Merge pull request #2506 from tmael/bio_mem_base64

Fix for BIO and base64 encoding/decoding

src/bio.c

@@ -869,20 +869,34 @@ size_t wolfSSL_BIO_ctrl_pending(WOLFSSL_BIO *bio)
 
 long wolfSSL_BIO_get_mem_ptr(WOLFSSL_BIO *bio, WOLFSSL_BUF_MEM **ptr)
 {
+    WOLFSSL_BIO* front = bio;
+    long ret = WOLFSSL_FAILURE;
+
     WOLFSSL_ENTER("wolfSSL_BIO_get_mem_ptr");
 
     if (bio == NULL || ptr == NULL) {
         return WOLFSSL_FAILURE;
     }
 
-    if (bio->type != WOLFSSL_BIO_MEMORY) {
-        WOLFSSL_MSG("BIO is not memory buffer type");
-        return SSL_FAILURE;
+    /* start at end and work backwards to find a memory BIO in the BIO chain */
+    while ((bio != NULL) && (bio->next != NULL)) {
+        bio = bio->next;
     }
 
-    *ptr = bio->mem_buf;
+    while (bio != NULL) {
 
-    return SSL_SUCCESS;
+        if (bio->type == WOLFSSL_BIO_MEMORY) {
+            *ptr = bio->mem_buf;
+            ret = WOLFSSL_SUCCESS;
+        }
+
+        if (bio == front) {
+            break;
+        }
+        bio = bio->prev;
+    }
+
+    return ret;
 }
 
 WOLFSSL_API long wolfSSL_BIO_int_ctrl(WOLFSSL_BIO *bp, int cmd, long larg, int iarg)

tests/api.c

@@ -22974,6 +22974,7 @@ static void test_wolfSSL_BIO_write(void)
     char msg[] = "conversion test";
     char out[40];
     char expected[] = "Y29udmVyc2lvbiB0ZXN0AA==\n";
+    BUF_MEM* buf = NULL;
 
     printf(testingFmt, "wolfSSL_BIO_write()");
 
@@ -22983,6 +22984,12 @@ static void test_wolfSSL_BIO_write(void)
     /* now should convert to base64 then write to memory */
     AssertIntEQ(BIO_write(bio, msg, sizeof(msg)), 25);
     BIO_flush(bio);
+
+    /* test BIO chain */
+    AssertIntEQ(SSL_SUCCESS, (int)BIO_get_mem_ptr(bio, &buf));
+    AssertNotNull(buf);
+    AssertIntEQ(buf->length, 25);
+
     AssertNotNull(ptr = BIO_find_type(bio, BIO_TYPE_MEM));
     sz = sizeof(out);
     XMEMSET(out, 0, sz);

wolfcrypt/src/coding.c

@@ -130,6 +130,10 @@ int Base64_Decode(const byte* in, word32 inLen, byte* out, word32* outLen)
             }
         }
     }
+
+    if (out && *outLen > i)
+        out[i]= '\0';
+
     *outLen = i;
 
     return 0;
@@ -321,9 +325,14 @@ static int DoBase64_Encode(const byte* in, word32 inLen, byte* out,
     if (i != outSz && escaped != 1 && ret == 0)
         return ASN_INPUT_E;
 
+    if (out && *outLen > i)
+        out[i]= '\0';
+
     *outLen = i;
+
     if (ret == 0)
         return getSzOnly ? LENGTH_ONLY_E : 0;
+
     return ret;
 }