Call CRYPTO_library_init before ChaCha20 and P-256 assembly

We really should remove the ia32cap references from those files, but now
that we're down to two files, let's go ahead and remove the
CRYPTO_library_init requirement from our callers and close out the
initialization hole.

Notably, use of bssl-crypto in Chromium is slightly shaky without this.
Although I think, prior to this CL, we'd already gotten to benign races
being all that are possible because these two remaining spots don't
change any in-memory representations. (Unlike C/C++, benign races from
assembly are actually well-defined and truly benign.) But no sense in
relying on this when we can just fix it directly.

This CL just adds some explicit CRYPTO_library_init calls. A subsequent
one will update the docs and clean up all the remnants of our messy
initialization story.

Bug: 40644931
Change-Id: Ife288a4817b930473210f43a2680a60b040bf9a0
Reviewed-on: https://boringssl-review.googlesource.com/c/boringssl/+/69507
Commit-Queue: David Benjamin <davidben@google.com>
Commit-Queue: Adam Langley <agl@google.com>
Auto-Submit: David Benjamin <davidben@google.com>
Reviewed-by: Adam Langley <agl@google.com>

crypto/cipher_extra/e_chacha20poly1305.c

diff --git a/crypto/cipher_extra/e_chacha20poly1305.c b/crypto/cipher_extra/e_chacha20poly1305.c
index 6510ff4..3ac2af8 100644
--- a/crypto/cipher_extra/e_chacha20poly1305.c
+++ b/crypto/cipher_extra/e_chacha20poly1305.c
@@ -41,6 +41,13 @@
 
 static int aead_chacha20_poly1305_init(EVP_AEAD_CTX *ctx, const uint8_t *key,
                                        size_t key_len, size_t tag_len) {
+  // TODO(crbug.com/42290548): The x86_64 assembly depends on initializing
+  // |OPENSSL_ia32cap_P|. Move the dispatch to C. While we're here, it may be
+  // worth adjusting the assembly calling convention. The assembly functions do
+  // too much work right now. For now, explicitly initialize |OPENSSL_ia32cap_P|
+  // first.
+  CRYPTO_library_init();
+
   struct aead_chacha20_poly1305_ctx *c20_ctx =
       (struct aead_chacha20_poly1305_ctx *)&ctx->state;
 

crypto/fipsmodule/ec/p256-nistz.c

diff --git a/crypto/fipsmodule/ec/p256-nistz.c b/crypto/fipsmodule/ec/p256-nistz.c
index cf09963..2773820 100644
--- a/crypto/fipsmodule/ec/p256-nistz.c
+++ b/crypto/fipsmodule/ec/p256-nistz.c
@@ -612,6 +612,11 @@
 }
 
 DEFINE_METHOD_FUNCTION(EC_METHOD, EC_GFp_nistz256_method) {
+  // TODO(crbug.com/42290548): The x86_64 assembly depends on initializing
+  // |OPENSSL_ia32cap_P|. Move the dispatch to C. For now, explicitly initialize
+  // things.
+  CRYPTO_library_init();
+
   out->point_get_affine_coordinates = ecp_nistz256_get_affine;
   out->add = ecp_nistz256_add;
   out->dbl = ecp_nistz256_dbl;