doc: note the alignment of wolfCrypt context structures

doc/dox_comments/header_files/aes.h

@@ -1098,6 +1098,9 @@ int wc_AesXtsFree(XtsAes* aes);
     \param heap heap hint to use for malloc / free if needed
     \param devId ID to use with crypto callbacks or async hardware. Set to INVALID_DEVID (-2) if not used
 
+    \note Aes has 16-byte alignment (64 on Xilinx Versal) if WOLFSSL_USE_ALIGN
+    is defined (default in configure and CMake, forced for AES-NI and asm).
+
     _Example_
     \code
     Aes enc;

doc/dox_comments/header_files/curve25519.h

@@ -151,6 +151,9 @@ int wc_curve25519_shared_secret_ex(curve25519_key* private_key,
 
     \param [in,out] key Pointer to the curve25519_key structure to initialize.
 
+    \note curve25519_key has 16-byte alignment when WOLFSSL_USE_ALIGN
+    is defined (default in configure and CMake, forced for AES-NI and asm).
+
     _Example_
     \code
     curve25519_key key;
@@ -975,6 +978,9 @@ int wc_curve25519_make_priv(WC_RNG* rng, int keysize, byte* priv);
     \param devId Device ID for hardware acceleration (use
     INVALID_DEVID for software only)
 
+    \note curve25519_key has 16-byte alignment when WOLFSSL_USE_ALIGN
+    is defined (default in configure and CMake, forced for AES-NI and asm).
+
     _Example_
     \code
     curve25519_key key;

doc/dox_comments/header_files/ed25519.h

@@ -531,6 +531,9 @@ int wc_ed25519ph_verify_msg(const byte* sig, word32 siglen, const byte* msg,
 
     \param [in,out] key Pointer to the ed25519_key object to initialize.
 
+    \note ed25519_key has 16-byte alignment when WOLFSSL_USE_ALIGN
+    is defined (default in configure and CMake, forced for AES-NI and asm).
+
     _Example_
     \code
     ed25519_key key;
@@ -1246,6 +1249,9 @@ int wc_ed25519_verify_msg_final(const byte* sig, word32 sigLen,
     \param heap Heap hint for memory allocation
     \param devId Device ID for hardware acceleration
 
+    \note ed25519_key has 16-byte alignment when WOLFSSL_USE_ALIGN
+    is defined (default in configure and CMake, forced for AES-NI and asm).
+
     _Example_
     \code
     ed25519_key key;

doc/dox_comments/header_files/hmac.h

@@ -1,3 +1,38 @@
+/*!
+    \ingroup HMAC
+
+    \brief This function initializes an Hmac object, setting the heap hint
+    and the device ID used with crypto callbacks or async hardware. It is up
+    to the user to call wc_HmacFree on the Hmac object when done.
+
+    \return 0 Returned on successfully initializing the Hmac object
+    \return BAD_FUNC_ARG Returned if hmac is NULL
+
+    \param hmac pointer to the Hmac object to initialize
+    \param heap heap hint to use for memory allocation, or NULL
+    \param devId ID to use with crypto callbacks or async hardware. Set to
+    INVALID_DEVID (-2) if not used
+
+    \note On 64-bit CPUs, Hmac has 16-byte alignment when WOLFSSL_USE_ALIGN
+    is defined (default in configure and CMake, forced for AES-NI and asm).
+
+    _Example_
+    \code
+    Hmac hmac;
+    byte key[] = { // initialize with key to use for encryption };
+    if (wc_HmacInit(&hmac, NULL, INVALID_DEVID) != 0) {
+        // error initializing Hmac object
+    }
+    else if (wc_HmacSetKey(&hmac, WC_SHA256, key, sizeof(key)) != 0) {
+        // error setting the key
+    }
+    wc_HmacFree(&hmac);
+    \endcode
+
+    \sa wc_HmacSetKey
+*/
+int wc_HmacInit(Hmac* hmac, void* heap, int devId);
+
 /*!
     \ingroup HMAC
 
@@ -29,6 +64,7 @@
     }
     \endcode
 
+    \sa wc_HmacInit
     \sa wc_HmacUpdate
     \sa wc_HmacFinal
 */

doc/dox_comments/header_files/sha256.h

@@ -8,6 +8,9 @@
 
     \param sha256 pointer to the sha256 structure to use for encryption
 
+    \note On 64-bit CPUs, wc_Sha256 has 16-byte alignment when WOLFSSL_USE_ALIGN
+    is defined (default in configure and CMake, forced for AES-NI and asm).
+
     _Example_
     \code
     Sha256 sha256[1];
@@ -202,6 +205,9 @@ int wc_Sha256GetHash(wc_Sha256* sha256, byte* hash);
 
     \param sha224 Pointer to a Sha224 struct to initialize.
 
+    \note On 64-bit CPUs, wc_Sha224 has 16-byte alignment when WOLFSSL_USE_ALIGN
+    is defined (default in configure and CMake, forced for AES-NI and asm).
+
     _Example_
     \code
     Sha224 sha224;
@@ -296,6 +302,9 @@ int wc_Sha224Final(wc_Sha224* sha224, byte* hash);
     \param heap Heap hint
     \param devId Device ID
 
+    \note On 64-bit CPUs, wc_Sha256 has 16-byte alignment when WOLFSSL_USE_ALIGN
+    is defined (default in configure and CMake, forced for AES-NI and asm).
+
     _Example_
     \code
     wc_Sha256 sha;
@@ -493,6 +502,9 @@ int wc_Sha256GetFlags(wc_Sha256* sha256, word32* flags);
     \param heap Heap hint
     \param devId Device ID
 
+    \note On 64-bit CPUs, wc_Sha224 has 16-byte alignment when WOLFSSL_USE_ALIGN
+    is defined (default in configure and CMake, forced for AES-NI and asm).
+
     _Example_
     \code
     wc_Sha224 sha;