From ebcee0c8dc5f3055597e0b574d98cbe65f55319e Mon Sep 17 00:00:00 2001
From: Robbie Harwood <rharwood@redhat.com>
Date: Fri, 9 Nov 2018 15:12:21 -0500
Subject: [PATCH] Become FIPS-aware

A lot of the FIPS error conditions from OpenSSL are incredibly
mysterious (at best, things return NULL unexpectedly; at worst,
internal assertions are tripped; most of the time, you just get
ENOMEM).  In order to cope with this, we need to have some level of
awareness of what we can and can't safely call.

This will slow down some calls slightly (FIPS_mode() takes multiple
locks), but not for any crypto we care about - AES is fine, for
instance.

(cherry picked from commit ee05742839df659d2136b37f91d0a888de2b5e26)
(cherry picked from commit b38ed4d97152f1dce126235935d30e549ead77b3)
---
 src/lib/crypto/openssl/enc_provider/camellia.c  | 6 ++++++
 src/lib/crypto/openssl/enc_provider/des.c       | 9 +++++++++
 src/lib/crypto/openssl/enc_provider/rc4.c       | 3 +++
 src/lib/crypto/openssl/hash_provider/hash_evp.c | 4 ++++
 src/lib/crypto/openssl/hmac.c                   | 6 +++++-
 5 files changed, 27 insertions(+), 1 deletion(-)

diff --git a/src/lib/crypto/openssl/enc_provider/camellia.c b/src/lib/crypto/openssl/enc_provider/camellia.c
index 2da691329..f79679a0b 100644
--- a/src/lib/crypto/openssl/enc_provider/camellia.c
+++ b/src/lib/crypto/openssl/enc_provider/camellia.c
@@ -304,6 +304,9 @@ krb5int_camellia_cbc_mac(krb5_key key, const krb5_crypto_iov *data,
     unsigned char blockY[CAMELLIA_BLOCK_SIZE], blockB[CAMELLIA_BLOCK_SIZE];
     struct iov_cursor cursor;
 
+    if (FIPS_mode())
+        return KRB5_CRYPTO_INTERNAL;
+
     if (output->length < CAMELLIA_BLOCK_SIZE)
         return KRB5_BAD_MSIZE;
 
@@ -331,6 +334,9 @@ static krb5_error_code
 krb5int_camellia_init_state (const krb5_keyblock *key, krb5_keyusage usage,
                              krb5_data *state)
 {
+    if (FIPS_mode())
+        return KRB5_CRYPTO_INTERNAL;
+
     state->length = 16;
     state->data = (void *) malloc(16);
     if (state->data == NULL)
diff --git a/src/lib/crypto/openssl/enc_provider/des.c b/src/lib/crypto/openssl/enc_provider/des.c
index a662db512..7d17d287e 100644
--- a/src/lib/crypto/openssl/enc_provider/des.c
+++ b/src/lib/crypto/openssl/enc_provider/des.c
@@ -85,6 +85,9 @@ k5_des_encrypt(krb5_key key, const krb5_data *ivec, krb5_crypto_iov *data,
     EVP_CIPHER_CTX *ctx;
     krb5_boolean empty;
 
+    if (FIPS_mode())
+        return KRB5_CRYPTO_INTERNAL;
+
     ret = validate(key, ivec, data, num_data, &empty);
     if (ret != 0 || empty)
         return ret;
@@ -133,6 +136,9 @@ k5_des_decrypt(krb5_key key, const krb5_data *ivec, krb5_crypto_iov *data,
     EVP_CIPHER_CTX *ctx;
     krb5_boolean empty;
 
+    if (FIPS_mode())
+        return KRB5_CRYPTO_INTERNAL;
+
     ret = validate(key, ivec, data, num_data, &empty);
     if (ret != 0 || empty)
         return ret;
@@ -182,6 +188,9 @@ k5_des_cbc_mac(krb5_key key, const krb5_crypto_iov *data, size_t num_data,
     DES_key_schedule sched;
     krb5_boolean empty;
 
+    if (FIPS_mode())
+        return KRB5_CRYPTO_INTERNAL;
+
     ret = validate(key, ivec, data, num_data, &empty);
     if (ret != 0)
         return ret;
diff --git a/src/lib/crypto/openssl/enc_provider/rc4.c b/src/lib/crypto/openssl/enc_provider/rc4.c
index 7f3c086ed..ef8205535 100644
--- a/src/lib/crypto/openssl/enc_provider/rc4.c
+++ b/src/lib/crypto/openssl/enc_provider/rc4.c
@@ -125,6 +125,9 @@ k5_arcfour_init_state(const krb5_keyblock *key,
 {
     struct arcfour_state *arcstate;
 
+    if (FIPS_mode())
+        return KRB5_CRYPTO_INTERNAL;
+
     /* Create a state structure with an uninitialized context. */
     arcstate = calloc(1, sizeof(*arcstate));
     if (arcstate == NULL)
diff --git a/src/lib/crypto/openssl/hash_provider/hash_evp.c b/src/lib/crypto/openssl/hash_provider/hash_evp.c
index 957ed8d9c..8c1fd7f59 100644
--- a/src/lib/crypto/openssl/hash_provider/hash_evp.c
+++ b/src/lib/crypto/openssl/hash_provider/hash_evp.c
@@ -64,12 +64,16 @@ hash_evp(const EVP_MD *type, const krb5_crypto_iov *data, size_t num_data,
 static krb5_error_code
 hash_md4(const krb5_crypto_iov *data, size_t num_data, krb5_data *output)
 {
+    if (FIPS_mode())
+        return KRB5_CRYPTO_INTERNAL;
     return hash_evp(EVP_md4(), data, num_data, output);
 }
 
 static krb5_error_code
 hash_md5(const krb5_crypto_iov *data, size_t num_data, krb5_data *output)
 {
+    if (FIPS_mode())
+        return KRB5_CRYPTO_INTERNAL;
     return hash_evp(EVP_md5(), data, num_data, output);
 }
 
diff --git a/src/lib/crypto/openssl/hmac.c b/src/lib/crypto/openssl/hmac.c
index b2db6ec02..d94d9ac94 100644
--- a/src/lib/crypto/openssl/hmac.c
+++ b/src/lib/crypto/openssl/hmac.c
@@ -103,7 +103,11 @@ map_digest(const struct krb5_hash_provider *hash)
         return EVP_sha256();
     else if (!strncmp(hash->hash_name, "SHA-384",7))
         return EVP_sha384();
-    else if (!strncmp(hash->hash_name, "MD5", 3))
+
+    if (FIPS_mode())
+        return NULL;
+
+    if (!strncmp(hash->hash_name, "MD5", 3))
         return EVP_md5();
     else if (!strncmp(hash->hash_name, "MD4", 3))
         return EVP_md4();