Don't crash when processing a zero-length, TLS >= 1.1 record.

The previous CBC patch was bugged in that there was a path through enc()
in s3_pkt.c/d1_pkt.c which didn't set orig_len. orig_len would be left
at the previous value which could suggest that the packet was a
sufficient length when it wasn't.
(cherry picked from commit 6cb19b7681f600b2f165e4adc57547b097b475fd)

diff --git a/ssl/d1_enc.c b/ssl/d1_enc.c
index c13b495a081f56941bea4e372ca149592cd035ee..da42348b3df2f50677f23f52558abc676b110f0f 100644 (file)
--- a/ssl/d1_enc.c
+++ b/ssl/d1_enc.c
@@ -245,7 +245,6 @@ int dtls1_enc(SSL *s, int send)
                 }
 #endif /* KSSL_DEBUG */
 
-               rec->orig_len = rec->length;
                if ((bs != 1) && !send)
                        return tls1_cbc_remove_padding(s, rec, bs, mac_size);
                }

diff --git a/ssl/d1_pkt.c b/ssl/d1_pkt.c
index 5e2c56c9833ddcb85c0286de0e2cb89c9cbf9578..4763d5cd1f9398f42646f16a89c061095c0c9187 100644 (file)
--- a/ssl/d1_pkt.c
+++ b/ssl/d1_pkt.c
@@ -414,6 +414,7 @@ dtls1_process_record(SSL *s)
 
        /* decrypt in place in 'rr->input' */
        rr->data=rr->input;
+       rr->orig_len=rr->length;
 
        enc_err = s->method->ssl3_enc->enc(s,0);
        if (enc_err <= 0)

diff --git a/ssl/s3_enc.c b/ssl/s3_enc.c
index 13ebfc6996f48c968c81113abd14f668a60b3ebe..98f38949549785b66949ebe4335300f1503dbbb7 100644 (file)
--- a/ssl/s3_enc.c
+++ b/ssl/s3_enc.c
@@ -487,6 +487,15 @@ void ssl3_cleanup_key_block(SSL *s)
        s->s3->tmp.key_block_length=0;
        }
 
+/* ssl3_enc encrypts/decrypts the record in |s->wrec| / |s->rrec|, respectively.
+ *
+ * Returns:
+ *   0: (in non-constant time) if the record is publically invalid (i.e. too
+ *       short etc).
+ *   1: if the record's padding is valid / the encryption was successful.
+ *   -1: if the record's padding is invalid or, if sending, an internal error
+ *       occured.
+ */
 int ssl3_enc(SSL *s, int send)
        {
        SSL3_RECORD *rec;
@@ -553,8 +562,6 @@ int ssl3_enc(SSL *s, int send)
                
                EVP_Cipher(ds,rec->data,rec->input,l);
 
-               rec->orig_len = rec->length;
-
                if (EVP_MD_CTX_md(s->read_hash) != NULL)
                        mac_size = EVP_MD_CTX_size(s->read_hash);
                if ((bs != 1) && !send)

diff --git a/ssl/s3_pkt.c b/ssl/s3_pkt.c
index b2e5dc188231f4dac8ed5bb1e60a3bfc7cb94a3b..3e60f5018c41c3e11fdb6298dcc68235f6c85eaf 100644 (file)
--- a/ssl/s3_pkt.c
+++ b/ssl/s3_pkt.c
@@ -401,8 +401,13 @@ fprintf(stderr, "Record type=%d, Length=%d\n", rr->type, rr->length);
 
        /* decrypt in place in 'rr->input' */
        rr->data=rr->input;
+       rr->orig_len=rr->length;
 
        enc_err = s->method->ssl3_enc->enc(s,0);
+       /* enc_err is:
+        *    0: (in non-constant time) if the record is publically invalid.
+        *    1: if the padding is valid
+        *    -1: if the padding is invalid */
        if (enc_err == 0)
                {
                /* SSLerr() and ssl3_send_alert() have been called */

diff --git a/ssl/t1_enc.c b/ssl/t1_enc.c
index 8153b2ca4326dfbd9b54f3a47e18e8266c3d4b59..4b31742783d6d60308d8c52281b06bf9e5a6768b 100644 (file)
--- a/ssl/t1_enc.c
+++ b/ssl/t1_enc.c
@@ -691,6 +691,15 @@ err:
        return(ret);
        }
 
+/* tls1_enc encrypts/decrypts the record in |s->wrec| / |s->rrec|, respectively.
+ *
+ * Returns:
+ *   0: (in non-constant time) if the record is publically invalid (i.e. too
+ *       short etc).
+ *   1: if the record's padding is valid / the encryption was successful.
+ *   -1: if the record's padding/AEAD-authenticator is invalid or, if sending,
+ *       an internal error occured.
+ */
 int tls1_enc(SSL *s, int send)
        {
        SSL3_RECORD *rec;
@@ -841,8 +850,6 @@ int tls1_enc(SSL *s, int send)
                        {
                        if (l == 0 || l%bs != 0)
                                {
-                               if (s->version >= TLS1_1_VERSION)
-                                       return -1;
                                SSLerr(SSL_F_TLS1_ENC,SSL_R_BLOCK_CIPHER_PAD_IS_WRONG);
                                ssl3_send_alert(s,SSL3_AL_FATAL,SSL_AD_DECRYPTION_FAILED);
                                return 0;
@@ -870,8 +877,6 @@ int tls1_enc(SSL *s, int send)
                }
 #endif /* KSSL_DEBUG */
 
-               rec->orig_len = rec->length;
-
                ret = 1;
                if (EVP_MD_CTX_md(s->read_hash) != NULL)
                        mac_size = EVP_MD_CTX_size(s->read_hash);