crypt: use hard-wired cipher block sizes consistently

src/crypt.c

@@ -96,11 +96,12 @@ crypt_init(LIBSSH2_SESSION * session,
 
 static int
 crypt_encrypt(LIBSSH2_SESSION * session, unsigned char *block,
-                 void **abstract)
+              size_t blocksize, void **abstract)
 {
     struct crypt_ctx *cctx = *(struct crypt_ctx **) abstract;
     (void) session;
-    return _libssh2_cipher_crypt(&cctx->h, cctx->algo, cctx->encrypt, block);
+    return _libssh2_cipher_crypt(&cctx->h, cctx->algo, cctx->encrypt, block,
+                                 blocksize);
 }
 
 static int
@@ -248,7 +249,8 @@ crypt_init_arcfour128(LIBSSH2_SESSION * session,
         unsigned char block[8];
         size_t discard = 1536;
         for (; discard; discard -= 8)
-            _libssh2_cipher_crypt(&cctx->h, cctx->algo, cctx->encrypt, block);
+            _libssh2_cipher_crypt(&cctx->h, cctx->algo, cctx->encrypt, block,
+                                  method->blocksize);
     }
 
     return rc;

src/crypto.h

@@ -103,7 +103,7 @@ int _libssh2_cipher_init(_libssh2_cipher_ctx * h,
 
 int _libssh2_cipher_crypt(_libssh2_cipher_ctx * ctx,
                           _libssh2_cipher_type(algo),
-                          int encrypt, unsigned char *block);
+                          int encrypt, unsigned char *block, size_t blocksize);
 
 int _libssh2_pub_priv_keyfile(LIBSSH2_SESSION *session,
                               unsigned char **method,

src/libgcrypt.c

@@ -553,17 +553,11 @@ _libssh2_cipher_init(_libssh2_cipher_ctx * h,
 int
 _libssh2_cipher_crypt(_libssh2_cipher_ctx * ctx,
                       _libssh2_cipher_type(algo),
-                      int encrypt, unsigned char *block)
+                      int encrypt, unsigned char *block, size_t blklen)
 {
     int cipher = _libssh2_gcry_cipher (algo);
-    size_t blklen = gcry_cipher_get_algo_blklen(cipher);
     int ret;
 
-    if (blklen == 1) {
-/* Hack for arcfour. */
-        blklen = 8;
-    }
-
     if (encrypt) {
         ret = gcry_cipher_encrypt(*ctx, block, blklen, block, blklen);
     } else {

src/libssh2_priv.h

@@ -883,7 +883,7 @@ struct _LIBSSH2_CRYPT_METHOD
                  int *free_iv, unsigned char *secret, int *free_secret,
                  int encrypt, void **abstract);
     int (*crypt) (LIBSSH2_SESSION * session, unsigned char *block,
-                  void **abstract);
+                  size_t blocksize, void **abstract);
     int (*dtor) (LIBSSH2_SESSION * session, void **abstract);
 
       _libssh2_cipher_type(algo);

src/openssl.c

@@ -181,18 +181,13 @@ _libssh2_cipher_init(_libssh2_cipher_ctx * h,
 int
 _libssh2_cipher_crypt(_libssh2_cipher_ctx * ctx,
                       _libssh2_cipher_type(algo),
-                      int encrypt, unsigned char *block)
+                      int encrypt, unsigned char *block, size_t blocksize)
 {
-    int blocksize = ctx->cipher->block_size;
     unsigned char buf[EVP_MAX_BLOCK_LENGTH];
     int ret;
     (void) algo;
     (void) encrypt;
 
-    if (blocksize == 1) {
-/* Hack for arcfour. */
-        blocksize = 8;
-    }
     ret = EVP_Cipher(ctx, buf, block, blocksize);
     if (ret == 1) {
         memcpy(block, buf, blocksize);

src/transport.c

@@ -139,7 +139,7 @@ decrypt(LIBSSH2_SESSION * session, unsigned char *source,
     assert((len % blocksize) == 0);
 
     while (len >= blocksize) {
-        if (session->remote.crypt->crypt(session, source,
+        if (session->remote.crypt->crypt(session, source, blocksize,
                                          &session->remote.crypt_abstract)) {
             LIBSSH2_FREE(session, p->payload);
             return LIBSSH2_ERROR_DECRYPT;
@@ -846,6 +846,7 @@ int _libssh2_transport_send(LIBSSH2_SESSION *session,
         for(i = 0; i < packet_length; i += session->local.crypt->blocksize) {
             unsigned char *ptr = &p->outbuf[i];
             if (session->local.crypt->crypt(session, ptr,
+                                            session->local.crypt->blocksize,
                                             &session->local.crypt_abstract))
                 return LIBSSH2_ERROR_ENCRYPT;     /* encryption failure */
         }