Improve wc_HmacUpdate to return early if input length == 0. Fixes QAT issue with HKDF test.

dgarske · dgarske · commit 4e1b719236f9 · 2025-11-14T09:40:56.000-08:00
diff --git a/wolfcrypt/src/hmac.c b/wolfcrypt/src/hmac.c
@@ -814,6 +814,9 @@ int wc_HmacUpdate(Hmac* hmac, const byte* msg, word32 length)
     if (hmac == NULL || (msg == NULL && length > 0)) {
         return BAD_FUNC_ARG;
     }
+    if (length == 0) {
+        return 0; /* nothing to do, return success */
+    }
 
 #ifdef WOLF_CRYPTO_CB
     if (hmac->devId != INVALID_DEVID) {

Original file line number	Diff line number	Diff line change
`@@ -814,6 +814,9 @@ int wc_HmacUpdate(Hmac* hmac, const byte* msg, word32 length)`
`814`	`814`	`if (hmac == NULL \|\| (msg == NULL && length > 0)) {`
`815`	`815`	`return BAD_FUNC_ARG;`
`816`	`816`	`}`
	`817`	`+ if (length == 0) {`
	`818`	`+ return 0; /* nothing to do, return success */`
	`819`	`+ }`
`817`	`820`
`818`	`821`	`#ifdef WOLF_CRYPTO_CB`
`819`	`822`	`if (hmac->devId != INVALID_DEVID) {`