From 7cba52d8523869237c0f7708cfac39a98558490d Mon Sep 17 00:00:00 2001
From: Jouni Malinen <j@w1.fi>
Date: Sun, 16 Aug 2009 22:26:13 +0300
Subject: [PATCH] Use OpenSSL for RC4 instead of internal implementation

---
 hostapd/Makefile            |  1 -
 src/crypto/crypto_openssl.c | 37 +++++++++++++++++++++++++++++++++++++
 wpa_supplicant/Makefile     |  1 -
 3 files changed, 37 insertions(+), 2 deletions(-)

diff --git a/hostapd/Makefile b/hostapd/Makefile
index 226f0fccb..9f8ec81fe 100644
--- a/hostapd/Makefile
+++ b/hostapd/Makefile
@@ -436,7 +436,6 @@ ifdef NEED_FIPS186_2_PRF
 OBJS += ../src/crypto/fips_prf_openssl.o
 OBJS_p += ../src/crypto/fips_prf_openssl.o
 endif
-CONFIG_INTERNAL_RC4=y
 endif
 ifeq ($(CONFIG_TLS), gnutls)
 OBJS += ../src/crypto/crypto_gnutls.o
diff --git a/src/crypto/crypto_openssl.c b/src/crypto/crypto_openssl.c
index 2c865f0de..e8ea89584 100644
--- a/src/crypto/crypto_openssl.c
+++ b/src/crypto/crypto_openssl.c
@@ -96,6 +96,43 @@ void des_encrypt(const u8 *clear, const u8 *key, u8 *cypher)
 }
 
 
+int rc4_skip(const u8 *key, size_t keylen, size_t skip,
+	     u8 *data, size_t data_len)
+{
+#ifdef OPENSSL_NO_RC4
+	return -1;
+#else /* OPENSSL_NO_RC4 */
+	EVP_CIPHER_CTX ctx;
+	int outl;
+	int res = -1;
+	unsigned char skip_buf[16];
+
+	EVP_CIPHER_CTX_init(&ctx);
+	if (!EVP_CIPHER_CTX_set_padding(&ctx, 0) ||
+	    !EVP_CipherInit_ex(&ctx, EVP_rc4(), NULL, NULL, NULL, 1) ||
+	    !EVP_CIPHER_CTX_set_key_length(&ctx, keylen) ||
+	    !EVP_CipherInit_ex(&ctx, NULL, NULL, key, NULL, 1))
+		goto out;
+
+	while (skip >= sizeof(skip_buf)) {
+		size_t len = skip;
+		if (len > sizeof(skip_buf))
+			len = sizeof(skip_buf);
+		if (!EVP_CipherUpdate(&ctx, skip_buf, &outl, skip_buf, len))
+			goto out;
+		skip -= len;
+	}
+
+	if (EVP_CipherUpdate(&ctx, data, &outl, data, data_len))
+		res = 0;
+
+out:
+	EVP_CIPHER_CTX_cleanup(&ctx);
+	return res;
+#endif /* OPENSSL_NO_RC4 */
+}
+
+
 int md5_vector(size_t num_elem, const u8 *addr[], const size_t *len, u8 *mac)
 {
 	return openssl_digest_vector(EVP_md5(), 0, num_elem, addr, len, mac);
diff --git a/wpa_supplicant/Makefile b/wpa_supplicant/Makefile
index ac200d268..e4bef9680 100644
--- a/wpa_supplicant/Makefile
+++ b/wpa_supplicant/Makefile
@@ -732,7 +732,6 @@ OBJS_p += ../src/crypto/crypto_openssl.o
 ifdef NEED_FIPS186_2_PRF
 OBJS += ../src/crypto/fips_prf_openssl.o
 endif
-CONFIG_INTERNAL_RC4=y
 endif
 ifeq ($(CONFIG_TLS), gnutls)
 OBJS += ../src/crypto/crypto_gnutls.o