cherry pick bugfixes for http://www.openssl.org/news/secadv_20130205.txt

from the openssl git (changes between openssl 1.0.1c and 1.0.1d).
ok djm@

1 files changed, 74 insertions, 83 deletions

diff --git a/src/lib/libssl/t1_enc.c b/src/lib/libssl/t1_enc.c
index f7bdeb3b9d..448eef274f 100644
--- a/src/lib/libssl/t1_enc.c
+++ b/src/lib/libssl/t1_enc.c
@@ -667,12 +667,21 @@ 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;
         EVP_CIPHER_CTX *ds;
         unsigned long l;
-        int bs,i,ii,j,k,pad=0;
+        int bs,i,j,k,pad=0,ret,mac_size=0;
         const EVP_CIPHER *enc;
 
         if (send)
@@ -729,11 +738,11 @@ int tls1_enc(SSL *s, int send)
         printf("tls1_enc(%d)\n", send);
 #endif    /* KSSL_DEBUG */
 
-        if ((s->session == NULL) || (ds == NULL) ||
-                (enc == NULL))
+        if ((s->session == NULL) || (ds == NULL) || (enc == NULL))
                 {
                 memmove(rec->data,rec->input,rec->length);
                 rec->input=rec->data;
+                ret = 1;
                 }
         else
                 {
@@ -797,13 +806,13 @@ int tls1_enc(SSL *s, int send)
 
 #ifdef KSSL_DEBUG
                 {
-                unsigned long ui;
+                unsigned long ui;
                 printf("EVP_Cipher(ds=%p,rec->data=%p,rec->input=%p,l=%ld) ==>\n",
-                        ds,rec->data,rec->input,l);
+                        ds,rec->data,rec->input,l);
                 printf("\tEVP_CIPHER_CTX: %d buf_len, %d key_len [%d %d], %d iv_len\n",
-                        ds->buf_len, ds->cipher->key_len,
-                        DES_KEY_SZ, DES_SCHEDULE_SZ,
-                        ds->cipher->iv_len);
+                        ds->buf_len, ds->cipher->key_len,
+                        DES_KEY_SZ, DES_SCHEDULE_SZ,
+                        ds->cipher->iv_len);
                 printf("\t\tIV: ");
                 for (i=0; i<ds->cipher->iv_len; i++) printf("%02X", ds->iv[i]);
                 printf("\n");
@@ -816,13 +825,7 @@ int tls1_enc(SSL *s, int send)
                 if (!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;
-                                }
                         }
                 
                 i = EVP_Cipher(ds,rec->data,rec->input,l);
@@ -839,68 +842,24 @@ int tls1_enc(SSL *s, int send)
 
 #ifdef KSSL_DEBUG
                 {
-                unsigned long i;
-                printf("\trec->data=");
+                unsigned long i;
+                printf("\trec->data=");
                 for (i=0; i<l; i++)
-                        printf(" %02x", rec->data[i]);  printf("\n");
-                }
+                        printf(" %02x", rec->data[i]);  printf("\n");
+                }
 #endif  /* KSSL_DEBUG */
 
+                ret = 1;
+                if (EVP_MD_CTX_md(s->read_hash) != NULL)
+                        mac_size = EVP_MD_CTX_size(s->read_hash);
                 if ((bs != 1) && !send)
-                        {
-                        ii=i=rec->data[l-1]; /* padding_length */
-                        i++;
-                        /* NB: if compression is in operation the first packet
-                         * may not be of even length so the padding bug check
-                         * cannot be performed. This bug workaround has been
-                         * around since SSLeay so hopefully it is either fixed
-                         * now or no buggy implementation supports compression 
-                         * [steve]
-                         */
-                        if ( (s->options&SSL_OP_TLS_BLOCK_PADDING_BUG)
-                                && !s->expand)
-                                {
-                                /* First packet is even in size, so check */
-                                if ((memcmp(s->s3->read_sequence,
-                                        "\0\0\0\0\0\0\0\0",8) == 0) && !(ii & 1))
-                                        s->s3->flags|=TLS1_FLAGS_TLS_PADDING_BUG;
-                                if (s->s3->flags & TLS1_FLAGS_TLS_PADDING_BUG)
-                                        i--;
-                                }
-                        /* TLS 1.0 does not bound the number of padding bytes by the block size.
-                         * All of them must have value 'padding_length'. */
-                        if (i > (int)rec->length)
-                                {
-                                /* Incorrect padding. SSLerr() and ssl3_alert are done
-                                 * by caller: we don't want to reveal whether this is
-                                 * a decryption error or a MAC verification failure
-                                 * (see http://www.openssl.org/~bodo/tls-cbc.txt) */
-                                return -1;
-                                }
-                        for (j=(int)(l-i); j<(int)l; j++)
-                                {
-                                if (rec->data[j] != ii)
-                                        {
-                                        /* Incorrect padding */
-                                        return -1;
-                                        }
-                                }
-                        rec->length -=i;
-                        if (s->version >= TLS1_1_VERSION
-                                && EVP_CIPHER_CTX_mode(ds) == EVP_CIPH_CBC_MODE)
-                                {
-                                if (bs > (int)rec->length)
-                                        return -1;
-                                rec->data += bs;    /* skip the explicit IV */
-                                rec->input += bs;
-                                rec->length -= bs;
-                                }
-                        }
+                        ret = tls1_cbc_remove_padding(s, rec, bs, mac_size);
                 if (pad && !send)
                         rec->length -= pad;
                 }
-        return(1);
+        return ret;
         }
+
 int tls1_cert_verify_mac(SSL *s, int md_nid, unsigned char *out)
         {
         unsigned int ret;
@@ -990,10 +949,10 @@ int tls1_mac(SSL *ssl, unsigned char *md, int send)
         SSL3_RECORD *rec;
         unsigned char *seq;
         EVP_MD_CTX *hash;
-        size_t md_size;
+        size_t md_size, orig_len;
         int i;
         EVP_MD_CTX hmac, *mac_ctx;
-        unsigned char buf[5]; 
+        unsigned char header[13];
         int stream_mac = (send?(ssl->mac_flags & SSL_MAC_FLAG_WRITE_MAC_STREAM):(ssl->mac_flags&SSL_MAC_FLAG_READ_MAC_STREAM));
         int t;
 
@@ -1014,12 +973,6 @@ int tls1_mac(SSL *ssl, unsigned char *md, int send)
         OPENSSL_assert(t >= 0);
         md_size=t;
 
-        buf[0]=rec->type;
-        buf[1]=(unsigned char)(ssl->version>>8);
-        buf[2]=(unsigned char)(ssl->version);
-        buf[3]=rec->length>>8;
-        buf[4]=rec->length&0xff;
-
         /* I should fix this up TLS TLS TLS TLS TLS XXXXXXXX */
         if (stream_mac) 
                 {
@@ -1038,17 +991,55 @@ int tls1_mac(SSL *ssl, unsigned char *md, int send)
                 s2n(send?ssl->d1->w_epoch:ssl->d1->r_epoch, p);
                 memcpy (p,&seq[2],6);
 
-                EVP_DigestSignUpdate(mac_ctx,dtlsseq,8);
+                memcpy(header, dtlsseq, 8);
                 }
         else
-                EVP_DigestSignUpdate(mac_ctx,seq,8);
+                memcpy(header, seq, 8);
 
-        EVP_DigestSignUpdate(mac_ctx,buf,5);
-        EVP_DigestSignUpdate(mac_ctx,rec->input,rec->length);
-        t=EVP_DigestSignFinal(mac_ctx,md,&md_size);
-        OPENSSL_assert(t > 0);
+        /* kludge: tls1_cbc_remove_padding passes padding length in rec->type */
+        orig_len = rec->length+md_size+((unsigned int)rec->type>>8);
+        rec->type &= 0xff;
+
+        header[8]=rec->type;
+        header[9]=(unsigned char)(ssl->version>>8);
+        header[10]=(unsigned char)(ssl->version);
+        header[11]=(rec->length)>>8;
+        header[12]=(rec->length)&0xff;
+
+        if (!send &&
+            EVP_CIPHER_CTX_mode(ssl->enc_read_ctx) == EVP_CIPH_CBC_MODE &&
+            ssl3_cbc_record_digest_supported(mac_ctx))
+                {
+                /* This is a CBC-encrypted record. We must avoid leaking any
+                 * timing-side channel information about how many blocks of
+                 * data we are hashing because that gives an attacker a
+                 * timing-oracle. */
+                ssl3_cbc_digest_record(
+                        mac_ctx,
+                        md, &md_size,
+                        header, rec->input,
+                        rec->length + md_size, orig_len,
+                        ssl->s3->read_mac_secret,
+                        ssl->s3->read_mac_secret_size,
+                        0 /* not SSLv3 */);
+                }
+        else
+                {
+                EVP_DigestSignUpdate(mac_ctx,header,sizeof(header));
+                EVP_DigestSignUpdate(mac_ctx,rec->input,rec->length);
+                t=EVP_DigestSignFinal(mac_ctx,md,&md_size);
+                OPENSSL_assert(t > 0);
+#ifdef OPENSSL_FIPS
+                if (!send && FIPS_mode())
+                        tls_fips_digest_extra(
+                                        ssl->enc_read_ctx,
+                                        mac_ctx, rec->input,
+                                        rec->length, orig_len);
+#endif
+                }
                 
-        if (!stream_mac) EVP_MD_CTX_cleanup(&hmac);
+        if (!stream_mac)
+                EVP_MD_CTX_cleanup(&hmac);
 #ifdef TLS_DEBUG
 printf("sec=");
 {unsigned int z; for (z=0; z<md_size; z++) printf("%02X ",mac_sec[z]); printf("\n"); }