refactor: cleanup prf header

aws · Feb 25, 2025 · 554ddf3 · 554ddf3
1 parent 5f93441
commit 554ddf3
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Showing 6 changed files with 40 additions and 38 deletions.
diff --git a/tests/unit/s2n_ssl_prf_test.c b/tests/unit/s2n_ssl_prf_test.c
@@ -22,8 +22,9 @@
 #include "testlib/s2n_testlib.h"
 #include "tls/s2n_prf.h"
 
-/*
+int s2n_tls_prf_master_secret(struct s2n_connection *conn, struct s2n_blob *premaster_secret);
 
+/*
  * Grabbed from gnutls-cli --insecure -d 9 www.example.com --ciphers AES --macs SHA --protocols SSLv3
  *
  * |<9>| INT: PREMASTER SECRET[48]: 03009e8e006a7f1451d32164088a8cba5077d1b819160662a97e90a765cec244b5f8f98fd50cfe8e4fba97994a7a4843

diff --git a/tests/unit/s2n_tls_hybrid_prf_test.c b/tests/unit/s2n_tls_hybrid_prf_test.c
@@ -106,7 +106,7 @@ int main(int argc, char **argv)
 
         EXPECT_MEMCPY_SUCCESS(conn->kex_params.client_key_exchange_message.data, client_key_exchange_message, client_key_exchange_message_length);
 
-        EXPECT_SUCCESS(s2n_hybrid_prf_master_secret(conn, &combined_pms));
+        EXPECT_SUCCESS(s2n_prf_hybrid_master_secret(conn, &combined_pms));
         EXPECT_BYTEARRAY_EQUAL(expected_master_secret, conn->secrets.version.tls12.master_secret, S2N_TLS_SECRET_LEN);
         EXPECT_SUCCESS(s2n_free(&conn->kex_params.client_key_exchange_message));
         EXPECT_SUCCESS(s2n_connection_free(conn));

diff --git a/tests/unit/s2n_tls_prf_test.c b/tests/unit/s2n_tls_prf_test.c
@@ -26,6 +26,16 @@
 
 #define TEST_BLOB_SIZE 64
 
+bool s2n_libcrypto_supports_tls_prf();
+int s2n_prf(struct s2n_connection *conn, struct s2n_blob *secret,
+        struct s2n_blob *label, struct s2n_blob *seed_a,
+        struct s2n_blob *seed_b, struct s2n_blob *seed_c, struct s2n_blob *out);
+S2N_RESULT s2n_prf_get_digest_for_ems(struct s2n_connection *conn,
+        struct s2n_blob *message, s2n_hash_algorithm hash_alg, struct s2n_blob *output);
+S2N_RESULT s2n_tls_prf_extended_master_secret(struct s2n_connection *conn,
+        struct s2n_blob *premaster_secret, struct s2n_blob *session_hash, struct s2n_blob *sha1_hash);
+int s2n_tls_prf_master_secret(struct s2n_connection *conn, struct s2n_blob *premaster_secret);
+
 /*
  * Grabbed from gnutls-cli --insecure -d 9 www.example.com --ciphers AES --macs SHA --protocols TLS1.0
  *

diff --git a/tls/s2n_kex.c b/tls/s2n_kex.c
@@ -245,7 +245,7 @@ const struct s2n_kex s2n_hybrid_ecdhe_kem = {
     .server_key_send = &s2n_hybrid_server_key_send,
     .client_key_recv = &s2n_hybrid_client_key_recv,
     .client_key_send = &s2n_hybrid_client_key_send,
-    .prf = &s2n_hybrid_prf_master_secret,
+    .prf = &s2n_prf_hybrid_master_secret,
 };
 
 /* TLS1.3 key exchange is implemented differently from previous versions and does

diff --git a/tls/s2n_prf.c b/tls/s2n_prf.c
@@ -34,6 +34,29 @@
 #include "utils/s2n_mem.h"
 #include "utils/s2n_safety.h"
 
+#if defined(OPENSSL_IS_AWSLC)
+    #define S2N_LIBCRYPTO_SUPPORTS_TLS_PRF 1
+#else
+    #define S2N_LIBCRYPTO_SUPPORTS_TLS_PRF 0
+#endif
+
+/* The s2n p_hash implementation is abstracted to allow for separate implementations, using
+ * either s2n's formally verified HMAC or OpenSSL's EVP HMAC, for use by the TLS PRF. */
+struct s2n_p_hash_hmac {
+    int (*alloc)(struct s2n_prf_working_space *ws);
+    int (*init)(struct s2n_prf_working_space *ws, s2n_hmac_algorithm alg, struct s2n_blob *secret);
+    int (*update)(struct s2n_prf_working_space *ws, const void *data, uint32_t size);
+    int (*final)(struct s2n_prf_working_space *ws, void *digest, uint32_t size);
+    int (*reset)(struct s2n_prf_working_space *ws);
+    int (*cleanup)(struct s2n_prf_working_space *ws);
+    int (*free)(struct s2n_prf_working_space *ws);
+};
+
+S2N_RESULT s2n_prf_get_digest_for_ems(struct s2n_connection *conn, struct s2n_blob *message,
+        s2n_hash_algorithm hash_alg, struct s2n_blob *output);
+S2N_RESULT s2n_tls_prf_extended_master_secret(struct s2n_connection *conn,
+        struct s2n_blob *premaster_secret, struct s2n_blob *session_hash, struct s2n_blob *sha1_hash);
+
 S2N_RESULT s2n_key_material_init(struct s2n_key_material *key_material, struct s2n_connection *conn)
 {
     RESULT_ENSURE_REF(key_material);
@@ -659,7 +682,7 @@ int s2n_tls_prf_master_secret(struct s2n_connection *conn, struct s2n_blob *prem
     return s2n_prf(conn, premaster_secret, &label, &client_random, &server_random, NULL, &master_secret);
 }
 
-int s2n_hybrid_prf_master_secret(struct s2n_connection *conn, struct s2n_blob *premaster_secret)
+int s2n_prf_hybrid_master_secret(struct s2n_connection *conn, struct s2n_blob *premaster_secret)
 {
     POSIX_ENSURE_REF(conn);
 

diff --git a/tls/s2n_prf.h b/tls/s2n_prf.h
@@ -17,19 +17,13 @@
 
 #include <stdint.h>
 
-#include "crypto/s2n_hash.h"
 #include "crypto/s2n_hmac.h"
+#include "tls/s2n_connection.h"
 #include "utils/s2n_blob.h"
 
 /* Enough to support TLS_ECDHE_RSA_WITH_AES_256_CBC_SHA384, 2*SHA384_DIGEST_LEN + 2*AES256_KEY_SIZE */
 #define S2N_MAX_KEY_BLOCK_LEN 160
 
-#if defined(OPENSSL_IS_AWSLC)
-    #define S2N_LIBCRYPTO_SUPPORTS_TLS_PRF 1
-#else
-    #define S2N_LIBCRYPTO_SUPPORTS_TLS_PRF 0
-#endif
-
 union p_hash_state {
     struct s2n_hmac_state s2n_hmac;
     struct s2n_evp_hmac_state evp_hmac;
@@ -41,18 +35,6 @@ struct s2n_prf_working_space {
     uint8_t digest1[S2N_MAX_DIGEST_LEN];
 };
 
-/* The s2n p_hash implementation is abstracted to allow for separate implementations, using
- * either s2n's formally verified HMAC or OpenSSL's EVP HMAC, for use by the TLS PRF. */
-struct s2n_p_hash_hmac {
-    int (*alloc)(struct s2n_prf_working_space *ws);
-    int (*init)(struct s2n_prf_working_space *ws, s2n_hmac_algorithm alg, struct s2n_blob *secret);
-    int (*update)(struct s2n_prf_working_space *ws, const void *data, uint32_t size);
-    int (*final)(struct s2n_prf_working_space *ws, void *digest, uint32_t size);
-    int (*reset)(struct s2n_prf_working_space *ws);
-    int (*cleanup)(struct s2n_prf_working_space *ws);
-    int (*free)(struct s2n_prf_working_space *ws);
-};
-
 /* TLS key expansion results in an array of contiguous data which is then
  * interpreted as the MAC, KEY and IV for the client and server.
  *
@@ -75,27 +57,13 @@ struct s2n_key_material {
 
 S2N_RESULT s2n_key_material_init(struct s2n_key_material *key_material, struct s2n_connection *conn);
 
-#include "tls/s2n_connection.h"
-
 S2N_RESULT s2n_prf_new(struct s2n_connection *conn);
 S2N_RESULT s2n_prf_wipe(struct s2n_connection *conn);
 S2N_RESULT s2n_prf_free(struct s2n_connection *conn);
 
-int s2n_prf(struct s2n_connection *conn, struct s2n_blob *secret, struct s2n_blob *label, struct s2n_blob *seed_a,
-        struct s2n_blob *seed_b, struct s2n_blob *seed_c, struct s2n_blob *out);
 int s2n_prf_calculate_master_secret(struct s2n_connection *conn, struct s2n_blob *premaster_secret);
-int s2n_tls_prf_master_secret(struct s2n_connection *conn, struct s2n_blob *premaster_secret);
-int s2n_hybrid_prf_master_secret(struct s2n_connection *conn, struct s2n_blob *premaster_secret);
-S2N_RESULT s2n_tls_prf_extended_master_secret(struct s2n_connection *conn, struct s2n_blob *premaster_secret, struct s2n_blob *session_hash, struct s2n_blob *sha1_hash);
-S2N_RESULT s2n_prf_get_digest_for_ems(struct s2n_connection *conn, struct s2n_blob *message, s2n_hash_algorithm hash_alg, struct s2n_blob *output);
+int s2n_prf_hybrid_master_secret(struct s2n_connection *conn, struct s2n_blob *premaster_secret);
 S2N_RESULT s2n_prf_generate_key_material(struct s2n_connection *conn, struct s2n_key_material *key_material);
 int s2n_prf_key_expansion(struct s2n_connection *conn);
 int s2n_prf_server_finished(struct s2n_connection *conn);
 int s2n_prf_client_finished(struct s2n_connection *conn);
-
-bool s2n_libcrypto_supports_tls_prf();
-
-S2N_RESULT s2n_custom_prf(struct s2n_connection *conn, struct s2n_blob *secret, struct s2n_blob *label,
-        struct s2n_blob *seed_a, struct s2n_blob *seed_b, struct s2n_blob *seed_c, struct s2n_blob *out);
-S2N_RESULT s2n_libcrypto_prf(struct s2n_connection *conn, struct s2n_blob *secret, struct s2n_blob *label,
-        struct s2n_blob *seed_a, struct s2n_blob *seed_b, struct s2n_blob *seed_c, struct s2n_blob *out);