Move SHA256-based PRF function into a separate C file

This makes it easier to conditionally build in SHA256 functions based
on which TLS/crypto library is used.

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

diff --git a/hostapd/Android.mk b/hostapd/Android.mk
index 5a0136b..23d86f0 100644 (file)
--- a/hostapd/Android.mk
+++ b/hostapd/Android.mk
@@ -721,6 +721,7 @@ endif
 
 ifdef NEED_SHA256
 OBJS += src/crypto/sha256.c
+OBJS += src/crypto/sha256-prf.c
 ifdef CONFIG_INTERNAL_SHA256
 OBJS += src/crypto/sha256-internal.c
 endif

diff --git a/hostapd/Makefile b/hostapd/Makefile
index 120eca6..c2f0530 100644 (file)
--- a/hostapd/Makefile
+++ b/hostapd/Makefile
@@ -713,6 +713,7 @@ endif
 ifdef NEED_SHA256
 CFLAGS += -DCONFIG_SHA256
 OBJS += ../src/crypto/sha256.o
+OBJS += ../src/crypto/sha256-prf.o
 ifdef CONFIG_INTERNAL_SHA256
 OBJS += ../src/crypto/sha256-internal.o
 endif

diff --git a/src/crypto/sha256-prf.c b/src/crypto/sha256-prf.c
new file mode 100644 (file)
index 0000000..0da6d13
--- /dev/null
+++ b/src/crypto/sha256-prf.c
@@ -0,0 +1,64 @@
+/*
+ * SHA256-based PRF (IEEE 802.11r)
+ * Copyright (c) 2003-2007, Jouni Malinen <j@w1.fi>
+ *
+ * This software may be distributed under the terms of the BSD license.
+ * See README for more details.
+ */
+
+#include "includes.h"
+
+#include "common.h"
+#include "sha256.h"
+#include "crypto.h"
+
+
+/**
+ * sha256_prf - SHA256-based Pseudo-Random Function (IEEE 802.11r, 8.5.1.5.2)
+ * @key: Key for PRF
+ * @key_len: Length of the key in bytes
+ * @label: A unique label for each purpose of the PRF
+ * @data: Extra data to bind into the key
+ * @data_len: Length of the data
+ * @buf: Buffer for the generated pseudo-random key
+ * @buf_len: Number of bytes of key to generate
+ *
+ * This function is used to derive new, cryptographically separate keys from a
+ * given key.
+ */
+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)
+{
+       u16 counter = 1;
+       size_t pos, plen;
+       u8 hash[SHA256_MAC_LEN];
+       const u8 *addr[4];
+       size_t len[4];
+       u8 counter_le[2], length_le[2];
+
+       addr[0] = counter_le;
+       len[0] = 2;
+       addr[1] = (u8 *) label;
+       len[1] = os_strlen(label);
+       addr[2] = data;
+       len[2] = data_len;
+       addr[3] = length_le;
+       len[3] = sizeof(length_le);
+
+       WPA_PUT_LE16(length_le, buf_len * 8);
+       pos = 0;
+       while (pos < buf_len) {
+               plen = buf_len - pos;
+               WPA_PUT_LE16(counter_le, counter);
+               if (plen >= SHA256_MAC_LEN) {
+                       hmac_sha256_vector(key, key_len, 4, addr, len,
+                                          &buf[pos]);
+                       pos += SHA256_MAC_LEN;
+               } else {
+                       hmac_sha256_vector(key, key_len, 4, addr, len, hash);
+                       os_memcpy(&buf[pos], hash, plen);
+                       break;
+               }
+               counter++;
+       }
+}

diff --git a/src/crypto/sha256.c b/src/crypto/sha256.c
index 5c09ed1..493acda 100644 (file)
--- a/src/crypto/sha256.c
+++ b/src/crypto/sha256.c
@@ -98,54 +98,3 @@ void hmac_sha256(const u8 *key, size_t key_len, const u8 *data,
 {
        hmac_sha256_vector(key, key_len, 1, &data, &data_len, mac);
 }
-
-
-/**
- * sha256_prf - SHA256-based Pseudo-Random Function (IEEE 802.11r, 8.5.1.5.2)
- * @key: Key for PRF
- * @key_len: Length of the key in bytes
- * @label: A unique label for each purpose of the PRF
- * @data: Extra data to bind into the key
- * @data_len: Length of the data
- * @buf: Buffer for the generated pseudo-random key
- * @buf_len: Number of bytes of key to generate
- *
- * This function is used to derive new, cryptographically separate keys from a
- * given key.
- */
-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)
-{
-       u16 counter = 1;
-       size_t pos, plen;
-       u8 hash[SHA256_MAC_LEN];
-       const u8 *addr[4];
-       size_t len[4];
-       u8 counter_le[2], length_le[2];
-
-       addr[0] = counter_le;
-       len[0] = 2;
-       addr[1] = (u8 *) label;
-       len[1] = os_strlen(label);
-       addr[2] = data;
-       len[2] = data_len;
-       addr[3] = length_le;
-       len[3] = sizeof(length_le);
-
-       WPA_PUT_LE16(length_le, buf_len * 8);
-       pos = 0;
-       while (pos < buf_len) {
-               plen = buf_len - pos;
-               WPA_PUT_LE16(counter_le, counter);
-               if (plen >= SHA256_MAC_LEN) {
-                       hmac_sha256_vector(key, key_len, 4, addr, len,
-                                          &buf[pos]);
-                       pos += SHA256_MAC_LEN;
-               } else {
-                       hmac_sha256_vector(key, key_len, 4, addr, len, hash);
-                       os_memcpy(&buf[pos], hash, plen);
-                       break;
-               }
-               counter++;
-       }
-}

diff --git a/wpa_supplicant/Android.mk b/wpa_supplicant/Android.mk
index 9b51f07..d0254ab 100644 (file)
--- a/wpa_supplicant/Android.mk
+++ b/wpa_supplicant/Android.mk
@@ -1123,6 +1123,7 @@ SHA256OBJS = # none by default
 ifdef NEED_SHA256
 L_CFLAGS += -DCONFIG_SHA256
 SHA256OBJS += src/crypto/sha256.c
+SHA256OBJS += src/crypto/sha256-prf.c
 ifdef CONFIG_INTERNAL_SHA256
 SHA256OBJS += src/crypto/sha256-internal.c
 endif

diff --git a/wpa_supplicant/Makefile b/wpa_supplicant/Makefile
index 70c5788..2f42ea1 100644 (file)
--- a/wpa_supplicant/Makefile
+++ b/wpa_supplicant/Makefile
@@ -1154,6 +1154,7 @@ SHA256OBJS = # none by default
 ifdef NEED_SHA256
 CFLAGS += -DCONFIG_SHA256
 SHA256OBJS += ../src/crypto/sha256.o
+SHA256OBJS += ../src/crypto/sha256-prf.o
 ifdef CONFIG_INTERNAL_SHA256
 SHA256OBJS += ../src/crypto/sha256-internal.o
 endif