Fix the ECDSA timing attack mentioned in the paper at:

[openssl.git] / crypto / ocsp / ocsp_ht.c

diff --git a/crypto/ocsp/ocsp_ht.c b/crypto/ocsp/ocsp_ht.c
index 38602fae4aad2a896e0a83917047611c458fa8d0..af5fc16691d432d4969126a5e64640e4a1775a14 100644 (file)
--- a/crypto/ocsp/ocsp_ht.c
+++ b/crypto/ocsp/ocsp_ht.c
@@ -118,39 +118,65 @@ void OCSP_REQ_CTX_free(OCSP_REQ_CTX *rctx)
        OPENSSL_free(rctx);
        }
 
-OCSP_REQ_CTX *OCSP_sendreq_new(BIO *io, char *path, OCSP_REQUEST *req,
-                                                               int maxline)
+int OCSP_REQ_CTX_set1_req(OCSP_REQ_CTX *rctx, OCSP_REQUEST *req)
        {
-       static const char post_hdr[] = "POST %s HTTP/1.0\r\n"
+       static const char req_hdr[] =
        "Content-Type: application/ocsp-request\r\n"
        "Content-Length: %d\r\n\r\n";
+        if (BIO_printf(rctx->mem, req_hdr, i2d_OCSP_REQUEST(req, NULL)) <= 0)
+               return 0;
+        if (i2d_OCSP_REQUEST_bio(rctx->mem, req) <= 0)
+               return 0;
+       rctx->state = OHS_ASN1_WRITE;
+       rctx->asn1_len = BIO_get_mem_data(rctx->mem, NULL);
+       return 1;
+       }
+
+int OCSP_REQ_CTX_add1_header(OCSP_REQ_CTX *rctx,
+               const char *name, const char *value)
+       {
+       if (!name)
+               return 0;
+       if (BIO_puts(rctx->mem, name) <= 0)
+               return 0;
+       if (value)
+               {
+               if (BIO_write(rctx->mem, ": ", 2) != 2)
+                       return 0;
+               if (BIO_puts(rctx->mem, value) <= 0)
+                       return 0;
+               }
+       if (BIO_write(rctx->mem, "\r\n", 2) != 2)
+               return 0;
+       return 1;
+       }
+
+OCSP_REQ_CTX *OCSP_sendreq_new(BIO *io, char *path, OCSP_REQUEST *req,
+                                                               int maxline)
+       {
+       static const char post_hdr[] = "POST %s HTTP/1.0\r\n";
 
        OCSP_REQ_CTX *rctx;
        rctx = OPENSSL_malloc(sizeof(OCSP_REQ_CTX));
-       rctx->state = OHS_FIRSTLINE;
+       rctx->state = OHS_ERROR;
        rctx->mem = BIO_new(BIO_s_mem());
        rctx->io = io;
+       rctx->asn1_len = 0;
        if (maxline > 0)
                rctx->iobuflen = maxline;
        else
                rctx->iobuflen = OCSP_MAX_LINE_LEN;
        rctx->iobuf = OPENSSL_malloc(rctx->iobuflen);
+       if (!rctx->iobuf)
+               return 0;
        if (!path)
                path = "/";
 
-        if (BIO_printf(rctx->mem, post_hdr, path,
-                               i2d_OCSP_REQUEST(req, NULL)) <= 0)
-               {
-               rctx->state = OHS_ERROR;
+        if (BIO_printf(rctx->mem, post_hdr, path) <= 0)
                return 0;
-               }
-        if (i2d_OCSP_REQUEST_bio(rctx->mem, req) <= 0)
-               {
-               rctx->state = OHS_ERROR;
+
+       if (req && !OCSP_REQ_CTX_set1_req(rctx, req))
                return 0;
-               }
-       rctx->state = OHS_ASN1_WRITE;
-       rctx->asn1_len = BIO_get_mem_data(rctx->mem, NULL);
 
        return rctx;
        }
@@ -371,11 +397,12 @@ int OCSP_sendreq_nbio(OCSP_RESPONSE **presp, OCSP_REQ_CTX *rctx)
 
 
                case OHS_ASN1_HEADER:
-               /* Now reading ASN1 header: can read at least 6 bytes which
-                * is more than enough for any valid ASN1 SEQUENCE header
+               /* Now reading ASN1 header: can read at least 2 bytes which
+                * is enough for ASN1 SEQUENCE header and either length field
+                * or at least the length of the length field.
                 */
                n = BIO_get_mem_data(rctx->mem, &p);
-               if (n < 6)
+               if (n < 2)
                        goto next_io;
 
                /* Check it is an ASN1 SEQUENCE */
@@ -388,6 +415,11 @@ int OCSP_sendreq_nbio(OCSP_RESPONSE **presp, OCSP_REQ_CTX *rctx)
                /* Check out length field */
                if (*p & 0x80)
                        {
+                       /* If MSB set on initial length octet we can now
+                        * always read 6 octets: make sure we have them.
+                        */
+                       if (n < 6)
+                               goto next_io;
                        n = *p & 0x7F;
                        /* Not NDEF or excessive length */
                        if (!n || (n > 4))