diff options
author | Matt Caswell <matt@openssl.org> | 2016-09-29 14:45:49 +0100 |
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committer | Matt Caswell <matt@openssl.org> | 2016-09-29 15:09:02 +0100 |
commit | 0023baffb8f648c22d397bfa5e1cc8749749bd29 (patch) | |
tree | df7330e76ec84d8eb7a38b4a074ca28d7afb9a29 /ssl/packet_locl.h | |
parent | ff8194774ca2d8e30223c6f8e2583112514e9fb7 (diff) |
Add an example of usage to the WPACKET_reserve_bytes() documentation
Reviewed-by: Rich Salz <rsalz@openssl.org>
Diffstat (limited to 'ssl/packet_locl.h')
-rw-r--r-- | ssl/packet_locl.h | 10 |
1 files changed, 10 insertions, 0 deletions
diff --git a/ssl/packet_locl.h b/ssl/packet_locl.h index 0e50c7ddae..8d3fd37c56 100644 --- a/ssl/packet_locl.h +++ b/ssl/packet_locl.h @@ -707,6 +707,16 @@ int WPACKET_sub_allocate_bytes__(WPACKET *pkt, size_t len, * maximum size will be. If this function is used, then it should be immediately * followed by a WPACKET_allocate_bytes() call before any other WPACKET * functions are called (unless the write to the allocated bytes is abandoned). + * + * For example: If we are generating a signature, then the size of that + * signature may not be known in advance. We can use WPACKET_reserve_bytes() to + * handle this: + * + * if (!WPACKET_sub_reserve_bytes_u16(&pkt, EVP_PKEY_size(pkey), &sigbytes1) + * || EVP_SignFinal(md_ctx, sigbytes1, &siglen, pkey) <= 0 + * || !WPACKET_sub_allocate_bytes_u16(&pkt, siglen, &sigbytes2) + * || sigbytes1 != sigbytes2) + * goto err; */ int WPACKET_reserve_bytes(WPACKET *pkt, size_t len, unsigned char **allocbytes); |