libfreerdp-auth: client signing and sealing

diff --git a/libfreerdp-auth/NTLM/ntlm.h b/libfreerdp-auth/NTLM/ntlm.h
index b0f360e..fbb07e0 100644 (file)
--- a/libfreerdp-auth/NTLM/ntlm.h
+++ b/libfreerdp-auth/NTLM/ntlm.h
@@ -21,6 +21,7 @@
 #define FREERDP_AUTH_NTLM_PRIVATE_H
 
 #include <freerdp/auth/sspi.h>
+#include <freerdp/crypto/crypto.h>
 
 #include <freerdp/utils/unicode.h>
 
@@ -79,7 +80,11 @@ struct _NTLM_CONTEXT
        boolean ntlm_v2;
        NTLM_STATE state;
        UNICONV* uniconv;
+       int send_seq_num;
+       int recv_seq_num;
        AV_PAIRS* av_pairs;
+       CryptoRc4 send_rc4_seal;
+       CryptoRc4 recv_rc4_seal;
        uint32 NegotiateFlags;
        uint16* Workstation;
        uint32 WorkstationLength;

diff --git a/libfreerdp-auth/NTLM/ntlm_compute.c b/libfreerdp-auth/NTLM/ntlm_compute.c
index e6840c9..4aeabf3 100644 (file)
--- a/libfreerdp-auth/NTLM/ntlm_compute.c
+++ b/libfreerdp-auth/NTLM/ntlm_compute.c
@@ -26,6 +26,7 @@
 #include <openssl/hmac.h>
 #include <openssl/rand.h>
 #include <openssl/engine.h>
+#include <freerdp/crypto/crypto.h>
 
 #include <freerdp/utils/stream.h>
 #include <freerdp/utils/memory.h>
@@ -48,6 +49,13 @@ const char* const AV_PAIRS_STRINGS[] =
        "MsvChannelBindings"
 };
 
+static const char lm_magic[] = "KGS!@#$%";
+
+static const char client_sign_magic[] = "session key to client-to-server signing key magic constant";
+static const char server_sign_magic[] = "session key to server-to-client signing key magic constant";
+static const char client_seal_magic[] = "session key to client-to-server sealing key magic constant";
+static const char server_seal_magic[] = "session key to server-to-client sealing key magic constant";
+
 /**
  * Output Restriction_Encoding.\n
  * Restriction_Encoding @msdn{cc236647}
@@ -663,3 +671,212 @@ void ntlm_compute_ntlm_v2_response(NTLM_CONTEXT* context)
        sspi_SecBufferFree(&ntlm_v2_temp);
        sspi_SecBufferFree(&ntlm_v2_temp_chal);
 }
+
+/**
+ * Encrypt the given plain text using RC4 and the given key.
+ * @param key RC4 key
+ * @param length text length
+ * @param plaintext plain text
+ * @param ciphertext cipher text
+ */
+
+void ntlm_rc4k(uint8* key, int length, uint8* plaintext, uint8* ciphertext)
+{
+       CryptoRc4 rc4;
+
+       /* Initialize RC4 cipher with key */
+       rc4 = crypto_rc4_init((void*) key, 16);
+
+       /* Encrypt plaintext with key */
+       crypto_rc4(rc4, length, (void*) plaintext, (void*) ciphertext);
+
+       /* Free RC4 Cipher */
+       crypto_rc4_free(rc4);
+}
+
+/**
+ * Generate client challenge (8-byte nonce).
+ * @param NTLM context
+ */
+
+void ntlm_generate_client_challenge(NTLM_CONTEXT* context)
+{
+       /* ClientChallenge is used in computation of LMv2 and NTLMv2 responses */
+       crypto_nonce(context->ClientChallenge, 8);
+}
+
+/**
+ * Generate server challenge (8-byte nonce).
+ * @param NTLM context
+ */
+
+void ntlm_generate_server_challenge(NTLM_CONTEXT* context)
+{
+       crypto_nonce(context->ServerChallenge, 8);
+}
+
+/**
+ * Generate KeyExchangeKey (the 128-bit SessionBaseKey).\n
+ * @msdn{cc236710}
+ * @param NTLM context
+ */
+
+void ntlm_generate_key_exchange_key(NTLM_CONTEXT* context)
+{
+       /* In NTLMv2, KeyExchangeKey is the 128-bit SessionBaseKey */
+       memcpy(context->KeyExchangeKey, context->SessionBaseKey, 16);
+}
+
+/**
+ * Generate RandomSessionKey (16-byte nonce).
+ * @param NTLM context
+ */
+
+void ntlm_generate_random_session_key(NTLM_CONTEXT* context)
+{
+       crypto_nonce(context->RandomSessionKey, 16);
+}
+
+/**
+ * Generate ExportedSessionKey (the RandomSessionKey, exported)
+ * @param NTLM context
+ */
+
+void ntlm_generate_exported_session_key(NTLM_CONTEXT* context)
+{
+       memcpy(context->ExportedSessionKey, context->RandomSessionKey, 16);
+}
+
+/**
+ * Encrypt RandomSessionKey (RC4-encrypted RandomSessionKey, using KeyExchangeKey as the key).
+ * @param NTLM context
+ */
+
+void ntlm_encrypt_random_session_key(NTLM_CONTEXT* context)
+{
+       /* In NTLMv2, EncryptedRandomSessionKey is the ExportedSessionKey RC4-encrypted with the KeyExchangeKey */
+       ntlm_rc4k(context->KeyExchangeKey, 16, context->RandomSessionKey, context->EncryptedRandomSessionKey);
+}
+
+/**
+ * Generate signing key.\n
+ * @msdn{cc236711}
+ * @param exported_session_key ExportedSessionKey
+ * @param sign_magic Sign magic string
+ * @param signing_key Destination signing key
+ */
+
+void ntlm_generate_signing_key(uint8* exported_session_key, SEC_BUFFER* sign_magic, uint8* signing_key)
+{
+       int length;
+       uint8* value;
+       CryptoMd5 md5;
+
+       length = 16 + sign_magic->cbBuffer;
+       value = (uint8*) xmalloc(length);
+
+       /* Concatenate ExportedSessionKey with sign magic */
+       memcpy(value, exported_session_key, 16);
+       memcpy(&value[16], sign_magic->pvBuffer, sign_magic->cbBuffer);
+
+       md5 = crypto_md5_init();
+       crypto_md5_update(md5, value, length);
+       crypto_md5_final(md5, signing_key);
+
+       xfree(value);
+}
+
+/**
+ * Generate client signing key (ClientSigningKey).\n
+ * @msdn{cc236711}
+ * @param NTLM context
+ */
+
+void ntlm_generate_client_signing_key(NTLM_CONTEXT* context)
+{
+       SEC_BUFFER sign_magic;
+       sign_magic.pvBuffer = (void*) client_sign_magic;
+       sign_magic.cbBuffer = sizeof(client_sign_magic);
+       ntlm_generate_signing_key(context->ExportedSessionKey, &sign_magic, context->ClientSigningKey);
+}
+
+/**
+ * Generate server signing key (ServerSigningKey).\n
+ * @msdn{cc236711}
+ * @param NTLM context
+ */
+
+void ntlm_generate_server_signing_key(NTLM_CONTEXT* context)
+{
+       SEC_BUFFER sign_magic;
+       sign_magic.pvBuffer = (void*) server_sign_magic;
+       sign_magic.cbBuffer = sizeof(server_sign_magic);
+       ntlm_generate_signing_key(context->ExportedSessionKey, &sign_magic, context->ServerSigningKey);
+}
+
+/**
+ * Generate sealing key.\n
+ * @msdn{cc236712}
+ * @param exported_session_key ExportedSessionKey
+ * @param seal_magic Seal magic string
+ * @param sealing_key Destination sealing key
+ */
+
+void ntlm_generate_sealing_key(uint8* exported_session_key, SEC_BUFFER* seal_magic, uint8* sealing_key)
+{
+       uint8* p;
+       CryptoMd5 md5;
+       SEC_BUFFER buffer;
+
+       sspi_SecBufferAlloc(&buffer, 16 + seal_magic->cbBuffer);
+       p = (uint8*) buffer.pvBuffer;
+
+       /* Concatenate ExportedSessionKey with seal magic */
+       memcpy(p, exported_session_key, 16);
+       memcpy(&p[16], seal_magic->pvBuffer, seal_magic->cbBuffer);
+
+       md5 = crypto_md5_init();
+       crypto_md5_update(md5, buffer.pvBuffer, buffer.cbBuffer);
+       crypto_md5_final(md5, sealing_key);
+
+       sspi_SecBufferFree(&buffer);
+}
+
+/**
+ * Generate client sealing key (ClientSealingKey).\n
+ * @msdn{cc236712}
+ * @param NTLM context
+ */
+
+void ntlm_generate_client_sealing_key(NTLM_CONTEXT* context)
+{
+       SEC_BUFFER seal_magic;
+       seal_magic.pvBuffer = (void*) client_seal_magic;
+       seal_magic.cbBuffer = sizeof(client_seal_magic);
+       ntlm_generate_signing_key(context->ExportedSessionKey, &seal_magic, context->ClientSealingKey);
+}
+
+/**
+ * Generate server sealing key (ServerSealingKey).\n
+ * @msdn{cc236712}
+ * @param NTLM context
+ */
+
+void ntlm_generate_server_sealing_key(NTLM_CONTEXT* context)
+{
+       SEC_BUFFER seal_magic;
+       seal_magic.pvBuffer = (void*) server_seal_magic;
+       seal_magic.cbBuffer = sizeof(server_seal_magic);
+       ntlm_generate_signing_key(context->ExportedSessionKey, &seal_magic, context->ServerSealingKey);
+}
+
+/**
+ * Initialize RC4 stream cipher states for sealing.
+ * @param NTLM context
+ */
+
+void ntlm_init_rc4_seal_states(NTLM_CONTEXT* context)
+{
+       context->send_rc4_seal = crypto_rc4_init(context->ClientSealingKey, 16);
+       context->recv_rc4_seal = crypto_rc4_init(context->ServerSealingKey, 16);
+}

diff --git a/libfreerdp-auth/NTLM/ntlm_compute.h b/libfreerdp-auth/NTLM/ntlm_compute.h
index 5b484d5..fc4e78b 100644 (file)
--- a/libfreerdp-auth/NTLM/ntlm_compute.h
+++ b/libfreerdp-auth/NTLM/ntlm_compute.h
@@ -40,5 +40,19 @@ void ntlm_compute_ntlm_v2_hash(NTLM_CONTEXT* context, char* hash);
 void ntlm_compute_lm_v2_response(NTLM_CONTEXT* context);
 void ntlm_compute_ntlm_v2_response(NTLM_CONTEXT* context);
 
+void ntlm_rc4k(uint8* key, int length, uint8* plaintext, uint8* ciphertext);
+void ntlm_generate_client_challenge(NTLM_CONTEXT* context);
+void ntlm_generate_server_challenge(NTLM_CONTEXT* context);
+void ntlm_generate_key_exchange_key(NTLM_CONTEXT* context);
+void ntlm_generate_random_session_key(NTLM_CONTEXT* context);
+void ntlm_generate_exported_session_key(NTLM_CONTEXT* context);
+void ntlm_encrypt_random_session_key(NTLM_CONTEXT* context);
+
+void ntlm_generate_client_signing_key(NTLM_CONTEXT* context);
+void ntlm_generate_server_signing_key(NTLM_CONTEXT* context);
+void ntlm_generate_client_sealing_key(NTLM_CONTEXT* context);
+void ntlm_generate_server_sealing_key(NTLM_CONTEXT* context);
+void ntlm_init_rc4_seal_states(NTLM_CONTEXT* context);
+
 #endif /*  FREERDP_AUTH_NTLM_COMPUTE_H */
 

diff --git a/libfreerdp-auth/NTLM/ntlm_message.c b/libfreerdp-auth/NTLM/ntlm_message.c
index 96b094f..ec5e13b 100644 (file)
--- a/libfreerdp-auth/NTLM/ntlm_message.c
+++ b/libfreerdp-auth/NTLM/ntlm_message.c
@@ -352,7 +352,6 @@ SECURITY_STATUS ntlm_read_ChallengeMessage(NTLM_CONTEXT* context, SEC_BUFFER* bu
        /* NtChallengeResponse */
        ntlm_compute_ntlm_v2_response(context);
 
-#if 0
        /* KeyExchangeKey */
        ntlm_generate_key_exchange_key(context);
 
@@ -408,8 +407,6 @@ SECURITY_STATUS ntlm_read_ChallengeMessage(NTLM_CONTEXT* context, SEC_BUFFER* bu
        printf("\n");
 #endif
 
-#endif
-
        context->state = NTLM_STATE_AUTHENTICATE;
 
        return SEC_I_CONTINUE_NEEDED;