ruby: Security fix for CVE-2016-7798

affectes ruby < 2.3.1

(From OE-Core rev: 6af2319008dc16c61092f71ff227c285aac51288)

Signed-off-by: Thiruvadi Rajaraman <trajaraman@mvista.com>
Signed-off-by: Armin Kuster <akuster@mvista.com>
Signed-off-by: Richard Purdie <richard.purdie@linuxfoundation.org>

2 files changed, 167 insertions, 1 deletions

diff --git a/meta/recipes-devtools/ruby/ruby/CVE-2016-7798.patch b/meta/recipes-devtools/ruby/ruby/CVE-2016-7798.patch
new file mode 100644
index 0000000000..2b8772ba41
--- /dev/null
+++ b/meta/recipes-devtools/ruby/ruby/CVE-2016-7798.patch
@@ -0,0 +1,164 @@
+cipher: don't set dummy encryption key in Cipher#initialize
+Remove the encryption key initialization from Cipher#initialize. This
+is effectively a revert of r32723 ("Avoid possible SEGV from AES
+encryption/decryption", 2011-07-28).
+
+r32723, which added the key initialization, was a workaround for
+Ruby Bug #2768. For some certain ciphers, calling EVP_CipherUpdate()
+before setting an encryption key caused segfault. It was not a problem
+until OpenSSL implemented GCM mode - the encryption key could be
+overridden by repeated calls of EVP_CipherInit_ex(). But, it is not the
+case for AES-GCM ciphers. Setting a key, an IV, a key, in this order
+causes the IV to be reset to an all-zero IV.
+
+The problem of Bug #2768 persists on the current versions of OpenSSL.
+So, make Cipher#update raise an exception if a key is not yet set by the
+user. Since encrypting or decrypting without key does not make any
+sense, this should not break existing applications.
+
+Users can still call Cipher#key= and Cipher#iv= multiple times with
+their own responsibility.
+
+Reference: https://bugs.ruby-lang.org/issues/2768
+Reference: https://bugs.ruby-lang.org/issues/8221
+
+Upstream-Status: Backport
+CVE: CVE-2016-7798
+
+Signed-off-by: Thiruvadi Rajaraman <trajaraman@mvista.com>
+
+Index: ruby-2.2.2/ext/openssl/ossl_cipher.c
+===================================================================
+--- ruby-2.2.2.orig/ext/openssl/ossl_cipher.c
++++ ruby-2.2.2/ext/openssl/ossl_cipher.c
+@@ -35,6 +35,7 @@
+  */
+ VALUE cCipher;
+ VALUE eCipherError;
++static ID id_key_set;
+ 
+ static VALUE ossl_cipher_alloc(VALUE klass);
+ static void ossl_cipher_free(void *ptr);
+@@ -119,7 +120,6 @@ ossl_cipher_initialize(VALUE self, VALUE
+     EVP_CIPHER_CTX *ctx;
+     const EVP_CIPHER *cipher;
+     char *name;
+-    unsigned char key[EVP_MAX_KEY_LENGTH];
+ 
+     name = StringValuePtr(str);
+     GetCipherInit(self, ctx);
+@@ -131,14 +131,7 @@ ossl_cipher_initialize(VALUE self, VALUE
+     if (!(cipher = EVP_get_cipherbyname(name))) {
+        ossl_raise(rb_eRuntimeError, "unsupported cipher algorithm (%s)", name);
+     }
+-    /*
+-     * The EVP which has EVP_CIPH_RAND_KEY flag (such as DES3) allows
+-     * uninitialized key, but other EVPs (such as AES) does not allow it.
+-     * Calling EVP_CipherUpdate() without initializing key causes SEGV so we
+-     * set the data filled with "\0" as the key by default.
+-     */
+-    memset(key, 0, EVP_MAX_KEY_LENGTH);
+-    if (EVP_CipherInit_ex(ctx, cipher, NULL, key, NULL, -1) != 1)
++    if (EVP_CipherInit_ex(ctx, cipher, NULL, NULL, NULL, -1) != 1)
+        ossl_raise(eCipherError, NULL);
+ 
+     return self;
+@@ -256,6 +249,8 @@ ossl_cipher_init(int argc, VALUE *argv,
+     if (EVP_CipherInit_ex(ctx, NULL, NULL, p_key, p_iv, mode) != 1) {
+        ossl_raise(eCipherError, NULL);
+     }
++    if (p_key)
++       rb_ivar_set(self, id_key_set, Qtrue);
+ 
+     return self;
+ }
+@@ -343,6 +338,8 @@ ossl_cipher_pkcs5_keyivgen(int argc, VAL
+     OPENSSL_cleanse(key, sizeof key);
+     OPENSSL_cleanse(iv, sizeof iv);
+ 
++    rb_ivar_set(self, id_key_set, Qtrue);
++
+     return Qnil;
+ }
+ 
+@@ -396,6 +393,9 @@ ossl_cipher_update(int argc, VALUE *argv
+ 
+     rb_scan_args(argc, argv, "11", &data, &str);
+ 
++    if (!RTEST(rb_attr_get(self, id_key_set)))
++       ossl_raise(eCipherError, "key not set");
++
+     StringValue(data);
+     in = (unsigned char *)RSTRING_PTR(data);
+     if ((in_len = RSTRING_LEN(data)) == 0)
+@@ -495,6 +495,8 @@ ossl_cipher_set_key(VALUE self, VALUE ke
+     if (EVP_CipherInit_ex(ctx, NULL, NULL, (unsigned char *)RSTRING_PTR(key), NULL, -1) != 1)
+         ossl_raise(eCipherError, NULL);
+ 
++    rb_ivar_set(self, id_key_set, Qtrue);
++
+     return key;
+ }
+ 
+@@ -1013,5 +1015,7 @@ Init_ossl_cipher(void)
+     rb_define_method(cCipher, "iv_len", ossl_cipher_iv_length, 0);
+     rb_define_method(cCipher, "block_size", ossl_cipher_block_size, 0);
+     rb_define_method(cCipher, "padding=", ossl_cipher_set_padding, 1);
++    
++    id_key_set = rb_intern_const("key_set");
+ }
+ 
+Index: ruby-2.2.2/test/openssl/test_cipher.rb
+===================================================================
+--- ruby-2.2.2.orig/test/openssl/test_cipher.rb
++++ ruby-2.2.2/test/openssl/test_cipher.rb
+@@ -80,6 +80,7 @@ class OpenSSL::TestCipher < Test::Unit::
+ 
+   def test_empty_data
+     @c1.encrypt
++    @c1.random_key
+     assert_raise(ArgumentError){ @c1.update("") }
+   end
+ 
+@@ -127,13 +128,10 @@ class OpenSSL::TestCipher < Test::Unit::
+         assert_equal(pt, c2.update(ct) + c2.final)
+       }
+     end
+-
+-    def test_AES_crush
+-      500.times do
+-        assert_nothing_raised("[Bug #2768]") do
+-          # it caused OpenSSL SEGV by uninitialized key
+-          OpenSSL::Cipher::AES128.new("ECB").update "." * 17
+-        end
++    def test_update_raise_if_key_not_set
++    assert_raise(OpenSSL::Cipher::CipherError) do
++      # it caused OpenSSL SEGV by uninitialized key [Bug #2768]
++      OpenSSL::Cipher::AES128.new("ECB").update "." * 17
+       end
+     end
+   end
+@@ -236,6 +234,23 @@ class OpenSSL::TestCipher < Test::Unit::
+     end
+ 
+   end
++  def test_aes_gcm_key_iv_order_issue
++    pt = "[ruby/openssl#49]"
++    cipher = OpenSSL::Cipher.new("aes-128-gcm").encrypt
++    cipher.key = "x" * 16
++    cipher.iv = "a" * 12
++    ct1 = cipher.update(pt) << cipher.final
++    tag1 = cipher.auth_tag
++
++    cipher = OpenSSL::Cipher.new("aes-128-gcm").encrypt
++    cipher.iv = "a" * 12
++    cipher.key = "x" * 16
++    ct2 = cipher.update(pt) << cipher.final
++    tag2 = cipher.auth_tag
++
++    assert_equal ct1, ct2
++    assert_equal tag1, tag2
++  end if has_cipher?("aes-128-gcm")
+ 
+   private
+ 
diff --git a/meta/recipes-devtools/ruby/ruby_2.2.5.bb b/meta/recipes-devtools/ruby/ruby_2.2.5.bb
index 66ba1d4b84..35882d18e6 100644
--- a/meta/recipes-devtools/ruby/ruby_2.2.5.bb
+++ b/meta/recipes-devtools/ruby/ruby_2.2.5.bb
@@ -3,7 +3,9 @@ require ruby.inc
 SRC_URI[md5sum] = "bd8e349d4fb2c75d90817649674f94be"
 SRC_URI[sha256sum] = "30c4b31697a4ca4ea0c8db8ad30cf45e6690a0f09687e5d483c933c03ca335e3"
 
-SRC_URI += "file://prevent-gc.patch"
+SRC_URI += "file://prevent-gc.patch \
+            file://CVE-2016-7798.patch \
+"
 
 # it's unknown to configure script, but then passed to extconf.rb
 # maybe it's not really needed as we're hardcoding the result with