Switch ssl3_send_channel_id to BN_bn2bin_padded.
Check the return value while we're here. This avoids some arithmetic and
appease scan-build's dead assignment flagger.
Change-Id: If3615076e091eb44b9e3e9d50cd64f80e645337e
Reviewed-on: https://boringssl-review.googlesource.com/2204
Reviewed-by: Adam Langley <agl@google.com>
diff --git a/ssl/s3_clnt.c b/ssl/s3_clnt.c
index 64bccfa..0806d77 100644
--- a/ssl/s3_clnt.c
+++ b/ssl/s3_clnt.c
@@ -2699,11 +2699,12 @@
/* The first byte of public_key will be 0x4, denoting an uncompressed key. */
memcpy(d, public_key + 1, 64);
d += 64;
- memset(d, 0, 2 * 32);
- BN_bn2bin(sig->r, d + 32 - BN_num_bytes(sig->r));
- d += 32;
- BN_bn2bin(sig->s, d + 32 - BN_num_bytes(sig->s));
- d += 32;
+ if (!BN_bn2bin_padded(d, 32, sig->r) ||
+ !BN_bn2bin_padded(d + 32, 32, sig->s))
+ {
+ OPENSSL_PUT_ERROR(SSL, ssl3_send_channel_id, ERR_R_INTERNAL_ERROR);
+ goto err;
+ }
s->state = SSL3_ST_CW_CHANNEL_ID_B;
s->init_num = 4 + 2 + 2 + TLSEXT_CHANNEL_ID_SIZE;
