Replace malloc+strcpy with strdup

Reviewed-by: NRichard Levitte <levitte@openssl.org>
(Merged from https://github.com/openssl/openssl/pull/4371)

crypto/dso/dso_dl.c

@@ -156,23 +156,21 @@ static char *dl_merger(DSO *dso, const char *filespec1, const char *filespec2)
      * if the second file specification is missing.
      */
     if (!filespec2 || filespec1[0] == '/') {
-        merged = OPENSSL_malloc(strlen(filespec1) + 1);
+        merged = OPENSSL_strdup(filespec1);
         if (merged == NULL) {
             DSOerr(DSO_F_DL_MERGER, ERR_R_MALLOC_FAILURE);
             return (NULL);
         }
-        strcpy(merged, filespec1);
     }
     /*
      * If the first file specification is missing, the second one rules.
      */
     else if (!filespec1) {
-        merged = OPENSSL_malloc(strlen(filespec2) + 1);
+        merged = OPENSSL_strdup(filespec2);
         if (merged == NULL) {
             DSOerr(DSO_F_DL_MERGER, ERR_R_MALLOC_FAILURE);
             return (NULL);
         }
-        strcpy(merged, filespec2);
     } else
         /*
          * This part isn't as trivial as it looks.  It assumes that the

crypto/dso/dso_dlfcn.c

@@ -196,23 +196,21 @@ static char *dlfcn_merger(DSO *dso, const char *filespec1,
      * if the second file specification is missing.
      */
     if (!filespec2 || (filespec1 != NULL && filespec1[0] == '/')) {
-        merged = OPENSSL_malloc(strlen(filespec1) + 1);
+        merged = OPENSSL_strdup(filespec1);
         if (merged == NULL) {
             DSOerr(DSO_F_DLFCN_MERGER, ERR_R_MALLOC_FAILURE);
             return (NULL);
         }
-        strcpy(merged, filespec1);
     }
     /*
      * If the first file specification is missing, the second one rules.
      */
     else if (!filespec1) {
-        merged = OPENSSL_malloc(strlen(filespec2) + 1);
+        merged = OPENSSL_strdup(filespec2);
         if (merged == NULL) {
             DSOerr(DSO_F_DLFCN_MERGER, ERR_R_MALLOC_FAILURE);
             return (NULL);
         }
-        strcpy(merged, filespec2);
     } else {
         /*
          * This part isn't as trivial as it looks.  It assumes that the

crypto/dso/dso_win32.c

@@ -398,19 +398,17 @@ static char *win32_merger(DSO *dso, const char *filespec1,
         return (NULL);
     }
     if (!filespec2) {
-        merged = OPENSSL_malloc(strlen(filespec1) + 1);
+        merged = OPENSSL_strdup(filespec1);
         if (merged == NULL) {
             DSOerr(DSO_F_WIN32_MERGER, ERR_R_MALLOC_FAILURE);
             return (NULL);
         }
-        strcpy(merged, filespec1);
     } else if (!filespec1) {
-        merged = OPENSSL_malloc(strlen(filespec2) + 1);
+        merged = OPENSSL_strdup(filespec2);
         if (merged == NULL) {
             DSOerr(DSO_F_WIN32_MERGER, ERR_R_MALLOC_FAILURE);
             return (NULL);
         }
-        strcpy(merged, filespec2);
     } else {
         filespec1_split = win32_splitter(dso, filespec1, 0);
         if (!filespec1_split) {