fixup! Add SM4 block cipher

Document SM4 in the table with all other cipher descriptors.  Also, give
it a lower cipher ID, simply picking the next available.

Author: levitte

doc/crypt.tex

@@ -600,7 +600,7 @@ \subsection{Simple Encryption Demonstration}
 \index{Cipher descriptor table}
 \index{blowfish\_desc} \index{xtea\_desc} \index{rc2\_desc} \index{rc5\_desc} \index{rc6\_desc} \index{saferp\_desc} \index{aes\_desc} \index{twofish\_desc}
 \index{des\_desc} \index{des3\_desc} \index{noekeon\_desc} \index{skipjack\_desc} \index{anubis\_desc} \index{khazad\_desc} \index{kseed\_desc} \index{kasumi\_desc} \index{camellia\_desc} \index{aes\_enc\_desc}
-\index{idea\_desc} \index{serpent\_desc} \index{tea\_desc}
+\index{idea\_desc} \index{serpent\_desc} \index{tea\_desc} \index{sm4\_desc}
 \begin{figure}[hpbt]
 \begin{small}
 \begin{center}
@@ -632,6 +632,7 @@ \subsection{Simple Encryption Demonstration}
      \hline IDEA & idea\_desc & 8 & 16 & 8 & 24 \\
      \hline Serpent & serpent\_desc & 16 & 16, 24, 32 & 32 & 25 \\
      \hline TEA & tea\_desc & 8 & 16 & 32 & 26 \\
+     \hline SM4 & sm4\_desc & 16 & 16 & 32 & 27 \\
      \hline
 \end{tabular}
 \end{center}

src/ciphers/sm4.c

@@ -470,8 +470,8 @@ int sm4_test(void)
 
 const struct ltc_cipher_descriptor sm4_desc = {
     "sm4",
-    127,
-    16, 16, 16, 32,
+    27,
+    16, 16, 16, 32,        /* min_key_len, max_key_len, block_len, default_rounds */
     &sm4_setup,
     &sm4_ecb_encrypt,
     &sm4_ecb_decrypt,