 @@ struct netlogon_creds_CredentialState *netlogon_creds_server_init(TALLOC_CTX *me
 
        netlogon_creds_first_step(creds, client_challenge, server_challenge);
 
+       dump_data_pw("Session key", creds->session_key, 16);
+       dump_data_pw("Client Credential ", creds->client.data, 8);
+       dump_data_pw("Server Credential ", creds->server.data, 8);
+
+       dump_data_pw("Credentials in", credentials_in->data, sizeof(credentials_in->data));
+
        /* And before we leak information about the machine account
         * password, check that they got the first go right */
        if (!netlogon_creds_server_check_internal(creds, credentials_in)) {
@@ -368,6 +426,8 @@ struct netlogon_creds_CredentialState *netlogon_creds_server_init(TALLOC_CTX *me
 
        *credentials_out = creds->server;
 
+       dump_data_pw("Credentials out", credentials_out->data, sizeof(credentials_out->data));
+
        return creds;
 }