api: add gnutls_hmac_copy() function

Add gnutls_hmac_copy() API to duplicate MAC handler state, which is
necessary for SMB3 support.

Resolves: #787

Signed-off-by: Dmitry Eremin-Solenikov <dbaryshkov@gmail.com>

7 files changed, 39 insertions, 0 deletions

diff --git a/devel/libgnutls-latest-x86_64.abi b/devel/libgnutls-latest-x86_64.abi
index 11c4174508..c63a68d94e 100644
--- a/devel/libgnutls-latest-x86_64.abi
+++ b/devel/libgnutls-latest-x86_64.abi
@@ -309,6 +309,7 @@
     <elf-symbol name='gnutls_hex_encode2' version='GNUTLS_3_4' is-default-version='yes' type='func-type' binding='global-binding' visibility='default-visibility' is-defined='yes'/>
     <elf-symbol name='gnutls_hex_encode' version='GNUTLS_3_4' is-default-version='yes' type='func-type' binding='global-binding' visibility='default-visibility' is-defined='yes'/>
     <elf-symbol name='gnutls_hmac' version='GNUTLS_3_4' is-default-version='yes' type='func-type' binding='global-binding' visibility='default-visibility' is-defined='yes'/>
+    <elf-symbol name='gnutls_hmac_copy' version='GNUTLS_3_6_9' is-default-version='yes' type='func-type' binding='global-binding' visibility='default-visibility' is-defined='yes'/>
     <elf-symbol name='gnutls_hmac_deinit' version='GNUTLS_3_4' is-default-version='yes' type='func-type' binding='global-binding' visibility='default-visibility' is-defined='yes'/>
     <elf-symbol name='gnutls_hmac_fast' version='GNUTLS_3_4' is-default-version='yes' type='func-type' binding='global-binding' visibility='default-visibility' is-defined='yes'/>
     <elf-symbol name='gnutls_hmac_get_len' version='GNUTLS_3_4' is-default-version='yes' type='func-type' binding='global-binding' visibility='default-visibility' is-defined='yes'/>
diff --git a/devel/symbols.last b/devel/symbols.last
index c2287e0f53..e3d5fa22a5 100644
--- a/devel/symbols.last
+++ b/devel/symbols.last
@@ -279,6 +279,7 @@ gnutls_hex_decode@GNUTLS_3_4
 gnutls_hex_encode2@GNUTLS_3_4
 gnutls_hex_encode@GNUTLS_3_4
 gnutls_hmac@GNUTLS_3_4
+gnutls_hmac_copy@GNUTLS_3_6_9
 gnutls_hmac_deinit@GNUTLS_3_4
 gnutls_hmac_fast@GNUTLS_3_4
 gnutls_hmac_get_len@GNUTLS_3_4
diff --git a/doc/Makefile.am b/doc/Makefile.am
index 3ab2ad0049..f5788e7618 100644
--- a/doc/Makefile.am
+++ b/doc/Makefile.am
@@ -1113,6 +1113,8 @@ FUNCS += functions/gnutls_hex_encode2
 FUNCS += functions/gnutls_hex_encode2.short
 FUNCS += functions/gnutls_hmac
 FUNCS += functions/gnutls_hmac.short
+FUNCS += functions/gnutls_hmac_copy
+FUNCS += functions/gnutls_hmac_copy.short
 FUNCS += functions/gnutls_hmac_deinit
 FUNCS += functions/gnutls_hmac_deinit.short
 FUNCS += functions/gnutls_hmac_fast
diff --git a/doc/manpages/Makefile.am b/doc/manpages/Makefile.am
index 063ebcb659..d4d358ea5c 100644
--- a/doc/manpages/Makefile.am
+++ b/doc/manpages/Makefile.am
@@ -358,6 +358,7 @@ APIMANS += gnutls_hex_decode2.3
 APIMANS += gnutls_hex_encode.3
 APIMANS += gnutls_hex_encode2.3
 APIMANS += gnutls_hmac.3
+APIMANS += gnutls_hmac_copy.3
 APIMANS += gnutls_hmac_deinit.3
 APIMANS += gnutls_hmac_fast.3
 APIMANS += gnutls_hmac_get_len.3
diff --git a/lib/crypto-api.c b/lib/crypto-api.c
index 0b6be4eed2..db7a08fd92 100644
--- a/lib/crypto-api.c
+++ b/lib/crypto-api.c
@@ -482,6 +482,38 @@ gnutls_hmac_fast(gnutls_mac_algorithm_t algorithm,
 				digest);
 }
 
+/**
+ * gnutls_hmac_copy:
+ * @handle: is a #gnutls_hmac_hd_t type
+ *
+ * This function will create a copy of MAC context, containing all its current
+ * state. Copying contexts for MACs registered using
+ * gnutls_crypto_register_mac() is not supported and will always result in an
+ * error.
+ *
+ * Returns: new MAC context or NULL in case of an error.
+ *
+ * Since: 3.6.9
+ */
+gnutls_hmac_hd_t gnutls_hmac_copy(gnutls_hmac_hd_t handle)
+{
+	gnutls_hmac_hd_t dig;
+
+	dig = gnutls_malloc(sizeof(mac_hd_st));
+	if (dig == NULL) {
+		gnutls_assert();
+		return NULL;
+	}
+
+	if (_gnutls_mac_copy((const mac_hd_st *) handle, (mac_hd_st *)dig) != GNUTLS_E_SUCCESS) {
+		gnutls_assert();
+		gnutls_free(dig);
+		return NULL;
+	}
+
+	return dig;
+}
+
 /* HASH */
 
 /**
diff --git a/lib/includes/gnutls/crypto.h b/lib/includes/gnutls/crypto.h
index 640924bed5..1afadd8759 100644
--- a/lib/includes/gnutls/crypto.h
+++ b/lib/includes/gnutls/crypto.h
@@ -112,6 +112,7 @@ unsigned gnutls_hmac_get_len(gnutls_mac_algorithm_t algorithm) __GNUTLS_CONST__;
 int gnutls_hmac_fast(gnutls_mac_algorithm_t algorithm,
 		     const void *key, size_t keylen,
 		     const void *text, size_t textlen, void *digest);
+gnutls_hmac_hd_t gnutls_hmac_copy(gnutls_hmac_hd_t handle);
 
 int gnutls_hash_init(gnutls_hash_hd_t * dig,
 		     gnutls_digest_algorithm_t algorithm);
diff --git a/lib/libgnutls.map b/lib/libgnutls.map
index 338cae2b1b..8f504b70f0 100644
--- a/lib/libgnutls.map
+++ b/lib/libgnutls.map
@@ -1290,6 +1290,7 @@ GNUTLS_3_6_9
 {
  global:
 	gnutls_get_system_config_file;
+	gnutls_hmac_copy;
 } GNUTLS_3_6_8;
 
 GNUTLS_FIPS140_3_4 {