EVP_MAC: Add HMAC implementation

Reviewed-by: Paul Dale <paul.dale@oracle.com>
(Merged from https://github.com/openssl/openssl/pull/7483)

2 files changed, 174 insertions, 1 deletions

diff --git a/crypto/hmac/build.info b/crypto/hmac/build.info
index 09f67c2a02..615f170221 100644
--- a/crypto/hmac/build.info
+++ b/crypto/hmac/build.info
@@ -1,3 +1,3 @@
 LIBS=../../libcrypto
 SOURCE[../../libcrypto]=\
-        hmac.c hm_ameth.c hm_pmeth.c
+        hmac.c hm_ameth.c hm_pmeth.c hm_meth.c
diff --git a/crypto/hmac/hm_meth.c b/crypto/hmac/hm_meth.c
new file mode 100644
index 0000000000..fb48830601
--- /dev/null
+++ b/crypto/hmac/hm_meth.c
@@ -0,0 +1,173 @@
+/*
+ * Copyright 2018 The OpenSSL Project Authors. All Rights Reserved.
+ *
+ * Licensed under the OpenSSL license (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 <string.h>
+#include <openssl/err.h>
+#include <openssl/ossl_typ.h>
+#include <openssl/asn1.h>
+#include <openssl/hmac.h>
+#include "internal/evp_int.h"
+
+/* local HMAC context structure */
+
+/* typedef EVP_MAC_IMPL */
+struct evp_mac_impl_st {
+    /* tmpmd and tmpengine are set to NULL after a CMAC_Init call */
+    const EVP_MD *tmpmd;         /* HMAC digest */
+    const ENGINE *tmpengine;     /* HMAC digest engine */
+    HMAC_CTX *ctx;               /* HMAC context */
+};
+
+static EVP_MAC_IMPL *hmac_new(void)
+{
+    EVP_MAC_IMPL *hctx;
+
+    if ((hctx = OPENSSL_zalloc(sizeof(*hctx))) == NULL
+        || (hctx->ctx = HMAC_CTX_new()) == NULL) {
+        OPENSSL_free(hctx);
+        return NULL;
+    }
+
+    return hctx;
+}
+
+static void hmac_free(EVP_MAC_IMPL *hctx)
+{
+    if (hctx != NULL) {
+        HMAC_CTX_free(hctx->ctx);
+        OPENSSL_free(hctx);
+    }
+}
+
+static int hmac_copy(EVP_MAC_IMPL *hdst, EVP_MAC_IMPL *hsrc)
+{
+    if (!HMAC_CTX_copy(hdst->ctx, hsrc->ctx))
+        return 0;
+
+    hdst->tmpengine = hsrc->tmpengine;
+    hdst->tmpmd = hsrc->tmpmd;
+    return 1;
+}
+
+static size_t hmac_size(EVP_MAC_IMPL *hctx)
+{
+    return HMAC_size(hctx->ctx);
+}
+
+static int hmac_init(EVP_MAC_IMPL *hctx)
+{
+    int rv = 1;
+
+    /* HMAC_Init_ex doesn't tolerate all zero params, so we must be careful */
+    if (hctx->tmpmd != NULL)
+        rv = HMAC_Init_ex(hctx->ctx, NULL, 0, hctx->tmpmd,
+                          (ENGINE * )hctx->tmpengine);
+    hctx->tmpengine = NULL;
+    hctx->tmpmd = NULL;
+    return rv;
+}
+
+static int hmac_update(EVP_MAC_IMPL *hctx, const unsigned char *data,
+                       size_t datalen)
+{
+    return HMAC_Update(hctx->ctx, data, datalen);
+}
+
+static int hmac_final(EVP_MAC_IMPL *hctx, unsigned char *out)
+{
+    unsigned int hlen;
+
+    return HMAC_Final(hctx->ctx, out, &hlen);
+}
+
+static int hmac_ctrl(EVP_MAC_IMPL *hctx, int cmd, va_list args)
+{
+    switch (cmd) {
+    case EVP_MAC_CTRL_SET_FLAGS:
+        {
+            unsigned long flags = va_arg(args, unsigned long);
+
+            HMAC_CTX_set_flags(hctx->ctx, flags);
+        }
+        break;
+    case EVP_MAC_CTRL_SET_KEY:
+        {
+            const unsigned char *key = va_arg(args, const unsigned char *);
+            size_t keylen = va_arg(args, size_t);
+            int rv = HMAC_Init_ex(hctx->ctx, key, keylen, hctx->tmpmd,
+                                  (ENGINE *)hctx->tmpengine);
+
+            hctx->tmpengine = NULL;
+            hctx->tmpmd = NULL;
+            return rv;
+        }
+        break;
+    case EVP_MAC_CTRL_SET_MD:
+        hctx->tmpmd = va_arg(args, const EVP_MD *);
+        break;
+    case EVP_MAC_CTRL_SET_ENGINE:
+        hctx->tmpengine = va_arg(args, const ENGINE *);
+        break;
+    default:
+        return -2;
+
+    }
+    return 1;
+}
+
+static int hmac_ctrl_int(EVP_MAC_IMPL *hctx, int cmd, ...)
+{
+    int rv;
+    va_list args;
+
+    va_start(args, cmd);
+    rv = hmac_ctrl(hctx, cmd, args);
+    va_end(args);
+
+    return rv;
+}
+
+static int hmac_ctrl_str_cb(void *hctx, int cmd, void *buf, size_t buflen)
+{
+    return hmac_ctrl_int(hctx, cmd, buf, buflen);
+}
+
+static int hmac_ctrl_str(EVP_MAC_IMPL *hctx, const char *type,
+                         const char *value)
+{
+    if (!value)
+        return 0;
+    if (strcmp(type, "digest") == 0) {
+        const EVP_MD *d = EVP_get_digestbyname(value);
+
+        if (d == NULL)
+            return 0;
+        return hmac_ctrl_int(hctx, EVP_MAC_CTRL_SET_MD, d);
+    }
+    if (strcmp(type, "key") == 0)
+        return EVP_str2ctrl(hmac_ctrl_str_cb, hctx, EVP_MAC_CTRL_SET_KEY,
+                            value);
+    if (strcmp(type, "hexkey") == 0)
+        return EVP_hex2ctrl(hmac_ctrl_str_cb, hctx, EVP_MAC_CTRL_SET_KEY,
+                            value);
+    return -2;
+}
+
+const EVP_MAC hmac_meth = {
+    EVP_MAC_HMAC,
+    hmac_new,
+    hmac_copy,
+    hmac_free,
+    hmac_size,
+    hmac_init,
+    hmac_update,
+    hmac_final,
+    hmac_ctrl,
+    hmac_ctrl_str
+};