evp: prevent underflow in base64 decoding

[openssl.git] / ssl / t1_enc.c

diff --git a/ssl/t1_enc.c b/ssl/t1_enc.c
index 6fbe2c33aa7ed88beaa7a8a2d413a5c86705d302..0c4cddedf85c703e55d7b5bbf5be6612dabaf221 100644 (file)
--- a/ssl/t1_enc.c
+++ b/ssl/t1_enc.c
@@ -414,15 +414,20 @@ int tls1_change_cipher_state(SSL *s, int which)
                        s->mac_flags |= SSL_MAC_FLAG_WRITE_MAC_STREAM;
                        else
                        s->mac_flags &= ~SSL_MAC_FLAG_WRITE_MAC_STREAM;
-               if (s->enc_write_ctx != NULL)
+               if (s->enc_write_ctx != NULL && !SSL_IS_DTLS(s))
                        reuse_dd = 1;
-               else if ((s->enc_write_ctx=OPENSSL_malloc(sizeof(EVP_CIPHER_CTX))) == NULL)
+               else if ((s->enc_write_ctx=EVP_CIPHER_CTX_new()) == NULL)
                        goto err;
-               else
-                       /* make sure it's intialized in case we exit later with an error */
-                       EVP_CIPHER_CTX_init(s->enc_write_ctx);
                dd= s->enc_write_ctx;
-               mac_ctx = ssl_replace_hash(&s->write_hash,NULL);
+               if (SSL_IS_DTLS(s))
+                       {
+                       mac_ctx = EVP_MD_CTX_create();
+                       if (!mac_ctx)
+                               goto err;
+                       s->write_hash = mac_ctx;
+                       }
+               else
+                       mac_ctx = ssl_replace_hash(&s->write_hash,NULL);
 #ifndef OPENSSL_NO_COMP
                if (s->compress != NULL)
                        {
@@ -915,18 +920,19 @@ int tls1_final_finish_mac(SSL *s,
                if (mask & ssl_get_algorithm2(s))
                        {
                        int hashsize = EVP_MD_size(md);
-                       if (hashsize < 0 || hashsize > (int)(sizeof buf - (size_t)(q-buf)))
+                       EVP_MD_CTX *hdgst = s->s3->handshake_dgst[idx];
+                       if (!hdgst || hashsize < 0 || hashsize > (int)(sizeof buf - (size_t)(q-buf)))
                                {
                                /* internal error: 'buf' is too small for this cipersuite! */
                                err = 1;
                                }
                        else
                                {
-                               EVP_MD_CTX_copy_ex(&ctx,s->s3->handshake_dgst[idx]);
-                               EVP_DigestFinal_ex(&ctx,q,&i);
-                               if (i != (unsigned int)hashsize) /* can't really happen */
+                               if (!EVP_MD_CTX_copy_ex(&ctx, hdgst) ||
+                                       !EVP_DigestFinal_ex(&ctx,q,&i) ||
+                                       (i != (unsigned int)hashsize))
                                        err = 1;
-                               q+=i;
+                               q+=hashsize;
                                }
                        }
                }
@@ -949,7 +955,7 @@ 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 header[13];
@@ -980,7 +986,8 @@ int tls1_mac(SSL *ssl, unsigned char *md, int send)
                }
                else
                {
-                       EVP_MD_CTX_copy(&hmac,hash);
+                       if (!EVP_MD_CTX_copy(&hmac,hash))
+                               return -1;
                        mac_ctx = &hmac;
                }
 
@@ -996,6 +1003,10 @@ int tls1_mac(SSL *ssl, unsigned char *md, int send)
        else
                memcpy(header, seq, 8);
 
+       /* 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);
@@ -1014,7 +1025,7 @@ int tls1_mac(SSL *ssl, unsigned char *md, int send)
                        mac_ctx,
                        md, &md_size,
                        header, rec->input,
-                       rec->length + md_size, rec->orig_len,
+                       rec->length + md_size, orig_len,
                        ssl->s3->read_mac_secret,
                        ssl->s3->read_mac_secret_size,
                        0 /* not SSLv3 */);
@@ -1030,7 +1041,7 @@ int tls1_mac(SSL *ssl, unsigned char *md, int send)
                        tls_fips_digest_extra(
                                        ssl->enc_read_ctx,
                                        mac_ctx, rec->input,
-                                       rec->length, rec->orig_len);
+                                       rec->length, orig_len);
 #endif
                }