src/bio.c and related:

* refactor WOLFSSL_BIO.num and WOLFSSL_BIO.ptr as unions, for clarity and bug resistance (no functional changes).

* in wolfSSL_BIO_free(), add WOLFSSL_BIO_DGRAM to the test for closing bio->num.fd, fixing a descriptor leak.

* use SOCKET_INVALID consistently as the invalid value for WOLFSSL_BIO.num.fd, and use SOCKET_T consistently as the internal type for file descriptors.

* move the definitions for SOCKET_T and SOCKET_INVALID from wolfio.h to the filesystem section of wc_port.h, and allow override definitions of SOCKET_T.

detected and tested with wolfssl-multi-test.sh ... pq-hybrid-all-rpk-valgrind-unittest. also tested with wolfssl-multi-test.sh ... super-quick-check.

src/ocsp.c

@@ -952,18 +952,18 @@ OcspResponse* wolfSSL_d2i_OCSP_RESPONSE_bio(WOLFSSL_BIO* bio,
         long fcur;
         long flen;
 
-        if (bio->ptr == NULL)
+        if (bio->ptr.fh == NULL)
             return NULL;
 
-        fcur = XFTELL((XFILE)bio->ptr);
+        fcur = XFTELL(bio->ptr.fh);
         if (fcur < 0)
             return NULL;
-        if(XFSEEK((XFILE)bio->ptr, 0, SEEK_END) != 0)
+        if(XFSEEK(bio->ptr.fh, 0, SEEK_END) != 0)
             return NULL;
-        flen = XFTELL((XFILE)bio->ptr);
+        flen = XFTELL(bio->ptr.fh);
         if (flen < 0)
             return NULL;
-        if (XFSEEK((XFILE)bio->ptr, fcur, SEEK_SET) != 0)
+        if (XFSEEK(bio->ptr.fh, fcur, SEEK_SET) != 0)
             return NULL;
 
         /* check calculated length */

src/wolfio.c

@@ -301,7 +301,8 @@ int BioReceive(WOLFSSL* ssl, char* buf, int sz, void* ctx)
                 return WOLFSSL_CBIO_ERR_CONN_CLOSE;
             }
         #ifdef USE_WOLFSSL_IO
-            recvd = TranslateIoReturnCode(recvd, ssl->biord->num, SOCKET_RECEIVING);
+            recvd = TranslateIoReturnCode(recvd, ssl->biord->num.fd,
+                                          SOCKET_RECEIVING);
         #endif
             return recvd;
         }
@@ -346,7 +347,8 @@ int BioSend(WOLFSSL* ssl, char *buf, int sz, void *ctx)
     if (sent <= 0) {
         if (ssl->biowr->type == WOLFSSL_BIO_SOCKET) {
         #ifdef USE_WOLFSSL_IO
-            sent = TranslateIoReturnCode(sent, ssl->biowr->num, SOCKET_SENDING);
+            sent = TranslateIoReturnCode(sent, ssl->biowr->num.fd,
+                                         SOCKET_SENDING);
         #endif
             return sent;
         }

tests/api.c

@@ -601,14 +601,14 @@ static int testDevId = INVALID_DEVID;
 static int wolfssl_bio_s_fixed_mem_write(WOLFSSL_BIO* bio, const char* data,
     int len)
 {
-    if ((bio == NULL) || (bio->ptr == NULL) || (data == NULL)) {
+    if ((bio == NULL) || (bio->ptr.mem_buf_data == NULL) || (data == NULL)) {
         len = 0;
     }
     else {
         if (bio->wrSz - bio->wrIdx < len) {
             len = bio->wrSz - bio->wrIdx;
         }
-        XMEMCPY((char*)bio->ptr + bio->wrIdx, data, len);
+        XMEMCPY(bio->ptr.mem_buf_data + bio->wrIdx, data, len);
         bio->wrIdx += len;
     }
 
@@ -617,14 +617,14 @@ static int wolfssl_bio_s_fixed_mem_write(WOLFSSL_BIO* bio, const char* data,
 
 static int wolfssl_bio_s_fixed_mem_read(WOLFSSL_BIO* bio, char* data, int len)
 {
-    if ((bio == NULL) || (bio->ptr == NULL) || (data == NULL)) {
+    if ((bio == NULL) || (bio->ptr.mem_buf_data == NULL) || (data == NULL)) {
         len = 0;
     }
     else {
         if (bio->wrSz - bio->rdIdx < len) {
             len = bio->wrSz - bio->rdIdx;
         }
-        XMEMCPY(data, (char*)bio->ptr + bio->rdIdx, len);
+        XMEMCPY(data, bio->ptr.mem_buf_data + bio->rdIdx, len);
         bio->rdIdx += len;
     }
 

wolfssl/internal.h

@@ -2753,7 +2753,16 @@ struct WOLFSSL_BIO {
     WOLFSSL_BIO* next;          /* next in chain */
     WOLFSSL_BIO* pair;          /* BIO paired with */
     void*        heap;          /* user heap hint */
-    void*        ptr;           /* WOLFSSL, file descriptor, MD, or mem buf */
+    union {
+        byte*    mem_buf_data;
+#ifndef WOLFCRYPT_ONLY
+        WOLFSSL* ssl;
+        WOLFSSL_EVP_MD_CTX* md_ctx;
+#endif
+#ifndef NO_FILESYSTEM
+        XFILE    fh;
+#endif
+    } ptr;
     void*        usrCtx;        /* user set pointer */
     char*        ip;            /* IP address for wolfIO_TcpConnect */
     word16       port;          /* Port for wolfIO_TcpConnect */
@@ -2764,7 +2773,10 @@ struct WOLFSSL_BIO {
     int          wrIdx;         /* current index for write buffer */
     int          rdIdx;         /* current read index */
     int          readRq;        /* read request */
-    int          num;           /* socket num or length */
+    union {
+        SOCKET_T fd;
+        size_t   length;
+    } num;
     int          eof;           /* eof flag */
     int          flags;
     byte         type;          /* method type */

wolfssl/wolfcrypt/wc_port.h

@@ -859,6 +859,25 @@ WOLFSSL_ABI WOLFSSL_API int wolfCrypt_Cleanup(void);
     #define XSPRINTF   sprintf
 #endif
 
+#ifdef USE_WINDOWS_API
+    #ifndef SOCKET_T
+        #ifdef __MINGW64__
+            typedef size_t SOCKET_T;
+        #else
+            typedef unsigned int SOCKET_T;
+        #endif
+    #endif
+    #ifndef SOCKET_INVALID
+        #define SOCKET_INVALID INVALID_SOCKET
+    #endif
+#else
+    #ifndef SOCKET_T
+        typedef int SOCKET_T;
+    #endif
+    #ifndef SOCKET_INVALID
+        #define SOCKET_INVALID (-1)
+    #endif
+#endif
 
 /* MIN/MAX MACRO SECTION */
 /* Windows API defines its own min() macro. */

wolfssl/wolfio.h

@@ -404,22 +404,6 @@
     #endif
 #endif
 
-#ifdef USE_WINDOWS_API
-    #if defined(__MINGW64__)
-        typedef size_t SOCKET_T;
-    #else
-        typedef unsigned int SOCKET_T;
-    #endif
-    #ifndef SOCKET_INVALID
-        #define SOCKET_INVALID INVALID_SOCKET
-    #endif
-#else
-    typedef int SOCKET_T;
-    #ifndef SOCKET_INVALID
-        #define SOCKET_INVALID (-1)
-    #endif
-#endif
-
 #ifndef WOLFSSL_NO_SOCK
     #ifndef XSOCKLENT
         #ifdef USE_WINDOWS_API