Rework cipher / digest fetching for legacy nids with multiple name support

With multiple names, it's no longer viable to just grab the "first" in
the set and use that to find the legacy NID.  Instead, all names for
an algorithm must be checked, and if we encounter more than one NID
asssociated with those names, we consider it an error and make that
method unloadable.

This ensures that all methods that do have an internal NID associated
will get that NID in their structure, thereby ensuring that other
parts of libcrypto that haven't gone away from using NIDs for
comparison will continue to work as expected.

Reviewed-by: Paul Dale <paul.dale@oracle.com>
(Merged from https://github.com/openssl/openssl/pull/9969)

4 files changed, 81 insertions, 20 deletions

diff --git a/crypto/evp/digest.c b/crypto/evp/digest.c
index f39a443c89..92012f917e 100644
--- a/crypto/evp/digest.c
+++ b/crypto/evp/digest.c
@@ -636,6 +636,31 @@ EVP_MD *evp_md_new(void)
     return md;
 }
 
+/*
+ * FIPS module note: since internal fetches will be entirely
+ * provider based, we know that none of its code depends on legacy
+ * NIDs or any functionality that use them.
+ */
+#ifndef FIPS_MODE
+/* TODO(3.x) get rid of the need for legacy NIDs */
+static void set_legacy_nid(const char *name, void *vlegacy_nid)
+{
+    int nid;
+    int *legacy_nid = vlegacy_nid;
+
+    if (*legacy_nid == -1)       /* We found a clash already */
+        return;
+    if ((nid = OBJ_sn2nid(name)) == NID_undef
+        && (nid = OBJ_ln2nid(name)) == NID_undef)
+        return;
+    if (*legacy_nid != NID_undef && *legacy_nid != nid) {
+        *legacy_nid = -1;
+        return;
+    }
+    *legacy_nid = nid;
+}
+#endif
+
 static void *evp_md_from_dispatch(int name_id,
                                   const OSSL_DISPATCH *fns,
                                   OSSL_PROVIDER *prov, void *unused)
@@ -648,21 +673,20 @@ static void *evp_md_from_dispatch(int name_id,
         EVPerr(0, ERR_R_MALLOC_FAILURE);
         return NULL;
     }
-    md->name_id = name_id;
 
 #ifndef FIPS_MODE
-    {
-        /*
-         * FIPS module note: since internal fetches will be entirely
-         * provider based, we know that none of its code depends on legacy
-         * NIDs or any functionality that use them.
-         *
-         * TODO(3.x) get rid of the need for legacy NIDs
-         */
-        md->type = OBJ_sn2nid(evp_first_name(prov, name_id));
+    /* TODO(3.x) get rid of the need for legacy NIDs */
+    md->type = NID_undef;
+    evp_doall_names(prov, name_id, set_legacy_nid, &md->type);
+    if (md->type == -1) {
+        ERR_raise(ERR_LIB_EVP, ERR_R_INTERNAL_ERROR);
+        EVP_MD_free(md);
+        return NULL;
     }
 #endif
 
+    md->name_id = name_id;
+
     for (; fns->function_id != 0; fns++) {
         switch (fns->function_id) {
         case OSSL_FUNC_DIGEST_NEWCTX:
diff --git a/crypto/evp/evp_enc.c b/crypto/evp/evp_enc.c
index 8290494cb0..4e61d75bbd 100644
--- a/crypto/evp/evp_enc.c
+++ b/crypto/evp/evp_enc.c
@@ -1293,6 +1293,31 @@ EVP_CIPHER *evp_cipher_new(void)
     return cipher;
 }
 
+/*
+ * FIPS module note: since internal fetches will be entirely
+ * provider based, we know that none of its code depends on legacy
+ * NIDs or any functionality that use them.
+ */
+#ifndef FIPS_MODE
+/* TODO(3.x) get rid of the need for legacy NIDs */
+static void set_legacy_nid(const char *name, void *vlegacy_nid)
+{
+    int nid;
+    int *legacy_nid = vlegacy_nid;
+
+    if (*legacy_nid == -1)       /* We found a clash already */
+        return;
+    if ((nid = OBJ_sn2nid(name)) == NID_undef
+        && (nid = OBJ_ln2nid(name)) == NID_undef)
+        return;
+    if (*legacy_nid != NID_undef && *legacy_nid != nid) {
+        *legacy_nid = -1;
+        return;
+    }
+    *legacy_nid = nid;
+}
+#endif
+
 static void *evp_cipher_from_dispatch(const int name_id,
                                       const OSSL_DISPATCH *fns,
                                       OSSL_PROVIDER *prov,
@@ -1305,21 +1330,20 @@ static void *evp_cipher_from_dispatch(const int name_id,
         EVPerr(0, ERR_R_MALLOC_FAILURE);
         return NULL;
     }
-    cipher->name_id = name_id;
 
 #ifndef FIPS_MODE
-    {
-        /*
-         * FIPS module note: since internal fetches will be entirely
-         * provider based, we know that none of its code depends on legacy
-         * NIDs or any functionality that use them.
-         *
-         * TODO(3.x) get rid of the need for legacy NIDs
-         */
-        cipher->nid = OBJ_sn2nid(evp_first_name(prov, name_id));
+    /* TODO(3.x) get rid of the need for legacy NIDs */
+    cipher->nid = NID_undef;
+    evp_doall_names(prov, name_id, set_legacy_nid, &cipher->nid);
+    if (cipher->nid == -1) {
+        ERR_raise(ERR_LIB_EVP, ERR_R_INTERNAL_ERROR);
+        EVP_CIPHER_free(cipher);
+        return NULL;
     }
 #endif
 
+    cipher->name_id = name_id;
+
     for (; fns->function_id != 0; fns++) {
         switch (fns->function_id) {
         case OSSL_FUNC_CIPHER_NEWCTX:
diff --git a/crypto/evp/evp_fetch.c b/crypto/evp/evp_fetch.c
index 6e31af79f2..cd2bacea5d 100644
--- a/crypto/evp/evp_fetch.c
+++ b/crypto/evp/evp_fetch.c
@@ -393,3 +393,13 @@ int evp_is_a(OSSL_PROVIDER *prov, int number, const char *name)
 
     return ossl_namemap_name2num(namemap, name) == number;
 }
+
+void evp_doall_names(OSSL_PROVIDER *prov, int number,
+                     void (*fn)(const char *name, void *data),
+                     void *data)
+{
+    OPENSSL_CTX *libctx = ossl_provider_library_context(prov);
+    OSSL_NAMEMAP *namemap = ossl_namemap_stored(libctx);
+
+    ossl_namemap_doall_names(namemap, number, fn, data);
+}
diff --git a/crypto/evp/evp_locl.h b/crypto/evp/evp_locl.h
index 3437e04b67..116c8e6ce0 100644
--- a/crypto/evp/evp_locl.h
+++ b/crypto/evp/evp_locl.h
@@ -251,3 +251,6 @@ void evp_pkey_ctx_free_old_ops(EVP_PKEY_CTX *ctx);
 /* OSSL_PROVIDER * is only used to get the library context */
 const char *evp_first_name(OSSL_PROVIDER *prov, int name_id);
 int evp_is_a(OSSL_PROVIDER *prov, int number, const char *name);
+void evp_doall_names(OSSL_PROVIDER *prov, int number,
+                     void (*fn)(const char *name, void *data),
+                     void *data);