Make tls_connection_get_keyblock_size() internal to tls_*.c

This function exposes internal state of the TLS negotiated parameters
for the sole purpose of being able to implement PRF for EAP-FAST. Since
tls_connection_prf() is now taking care of all TLS-based key derivation
cases, it is cleaner to keep this detail internal to each tls_*.c
wrapper implementation.

Signed-off-by: Jouni Malinen <jouni@qca.qualcomm.com>

diff --git a/src/crypto/tls.h b/src/crypto/tls.h
index 97ed8c1ceec31825d300904564b52c4e56fdf4b4..f9e2e10ef14cfaeadac02aa91116b29ed9ad2858 100644 (file)
--- a/src/crypto/tls.h
+++ b/src/crypto/tls.h
@@ -323,6 +323,7 @@ int __must_check tls_connection_get_keys(void *tls_ctx,
  * @label: Label (e.g., description of the key) for PRF
  * @server_random_first: seed is 0 = client_random|server_random,
  * 1 = server_random|client_random
+ * @skip_keyblock: Skip TLS key block from the beginning of PRF output
  * @out: Buffer for output data from TLS-PRF
  * @out_len: Length of the output buffer
  * Returns: 0 on success, -1 on failure
@@ -340,6 +341,7 @@ int __must_check  tls_connection_prf(void *tls_ctx,
                                     struct tls_connection *conn,
                                     const char *label,
                                     int server_random_first,
+                                    int skip_keyblock,
                                     u8 *out, size_t out_len);
 
 /**
@@ -525,16 +527,6 @@ int tls_connection_get_read_alerts(void *tls_ctx, struct tls_connection *conn);
 int tls_connection_get_write_alerts(void *tls_ctx,
                                    struct tls_connection *conn);
 
-/**
- * tls_connection_get_keyblock_size - Get TLS key_block size
- * @tls_ctx: TLS context data from tls_init()
- * @conn: Connection context data from tls_connection_init()
- * Returns: Size of the key_block for the negotiated cipher suite or -1 on
- * failure
- */
-int tls_connection_get_keyblock_size(void *tls_ctx,
-                                    struct tls_connection *conn);
-
 /**
  * tls_capabilities - Get supported TLS capabilities
  * @tls_ctx: TLS context data from tls_init()

diff --git a/src/crypto/tls_gnutls.c b/src/crypto/tls_gnutls.c
index 65db6fcc256539b8dd2f55c0bce5cf21464e2ab9..c7f6464b92e695e1793dc369340a8ffe91f4b994 100644 (file)
--- a/src/crypto/tls_gnutls.c
+++ b/src/crypto/tls_gnutls.c
@@ -747,9 +747,9 @@ int tls_connection_get_keys(void *ssl_ctx, struct tls_connection *conn,
 
 int tls_connection_prf(void *tls_ctx, struct tls_connection *conn,
                       const char *label, int server_random_first,
-                      u8 *out, size_t out_len)
+                      int skip_keyblock, u8 *out, size_t out_len)
 {
-       if (conn == NULL || conn->session == NULL)
+       if (conn == NULL || conn->session == NULL || skip_keyblock)
                return -1;
 
        return gnutls_prf(conn->session, os_strlen(label), label,
@@ -1476,14 +1476,6 @@ int tls_connection_get_write_alerts(void *ssl_ctx, struct tls_connection *conn)
 }
 
 
-int tls_connection_get_keyblock_size(void *tls_ctx,
-                                    struct tls_connection *conn)
-{
-       /* TODO */
-       return -1;
-}
-
-
 unsigned int tls_capabilities(void *tls_ctx)
 {
        return 0;

diff --git a/src/crypto/tls_internal.c b/src/crypto/tls_internal.c
index 0c955da29f1d51ff8839378a86e91ef8d38be33a..19a2d5a99d51219893b28e78268fdf4ba4e1c2f5 100644 (file)
--- a/src/crypto/tls_internal.c
+++ b/src/crypto/tls_internal.c
@@ -348,25 +348,57 @@ int tls_connection_get_keys(void *tls_ctx, struct tls_connection *conn,
 }
 
 
+static int tls_get_keyblock_size(struct tls_connection *conn)
+{
+#ifdef CONFIG_TLS_INTERNAL_CLIENT
+       if (conn->client)
+               return tlsv1_client_get_keyblock_size(conn->client);
+#endif /* CONFIG_TLS_INTERNAL_CLIENT */
+#ifdef CONFIG_TLS_INTERNAL_SERVER
+       if (conn->server)
+               return tlsv1_server_get_keyblock_size(conn->server);
+#endif /* CONFIG_TLS_INTERNAL_SERVER */
+       return -1;
+}
+
+
 int tls_connection_prf(void *tls_ctx, struct tls_connection *conn,
                       const char *label, int server_random_first,
-                      u8 *out, size_t out_len)
-{
+                      int skip_keyblock, u8 *out, size_t out_len)
+{
+       int ret = -1, skip = 0;
+       u8 *tmp_out = NULL;
+       u8 *_out = out;
+
+       if (skip_keyblock) {
+               skip = tls_get_keyblock_size(conn);
+               if (skip < 0)
+                       return -1;
+               tmp_out = os_malloc(skip + out_len);
+               if (!tmp_out)
+                       return -1;
+               _out = tmp_out;
+       }
+
 #ifdef CONFIG_TLS_INTERNAL_CLIENT
        if (conn->client) {
-               return tlsv1_client_prf(conn->client, label,
-                                       server_random_first,
-                                       out, out_len);
+               ret = tlsv1_client_prf(conn->client, label,
+                                      server_random_first,
+                                      _out, out_len);
        }
 #endif /* CONFIG_TLS_INTERNAL_CLIENT */
 #ifdef CONFIG_TLS_INTERNAL_SERVER
        if (conn->server) {
-               return tlsv1_server_prf(conn->server, label,
-                                       server_random_first,
-                                       out, out_len);
+               ret = tlsv1_server_prf(conn->server, label,
+                                      server_random_first,
+                                      _out, out_len);
        }
 #endif /* CONFIG_TLS_INTERNAL_SERVER */
-       return -1;
+       if (ret == 0 && skip_keyblock)
+               os_memcpy(out, _out + skip, out_len);
+       bin_clear_free(tmp_out, skip);
+
+       return ret;
 }
 
 
@@ -637,21 +669,6 @@ int tls_connection_get_write_alerts(void *tls_ctx,
 }
 
 
-int tls_connection_get_keyblock_size(void *tls_ctx,
-                                    struct tls_connection *conn)
-{
-#ifdef CONFIG_TLS_INTERNAL_CLIENT
-       if (conn->client)
-               return tlsv1_client_get_keyblock_size(conn->client);
-#endif /* CONFIG_TLS_INTERNAL_CLIENT */
-#ifdef CONFIG_TLS_INTERNAL_SERVER
-       if (conn->server)
-               return tlsv1_server_get_keyblock_size(conn->server);
-#endif /* CONFIG_TLS_INTERNAL_SERVER */
-       return -1;
-}
-
-
 unsigned int tls_capabilities(void *tls_ctx)
 {
        return 0;

diff --git a/src/crypto/tls_none.c b/src/crypto/tls_none.c
index a6d210afcf0f3bea47c47f336589a2f992e80a4e..1b1ba569755260679491704e8174b666f2e93104 100644 (file)
--- a/src/crypto/tls_none.c
+++ b/src/crypto/tls_none.c
@@ -87,7 +87,7 @@ int tls_connection_get_keys(void *tls_ctx, struct tls_connection *conn,
 
 int tls_connection_prf(void *tls_ctx, struct tls_connection *conn,
                       const char *label, int server_random_first,
-                      u8 *out, size_t out_len)
+                      int skip_keyblock, u8 *out, size_t out_len)
 {
        return -1;
 }
@@ -181,13 +181,6 @@ int tls_connection_get_write_alerts(void *tls_ctx,
 }
 
 
-int tls_connection_get_keyblock_size(void *tls_ctx,
-                                    struct tls_connection *conn)
-{
-       return -1;
-}
-
-
 unsigned int tls_capabilities(void *tls_ctx)
 {
        return 0;

diff --git a/src/crypto/tls_openssl.c b/src/crypto/tls_openssl.c
index 00e44799b5fa9c9e005312dde8365e8172e4b045..935add5aa72d9e187cff425bf51a04c7079dda36 100644 (file)
--- a/src/crypto/tls_openssl.c
+++ b/src/crypto/tls_openssl.c
@@ -2643,9 +2643,43 @@ int tls_connection_get_keys(void *ssl_ctx, struct tls_connection *conn,
 }
 
 
+static int openssl_get_keyblock_size(SSL *ssl)
+{
+       const EVP_CIPHER *c;
+       const EVP_MD *h;
+       int md_size;
+
+       if (ssl->enc_read_ctx == NULL || ssl->enc_read_ctx->cipher == NULL ||
+           ssl->read_hash == NULL)
+               return -1;
+
+       c = ssl->enc_read_ctx->cipher;
+#if OPENSSL_VERSION_NUMBER >= 0x00909000L
+       h = EVP_MD_CTX_md(ssl->read_hash);
+#else
+       h = conn->ssl->read_hash;
+#endif
+       if (h)
+               md_size = EVP_MD_size(h);
+#if OPENSSL_VERSION_NUMBER >= 0x10000000L
+       else if (ssl->s3)
+               md_size = ssl->s3->tmp.new_mac_secret_size;
+#endif
+       else
+               return -1;
+
+       wpa_printf(MSG_DEBUG, "OpenSSL: keyblock size: key_len=%d MD_size=%d "
+                  "IV_len=%d", EVP_CIPHER_key_length(c), md_size,
+                  EVP_CIPHER_iv_length(c));
+       return 2 * (EVP_CIPHER_key_length(c) +
+                   md_size +
+                   EVP_CIPHER_iv_length(c));
+}
+
+
 static int openssl_tls_prf(void *tls_ctx, struct tls_connection *conn,
                           const char *label, int server_random_first,
-                          u8 *out, size_t out_len)
+                          int skip_keyblock, u8 *out, size_t out_len)
 {
 #ifdef CONFIG_FIPS
        wpa_printf(MSG_ERROR, "OpenSSL: TLS keys cannot be exported in FIPS "
@@ -2655,6 +2689,9 @@ static int openssl_tls_prf(void *tls_ctx, struct tls_connection *conn,
        SSL *ssl;
        u8 *rnd;
        int ret = -1;
+       int skip = 0;
+       u8 *tmp_out = NULL;
+       u8 *_out = out;
 
        /*
         * TLS library did not support key generation, so get the needed TLS
@@ -2670,6 +2707,16 @@ static int openssl_tls_prf(void *tls_ctx, struct tls_connection *conn,
            ssl->session->master_key == NULL)
                return -1;
 
+       if (skip_keyblock) {
+               skip = openssl_get_keyblock_size(ssl);
+               if (skip < 0)
+                       return -1;
+               tmp_out = os_malloc(skip + out_len);
+               if (!tmp_out)
+                       return -1;
+               _out = tmp_out;
+       }
+
        rnd = os_malloc(2 * SSL3_RANDOM_SIZE);
        if (rnd == NULL)
                return -1;
@@ -2688,9 +2735,12 @@ static int openssl_tls_prf(void *tls_ctx, struct tls_connection *conn,
        if (tls_prf_sha1_md5(ssl->session->master_key,
                             ssl->session->master_key_length,
                             label, rnd, 2 * SSL3_RANDOM_SIZE,
-                            out, out_len) == 0)
+                            _out, skip + out_len) == 0)
                ret = 0;
        os_free(rnd);
+       if (ret == 0 && skip_keyblock)
+               os_memcpy(out, _out + skip, out_len);
+       bin_clear_free(tmp_out, skip);
 
        return ret;
 #endif /* CONFIG_FIPS */
@@ -2699,15 +2749,16 @@ static int openssl_tls_prf(void *tls_ctx, struct tls_connection *conn,
 
 int tls_connection_prf(void *tls_ctx, struct tls_connection *conn,
                       const char *label, int server_random_first,
-                      u8 *out, size_t out_len)
+                      int skip_keyblock, u8 *out, size_t out_len)
 {
 #if OPENSSL_VERSION_NUMBER >= 0x10001000L
        SSL *ssl;
        if (conn == NULL)
                return -1;
-       if (server_random_first)
+       if (server_random_first || skip_keyblock)
                return openssl_tls_prf(tls_ctx, conn, label,
-                                      server_random_first, out, out_len);
+                                      server_random_first, skip_keyblock,
+                                      out, out_len);
        ssl = conn->ssl;
        if (SSL_export_keying_material(ssl, out, out_len, label,
                                       os_strlen(label), NULL, 0, 0) == 1) {
@@ -2716,7 +2767,7 @@ int tls_connection_prf(void *tls_ctx, struct tls_connection *conn,
        }
 #endif
        return openssl_tls_prf(tls_ctx, conn, label, server_random_first,
-                              out, out_len);
+                              skip_keyblock, out, out_len);
 }
 
 
@@ -3569,43 +3620,6 @@ int tls_global_set_params(void *tls_ctx,
 }
 
 
-int tls_connection_get_keyblock_size(void *tls_ctx,
-                                    struct tls_connection *conn)
-{
-       const EVP_CIPHER *c;
-       const EVP_MD *h;
-       int md_size;
-
-       if (conn == NULL || conn->ssl == NULL ||
-           conn->ssl->enc_read_ctx == NULL ||
-           conn->ssl->enc_read_ctx->cipher == NULL ||
-           conn->ssl->read_hash == NULL)
-               return -1;
-
-       c = conn->ssl->enc_read_ctx->cipher;
-#if OPENSSL_VERSION_NUMBER >= 0x00909000L
-       h = EVP_MD_CTX_md(conn->ssl->read_hash);
-#else
-       h = conn->ssl->read_hash;
-#endif
-       if (h)
-               md_size = EVP_MD_size(h);
-#if OPENSSL_VERSION_NUMBER >= 0x10000000L
-       else if (conn->ssl->s3)
-               md_size = conn->ssl->s3->tmp.new_mac_secret_size;
-#endif
-       else
-               return -1;
-
-       wpa_printf(MSG_DEBUG, "OpenSSL: keyblock size: key_len=%d MD_size=%d "
-                  "IV_len=%d", EVP_CIPHER_key_length(c), md_size,
-                  EVP_CIPHER_iv_length(c));
-       return 2 * (EVP_CIPHER_key_length(c) +
-                   md_size +
-                   EVP_CIPHER_iv_length(c));
-}
-
-
 unsigned int tls_capabilities(void *tls_ctx)
 {
        return 0;

diff --git a/src/eap_common/eap_fast_common.c b/src/eap_common/eap_fast_common.c
index 5b4118935bdcd197c7b861edd29a722b2f623c13..151cc7859c5da8cf8e9972930da992530d382707 100644 (file)
--- a/src/eap_common/eap_fast_common.c
+++ b/src/eap_common/eap_fast_common.c
@@ -97,24 +97,16 @@ u8 * eap_fast_derive_key(void *ssl_ctx, struct tls_connection *conn,
                         const char *label, size_t len)
 {
        u8 *out;
-       int block_size;
 
-       block_size = tls_connection_get_keyblock_size(ssl_ctx, conn);
-       if (block_size < 0)
-               return NULL;
-
-       out = os_malloc(block_size + len);
+       out = os_malloc(len);
        if (out == NULL)
                return NULL;
 
-       if (tls_connection_prf(ssl_ctx, conn, label, 1, out, block_size + len))
-       {
+       if (tls_connection_prf(ssl_ctx, conn, label, 1, 1, out, len)) {
                os_free(out);
                return NULL;
        }
 
-       os_memmove(out, out + block_size, len);
-       os_memset(out + len, 0, block_size);
        return out;
 }
 

diff --git a/src/eap_peer/eap_tls_common.c b/src/eap_peer/eap_tls_common.c
index e5a6ee5e4ed2894f6cf3dc2f6f2e4e3d74aff468..b1180d5e75517007d4ce691be91c1f1d85a60b0e 100644 (file)
--- a/src/eap_peer/eap_tls_common.c
+++ b/src/eap_peer/eap_tls_common.c
@@ -319,7 +319,8 @@ u8 * eap_peer_tls_derive_key(struct eap_sm *sm, struct eap_ssl_data *data,
        if (out == NULL)
                return NULL;
 
-       if (tls_connection_prf(data->ssl_ctx, data->conn, label, 0, out, len)) {
+       if (tls_connection_prf(data->ssl_ctx, data->conn, label, 0, 0,
+                              out, len)) {
                os_free(out);
                return NULL;
        }

diff --git a/src/eap_server/eap_server_tls_common.c b/src/eap_server/eap_server_tls_common.c
index 09f2a82d01e3cf8d755d8be5b6211469fc26235b..23498c99865044abe72bdfd0fa6693cd41f0edb9 100644 (file)
--- a/src/eap_server/eap_server_tls_common.c
+++ b/src/eap_server/eap_server_tls_common.c
@@ -106,7 +106,8 @@ u8 * eap_server_tls_derive_key(struct eap_sm *sm, struct eap_ssl_data *data,
        if (out == NULL)
                return NULL;
 
-       if (tls_connection_prf(sm->ssl_ctx, data->conn, label, 0, out, len)) {
+       if (tls_connection_prf(sm->ssl_ctx, data->conn, label, 0, 0,
+                              out, len)) {
                os_free(out);
                return NULL;
        }