Create internal number<->name mapping API

This can be used as a general name to identity map.

Reviewed-by: Paul Dale <paul.dale@oracle.com>
(Merged from https://github.com/openssl/openssl/pull/8878)

1 files changed, 211 insertions, 0 deletions

diff --git a/crypto/core_namemap.c b/crypto/core_namemap.c
new file mode 100644
index 0000000000..5155a22134
--- /dev/null
+++ b/crypto/core_namemap.c
@@ -0,0 +1,211 @@
+/*
+ * Copyright 2019 The OpenSSL Project Authors. All Rights Reserved.
+ *
+ * Licensed under the Apache License 2.0 (the "License").  You may not use
+ * this file except in compliance with the License.  You can obtain a copy
+ * in the file LICENSE in the source distribution or at
+ * https://www.openssl.org/source/license.html
+ */
+
+#include "internal/namemap.h"
+#include <openssl/lhash.h>
+#include <openssl/safestack.h>
+
+/* The namemap entry */
+typedef struct {
+    int number;
+    const char *name;
+    char body[1];        /* Sized appropriately to contain the name */
+} NAMEMAP_ENTRY;
+
+DEFINE_LHASH_OF(NAMEMAP_ENTRY);
+DEFINE_STACK_OF(NAMEMAP_ENTRY)
+
+/* The namemap, which provides for bidirectional indexing */
+
+struct ossl_namemap_st {
+    /* Flags */
+    unsigned int stored:1; /* If 1, it's stored in a library context */
+
+    CRYPTO_RWLOCK *lock;
+    LHASH_OF(NAMEMAP_ENTRY) *namenum;  /* Name->number mapping */
+    STACK_OF(NAMEMAP_ENTRY) *numname;  /* Number->name mapping */
+};
+
+/* LHASH callbacks */
+
+static unsigned long namemap_hash(const NAMEMAP_ENTRY *n)
+{
+    return OPENSSL_LH_strhash(n->name);
+}
+
+static int namemap_cmp(const NAMEMAP_ENTRY *a, const NAMEMAP_ENTRY *b)
+{
+    return strcmp(a->name, b->name);
+}
+
+static void namemap_free(NAMEMAP_ENTRY *n)
+{
+    OPENSSL_free(n);
+}
+
+/* OPENSSL_CTX_METHOD functions for a namemap stored in a library context */
+
+static void *stored_namemap_new(OPENSSL_CTX *libctx)
+{
+    OSSL_NAMEMAP *namemap = ossl_namemap_new();
+
+    if (namemap != NULL)
+        namemap->stored = 1;
+
+    return namemap;
+}
+
+static void stored_namemap_free(void *vnamemap)
+{
+    OSSL_NAMEMAP *namemap = vnamemap;
+
+    /* Pretend it isn't stored, or ossl_namemap_free() will do nothing */
+    namemap->stored = 0;
+    ossl_namemap_free(namemap);
+}
+
+static const OPENSSL_CTX_METHOD stored_namemap_method = {
+    stored_namemap_new,
+    stored_namemap_free,
+};
+
+/* API functions */
+
+OSSL_NAMEMAP *ossl_namemap_stored(OPENSSL_CTX *libctx)
+{
+    return openssl_ctx_get_data(libctx, OPENSSL_CTX_NAMEMAP_INDEX,
+                                &stored_namemap_method);
+}
+
+OSSL_NAMEMAP *ossl_namemap_new(void)
+{
+    OSSL_NAMEMAP *namemap;
+
+    if ((namemap = OPENSSL_zalloc(sizeof(*namemap))) != NULL
+        && (namemap->lock = CRYPTO_THREAD_lock_new()) != NULL
+        && (namemap->numname = sk_NAMEMAP_ENTRY_new_null()) != NULL
+        && (namemap->namenum =
+            lh_NAMEMAP_ENTRY_new(namemap_hash, namemap_cmp)) != NULL) {
+        return namemap;
+    }
+
+    ossl_namemap_free(namemap);
+    return NULL;
+}
+
+void ossl_namemap_free(OSSL_NAMEMAP *namemap)
+{
+    if (namemap == NULL || namemap->stored)
+        return;
+
+     /* The elements will be freed by sk_NAMEMAP_ENTRY_pop_free() */
+    lh_NAMEMAP_ENTRY_free(namemap->namenum);
+
+    sk_NAMEMAP_ENTRY_pop_free(namemap->numname, namemap_free);
+
+    CRYPTO_THREAD_lock_free(namemap->lock);
+    OPENSSL_free(namemap);
+}
+
+/*
+ * TODO(3.0) It isn't currently possible to have a default namemap in the
+ * FIPS module because if init and cleanup constraints, so we currently
+ * disable the code that would allow it when FIPS_MODE is defined.
+ */
+
+const char *ossl_namemap_name(const OSSL_NAMEMAP *namemap, int number)
+{
+    NAMEMAP_ENTRY *entry;
+
+#ifndef FIPS_MODE
+    if (namemap == NULL)
+        namemap = ossl_namemap_stored(NULL);
+#endif
+
+    if (namemap == NULL || number == 0)
+        return NULL;
+
+    CRYPTO_THREAD_read_lock(namemap->lock);
+    entry = sk_NAMEMAP_ENTRY_value(namemap->numname, number);
+    CRYPTO_THREAD_unlock(namemap->lock);
+
+    if (entry != NULL)
+        return entry->name;
+    return NULL;
+}
+
+int ossl_namemap_number(const OSSL_NAMEMAP *namemap, const char *name)
+{
+    NAMEMAP_ENTRY *entry, template;
+
+#ifndef FIPS_MODE
+    if (namemap == NULL)
+        namemap = ossl_namemap_stored(NULL);
+#endif
+
+    if (namemap == NULL)
+        return 0;
+
+    template.name = name;
+    CRYPTO_THREAD_read_lock(namemap->lock);
+    entry = lh_NAMEMAP_ENTRY_retrieve(namemap->namenum, &template);
+    CRYPTO_THREAD_unlock(namemap->lock);
+
+    if (entry == NULL)
+        return 0;
+
+    return entry->number;
+}
+
+int ossl_namemap_add(OSSL_NAMEMAP *namemap, const char *name)
+{
+    NAMEMAP_ENTRY *entry;
+    int number;
+
+#ifndef FIPS_MODE
+    if (namemap == NULL)
+        namemap = ossl_namemap_stored(NULL);
+#endif
+
+    if (name == NULL || namemap == NULL)
+        return 0;
+
+    if ((number = ossl_namemap_number(namemap, name)) != 0)
+        return number;           /* Pretend success */
+
+    if ((entry = OPENSSL_zalloc(sizeof(*entry) + strlen(name))) == NULL)
+        goto err;
+
+    strcpy(entry->body, name);
+    entry->name = entry->body;
+
+    CRYPTO_THREAD_write_lock(namemap->lock);
+
+    entry->number = sk_NAMEMAP_ENTRY_push(namemap->numname, entry);
+
+    if (entry->number == 0)
+        goto err;
+
+    (void)lh_NAMEMAP_ENTRY_insert(namemap->namenum, entry);
+    if (lh_NAMEMAP_ENTRY_error(namemap->namenum))
+        goto err;
+
+    CRYPTO_THREAD_unlock(namemap->lock);
+
+    return entry->number;
+
+ err:
+    if (entry != NULL) {
+        if (entry->number != 0)
+            (void)sk_NAMEMAP_ENTRY_pop(namemap->numname);
+        lh_NAMEMAP_ENTRY_delete(namemap->namenum, entry);
+        CRYPTO_THREAD_unlock(namemap->lock);
+    }
+    return 0;
+}