krb5/0011-downstream-Allow-KRB5KDF-MD5-and-MD4-in-FIPS-mode.patch
Julien Rische 19e63e55c9 New upstream version (1.21.1)
- Fix double-free in KDC TGS processing (CVE-2023-39975)
- Add support for "pac_privsvr_enctype" KDB string attribute

Resolves: rhbz#2060421
Signed-off-by: Julien Rische <jrische@redhat.com>
2023-08-08 17:22:24 +02:00

166 lines
5.3 KiB
Diff

From c002d03cce1c82e74a0c76b323c1bf1e619d022e Mon Sep 17 00:00:00 2001
From: Julien Rische <jrische@redhat.com>
Date: Thu, 19 Jan 2023 19:22:27 +0100
Subject: [PATCH] [downstream] Allow KRB5KDF, MD5, and MD4 in FIPS mode
OpenSSL's restrictions to use KRB5KDF, MD5, and MD4 in FIPS mode are
bypassed in case AES SHA-1 HMAC or RC4 encryption types are allowed by
the crypto policy.
---
.../crypto/openssl/hash_provider/hash_evp.c | 97 +++++++++++++++++--
src/lib/crypto/openssl/kdf.c | 2 +-
2 files changed, 89 insertions(+), 10 deletions(-)
diff --git a/src/lib/crypto/openssl/hash_provider/hash_evp.c b/src/lib/crypto/openssl/hash_provider/hash_evp.c
index 11659908bb..eb2e693e9f 100644
--- a/src/lib/crypto/openssl/hash_provider/hash_evp.c
+++ b/src/lib/crypto/openssl/hash_provider/hash_evp.c
@@ -44,6 +44,49 @@
#define EVP_MD_CTX_free EVP_MD_CTX_destroy
#endif
+#include <openssl/provider.h>
+#include <openssl/fips.h>
+#include <threads.h>
+
+typedef struct ossl_lib_md_context {
+ OSSL_LIB_CTX *libctx;
+ OSSL_PROVIDER *default_provider;
+ OSSL_PROVIDER *legacy_provider;
+} ossl_md_context_t;
+
+static thread_local ossl_md_context_t *ossl_md_ctx = NULL;
+
+static krb5_error_code
+init_ossl_md_ctx(ossl_md_context_t *ctx, const char *algo)
+{
+ ctx->libctx = OSSL_LIB_CTX_new();
+ if (!ctx->libctx)
+ return KRB5_CRYPTO_INTERNAL;
+
+ /* Load both legacy and default provider as both may be needed. */
+ ctx->default_provider = OSSL_PROVIDER_load(ctx->libctx, "default");
+ ctx->legacy_provider = OSSL_PROVIDER_load(ctx->libctx, "legacy");
+
+ if (!(ctx->default_provider && ctx->legacy_provider))
+ return KRB5_CRYPTO_INTERNAL;
+
+ return 0;
+}
+
+static void
+deinit_ossl_ctx(ossl_md_context_t *ctx)
+{
+ if (ctx->legacy_provider)
+ OSSL_PROVIDER_unload(ctx->legacy_provider);
+
+ if (ctx->default_provider)
+ OSSL_PROVIDER_unload(ctx->default_provider);
+
+ if (ctx->libctx)
+ OSSL_LIB_CTX_free(ctx->libctx);
+}
+
+
static krb5_error_code
hash_evp(const EVP_MD *type, const krb5_crypto_iov *data, size_t num_data,
krb5_data *output)
@@ -60,11 +103,6 @@ hash_evp(const EVP_MD *type, const krb5_crypto_iov *data, size_t num_data,
if (ctx == NULL)
return ENOMEM;
- if (type == EVP_md4() || type == EVP_md5()) {
- /* See comments below in hash_md4() and hash_md5(). */
- EVP_MD_CTX_set_flags(ctx, EVP_MD_CTX_FLAG_NON_FIPS_ALLOW);
- }
-
ok = EVP_DigestInit_ex(ctx, type, NULL);
for (i = 0; i < num_data; i++) {
if (!SIGN_IOV(&data[i]))
@@ -77,6 +115,43 @@ hash_evp(const EVP_MD *type, const krb5_crypto_iov *data, size_t num_data,
return ok ? 0 : KRB5_CRYPTO_INTERNAL;
}
+static krb5_error_code
+hash_legacy_evp(const char *algo, const krb5_crypto_iov *data, size_t num_data,
+ krb5_data *output)
+{
+ krb5_error_code err;
+ EVP_MD *md = NULL;
+
+ if (!ossl_md_ctx) {
+ ossl_md_ctx = malloc(sizeof(ossl_md_context_t));
+ if (!ossl_md_ctx) {
+ err = ENOMEM;
+ goto end;
+ }
+
+ err = init_ossl_md_ctx(ossl_md_ctx, algo);
+ if (err) {
+ deinit_ossl_ctx(ossl_md_ctx);
+ free(ossl_md_ctx);
+ ossl_md_ctx = NULL;
+ goto end;
+ }
+ }
+
+ md = EVP_MD_fetch(ossl_md_ctx->libctx, algo, NULL);
+ if (!md) {
+ err = KRB5_CRYPTO_INTERNAL;
+ goto end;
+ }
+
+ err = hash_evp(md, data, num_data, output);
+
+end:
+ if (md)
+ EVP_MD_free(md);
+
+ return err;
+}
#endif
#ifdef K5_OPENSSL_MD4
@@ -88,7 +163,8 @@ hash_md4(const krb5_crypto_iov *data, size_t num_data, krb5_data *output)
* by IPA. These keys are only used along a (separately) secured channel
* for legacy reasons when performing trusts to Active Directory.
*/
- return hash_evp(EVP_md4(), data, num_data, output);
+ return FIPS_mode() ? hash_legacy_evp("MD4", data, num_data, output)
+ : hash_evp(EVP_md4(), data, num_data, output);
}
const struct krb5_hash_provider krb5int_hash_md4 = {
@@ -100,9 +176,12 @@ const struct krb5_hash_provider krb5int_hash_md4 = {
static krb5_error_code
hash_md5(const krb5_crypto_iov *data, size_t num_data, krb5_data *output)
{
- /* MD5 is needed in FIPS mode for communication with RADIUS servers. This
- * is gated in libkrad by libdefaults->radius_md5_fips_override. */
- return hash_evp(EVP_md5(), data, num_data, output);
+ /*
+ * MD5 is needed in FIPS mode for communication with RADIUS servers. This
+ * is gated in libkrad by libdefaults->radius_md5_fips_override.
+ */
+ return FIPS_mode() ? hash_legacy_evp("MD5", data, num_data, output)
+ : hash_evp(EVP_md5(), data, num_data, output);
}
const struct krb5_hash_provider krb5int_hash_md5 = {
diff --git a/src/lib/crypto/openssl/kdf.c b/src/lib/crypto/openssl/kdf.c
index 5a43c3d9eb..8528ddc4a9 100644
--- a/src/lib/crypto/openssl/kdf.c
+++ b/src/lib/crypto/openssl/kdf.c
@@ -198,7 +198,7 @@ k5_derive_random_rfc3961(const struct krb5_enc_provider *enc, krb5_key key,
goto done;
}
- kdf = EVP_KDF_fetch(NULL, "KRB5KDF", NULL);
+ kdf = EVP_KDF_fetch(NULL, "KRB5KDF", "-fips");
if (kdf == NULL) {
ret = KRB5_CRYPTO_INTERNAL;
goto done;
--
2.41.0