Index: net/cert/sha256_legacy_support_openssl_win.cc |
diff --git a/net/cert/sha256_legacy_support_openssl_win.cc b/net/cert/sha256_legacy_support_openssl_win.cc |
new file mode 100644 |
index 0000000000000000000000000000000000000000..991f05196128bef71e888e04a39cc1e0cb674ea5 |
--- /dev/null |
+++ b/net/cert/sha256_legacy_support_openssl_win.cc |
@@ -0,0 +1,154 @@ |
+// Copyright 2014 The Chromium Authors. All rights reserved. |
+// Use of this source code is governed by a BSD-style license that can be |
+// found in the LICENSE file. |
+ |
+#include <openssl/asn1.h> |
+#include <openssl/bytestring.h> |
+#include <openssl/evp.h> |
+#include <openssl/obj.h> |
+#include <openssl/x509.h> |
+ |
+#include "base/logging.h" |
+#include "crypto/scoped_openssl_types.h" |
+#include "net/cert/sha256_legacy_support_win.h" |
+ |
+namespace net { |
+ |
+namespace sha256_interception { |
+ |
+namespace { |
+ |
+typedef crypto::ScopedOpenSSL<X509_ALGOR, X509_ALGOR_free>::Type |
+ ScopedX509_ALGOR; |
+ |
+// Parses |subject_signature| and writes the components into |*out_tbs_data|, |
+// |*out_algor|, and |*out_signature|. The BIT STRING in the signature must be |
+// a multiple of 8 bits. |*out_signature| will have the padding byte removed. |
+// It returns true on success and false on failure. |
+bool ParseSubjectSignature(const base::StringPiece& subject_signature, |
+ CBS* out_tbs_data, |
+ ScopedX509_ALGOR* out_algor, |
+ CBS* out_signature) { |
+ CBS cbs, sequence, tbs_data, algorithm, signature; |
+ CBS_init(&cbs, reinterpret_cast<const uint8_t*>(subject_signature.data()), |
+ subject_signature.size()); |
+ if (!CBS_get_asn1(&cbs, &sequence, CBS_ASN1_SEQUENCE) || |
+ CBS_len(&cbs) != 0 || |
+ !CBS_get_any_asn1_element(&sequence, &tbs_data, nullptr, nullptr) || |
+ !CBS_get_asn1_element(&sequence, &algorithm, |
+ CBS_ASN1_SEQUENCE) || |
+ !CBS_get_asn1(&sequence, &signature, CBS_ASN1_BITSTRING) || |
+ CBS_len(&sequence) != 0) { |
+ return false; |
+ } |
+ |
+ // Decode the algorithm. |
+ const uint8_t* ptr = CBS_data(&algorithm); |
+ ScopedX509_ALGOR algor(d2i_X509_ALGOR(NULL, &ptr, CBS_len(&algorithm))); |
+ if (!algor || ptr != CBS_data(&algorithm) + CBS_len(&algorithm)) |
+ return false; |
+ |
+ // An ASN.1 BIT STRING is encoded with a leading byte denoting the number of |
+ // padding bits. All supported signature algorithms output octets, so the |
+ // leading byte must be zero. |
+ uint8_t padding; |
+ if (!CBS_get_u8(&signature, &padding) || padding != 0) |
+ return false; |
+ |
+ *out_tbs_data = tbs_data; |
+ *out_algor = algor.Pass(); |
+ *out_signature = signature; |
+ return true; |
+} |
+ |
+} // namespace |
+ |
+BOOL CryptVerifyCertificateSignatureExHook( |
+ CryptVerifyCertificateSignatureExFunc original_func, |
+ HCRYPTPROV_LEGACY provider, |
+ DWORD encoding_type, |
+ DWORD subject_type, |
+ void* subject_data, |
+ DWORD issuer_type, |
+ void* issuer_data, |
+ DWORD flags, |
+ void* extra) { |
+ CHECK(original_func); |
+ |
+ // Only intercept if the arguments are supported. |
+ if (provider != NULL || (encoding_type != X509_ASN_ENCODING) || |
+ !IsSupportedSubjectType(subject_type) || subject_data == NULL || |
+ !IsSupportedIssuerType(issuer_type) || issuer_data == NULL) { |
+ return original_func(provider, encoding_type, subject_type, subject_data, |
+ issuer_type, issuer_data, flags, extra); |
+ } |
+ |
+ base::StringPiece subject_signature = |
+ GetSubjectSignature(subject_type, subject_data); |
+ bool should_intercept = false; |
+ |
+ // Parse out the data, AlgorithmIdentifier, and signature. |
+ CBS tbs_data, signature; |
+ ScopedX509_ALGOR algor; |
+ if (ParseSubjectSignature(subject_signature, &tbs_data, &algor, |
+ &signature)) { |
+ // If the signature algorithm is RSA with one of the SHA-2 algorithms |
+ // supported by BoringSSL (excluding SHA-224, which is pointless), then |
+ // defer to the BoringSSL implementation. Otherwise, fall back and let the |
+ // OS handle it (e.g. in case there are any algorithm policies in effect). |
+ int nid = OBJ_obj2nid(algor->algorithm); |
+ if (nid == NID_sha256WithRSAEncryption || |
+ nid == NID_sha384WithRSAEncryption || |
+ nid == NID_sha512WithRSAEncryption) { |
+ should_intercept = true; |
+ } |
+ } |
+ |
+ if (!should_intercept) { |
+ return original_func(provider, encoding_type, subject_type, subject_data, |
+ issuer_type, issuer_data, flags, extra); |
+ } |
+ |
+ // Rather than attempting to synthesize an EVP_PKEY by hand, just force the |
+ // OS to do an ASN.1 encoding and then decode it back into BoringSSL. This |
+ // is silly for performance, but safest for consistency. |
+ PCERT_PUBLIC_KEY_INFO issuer_public_key = |
+ GetIssuerPublicKey(issuer_type, issuer_data); |
+ if (!issuer_public_key) { |
+ SetLastError(static_cast<DWORD>(NTE_BAD_ALGID)); |
+ return FALSE; |
+ } |
+ |
+ uint8_t* issuer_spki_data = NULL; |
+ DWORD issuer_spki_len = 0; |
+ if (!CryptEncodeObjectEx(X509_ASN_ENCODING, X509_PUBLIC_KEY_INFO, |
+ issuer_public_key, CRYPT_ENCODE_ALLOC_FLAG, NULL, |
+ &issuer_spki_data, &issuer_spki_len)) { |
+ return FALSE; |
+ } |
+ |
+ const uint8_t* ptr = issuer_spki_data; |
+ crypto::ScopedEVP_PKEY pubkey(d2i_PUBKEY(NULL, &ptr, issuer_spki_len)); |
+ if (!pubkey.get() || ptr != issuer_spki_data + issuer_spki_len) { |
+ ::LocalFree(issuer_spki_data); |
+ SetLastError(static_cast<DWORD>(NTE_BAD_ALGID)); |
+ return FALSE; |
+ } |
+ ::LocalFree(issuer_spki_data); |
+ |
+ crypto::ScopedEVP_MD_CTX md_ctx(EVP_MD_CTX_create()); |
+ if (!EVP_DigestVerifyInitFromAlgorithm(md_ctx.get(), algor.get(), |
+ pubkey.get()) || |
+ !EVP_DigestVerifyUpdate(md_ctx.get(), CBS_data(&tbs_data), |
+ CBS_len(&tbs_data)) || |
+ !EVP_DigestVerifyFinal(md_ctx.get(), CBS_data(&signature), |
+ CBS_len(&signature))) { |
+ SetLastError(static_cast<DWORD>(NTE_BAD_SIGNATURE)); |
+ return FALSE; |
+ } |
+ return TRUE; |
+} |
+ |
+} // namespace sha256_interception |
+ |
+} // namespace net |