Cache Digest constants

EVP_CIPHER already caches certain constants so that we don't have to
query the provider every time. We do the same thing with EVP_MD constants.
Without this we can get performance issues, e.g. running "speed" with
small blocks of data to digest can spend a long time in EVP_MD_size(),
which should be quick.

Partialy fixes #13578

Reviewed-by: Dmitry Belyavskiy <beldmit@gmail.com>
(Merged from https://github.com/openssl/openssl/pull/13730)

1 files changed, 29 insertions, 0 deletions

diff --git a/crypto/evp/digest.c b/crypto/evp/digest.c
index 1d16c52060..46f4d201d9 100644
--- a/crypto/evp/digest.c
+++ b/crypto/evp/digest.c
@@ -827,6 +827,29 @@ static void set_legacy_nid(const char *name, void *vlegacy_nid)
 }
 #endif
 
+static int evp_md_cache_constants(EVP_MD *md)
+{
+    int ok;
+    size_t blksz = 0;
+    size_t mdsize = 0;
+    unsigned long flags = 0;
+    OSSL_PARAM params[4];
+
+    params[0] = OSSL_PARAM_construct_size_t(OSSL_DIGEST_PARAM_BLOCK_SIZE, &blksz);
+    params[1] = OSSL_PARAM_construct_size_t(OSSL_DIGEST_PARAM_SIZE, &mdsize);
+    params[2] = OSSL_PARAM_construct_ulong(OSSL_DIGEST_PARAM_FLAGS, &flags);
+    params[3] = OSSL_PARAM_construct_end();
+    ok = evp_do_md_getparams(md, params);
+    if (mdsize > INT_MAX || blksz > INT_MAX)
+        ok = 0;
+    if (ok) {
+        md->block_size = (int)blksz;
+        md->md_size = (int)mdsize;
+        md->flags = flags;
+    }
+    return ok;
+}
+
 static void *evp_md_from_dispatch(int name_id,
                                   const OSSL_DISPATCH *fns,
                                   OSSL_PROVIDER *prov)
@@ -938,6 +961,12 @@ static void *evp_md_from_dispatch(int name_id,
     if (prov != NULL)
         ossl_provider_up_ref(prov);
 
+    if (!evp_md_cache_constants(md)) {
+        EVP_MD_free(md);
+        ERR_raise(ERR_LIB_EVP, EVP_R_CACHE_CONSTANTS_FAILED);
+        md = NULL;
+    }
+
     return md;
 }