Eliminate TWRITE macros in GSS library

Use dynamic k5buf structures to replace the two uses of the TWRITE_
macros, and replace the uses of TREAD_ macros with the equivalent
pointer assignments.

4 files changed, 43 insertions, 106 deletions

diff --git a/src/lib/gssapi/generic/gssapiP_generic.h b/src/lib/gssapi/generic/gssapiP_generic.h
index 5d01fb492..3c6bfa53d 100644
--- a/src/lib/gssapi/generic/gssapiP_generic.h
+++ b/src/lib/gssapi/generic/gssapiP_generic.h
@@ -54,38 +54,6 @@
         (((o1)->length == (o2)->length) &&                              \
         (memcmp((o1)->elements, (o2)->elements, (o1)->length) == 0))
 
-/* this code knows that an int on the wire is 32 bits.  The type of
-   num should be at least this big, or the extra shifts may do weird
-   things */
-
-#define TWRITE_INT(ptr, num, bigend)                                    \
-   if (bigend) store_32_be(num, ptr); else store_32_le(num, ptr);       \
-   (ptr) += 4;
-
-#define TWRITE_INT16(ptr, num, bigend)                                  \
-   if (bigend) store_16_be((num)>>16, ptr); else store_16_le(num, ptr); \
-   (ptr) += 2;
-
-#define TREAD_INT(ptr, num, bigend)                        \
-   (num) = ((bigend) ? load_32_be(ptr) : load_32_le(ptr)); \
-   (ptr) += 4;
-
-#define TREAD_INT16(ptr, num, bigend)                              \
-   (num) = ((bigend) ? (load_16_be(ptr) << 16) : load_16_le(ptr)); \
-   (ptr) += 2;
-
-#define TWRITE_STR(ptr, str, len)               \
-   memcpy((ptr), (str), (len));                 \
-   (ptr) += (len);
-
-#define TREAD_STR(ptr, str, len)                \
-   (str) = (ptr);                               \
-   (ptr) += (len);
-
-#define TWRITE_BUF(ptr, buf, bigend)                    \
-   TWRITE_INT((ptr), (buf).length, (bigend));           \
-   TWRITE_STR((ptr), (buf).value, (buf).length);
-
 /** malloc wrappers; these may actually do something later */
 
 #define xmalloc(n) malloc(n)
diff --git a/src/lib/gssapi/krb5/accept_sec_context.c b/src/lib/gssapi/krb5/accept_sec_context.c
index dd4caf380..b35e11bfb 100644
--- a/src/lib/gssapi/krb5/accept_sec_context.c
+++ b/src/lib/gssapi/krb5/accept_sec_context.c
@@ -657,7 +657,6 @@ kg_accept_krb5(minor_status, context_handle,
 {
     krb5_context context;
     unsigned char *ptr;
-    char *sptr;
     krb5_gss_cred_id_t cred = 0;
     krb5_data ap_rep, ap_req;
     krb5_error_code code;
@@ -788,16 +787,13 @@ kg_accept_krb5(minor_status, context_handle,
     } else if (code == G_BAD_TOK_HEADER) {
         /* DCE style not encapsulated */
         ap_req.length = input_token->length;
-        ap_req.data = input_token->value;
         mech_used = gss_mech_krb5;
         no_encap = 1;
     } else {
         major_status = GSS_S_DEFECTIVE_TOKEN;
         goto fail;
     }
-
-    sptr = (char *) ptr;
-    TREAD_STR(sptr, ap_req.data, ap_req.length);
+    ap_req.data = (char *)ptr;
 
     /* construct the sender_addr */
 
diff --git a/src/lib/gssapi/krb5/init_sec_context.c b/src/lib/gssapi/krb5/init_sec_context.c
index 83fd514c1..5748b8434 100644
--- a/src/lib/gssapi/krb5/init_sec_context.c
+++ b/src/lib/gssapi/krb5/init_sec_context.c
@@ -246,14 +246,14 @@ make_gss_checksum (krb5_context context, krb5_auth_context auth_context,
 {
     krb5_error_code code;
     krb5_int32 con_flags;
-    unsigned char *ptr;
     struct gss_checksum_data *data = cksum_data;
     krb5_data credmsg;
     unsigned int junk;
     krb5_data *finished = NULL;
     krb5_key send_subkey;
+    struct k5buf buf;
 
-    data->checksum_data.data = 0;
+    data->checksum_data = empty_data();
     credmsg.data = 0;
     /* build the checksum field */
 
@@ -291,18 +291,12 @@ make_gss_checksum (krb5_context context, krb5_auth_context auth_context,
                request */
             data->ctx->gss_flags &= ~(GSS_C_DELEG_FLAG |
                                       GSS_C_DELEG_POLICY_FLAG);
-
-            data->checksum_data.length = 24;
         } else {
             if (credmsg.length+28 > KRB5_INT16_MAX) {
                 code = KRB5KRB_ERR_FIELD_TOOLONG;
                 goto cleanup;
             }
-
-            data->checksum_data.length = 28+credmsg.length;
         }
-    } else {
-        data->checksum_data.length = 24;
     }
 #ifdef CFX_EXERCISE
     if (data->ctx->auth_context->keyblock != NULL
@@ -335,40 +329,35 @@ make_gss_checksum (krb5_context context, krb5_auth_context auth_context,
         }
 
         krb5_k_free_key(context, key);
-        data->checksum_data.length += 8 + finished->length;
     }
 
-    data->checksum_data.length += junk;
-
     /* now allocate a buffer to hold the checksum data and
        (maybe) KRB_CRED msg */
-
-    if ((data->checksum_data.data =
-         (char *) xmalloc(data->checksum_data.length)) == NULL) {
-        code = ENOMEM;
-        goto cleanup;
+    k5_buf_init_dynamic(&buf);
+    k5_buf_add_uint32_le(&buf, data->md5.length);
+    k5_buf_add_len(&buf, data->md5.contents, data->md5.length);
+    k5_buf_add_uint32_le(&buf, data->ctx->gss_flags);
+    if (credmsg.data != NULL) {
+        k5_buf_add_uint16_le(&buf, KRB5_GSS_FOR_CREDS_OPTION);
+        k5_buf_add_uint16_le(&buf, credmsg.length);
+        k5_buf_add_len(&buf, credmsg.data, credmsg.length);
     }
+    if (data->exts->iakerb.conv != NULL) {
+        k5_buf_add_uint32_be(&buf, KRB5_GSS_EXTS_IAKERB_FINISHED);
+        k5_buf_add_uint32_be(&buf, finished->length);
+        k5_buf_add_len(&buf, finished->data, finished->length);
+    }
+    while (junk--)
+        k5_buf_add_byte(&buf, 'i');
 
-    ptr = (unsigned char *)data->checksum_data.data;
-
-    TWRITE_INT(ptr, data->md5.length, 0);
-    TWRITE_STR(ptr, data->md5.contents, data->md5.length);
-    TWRITE_INT(ptr, data->ctx->gss_flags, 0);
+    code = k5_buf_status(&buf);
+    if (code)
+        goto cleanup;
 
-    if (credmsg.data) {
-        TWRITE_INT16(ptr, KRB5_GSS_FOR_CREDS_OPTION, 0);
-        TWRITE_INT16(ptr, credmsg.length, 0);
-        TWRITE_STR(ptr, credmsg.data, credmsg.length);
-    }
-    if (data->exts->iakerb.conv) {
-        TWRITE_INT(ptr, KRB5_GSS_EXTS_IAKERB_FINISHED, 1);
-        TWRITE_INT(ptr, finished->length, 1);
-        TWRITE_STR(ptr, finished->data, finished->length);
-    }
-    if (junk)
-        memset(ptr, 'i', junk);
+    data->checksum_data = make_data(buf.data, buf.len);
     *out = &data->checksum_data;
     code = 0;
+
 cleanup:
     krb5_free_data_contents(context, &credmsg);
     krb5_free_data(context, finished);
@@ -726,7 +715,6 @@ mutual_auth(
 {
     OM_uint32 major_status;
     unsigned char *ptr;
-    char *sptr;
     krb5_data ap_rep;
     krb5_ap_rep_enc_part *ap_rep_data;
     krb5_timestamp now;
@@ -775,7 +763,6 @@ mutual_auth(
     if (ctx->gss_flags & GSS_C_DCE_STYLE) {
         /* Raw AP-REP */
         ap_rep.length = input_token->length;
-        ap_rep.data = (char *)input_token->value;
     } else if (g_verify_token_header(ctx->mech_used,
                                      &(ap_rep.length),
                                      &ptr, KG_TOK_CTX_AP_REP,
@@ -787,9 +774,7 @@ mutual_auth(
 
             /* Handle a KRB_ERROR message from the server */
 
-            sptr = (char *) ptr;           /* PC compiler bug */
-            TREAD_STR(sptr, ap_rep.data, ap_rep.length);
-
+            ap_rep.data = (char *)ptr;
             code = krb5_rd_error(context, &ap_rep, &krb_error);
             if (code)
                 goto fail;
@@ -804,9 +789,7 @@ mutual_auth(
             return(GSS_S_DEFECTIVE_TOKEN);
         }
     }
-
-    sptr = (char *) ptr;                      /* PC compiler bug */
-    TREAD_STR(sptr, ap_rep.data, ap_rep.length);
+    ap_rep.data = (char *)ptr;
 
     /* decode the ap_rep */
     if ((code = krb5_rd_rep(context, ctx->auth_context, &ap_rep,
diff --git a/src/lib/gssapi/krb5/util_cksum.c b/src/lib/gssapi/krb5/util_cksum.c
index 2d6b50b2a..5b8795639 100644
--- a/src/lib/gssapi/krb5/util_cksum.c
+++ b/src/lib/gssapi/krb5/util_cksum.c
@@ -33,9 +33,7 @@ kg_checksum_channel_bindings(context, cb, cksum)
     gss_channel_bindings_t cb;
     krb5_checksum *cksum;
 {
-    size_t len;
-    char *buf = 0;
-    char *ptr;
+    struct k5buf buf;
     size_t sumlen;
     krb5_data plaind;
     krb5_error_code code;
@@ -59,36 +57,28 @@ kg_checksum_channel_bindings(context, cb, cksum)
         return(0);
     }
 
-    /* create the buffer to checksum into */
-
-    len = (sizeof(krb5_int32)*5+
-           cb->initiator_address.length+
-           cb->acceptor_address.length+
-           cb->application_data.length);
-
-    if ((buf = (char *) xmalloc(len)) == NULL)
-        return(ENOMEM);
-
-    /* helper macros.  This code currently depends on a long being 32
-       bits, and htonl dtrt. */
-
-    ptr = buf;
-
-    TWRITE_INT(ptr, cb->initiator_addrtype, 0);
-    TWRITE_BUF(ptr, cb->initiator_address, 0);
-    TWRITE_INT(ptr, cb->acceptor_addrtype, 0);
-    TWRITE_BUF(ptr, cb->acceptor_address, 0);
-    TWRITE_BUF(ptr, cb->application_data, 0);
+    k5_buf_init_dynamic(&buf);
+    k5_buf_add_uint32_le(&buf, cb->initiator_addrtype);
+    k5_buf_add_uint32_le(&buf, cb->initiator_address.length);
+    k5_buf_add_len(&buf, cb->initiator_address.value,
+                   cb->initiator_address.length);
+    k5_buf_add_uint32_le(&buf, cb->acceptor_addrtype);
+    k5_buf_add_uint32_le(&buf, cb->acceptor_address.length);
+    k5_buf_add_len(&buf, cb->acceptor_address.value,
+                   cb->acceptor_address.length);
+    k5_buf_add_uint32_le(&buf, cb->application_data.length);
+    k5_buf_add_len(&buf, cb->application_data.value,
+                   cb->application_data.length);
+    code = k5_buf_status(&buf);
+    if (code)
+        return code;
 
     /* checksum the data */
 
-    plaind.length = len;
-    plaind.data = buf;
-
+    plaind = make_data(buf.data, buf.len);
     code = krb5_c_make_checksum(context, CKSUMTYPE_RSA_MD5, 0, 0,
                                 &plaind, cksum);
-    if (buf)
-        xfree(buf);
+    k5_buf_free(&buf);
     return code;
 }