openssl: make SSL_ERROR_to_str more future-proof

Rather than making assumptions about the values, use a switch-case.

Closes #1424

diff --git a/lib/vtls/openssl.c b/lib/vtls/openssl.c
index 5c4e34e91dfa53b3641a1522130664541e5b9949..35489f845026abd86a384f1184ac58b7e2a0dc0f 100644 (file)
--- a/lib/vtls/openssl.c
+++ b/lib/vtls/openssl.c
@@ -164,22 +164,40 @@ static unsigned long OpenSSL_version_num(void)
 
 static const char *SSL_ERROR_to_str(int err)
 {
-  static const char * const str[] = {
-    "SSL_ERROR_NONE",               /* 0 */
-    "SSL_ERROR_SSL",                /* 1 */
-    "SSL_ERROR_WANT_READ",          /* 2 */
-    "SSL_ERROR_WANT_WRITE",         /* 3 */
-    "SSL_ERROR_WANT_X509_LOOKUP",   /* 4 */
-    "SSL_ERROR_SYSCALL",            /* 5 */
-    "SSL_ERROR_ZERO_RETURN",        /* 6 */
-    "SSL_ERROR_WANT_CONNECT",       /* 7 */
-    "SSL_ERROR_WANT_ACCEPT",        /* 8 */
-    "SSL_ERROR_WANT_ASYNC",         /* 9 */
-    "SSL_ERROR_WANT_ASYNC_JOB",     /* 10 */
-    "SSL_ERROR_WANT_EARLY",         /* 11 */
-  };
-  return ((err >= 0 && err < (int)(sizeof str / sizeof str[0])) ?
-          str[err] : "SSL_ERROR unknown");
+  switch(err) {
+  case SSL_ERROR_NONE:
+    return "SSL_ERROR_NONE";
+  case SSL_ERROR_SSL:
+    return "SSL_ERROR_SSL";
+  case SSL_ERROR_WANT_READ:
+    return "SSL_ERROR_WANT_READ";
+  case SSL_ERROR_WANT_WRITE:
+    return "SSL_ERROR_WANT_WRITE";
+  case SSL_ERROR_WANT_X509_LOOKUP:
+    return "SSL_ERROR_WANT_X509_LOOKUP";
+  case SSL_ERROR_SYSCALL:
+    return "SSL_ERROR_SYSCALL";
+  case SSL_ERROR_ZERO_RETURN:
+    return "SSL_ERROR_ZERO_RETURN";
+  case SSL_ERROR_WANT_CONNECT:
+    return "SSL_ERROR_WANT_CONNECT";
+  case SSL_ERROR_WANT_ACCEPT:
+    return "SSL_ERROR_WANT_ACCEPT";
+#if defined(SSL_ERROR_WANT_ASYNC)
+  case SSL_ERROR_WANT_ASYNC:
+    return "SSL_ERROR_WANT_ASYNC";
+#endif
+#if defined(SSL_ERROR_WANT_ASYNC_JOB)
+  case SSL_ERROR_WANT_ASYNC_JOB:
+    return "SSL_ERROR_WANT_ASYNC_JOB";
+#endif
+#if defined(SSL_ERROR_WANT_EARLY)
+  case SSL_ERROR_WANT_EARLY:
+    return "SSL_ERROR_WANT_EARLY";
+#endif
+  default:
+    return "SSL_ERROR unknown";
+  }
 }
 
 static int passwd_callback(char *buf, int num, int encrypting,