Added comments in aes.c for locating software implementation of algorithm using Software AES.

wolfcrypt/src/aes.c

@@ -29,6 +29,8 @@
 
 #if !defined(NO_AES)
 
+/* Tip: Locate the software cipher modes by searching for "Software AES" */
+
 #if defined(HAVE_FIPS) && \
     defined(HAVE_FIPS_VERSION) && (HAVE_FIPS_VERSION >= 2)
 
@@ -737,7 +739,7 @@
 
 #else
 
-    /* using wolfCrypt software AES implementation */
+    /* using wolfCrypt software implementation */
     #define NEED_AES_TABLES
 #endif
 
@@ -1360,7 +1362,7 @@ static WC_INLINE word32 PreFetchTe(void)
     return x;
 }
 
-
+/* Software AES - ECB Encrypt */
 static void wc_AesEncrypt(Aes* aes, const byte* inBlock, byte* outBlock)
 {
     word32 s0, s1, s2, s3;
@@ -1370,7 +1372,7 @@ static void wc_AesEncrypt(Aes* aes, const byte* inBlock, byte* outBlock)
 
     if (r > 7 || r == 0) {
         WOLFSSL_MSG("AesEncrypt encountered improper key, set it up");
-        return;  /* stop instead of segfaulting, set up your keys! */
+        return;  /* stop instead of seg-faulting, set up your keys! */
     }
 
 #ifdef WOLFSSL_AESNI
@@ -1579,6 +1581,7 @@ static WC_INLINE word32 PreFetchTd4(void)
     return x;
 }
 
+/* Software AES - ECB Decrypt */
 static void wc_AesDecrypt(Aes* aes, const byte* inBlock, byte* outBlock)
 {
     word32 s0, s1, s2, s3;
@@ -1588,7 +1591,7 @@ static void wc_AesDecrypt(Aes* aes, const byte* inBlock, byte* outBlock)
     const word32* rk = aes->key;
     if (r > 7 || r == 0) {
         WOLFSSL_MSG("AesDecrypt encountered improper key, set it up");
-        return;  /* stop instead of segfaulting, set up your keys! */
+        return;  /* stop instead of seg-faulting, set up your keys! */
     }
 #ifdef WOLFSSL_AESNI
     if (haveAESNI && aes->use_aesni) {
@@ -1955,6 +1958,8 @@ static void wc_AesDecrypt(Aes* aes, const byte* inBlock, byte* outBlock)
     /* implemented in wolfcrypt/src/port/devcrypto/devcrypto_aes.c */
 
 #else
+
+    /* Software AES - SetKey */
     static int wc_AesSetKeyLocal(Aes* aes, const byte* userKey, word32 keylen,
                 const byte* iv, int dir)
     {
@@ -2828,6 +2833,7 @@ int wc_AesSetIV(Aes* aes, const byte* iv)
 
 #else
 
+    /* Software AES - CBC Encrypt */
     int wc_AesCbcEncrypt(Aes* aes, byte* out, const byte* in, word32 sz)
     {
         word32 blocks = (sz / AES_BLOCK_SIZE);
@@ -2917,6 +2923,7 @@ int wc_AesSetIV(Aes* aes, const byte* iv)
     }
 
     #ifdef HAVE_AES_DECRYPT
+    /* Software AES - CBC Decrypt */
     int wc_AesCbcDecrypt(Aes* aes, byte* out, const byte* in, word32 sz)
     {
         word32 blocks;
@@ -3171,6 +3178,7 @@ int wc_AesSetIV(Aes* aes, const byte* iv)
             }
         }
 
+        /* Software AES - CTR Encrypt */
         int wc_AesCtrEncrypt(Aes* aes, byte* out, const byte* in, word32 sz)
         {
             byte* tmp;
@@ -3348,7 +3356,7 @@ static void GenerateM0(Aes* aes)
 
 #endif /* GCM_TABLE */
 
-
+/* Software AES - GCM SetKey */
 int wc_AesGcmSetKey(Aes* aes, const byte* key, word32 len)
 {
     int  ret;
@@ -8367,6 +8375,7 @@ int AES_GCM_encrypt_C(Aes* aes, byte* out, const byte* in, word32 sz,
     return ret;
 }
 
+/* Software AES - GCM Encrypt */
 int wc_AesGcmEncrypt(Aes* aes, byte* out, const byte* in, word32 sz,
                    const byte* iv, word32 ivSz,
                    byte* authTag, word32 authTagSz,
@@ -8452,8 +8461,6 @@ int wc_AesGcmEncrypt(Aes* aes, byte* out, const byte* in, word32 sz,
     }
 #endif /* WOLFSSL_ASYNC_CRYPT */
 
-    /* Software AES-GCM */
-
 #ifdef WOLFSSL_AESNI
     #ifdef HAVE_INTEL_AVX2
     if (IS_INTEL_AVX2(intel_flags)) {
@@ -8765,6 +8772,7 @@ int AES_GCM_decrypt_C(Aes* aes, byte* out, const byte* in, word32 sz,
     return ret;
 }
 
+/* Software AES - GCM Decrypt */
 int wc_AesGcmDecrypt(Aes* aes, byte* out, const byte* in, word32 sz,
                      const byte* iv, word32 ivSz,
                      const byte* authTag, word32 authTagSz,
@@ -8852,8 +8860,6 @@ int wc_AesGcmDecrypt(Aes* aes, byte* out, const byte* in, word32 sz,
     }
 #endif /* WOLFSSL_ASYNC_CRYPT */
 
-    /* software AES GCM */
-
 #ifdef WOLFSSL_AESNI
     #ifdef HAVE_INTEL_AVX2
     if (IS_INTEL_AVX2(intel_flags)) {
@@ -9155,10 +9161,9 @@ int  wc_AesCcmDecrypt(Aes* aes, byte* out, const byte* in, word32 inSz,
 }
 #endif /* HAVE_AES_DECRYPT */
 
-
-/* software AES CCM */
 #else
 
+/* Software CCM */
 static void roll_x(Aes* aes, const byte* in, word32 inSz, byte* out)
 {
     /* process the bulk of the data */
@@ -9231,6 +9236,7 @@ static WC_INLINE void AesCcmCtrInc(byte* B, word32 lenSz)
     }
 }
 
+/* Software AES - CCM Encrypt */
 /* return 0 on success */
 int wc_AesCcmEncrypt(Aes* aes, byte* out, const byte* in, word32 inSz,
                    const byte* nonce, word32 nonceSz,
@@ -9299,6 +9305,7 @@ int wc_AesCcmEncrypt(Aes* aes, byte* out, const byte* in, word32 inSz,
 }
 
 #ifdef HAVE_AES_DECRYPT
+/* Software AES - CCM Decrypt */
 int  wc_AesCcmDecrypt(Aes* aes, byte* out, const byte* in, word32 inSz,
                    const byte* nonce, word32 nonceSz,
                    const byte* authTag, word32 authTagSz,
@@ -9390,7 +9397,7 @@ int  wc_AesCcmDecrypt(Aes* aes, byte* out, const byte* in, word32 inSz,
 }
 
 #endif /* HAVE_AES_DECRYPT */
-#endif /* software AES CCM */
+#endif /* software CCM */
 
 /* abstract functions that call lower level AESCCM functions */
 #ifndef WC_NO_RNG
@@ -9584,7 +9591,7 @@ int wc_AesGetKeySize(Aes* aes, word32* keySize)
 
 #else
 
-/* software implementation */
+/* Software AES - ECB */
 int wc_AesEcbEncrypt(Aes* aes, byte* out, const byte* in, word32 sz)
 {
     word32 blocks = sz / AES_BLOCK_SIZE;
@@ -9631,6 +9638,7 @@ int wc_AesEcbDecrypt(Aes* aes, byte* out, const byte* in, word32 sz)
  *
  * returns 0 on success and negative error values on failure
  */
+/* Software AES - CFB Encrypt */
 int wc_AesCfbEncrypt(Aes* aes, byte* out, const byte* in, word32 sz)
 {
     byte*  tmp = NULL;
@@ -9692,6 +9700,7 @@ int wc_AesCfbEncrypt(Aes* aes, byte* out, const byte* in, word32 sz)
  *
  * returns 0 on success and negative error values on failure
  */
+/* Software AES - CFB Decrypt */
 int wc_AesCfbDecrypt(Aes* aes, byte* out, const byte* in, word32 sz)
 {
     byte*  tmp;
@@ -10070,7 +10079,7 @@ static int _AesXtsHelper(Aes* aes, byte* out, const byte* in, word32 sz, int dir
         word32 j;
         byte carry = 0;
 
-        /* multiply by shift left and propogate carry */
+        /* multiply by shift left and propagate carry */
         for (j = 0; j < AES_BLOCK_SIZE && outSz > 0; j++, outSz--) {
             byte tmpC;
 
@@ -10108,6 +10117,7 @@ static int _AesXtsHelper(Aes* aes, byte* out, const byte* in, word32 sz, int dir
  *
  * returns 0 on success
  */
+/* Software AES - XTS Encrypt  */
 int wc_AesXtsEncrypt(XtsAes* xaes, byte* out, const byte* in, word32 sz,
         const byte* i, word32 iSz)
 {
@@ -10160,7 +10170,7 @@ int wc_AesXtsEncrypt(XtsAes* xaes, byte* out, const byte* in, word32 sz,
     #endif
             xorbuf(out, tmp, AES_BLOCK_SIZE);
 
-            /* multiply by shift left and propogate carry */
+            /* multiply by shift left and propagate carry */
             for (j = 0; j < AES_BLOCK_SIZE; j++) {
                 byte tmpC;
 
@@ -10215,6 +10225,7 @@ int wc_AesXtsEncrypt(XtsAes* xaes, byte* out, const byte* in, word32 sz,
  *
  * returns 0 on success
  */
+/* Software AES - XTS Decrypt */
 int wc_AesXtsDecrypt(XtsAes* xaes, byte* out, const byte* in, word32 sz,
         const byte* i, word32 iSz)
 {
@@ -10274,7 +10285,7 @@ int wc_AesXtsDecrypt(XtsAes* xaes, byte* out, const byte* in, word32 sz,
     #endif
             xorbuf(out, tmp, AES_BLOCK_SIZE);
 
-            /* multiply by shift left and propogate carry */
+            /* multiply by shift left and propagate carry */
             for (j = 0; j < AES_BLOCK_SIZE; j++) {
                 byte tmpC;
 
@@ -10298,7 +10309,7 @@ int wc_AesXtsDecrypt(XtsAes* xaes, byte* out, const byte* in, word32 sz,
             byte buf[AES_BLOCK_SIZE];
             byte tmp2[AES_BLOCK_SIZE];
 
-            /* multiply by shift left and propogate carry */
+            /* multiply by shift left and propagate carry */
             for (j = 0; j < AES_BLOCK_SIZE; j++) {
                 byte tmpC;