Add EVP_DigestSign and EVP_DigesVerify

Add "single part" digest sign and verify functions. These sign and verify
a message in one function. This simplifies some operations and it will later
be used as the API for algorithms which do not support the update/final
mechanism (e.g. PureEdDSA).

Reviewed-by: Andy Polyakov <appro@openssl.org>
(Merged from https://github.com/openssl/openssl/pull/3409)

3 files changed, 23 insertions, 17 deletions

diff --git a/crypto/asn1/a_sign.c b/crypto/asn1/a_sign.c
index 7e21a5ec9f..4e93b5a768 100644
--- a/crypto/asn1/a_sign.c
+++ b/crypto/asn1/a_sign.c
@@ -205,8 +205,7 @@ int ASN1_item_sign_ctx(const ASN1_ITEM *it,
         goto err;
     }
 
-    if (!EVP_DigestSignUpdate(ctx, buf_in, inl)
-        || !EVP_DigestSignFinal(ctx, buf_out, &outl)) {
+    if (!EVP_DigestSign(ctx, buf_out, &outl, buf_in, inl)) {
         outl = 0;
         ASN1err(ASN1_F_ASN1_ITEM_SIGN_CTX, ERR_R_EVP_LIB);
         goto err;
diff --git a/crypto/asn1/a_verify.c b/crypto/asn1/a_verify.c
index 00ab136f02..ec51d3e7cd 100644
--- a/crypto/asn1/a_verify.c
+++ b/crypto/asn1/a_verify.c
@@ -89,7 +89,7 @@ int ASN1_item_verify(const ASN1_ITEM *it, X509_ALGOR *a,
 {
     EVP_MD_CTX *ctx = NULL;
     unsigned char *buf_in = NULL;
-    int ret = -1, inl;
+    int ret = -1, inl = 0;
 
     int mdnid, pknid;
 
@@ -159,24 +159,15 @@ int ASN1_item_verify(const ASN1_ITEM *it, X509_ALGOR *a,
         goto err;
     }
 
-    ret = EVP_DigestVerifyUpdate(ctx, buf_in, inl);
-
-    OPENSSL_clear_free(buf_in, (unsigned int)inl);
-
-    if (!ret) {
-        ASN1err(ASN1_F_ASN1_ITEM_VERIFY, ERR_R_EVP_LIB);
-        goto err;
-    }
-    ret = -1;
-
-    if (EVP_DigestVerifyFinal(ctx, signature->data,
-                              (size_t)signature->length) <= 0) {
+    ret = EVP_DigestVerify(ctx, signature->data, (size_t)signature->length,
+                           buf_in, inl);
+    if (ret <= 0) {
         ASN1err(ASN1_F_ASN1_ITEM_VERIFY, ERR_R_EVP_LIB);
-        ret = 0;
         goto err;
     }
     ret = 1;
  err:
+    OPENSSL_clear_free(buf_in, (unsigned int)inl);
     EVP_MD_CTX_free(ctx);
-    return (ret);
+    return ret;
 }
diff --git a/crypto/evp/m_sigver.c b/crypto/evp/m_sigver.c
index 3b74f72295..d53e1d6bd2 100644
--- a/crypto/evp/m_sigver.c
+++ b/crypto/evp/m_sigver.c
@@ -135,6 +135,14 @@ int EVP_DigestSignFinal(EVP_MD_CTX *ctx, unsigned char *sigret,
     return 1;
 }
 
+int EVP_DigestSign(EVP_MD_CTX *ctx, unsigned char *sigret, size_t *siglen,
+                   const unsigned char *tbs, size_t tbslen)
+{
+    if (sigret != NULL && EVP_DigestSignUpdate(ctx, tbs, tbslen) <= 0)
+        return 0;
+    return EVP_DigestSignFinal(ctx, sigret, siglen);
+}
+
 int EVP_DigestVerifyFinal(EVP_MD_CTX *ctx, const unsigned char *sig,
                           size_t siglen)
 {
@@ -167,3 +175,11 @@ int EVP_DigestVerifyFinal(EVP_MD_CTX *ctx, const unsigned char *sig,
         return r;
     return EVP_PKEY_verify(ctx->pctx, sig, siglen, md, mdlen);
 }
+
+int EVP_DigestVerify(EVP_MD_CTX *ctx, const unsigned char *sigret,
+                     size_t siglen, const unsigned char *tbs, size_t tbslen)
+{
+    if (EVP_DigestVerifyUpdate(ctx, tbs, tbslen) <= 0)
+        return -1;
+    return EVP_DigestVerifyFinal(ctx, sigret, siglen);
+}