OpenSSL: Implement SHA256 HMAC functions using HMAC API

Use the OpenSSL HMAC implementation instead of the internal sha256.c
implementation of HMAC with SHA256.

Signed-hostap: Jouni Malinen <j@w1.fi>

hostapd/Android.mk

@@ -720,7 +720,9 @@ endif
 endif
 
 ifdef NEED_SHA256
+ifneq ($(CONFIG_TLS), openssl)
 OBJS += src/crypto/sha256.c
+endif
 OBJS += src/crypto/sha256-prf.c
 ifdef CONFIG_INTERNAL_SHA256
 OBJS += src/crypto/sha256-internal.c

hostapd/Makefile

@@ -712,7 +712,9 @@ endif
 
 ifdef NEED_SHA256
 CFLAGS += -DCONFIG_SHA256
+ifneq ($(CONFIG_TLS), openssl)
 OBJS += ../src/crypto/sha256.o
+endif
 OBJS += ../src/crypto/sha256-prf.o
 ifdef CONFIG_INTERNAL_SHA256
 OBJS += ../src/crypto/sha256-internal.o

src/crypto/crypto_openssl.c

@@ -744,6 +744,49 @@ int hmac_sha1(const u8 *key, size_t key_len, const u8 *data, size_t data_len,
 }
 
 
+#ifdef CONFIG_SHA256
+
+int hmac_sha256_vector(const u8 *key, size_t key_len, size_t num_elem,
+		       const u8 *addr[], const size_t *len, u8 *mac)
+{
+	HMAC_CTX ctx;
+	size_t i;
+	unsigned int mdlen;
+	int res;
+
+	HMAC_CTX_init(&ctx);
+#if OPENSSL_VERSION_NUMBER < 0x00909000
+	HMAC_Init_ex(&ctx, key, key_len, EVP_sha256(), NULL);
+#else /* openssl < 0.9.9 */
+	if (HMAC_Init_ex(&ctx, key, key_len, EVP_sha256(), NULL) != 1)
+		return -1;
+#endif /* openssl < 0.9.9 */
+
+	for (i = 0; i < num_elem; i++)
+		HMAC_Update(&ctx, addr[i], len[i]);
+
+	mdlen = 32;
+#if OPENSSL_VERSION_NUMBER < 0x00909000
+	HMAC_Final(&ctx, mac, &mdlen);
+	res = 1;
+#else /* openssl < 0.9.9 */
+	res = HMAC_Final(&ctx, mac, &mdlen);
+#endif /* openssl < 0.9.9 */
+	HMAC_CTX_cleanup(&ctx);
+
+	return res == 1 ? 0 : -1;
+}
+
+
+int hmac_sha256(const u8 *key, size_t key_len, const u8 *data,
+		size_t data_len, u8 *mac)
+{
+	return hmac_sha256_vector(key, key_len, 1, &data, &data_len, mac);
+}
+
+#endif /* CONFIG_SHA256 */
+
+
 int crypto_get_random(void *buf, size_t len)
 {
 	if (RAND_bytes(buf, len) != 1)

src/crypto/sha256.c

@@ -1,6 +1,6 @@
 /*
  * SHA-256 hash implementation and interface functions
- * Copyright (c) 2003-2007, Jouni Malinen <j@w1.fi>
+ * Copyright (c) 2003-2012, Jouni Malinen <j@w1.fi>
  *
  * This software may be distributed under the terms of the BSD license.
  * See README for more details.
@@ -21,9 +21,10 @@
  * @addr: Pointers to the data areas
  * @len: Lengths of the data blocks
  * @mac: Buffer for the hash (32 bytes)
+ * Returns: 0 on success, -1 on failure
  */
-void hmac_sha256_vector(const u8 *key, size_t key_len, size_t num_elem,
-			const u8 *addr[], const size_t *len, u8 *mac)
+int hmac_sha256_vector(const u8 *key, size_t key_len, size_t num_elem,
+		       const u8 *addr[], const size_t *len, u8 *mac)
 {
 	unsigned char k_pad[64]; /* padding - key XORd with ipad/opad */
 	unsigned char tk[32];
@@ -35,12 +36,13 @@ void hmac_sha256_vector(const u8 *key, size_t key_len, size_t num_elem,
 		 * Fixed limit on the number of fragments to avoid having to
 		 * allocate memory (which could fail).
 		 */
-		return;
+		return -1;
 	}
 
         /* if key is longer than 64 bytes reset it to key = SHA256(key) */
         if (key_len > 64) {
-		sha256_vector(1, &key, &key_len, tk);
+		if (sha256_vector(1, &key, &key_len, tk) < 0)
+			return -1;
 		key = tk;
 		key_len = 32;
         }
@@ -68,7 +70,8 @@ void hmac_sha256_vector(const u8 *key, size_t key_len, size_t num_elem,
 		_addr[i + 1] = addr[i];
 		_len[i + 1] = len[i];
 	}
-	sha256_vector(1 + num_elem, _addr, _len, mac);
+	if (sha256_vector(1 + num_elem, _addr, _len, mac) < 0)
+		return -1;
 
 	os_memset(k_pad, 0, sizeof(k_pad));
 	os_memcpy(k_pad, key, key_len);
@@ -81,7 +84,7 @@ void hmac_sha256_vector(const u8 *key, size_t key_len, size_t num_elem,
 	_len[0] = 64;
 	_addr[1] = mac;
 	_len[1] = SHA256_MAC_LEN;
-	sha256_vector(2, _addr, _len, mac);
+	return sha256_vector(2, _addr, _len, mac);
 }
 
 
@@ -91,10 +94,11 @@ void hmac_sha256_vector(const u8 *key, size_t key_len, size_t num_elem,
  * @key_len: Length of the key in bytes
  * @data: Pointers to the data area
  * @data_len: Length of the data area
- * @mac: Buffer for the hash (20 bytes)
+ * @mac: Buffer for the hash (32 bytes)
+ * Returns: 0 on success, -1 on failure
  */
-void hmac_sha256(const u8 *key, size_t key_len, const u8 *data,
-		 size_t data_len, u8 *mac)
+int hmac_sha256(const u8 *key, size_t key_len, const u8 *data,
+		size_t data_len, u8 *mac)
 {
-	hmac_sha256_vector(key, key_len, 1, &data, &data_len, mac);
+	return hmac_sha256_vector(key, key_len, 1, &data, &data_len, mac);
 }

src/crypto/sha256.h

@@ -11,10 +11,10 @@
 
 #define SHA256_MAC_LEN 32
 
-void hmac_sha256_vector(const u8 *key, size_t key_len, size_t num_elem,
-		      const u8 *addr[], const size_t *len, u8 *mac);
-void hmac_sha256(const u8 *key, size_t key_len, const u8 *data,
-		 size_t data_len, u8 *mac);
+int hmac_sha256_vector(const u8 *key, size_t key_len, size_t num_elem,
+		       const u8 *addr[], const size_t *len, u8 *mac);
+int hmac_sha256(const u8 *key, size_t key_len, const u8 *data,
+		size_t data_len, u8 *mac);
 void sha256_prf(const u8 *key, size_t key_len, const char *label,
 	      const u8 *data, size_t data_len, u8 *buf, size_t buf_len);
 void tls_prf_sha256(const u8 *secret, size_t secret_len,

wpa_supplicant/Android.mk

@@ -1122,7 +1122,9 @@ endif
 SHA256OBJS = # none by default
 ifdef NEED_SHA256
 L_CFLAGS += -DCONFIG_SHA256
+ifneq ($(CONFIG_TLS), openssl)
 SHA256OBJS += src/crypto/sha256.c
+endif
 SHA256OBJS += src/crypto/sha256-prf.c
 ifdef CONFIG_INTERNAL_SHA256
 SHA256OBJS += src/crypto/sha256-internal.c

wpa_supplicant/Makefile

@@ -1153,7 +1153,9 @@ endif
 SHA256OBJS = # none by default
 ifdef NEED_SHA256
 CFLAGS += -DCONFIG_SHA256
+ifneq ($(CONFIG_TLS), openssl)
 SHA256OBJS += ../src/crypto/sha256.o
+endif
 SHA256OBJS += ../src/crypto/sha256-prf.o
 ifdef CONFIG_INTERNAL_SHA256
 SHA256OBJS += ../src/crypto/sha256-internal.o