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-rw-r--r--crypto/asn1/a_d2i_fp.c36
1 files changed, 26 insertions, 10 deletions
diff --git a/crypto/asn1/a_d2i_fp.c b/crypto/asn1/a_d2i_fp.c
index a1864b42c977..51b6f245ab10 100644
--- a/crypto/asn1/a_d2i_fp.c
+++ b/crypto/asn1/a_d2i_fp.c
@@ -141,6 +141,7 @@ void *ASN1_item_d2i_fp(const ASN1_ITEM *it, FILE *in, void *x)
#endif
#define HEADER_SIZE 8
+#define ASN1_CHUNK_INITIAL_SIZE (16 * 1024)
static int asn1_d2i_read_bio(BIO *in, BUF_MEM **pb)
{
BUF_MEM *b;
@@ -217,29 +218,44 @@ static int asn1_d2i_read_bio(BIO *in, BUF_MEM **pb)
/* suck in c.slen bytes of data */
want = c.slen;
if (want > (len - off)) {
+ size_t chunk_max = ASN1_CHUNK_INITIAL_SIZE;
+
want -= (len - off);
if (want > INT_MAX /* BIO_read takes an int length */ ||
len + want < len) {
ASN1err(ASN1_F_ASN1_D2I_READ_BIO, ASN1_R_TOO_LONG);
goto err;
}
- if (!BUF_MEM_grow_clean(b, len + want)) {
- ASN1err(ASN1_F_ASN1_D2I_READ_BIO, ERR_R_MALLOC_FAILURE);
- goto err;
- }
while (want > 0) {
- i = BIO_read(in, &(b->data[len]), want);
- if (i <= 0) {
- ASN1err(ASN1_F_ASN1_D2I_READ_BIO,
- ASN1_R_NOT_ENOUGH_DATA);
+ /*
+ * Read content in chunks of increasing size
+ * so we can return an error for EOF without
+ * having to allocate the entire content length
+ * in one go.
+ */
+ size_t chunk = want > chunk_max ? chunk_max : want;
+
+ if (!BUF_MEM_grow_clean(b, len + chunk)) {
+ ASN1err(ASN1_F_ASN1_D2I_READ_BIO, ERR_R_MALLOC_FAILURE);
goto err;
}
+ want -= chunk;
+ while (chunk > 0) {
+ i = BIO_read(in, &(b->data[len]), chunk);
+ if (i <= 0) {
+ ASN1err(ASN1_F_ASN1_D2I_READ_BIO,
+ ASN1_R_NOT_ENOUGH_DATA);
+ goto err;
+ }
/*
* This can't overflow because |len+want| didn't
* overflow.
*/
- len += i;
- want -= i;
+ len += i;
+ chunk -= i;
+ }
+ if (chunk_max < INT_MAX/2)
+ chunk_max *= 2;
}
}
if (off + c.slen < off) {