Make BN_BLINDING internal

RSA is pretty bad. In my most optimistic moments I dream of a world that
stopped using it. That won't happen during my lifetime, unfortunately.
Blinding is one way of making it a little less leaky. Unfortunately this
side-channel leak mitigation leaked out of the library for no good reason.
Let's at least fix that aspect of it.

ok jsing

3 files changed, 24 insertions, 35 deletions

diff --git a/src/lib/libcrypto/bn/bn.h b/src/lib/libcrypto/bn/bn.h
index 7dc138d170..689196c911 100644
--- a/src/lib/libcrypto/bn/bn.h
+++ b/src/lib/libcrypto/bn/bn.h
@@ -1,4 +1,4 @@
-/* $OpenBSD: bn.h,v 1.72 2023/06/13 09:12:22 tb Exp $ */
+/* $OpenBSD: bn.h,v 1.73 2023/07/28 10:05:16 tb Exp $ */
 /* Copyright (C) 1995-1997 Eric Young (eay@cryptsoft.com)
  * All rights reserved.
  *
@@ -449,27 +449,6 @@ BN_MONT_CTX *BN_MONT_CTX_copy(BN_MONT_CTX *to, BN_MONT_CTX *from);
 BN_MONT_CTX *BN_MONT_CTX_set_locked(BN_MONT_CTX **pmont, int lock,
     const BIGNUM *mod, BN_CTX *ctx);
 
-/* BN_BLINDING flags */
-#define BN_BLINDING_NO_UPDATE   0x00000001
-#define BN_BLINDING_NO_RECREATE 0x00000002
-
-BN_BLINDING *BN_BLINDING_new(const BIGNUM *A, const BIGNUM *Ai, BIGNUM *mod);
-void BN_BLINDING_free(BN_BLINDING *b);
-int BN_BLINDING_update(BN_BLINDING *b, BN_CTX *ctx);
-int BN_BLINDING_convert(BIGNUM *n, BN_BLINDING *b, BN_CTX *ctx);
-int BN_BLINDING_invert(BIGNUM *n, BN_BLINDING *b, BN_CTX *ctx);
-int BN_BLINDING_convert_ex(BIGNUM *n, BIGNUM *r, BN_BLINDING *b, BN_CTX *);
-int BN_BLINDING_invert_ex(BIGNUM *n, const BIGNUM *r, BN_BLINDING *b, BN_CTX *);
-
-CRYPTO_THREADID *BN_BLINDING_thread_id(BN_BLINDING *);
-unsigned long BN_BLINDING_get_flags(const BN_BLINDING *);
-void BN_BLINDING_set_flags(BN_BLINDING *, unsigned long);
-BN_BLINDING *BN_BLINDING_create_param(BN_BLINDING *b,
-    const BIGNUM *e, BIGNUM *m, BN_CTX *ctx,
-    int (*bn_mod_exp)(BIGNUM *r, const BIGNUM *a, const BIGNUM *p,
-    const BIGNUM *m, BN_CTX *ctx, BN_MONT_CTX *m_ctx),
-    BN_MONT_CTX *m_ctx);
-
 /* Primes from RFC 2409 */
 BIGNUM *get_rfc2409_prime_768(BIGNUM *bn);
 BIGNUM *get_rfc2409_prime_1024(BIGNUM *bn);
diff --git a/src/lib/libcrypto/bn/bn_blind.c b/src/lib/libcrypto/bn/bn_blind.c
index 07cd359e7e..7332df2b56 100644
--- a/src/lib/libcrypto/bn/bn_blind.c
+++ b/src/lib/libcrypto/bn/bn_blind.c
@@ -1,4 +1,4 @@
-/* $OpenBSD: bn_blind.c,v 1.23 2023/07/08 12:21:58 beck Exp $ */
+/* $OpenBSD: bn_blind.c,v 1.24 2023/07/28 10:05:16 tb Exp $ */
 /* ====================================================================
  * Copyright (c) 1998-2006 The OpenSSL Project.  All rights reserved.
  *
@@ -169,7 +169,6 @@ err:
                 BN_BLINDING_free(ret);
         return (NULL);
 }
-LCRYPTO_ALIAS(BN_BLINDING_new);
 
 void
 BN_BLINDING_free(BN_BLINDING *r)
@@ -183,7 +182,6 @@ BN_BLINDING_free(BN_BLINDING *r)
         BN_free(r->mod);
         free(r);
 }
-LCRYPTO_ALIAS(BN_BLINDING_free);
 
 int
 BN_BLINDING_update(BN_BLINDING *b, BN_CTX *ctx)
@@ -217,14 +215,12 @@ err:
                 b->counter = 0;
         return (ret);
 }
-LCRYPTO_ALIAS(BN_BLINDING_update);
 
 int
 BN_BLINDING_convert(BIGNUM *n, BN_BLINDING *b, BN_CTX *ctx)
 {
         return BN_BLINDING_convert_ex(n, NULL, b, ctx);
 }
-LCRYPTO_ALIAS(BN_BLINDING_convert);
 
 int
 BN_BLINDING_convert_ex(BIGNUM *n, BIGNUM *r, BN_BLINDING *b, BN_CTX *ctx)
@@ -253,14 +249,12 @@ BN_BLINDING_convert_ex(BIGNUM *n, BIGNUM *r, BN_BLINDING *b, BN_CTX *ctx)
 
         return ret;
 }
-LCRYPTO_ALIAS(BN_BLINDING_convert_ex);
 
 int
 BN_BLINDING_invert(BIGNUM *n, BN_BLINDING *b, BN_CTX *ctx)
 {
         return BN_BLINDING_invert_ex(n, NULL, b, ctx);
 }
-LCRYPTO_ALIAS(BN_BLINDING_invert);
 
 int
 BN_BLINDING_invert_ex(BIGNUM *n, const BIGNUM *r, BN_BLINDING *b, BN_CTX *ctx)
@@ -280,28 +274,24 @@ BN_BLINDING_invert_ex(BIGNUM *n, const BIGNUM *r, BN_BLINDING *b, BN_CTX *ctx)
 
         return (ret);
 }
-LCRYPTO_ALIAS(BN_BLINDING_invert_ex);
 
 CRYPTO_THREADID *
 BN_BLINDING_thread_id(BN_BLINDING *b)
 {
         return &b->tid;
 }
-LCRYPTO_ALIAS(BN_BLINDING_thread_id);
 
 unsigned long
 BN_BLINDING_get_flags(const BN_BLINDING *b)
 {
         return b->flags;
 }
-LCRYPTO_ALIAS(BN_BLINDING_get_flags);
 
 void
 BN_BLINDING_set_flags(BN_BLINDING *b, unsigned long flags)
 {
         b->flags = flags;
 }
-LCRYPTO_ALIAS(BN_BLINDING_set_flags);
 
 BN_BLINDING *
 BN_BLINDING_create_param(BN_BLINDING *b, const BIGNUM *e, BIGNUM *m,
@@ -373,4 +363,3 @@ err:
 
         return ret;
 }
-LCRYPTO_ALIAS(BN_BLINDING_create_param);
diff --git a/src/lib/libcrypto/bn/bn_local.h b/src/lib/libcrypto/bn/bn_local.h
index a8d40fbcc8..989770f2d6 100644
--- a/src/lib/libcrypto/bn/bn_local.h
+++ b/src/lib/libcrypto/bn/bn_local.h
@@ -1,4 +1,4 @@
-/* $OpenBSD: bn_local.h,v 1.26 2023/07/09 18:27:22 tb Exp $ */
+/* $OpenBSD: bn_local.h,v 1.27 2023/07/28 10:05:16 tb Exp $ */
 /* Copyright (C) 1995-1998 Eric Young (eay@cryptsoft.com)
  * All rights reserved.
  *
@@ -291,6 +291,27 @@ int	BN_mod_exp_recp(BIGNUM *r, const BIGNUM *a, const BIGNUM *p,
 int     BN_div_recp(BIGNUM *dv, BIGNUM *rem, const BIGNUM *m,
     BN_RECP_CTX *recp, BN_CTX *ctx);
 
+/* BN_BLINDING flags */
+#define BN_BLINDING_NO_UPDATE   0x00000001
+#define BN_BLINDING_NO_RECREATE 0x00000002
+
+BN_BLINDING *BN_BLINDING_new(const BIGNUM *A, const BIGNUM *Ai, BIGNUM *mod);
+void BN_BLINDING_free(BN_BLINDING *b);
+int BN_BLINDING_update(BN_BLINDING *b, BN_CTX *ctx);
+int BN_BLINDING_convert(BIGNUM *n, BN_BLINDING *b, BN_CTX *ctx);
+int BN_BLINDING_invert(BIGNUM *n, BN_BLINDING *b, BN_CTX *ctx);
+int BN_BLINDING_convert_ex(BIGNUM *n, BIGNUM *r, BN_BLINDING *b, BN_CTX *);
+int BN_BLINDING_invert_ex(BIGNUM *n, const BIGNUM *r, BN_BLINDING *b, BN_CTX *);
+
+CRYPTO_THREADID *BN_BLINDING_thread_id(BN_BLINDING *);
+unsigned long BN_BLINDING_get_flags(const BN_BLINDING *);
+void BN_BLINDING_set_flags(BN_BLINDING *, unsigned long);
+BN_BLINDING *BN_BLINDING_create_param(BN_BLINDING *b,
+    const BIGNUM *e, BIGNUM *m, BN_CTX *ctx,
+    int (*bn_mod_exp)(BIGNUM *r, const BIGNUM *a, const BIGNUM *p,
+    const BIGNUM *m, BN_CTX *ctx, BN_MONT_CTX *m_ctx),
+    BN_MONT_CTX *m_ctx);
+
 /* Explicitly const time / non-const time versions for internal use */
 int BN_mod_exp_ct(BIGNUM *r, const BIGNUM *a, const BIGNUM *p,
     const BIGNUM *m, BN_CTX *ctx);