Clean up create_digest()

The ts code is its own kind of special. I only sent this diff out to hear
beck squeal. This diff doesn't actually fix anything, apart from (maybe)
appeasing some obscure static analyzer. It is decidedly less bad than a
similar change in openssl's issue tracker.

ok beck

diff --git a/usr.bin/openssl/ts.c b/usr.bin/openssl/ts.c
index c62f1dd..dfcf5dd 100644 (file)
--- a/usr.bin/openssl/ts.c
+++ b/usr.bin/openssl/ts.c
@@ -1,4 +1,4 @@
-/* $OpenBSD: ts.c,v 1.27 2023/11/19 09:19:54 tb Exp $ */
+/* $OpenBSD: ts.c,v 1.28 2024/03/25 10:16:02 tb Exp $ */
 /* Written by Zoltan Glozik (zglozik@stones.com) for the OpenSSL
  * project 2002.
  */
@@ -676,10 +676,12 @@ create_query(BIO *data_bio, char *digest, const EVP_MD *md, const char *policy,
 
 static int
 create_digest(BIO *input, char *digest, const EVP_MD *md,
-    unsigned char **md_value)
+    unsigned char **out_md_value)
 {
-       int md_value_len;
        EVP_MD_CTX *md_ctx = NULL;
+       unsigned char *md_value = NULL;
+       int md_value_len;
+       int ret = 0;
 
        md_value_len = EVP_MD_size(md);
        if (md_value_len < 0)
@@ -690,8 +692,8 @@ create_digest(BIO *input, char *digest, const EVP_MD *md,
                unsigned char buffer[4096];
                int length;
 
-               *md_value = malloc(md_value_len);
-               if (*md_value == NULL)
+               md_value = malloc(md_value_len);
+               if (md_value == NULL)
                        goto err;
 
                if ((md_ctx = EVP_MD_CTX_new()) == NULL)
@@ -705,31 +707,30 @@ create_digest(BIO *input, char *digest, const EVP_MD *md,
                                goto err;
                }
 
-               if (!EVP_DigestFinal(md_ctx, *md_value, NULL))
+               if (!EVP_DigestFinal(md_ctx, md_value, NULL))
                        goto err;
-
-               EVP_MD_CTX_free(md_ctx);
-               md_ctx = NULL;
-
        } else {
                /* Digest bytes are specified with digest. */
                long digest_len;
 
-               *md_value = string_to_hex(digest, &digest_len);
-               if (*md_value == NULL || md_value_len != digest_len) {
-                       free(*md_value);
-                       *md_value = NULL;
+               md_value = string_to_hex(digest, &digest_len);
+               if (md_value == NULL || md_value_len != digest_len) {
                        BIO_printf(bio_err, "bad digest, %d bytes "
                            "must be specified\n", md_value_len);
                        goto err;
                }
        }
 
-       return md_value_len;
+       *out_md_value = md_value;
+       md_value = NULL;
+
+       ret = md_value_len;
 
  err:
+       free(md_value);
        EVP_MD_CTX_free(md_ctx);
-       return 0;
+
+       return ret;
 }
 
 static ASN1_INTEGER *