Added comparibility with OpenSSL 1.0

autogen.sh

@@ -18,5 +18,4 @@ rm -f config.h config.h.in *~ Makefile configure #*
 
 echo "Wait please..."
 autoreconf -if
-echo ""
+./configure
-echo "Now run ./configure"

configure.seed

@@ -23,13 +23,17 @@ else
   N2N_LIBS=-lcrypto
 fi
 
+OLD_CFLAGS="${CFLAGS}"
+OLD_LDFLAGS="${LDFLAGS}"
+
 CFLAGS="${CFLAGS} -I/usr/local/opt/openssl@1.1/include"
 LDFLAGS="${LDFLAGS} -L/usr/local/opt/openssl@1.1/lib/"
 AC_CHECK_LIB([crypto], [EVP_CIPHER_CTX_reset])
 if test "x$ac_cv_lib_crypto_EVP_CIPHER_CTX_reset" != xyes; then
-   echo ""
+   CFLAGS="${OLD_CFLAGS}"
-   echo "You do not seem to use OpenSSL 1.1 or better. Please upgrade"
+   LDFLAGS="${OLD_LDFLAGS}"
-   echo ""
+else
+   AC_DEFINE([HAVE_OPENSSL_1_1], [], [OpenSSL 1.1 is present])
 fi
 
 AC_CHECK_LIB([pcap], [pcap_open_live], pcap=true)

transform_aes.c

@@ -43,19 +43,28 @@
 typedef unsigned char n2n_aes_ivec_t[N2N_AES_IVEC_SIZE];
 
 typedef struct transop_aes {
+#ifdef OPENSSL_1_1
   EVP_CIPHER_CTX      *enc_ctx;	      /* openssl's reusable evp_* encryption context */
   EVP_CIPHER_CTX      *dec_ctx;	      /* openssl's reusable evp_* decryption context */
   const EVP_CIPHER    *cipher;	      /* cipher to use: e.g. EVP_aes_128_cbc */
   uint8_t  	      key[32];	      /* the pure key data for payload encryption & decryption */
+#else
+  AES_KEY             enc_key;        /* tx key */
+  AES_KEY             dec_key;        /* tx key */
+#endif
   AES_KEY             iv_enc_key;     /* key used to encrypt the IV */
   uint8_t             iv_pad_val[TRANSOP_AES_IV_PADDING_SIZE]; /* key used to pad the random IV seed to full block size */
 } transop_aes_t;
 
+/* ****************************************************** */
+
 static int transop_deinit_aes(n2n_trans_op_t *arg) {
   transop_aes_t *priv = (transop_aes_t *)arg->priv;
 
+#ifdef OPENSSL_1_1
   EVP_CIPHER_CTX_free(priv->enc_ctx);
   EVP_CIPHER_CTX_free(priv->dec_ctx);
+#endif
 
   if(priv)
     free(priv);
@@ -63,6 +72,9 @@ static int transop_deinit_aes(n2n_trans_op_t *arg) {
   return 0;
 }
 
+/* ****************************************************** */
+
+#ifdef OPENSSL_1_1
 /* get any erorr message out of openssl
    taken from https://en.wikibooks.org/wiki/OpenSSL/Error_handling */
 char *openssl_err_as_string (void) {
@@ -76,6 +88,9 @@ char *openssl_err_as_string (void) {
   BIO_free (bio);
   return ret;
 }
+#endif
+
+/* ****************************************************** */
 
 static void set_aes_cbc_iv(transop_aes_t *priv, n2n_aes_ivec_t ivec, uint64_t iv_seed) {
   uint8_t iv_full[N2N_AES_IVEC_SIZE];
@@ -93,6 +108,8 @@ static void set_aes_cbc_iv(transop_aes_t *priv, n2n_aes_ivec_t ivec, uint64_t iv
   AES_ecb_encrypt(iv_full, ivec, &priv->iv_enc_key, AES_ENCRYPT);
 }
 
+/* ****************************************************** */
+
 /** The aes packet format consists of:
  *
  *  - a 8-bit aes encoding version in clear text
@@ -107,8 +124,7 @@ static int transop_encode_aes( n2n_trans_op_t * arg,
 			       size_t out_len,
 			       const uint8_t * inbuf,
 			       size_t in_len,
-			       const uint8_t * peer_mac)
+			       const uint8_t * peer_mac) {
-{
   int len2=-1;
   transop_aes_t * priv = (transop_aes_t *)arg->priv;
   uint8_t assembly[N2N_PKT_BUF_SIZE] = {0};
@@ -150,15 +166,18 @@ static int transop_encode_aes( n2n_trans_op_t * arg,
 
       set_aes_cbc_iv(priv, enc_ivec, iv_seed);
 
+#ifdef OPENSSL_1_1
       EVP_CIPHER_CTX *ctx = priv->enc_ctx;
       int evp_len;
       int evp_ciphertext_len;
+
       if(1 == EVP_EncryptInit_ex(ctx, priv->cipher, NULL, priv->key, enc_ivec)) {
 	if(1 == EVP_CIPHER_CTX_set_padding(ctx, 0)) {
 	  if(1 == EVP_EncryptUpdate(ctx, outbuf + TRANSOP_AES_PREAMBLE_SIZE, &evp_len, assembly, len2)) {
 	    evp_ciphertext_len = evp_len;
 	    if(1 == EVP_EncryptFinal_ex(ctx, outbuf + TRANSOP_AES_PREAMBLE_SIZE + evp_len, &evp_len)) {
 	      evp_ciphertext_len += evp_len;
+
 	      if(evp_ciphertext_len != len2)
 		traceEvent(TRACE_ERROR, "encode_aes openssl encryption: encrypted %u bytes where %u were expected.\n",
 			    evp_ciphertext_len, len2);
@@ -170,7 +189,14 @@ static int transop_encode_aes( n2n_trans_op_t * arg,
 	  traceEvent(TRACE_ERROR, "encode_aes openssl padding setup: %s\n", openssl_err_as_string());
       } else
 	traceEvent(TRACE_ERROR, "encode_aes openssl init: %s\n", openssl_err_as_string());
+
       EVP_CIPHER_CTX_reset(ctx);
+#else
+      AES_cbc_encrypt( assembly, /* source */
+		       outbuf + TRANSOP_AES_PREAMBLE_SIZE, /* dest */
+		       len2, /* enc size */
+		       &(priv->enc_key), enc_ivec, AES_ENCRYPT);
+#endif
 
       len2 += TRANSOP_AES_PREAMBLE_SIZE; /* size of data carried in UDP. */
     } else
@@ -181,6 +207,8 @@ static int transop_encode_aes( n2n_trans_op_t * arg,
   return len2;
 }
 
+/* ****************************************************** */
+
 /* See transop_encode_aes for packet format */
 static int transop_decode_aes( n2n_trans_op_t * arg,
 			       uint8_t * outbuf,
@@ -218,15 +246,18 @@ static int transop_decode_aes( n2n_trans_op_t * arg,
 
 	  set_aes_cbc_iv(priv, dec_ivec, iv_seed);
 
+#ifdef OPENSSL_1_1
 	  EVP_CIPHER_CTX *ctx = priv->dec_ctx;
 	  int evp_len;
 	  int evp_plaintext_len;
+
 	  if(1 == EVP_DecryptInit_ex(ctx, priv->cipher, NULL, priv->key, dec_ivec)) {
 	    if(1 == EVP_CIPHER_CTX_set_padding(ctx, 0)) {
 	      if(1 == EVP_DecryptUpdate(ctx, assembly, &evp_len, inbuf + TRANSOP_AES_PREAMBLE_SIZE, len)) {
 		evp_plaintext_len = evp_len;
 		if(1 == EVP_DecryptFinal_ex(ctx, assembly + evp_len, &evp_len)) {
 		  evp_plaintext_len += evp_len;
+		  
 		  if(evp_plaintext_len != len)
 		    traceEvent(TRACE_ERROR, "decode_aes openssl decryption: decrypted %u bytes where %u were expected.\n",
 				evp_plaintext_len, len);
@@ -236,16 +267,23 @@ static int transop_decode_aes( n2n_trans_op_t * arg,
 		traceEvent(TRACE_ERROR, "decode_aes openssl decrpytion: %s\n", openssl_err_as_string());
 	    } else
 	      traceEvent(TRACE_ERROR, "decode_aes openssl padding setup: %s\n", openssl_err_as_string());
+
 	  } else
 	    traceEvent(TRACE_ERROR, "decode_aes openssl init: %s\n", openssl_err_as_string());
-	  EVP_CIPHER_CTX_reset(ctx);
 
+	  EVP_CIPHER_CTX_reset(ctx);
+#else
+	  AES_cbc_encrypt( (inbuf + TRANSOP_AES_PREAMBLE_SIZE),
+			   assembly, /* destination */
+			   len, 
+			   &(priv->dec_key),
+			   dec_ivec, AES_DECRYPT);
+#endif
 	  /* last byte is how much was padding: max value should be
 	   * AES_BLOCKSIZE-1 */
 	  padding = assembly[ len-1 ] & 0xff; 
 
-	  if ( len >= padding)
+	  if(len >= padding) {
-	    {
 	      /* strictly speaking for this to be an ethernet packet
 	       * it is going to need to be even bigger; but this is
 	       * enough to prevent segfaults. */
@@ -269,6 +307,8 @@ static int transop_decode_aes( n2n_trans_op_t * arg,
   return len;
 }
 
+/* ****************************************************** */
+
 static int setup_aes_key(transop_aes_t *priv, const uint8_t *key, ssize_t key_size) {
   size_t aes_key_size_bytes;
   size_t aes_key_size_bits;
@@ -277,7 +317,12 @@ static int setup_aes_key(transop_aes_t *priv, const uint8_t *key, ssize_t key_si
   size_t key_mat_buf_length;
 
   /* Clear out any old possibly longer key matter. */
+#ifdef OPENSSL_1_1
   memset( &(priv->key), 0, sizeof(priv->key) );
+#else
+  memset( &(priv->enc_key), 0, sizeof(priv->enc_key) );
+  memset( &(priv->dec_key), 0, sizeof(priv->dec_key) );
+#endif
   memset( &(priv->iv_enc_key), 0, sizeof(priv->iv_enc_key) );
   memset( &(priv->iv_pad_val), 0, sizeof(priv->iv_pad_val) );
 
@@ -296,25 +341,26 @@ static int setup_aes_key(transop_aes_t *priv, const uint8_t *key, ssize_t key_si
    * actual "filling level" of the buffer
    */
 
-  if (key_size >= 65)
+  if(key_size >= 65) {
-    {
+#ifdef OPENSSL_1_1
       priv->cipher = EVP_aes_256_cbc();
+#endif
       aes_key_size_bytes = AES256_KEY_BYTES;
       SHA512(key, key_size, key_mat_buf);
       key_mat_buf_length = SHA512_DIGEST_LENGTH;
-    }
+    } else if(key_size >= 44) {
-  else if (key_size >= 44)
+#ifdef OPENSSL_1_1
-    {
       priv->cipher = EVP_aes_192_cbc();
+#endif
       aes_key_size_bytes = AES192_KEY_BYTES;
       SHA384(key, key_size, key_mat_buf);
       /* append a hash of the first hash to create enough material for IV padding */
       SHA256(key_mat_buf, SHA384_DIGEST_LENGTH, key_mat_buf + SHA384_DIGEST_LENGTH);
       key_mat_buf_length = SHA384_DIGEST_LENGTH + SHA256_DIGEST_LENGTH;
-    }
+    } else {
-  else
+#ifdef OPENSSL_1_1
-    {
       priv->cipher = EVP_aes_128_cbc();
+#endif
       aes_key_size_bytes = AES128_KEY_BYTES;
       SHA256(key, key_size, key_mat_buf);
       /* append a hash of the first hash to create enough material for IV padding */
@@ -323,8 +369,7 @@ static int setup_aes_key(transop_aes_t *priv, const uint8_t *key, ssize_t key_si
     }
 
   /* is there enough material available? */
-  if (key_mat_buf_length < (aes_key_size_bytes + TRANSOP_AES_IV_KEY_BYTES + TRANSOP_AES_IV_PADDING_SIZE))
+  if(key_mat_buf_length < (aes_key_size_bytes + TRANSOP_AES_IV_KEY_BYTES + TRANSOP_AES_IV_PADDING_SIZE)) {
-    {
       /* this should never happen */
       traceEvent( TRACE_ERROR, "AES missing %u bits hashed key material\n",
 		  (aes_key_size_bytes + TRANSOP_AES_IV_KEY_BYTES + TRANSOP_AES_IV_PADDING_SIZE - key_mat_buf_length) * 8);
@@ -333,7 +378,13 @@ static int setup_aes_key(transop_aes_t *priv, const uint8_t *key, ssize_t key_si
 
   /* setup of key, used for the CBC encryption */
   aes_key_size_bits = 8 * aes_key_size_bytes;
+
+#ifdef OPENSSL_1_1
   memcpy (priv->key, key_mat_buf, aes_key_size_bytes);
+#else
+  AES_set_encrypt_key(key_mat_buf, aes_key_size_bits, &(priv->enc_key));
+  AES_set_decrypt_key(key_mat_buf, aes_key_size_bits, &(priv->dec_key));
+#endif
 
   /* setup of iv_enc_key (AES128 key) and iv_pad_val, used for generating the CBC IV */
   AES_set_encrypt_key(key_mat_buf + aes_key_size_bytes, TRANSOP_AES_IV_KEY_BYTES * 8, &(priv->iv_enc_key));
@@ -345,7 +396,11 @@ static int setup_aes_key(transop_aes_t *priv, const uint8_t *key, ssize_t key_si
   return(0);
 }
 
-static void transop_tick_aes(n2n_trans_op_t * arg, time_t now) {}
+/* ****************************************************** */
+
+static void transop_tick_aes(n2n_trans_op_t * arg, time_t now) { ; }
+
+/* ****************************************************** */
 
 /* AES initialization function */
 int n2n_transop_aes_cbc_init(const n2n_edge_conf_t *conf, n2n_trans_op_t *ttt) {
@@ -368,15 +423,18 @@ int n2n_transop_aes_cbc_init(const n2n_edge_conf_t *conf, n2n_trans_op_t *ttt) {
   }
   ttt->priv = priv;
 
+#ifdef OPENSSL_1_1
   /* Setup openssl's reusable evp_* contexts for encryption and decryption*/
   if(!(priv->enc_ctx = EVP_CIPHER_CTX_new())) {
     traceEvent(TRACE_ERROR, "openssl's evp_* encryption context creation: %s\n", openssl_err_as_string());
     return(-1);
   }
+
   if(!(priv->dec_ctx = EVP_CIPHER_CTX_new())) {
     traceEvent(TRACE_ERROR, "openssl's evp_* decryption context creation: %s\n", openssl_err_as_string());
     return(-1);
   }
+#endif
 
   /* Setup the cipher and key */
   return(setup_aes_key(priv, encrypt_key, encrypt_key_len));