Remove HMAC_CTX_cleanup and combine its functionality into EVP_MD_CTX_init

This follows the same idea as the combination of EVP_MD_CTX_cleanup
and EVP_MD_CTX_init into one function.
Reviewed-by: NRich Salz <rsalz@openssl.org>

crypto/hmac/hmac.c

@@ -180,38 +180,46 @@ HMAC_CTX *HMAC_CTX_new(void)
     return ctx;
 }
 
+static void hmac_ctx_cleanup(HMAC_CTX *ctx)
+{
+    EVP_MD_CTX_init(ctx->i_ctx);
+    EVP_MD_CTX_init(ctx->o_ctx);
+    EVP_MD_CTX_init(ctx->md_ctx);
+    ctx->md = NULL;
+    ctx->key_length = 0;
+    memset(ctx->key, 0, sizeof(HMAC_MAX_MD_CBLOCK));
+}
+
 void HMAC_CTX_free(HMAC_CTX *ctx)
 {
     if (ctx != NULL) {
-        HMAC_CTX_cleanup(ctx);
+        hmac_ctx_cleanup(ctx);
+        EVP_MD_CTX_destroy(ctx->i_ctx);
+        EVP_MD_CTX_destroy(ctx->o_ctx);
+        EVP_MD_CTX_destroy(ctx->md_ctx);
         OPENSSL_free(ctx);
     }
 }
 
 int HMAC_CTX_init(HMAC_CTX *ctx)
 {
+    hmac_ctx_cleanup(ctx);
     if (ctx->i_ctx == NULL)
         ctx->i_ctx = EVP_MD_CTX_create();
-    else
-        EVP_MD_CTX_init(ctx->i_ctx);
     if (ctx->i_ctx == NULL)
         goto err;
     if (ctx->o_ctx == NULL)
         ctx->o_ctx = EVP_MD_CTX_create();
-    else
-        EVP_MD_CTX_init(ctx->o_ctx);
     if (ctx->o_ctx == NULL)
         goto err;
     if (ctx->md_ctx == NULL)
         ctx->md_ctx = EVP_MD_CTX_create();
-    else
-        EVP_MD_CTX_init(ctx->md_ctx);
     if (ctx->md_ctx == NULL)
         goto err;
     ctx->md = NULL;
     return 1;
  err:
-    HMAC_CTX_cleanup(ctx);
+    hmac_ctx_cleanup(ctx);
     return 0;
 }
 
@@ -230,18 +238,10 @@ int HMAC_CTX_copy(HMAC_CTX *dctx, HMAC_CTX *sctx)
     dctx->md = sctx->md;
     return 1;
  err:
-    HMAC_CTX_cleanup(dctx);
+    hmac_ctx_cleanup(dctx);
     return 0;
 }
 
-void HMAC_CTX_cleanup(HMAC_CTX *ctx)
-{
-    EVP_MD_CTX_destroy(ctx->i_ctx);
-    EVP_MD_CTX_destroy(ctx->o_ctx);
-    EVP_MD_CTX_destroy(ctx->md_ctx);
-    memset(ctx, 0, sizeof(*ctx));
-}
-
 unsigned char *HMAC(const EVP_MD *evp_md, const void *key, int key_len,
                     const unsigned char *d, size_t n, unsigned char *md,
                     unsigned int *md_len)

include/openssl/hmac.h

@@ -70,9 +70,8 @@ extern "C" {
 
 size_t HMAC_size(HMAC_CTX *e);
 HMAC_CTX *HMAC_CTX_new(void);
-void HMAC_CTX_free(HMAC_CTX *ctx);
 int HMAC_CTX_init(HMAC_CTX *ctx);
-void HMAC_CTX_cleanup(HMAC_CTX *ctx);
+void HMAC_CTX_free(HMAC_CTX *ctx);
 
 #ifdef OPENSSL_USE_DEPRECATED