Move OSSL_CMP_X509_digest() to x_all.c, renaming it to X509_digest_sig()

Reviewed-by: Matt Caswell <matt@openssl.org>
Reviewed-by: David von Oheimb <david.von.oheimb@siemens.com>
(Merged from https://github.com/openssl/openssl/pull/11142)

1 files changed, 29 insertions, 0 deletions

diff --git a/crypto/x509/x_all.c b/crypto/x509/x_all.c
index 6a6748bad4..2d7387b9e0 100644
--- a/crypto/x509/x_all.c
+++ b/crypto/x509/x_all.c
@@ -450,6 +450,35 @@ int X509_digest(const X509 *data, const EVP_MD *type, unsigned char *md,
             (ASN1_ITEM_rptr(X509), type, (char *)data, md, len));
 }
 
+/* calculate cert digest using the same hash algorithm as in its signature */
+ASN1_OCTET_STRING *X509_digest_sig(const X509 *cert)
+{
+    unsigned int len;
+    unsigned char hash[EVP_MAX_MD_SIZE];
+    int md_NID;
+    const EVP_MD *md = NULL;
+    ASN1_OCTET_STRING *new = NULL;
+
+    if (cert == NULL) {
+        X509err(0, ERR_R_PASSED_NULL_PARAMETER);
+        return NULL;
+    }
+
+    if (!OBJ_find_sigid_algs(X509_get_signature_nid(cert), &md_NID, NULL)
+            || (md = EVP_get_digestbynid(md_NID)) == NULL) {
+        CMPerr(0, X509_R_UNSUPPORTED_ALGORITHM);
+        return NULL;
+    }
+    if (!X509_digest(cert, md, hash, &len)
+            || (new = ASN1_OCTET_STRING_new()) == NULL)
+        return NULL;
+    if (!(ASN1_OCTET_STRING_set(new, hash, len))) {
+        ASN1_OCTET_STRING_free(new);
+        return NULL;
+    }
+    return new;
+}
+
 int X509_CRL_digest(const X509_CRL *data, const EVP_MD *type,
                     unsigned char *md, unsigned int *len)
 {