File openssl-CVE-2019-1543.patch of Package openssl-1_1.17236

commit f426625b6ae9a7831010750490a5f0ad689c5ba3
Author: Matt Caswell <matt@openssl.org>
Date:   Tue Mar 5 14:39:15 2019 +0000

    Prevent over long nonces in ChaCha20-Poly1305
    
    ChaCha20-Poly1305 is an AEAD cipher, and requires a unique nonce input for
    every encryption operation. RFC 7539 specifies that the nonce value (IV)
    should be 96 bits (12 bytes). OpenSSL allows a variable nonce length and
    front pads the nonce with 0 bytes if it is less than 12 bytes. However it
    also incorrectly allows a nonce to be set of up to 16 bytes. In this case
    only the last 12 bytes are significant and any additional leading bytes are
    ignored.
    
    It is a requirement of using this cipher that nonce values are unique.
    Messages encrypted using a reused nonce value are susceptible to serious
    confidentiality and integrity attacks. If an application changes the
    default nonce length to be longer than 12 bytes and then makes a change to
    the leading bytes of the nonce expecting the new value to be a new unique
    nonce then such an application could inadvertently encrypt messages with a
    reused nonce.
    
    Additionally the ignored bytes in a long nonce are not covered by the
    integrity guarantee of this cipher. Any application that relies on the
    integrity of these ignored leading bytes of a long nonce may be further
    affected.
    
    Any OpenSSL internal use of this cipher, including in SSL/TLS, is safe
    because no such use sets such a long nonce value. However user
    applications that use this cipher directly and set a non-default nonce
    length to be longer than 12 bytes may be vulnerable.
    
    CVE-2019-1543
    
    Fixes #8345
    
    Reviewed-by: Paul Dale <paul.dale@oracle.com>
    Reviewed-by: Richard Levitte <levitte@openssl.org>
    (Merged from https://github.com/openssl/openssl/pull/8406)
    
    (cherry picked from commit 2a3d0ee9d59156c48973592331404471aca886d6)

diff --git a/crypto/evp/e_chacha20_poly1305.c b/crypto/evp/e_chacha20_poly1305.c
index c1917bb86a..d3e2c622a1 100644
--- a/crypto/evp/e_chacha20_poly1305.c
+++ b/crypto/evp/e_chacha20_poly1305.c
@@ -30,6 +30,8 @@ typedef struct {
 
 #define data(ctx)   ((EVP_CHACHA_KEY *)(ctx)->cipher_data)
 
+#define CHACHA20_POLY1305_MAX_IVLEN     12
+
 static int chacha_init_key(EVP_CIPHER_CTX *ctx,
                            const unsigned char user_key[CHACHA_KEY_SIZE],
                            const unsigned char iv[CHACHA_CTR_SIZE], int enc)
@@ -533,7 +535,7 @@ static int chacha20_poly1305_ctrl(EVP_CIPHER_CTX *ctx, int type, int arg,
         return 1;
 
     case EVP_CTRL_AEAD_SET_IVLEN:
-        if (arg <= 0 || arg > CHACHA_CTR_SIZE)
+        if (arg <= 0 || arg > CHACHA20_POLY1305_MAX_IVLEN)
             return 0;
         actx->nonce_len = arg;
         return 1;