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[stg.git] / libs / smux / der_encoder.c

diff --git a/libs/smux/der_encoder.c b/libs/smux/der_encoder.c
index 6c859e1b08bba9600c97970df2fceede5716ddc0..2c6a6f769b92c34f9e5809d2d38bd1f3f40f69b3 100644 (file)
--- a/libs/smux/der_encoder.c
+++ b/libs/smux/der_encoder.c
@@ -12,19 +12,17 @@ static ssize_t der_write_TL(ber_tlv_tag_t tag, ber_tlv_len_t len,
  * The DER encoder of any type.
  */
 asn_enc_rval_t
-der_encode(asn_TYPE_descriptor_t *type_descriptor, void *struct_ptr,
-       asn_app_consume_bytes_f *consume_bytes, void *app_key) {
-
-       ASN_DEBUG("DER encoder invoked for %s",
+der_encode(const asn_TYPE_descriptor_t *type_descriptor, const void *struct_ptr,
+           asn_app_consume_bytes_f *consume_bytes, void *app_key) {
+    ASN_DEBUG("DER encoder invoked for %s",
                type_descriptor->name);
 
        /*
         * Invoke type-specific encoder.
         */
-       return type_descriptor->der_encoder(type_descriptor,
-               struct_ptr,     /* Pointer to the destination structure */
-               0, 0,
-               consume_bytes, app_key);
+    return type_descriptor->op->der_encoder(
+        type_descriptor, struct_ptr, /* Pointer to the destination structure */
+        0, 0, consume_bytes, app_key);
 }
 
 /*
@@ -51,15 +49,15 @@ static int encode_to_buffer_cb(const void *buffer, size_t size, void *key) {
  * A variant of the der_encode() which encodes the data into the provided buffer
  */
 asn_enc_rval_t
-der_encode_to_buffer(asn_TYPE_descriptor_t *type_descriptor, void *struct_ptr,
-       void *buffer, size_t buffer_size) {
-       enc_to_buf_arg arg;
+der_encode_to_buffer(const asn_TYPE_descriptor_t *type_descriptor,
+                     const void *struct_ptr, void *buffer, size_t buffer_size) {
+    enc_to_buf_arg arg;
        asn_enc_rval_t ec;
 
        arg.buffer = buffer;
        arg.left = buffer_size;
 
-       ec = type_descriptor->der_encoder(type_descriptor,
+       ec = type_descriptor->op->der_encoder(type_descriptor,
                struct_ptr,     /* Pointer to the destination structure */
                0, 0, encode_to_buffer_cb, &arg);
        if(ec.encoded != -1) {
@@ -74,19 +72,20 @@ der_encode_to_buffer(asn_TYPE_descriptor_t *type_descriptor, void *struct_ptr,
  * Write out leading TL[v] sequence according to the type definition.
  */
 ssize_t
-der_write_tags(asn_TYPE_descriptor_t *sd,
-               size_t struct_length,
-               int tag_mode, int last_tag_form,
-               ber_tlv_tag_t tag,      /* EXPLICIT or IMPLICIT tag */
-               asn_app_consume_bytes_f *cb,
-               void *app_key) {
-       ber_tlv_tag_t *tags;    /* Copy of tags stream */
-       int tags_count;         /* Number of tags */
-       size_t overall_length;
-       ssize_t *lens;
-       int i;
-
-       ASN_DEBUG("Writing tags (%s, tm=%d, tc=%d, tag=%s, mtc=%d)",
+der_write_tags(const asn_TYPE_descriptor_t *sd, size_t struct_length,
+               int tag_mode, int last_tag_form,
+               ber_tlv_tag_t tag, /* EXPLICIT or IMPLICIT tag */
+               asn_app_consume_bytes_f *cb, void *app_key) {
+#define ASN1_DER_MAX_TAGS_COUNT 4
+    ber_tlv_tag_t
+        tags_buf_scratch[ASN1_DER_MAX_TAGS_COUNT * sizeof(ber_tlv_tag_t)];
+    ssize_t lens[ASN1_DER_MAX_TAGS_COUNT * sizeof(ssize_t)];
+    const ber_tlv_tag_t *tags; /* Copy of tags stream */
+    int tags_count;            /* Number of tags */
+    size_t overall_length;
+    int i;
+
+    ASN_DEBUG("Writing tags (%s, tm=%d, tc=%d, tag=%s, mtc=%d)",
                sd->name, tag_mode, sd->tags_count,
                ber_tlv_tag_string(tag),
                tag_mode
@@ -95,6 +94,11 @@ der_write_tags(asn_TYPE_descriptor_t *sd,
                        :sd->tags_count
        );
 
+    if(sd->tags_count + 1 > ASN1_DER_MAX_TAGS_COUNT) {
+        ASN_DEBUG("System limit %d on tags count", ASN1_DER_MAX_TAGS_COUNT);
+        return -1;
+    }
+
        if(tag_mode) {
                /*
                 * Instead of doing shaman dance like we do in ber_check_tags(),
@@ -102,19 +106,16 @@ der_write_tags(asn_TYPE_descriptor_t *sd,
                 * and initialize it appropriately.
                 */
                int stag_offset;
-               tags = (ber_tlv_tag_t *)alloca((sd->tags_count + 1) * sizeof(ber_tlv_tag_t));
-               if(!tags) {     /* Can fail on !x86 */
-                       errno = ENOMEM;
-                       return -1;
-               }
+               ber_tlv_tag_t *tags_buf = tags_buf_scratch;
                tags_count = sd->tags_count
                        + 1     /* EXPLICIT or IMPLICIT tag is given */
                        - ((tag_mode == -1) && sd->tags_count);
                /* Copy tags over */
-               tags[0] = tag;
+               tags_buf[0] = tag;
                stag_offset = -1 + ((tag_mode == -1) && sd->tags_count);
                for(i = 1; i < tags_count; i++)
-                       tags[i] = sd->tags[i + stag_offset];
+                       tags_buf[i] = sd->tags[i + stag_offset];
+               tags = tags_buf;
        } else {
                tags = sd->tags;
                tags_count = sd->tags_count;
@@ -124,12 +125,6 @@ der_write_tags(asn_TYPE_descriptor_t *sd,
        if(tags_count == 0)
                return 0;
 
-       lens = (ssize_t *)alloca(tags_count * sizeof(lens[0]));
-       if(!lens) {
-               errno = ENOMEM;
-               return -1;
-       }
-
        /*
         * Array of tags is initialized.
         * Now, compute the size of the TLV pairs, from right to left.
@@ -144,8 +139,8 @@ der_write_tags(asn_TYPE_descriptor_t *sd,
 
        if(!cb) return overall_length - struct_length;
 
-       ASN_DEBUG("%s %s TL sequence (%d elements)",
-               cb?"Encoding":"Estimating", sd->name, tags_count);
+       ASN_DEBUG("Encoding %s TL sequence (%d elements)", sd->name,
+                  tags_count);
 
        /*
         * Encode the TL sequence for real.