Commit 63262bd2 authored by David Woodhouse's avatar David Woodhouse Committed by Nicola Tuveri
Browse files

Honour mandatory digest on private key in tls1_process_sigalgs() 



If the private key says it can only support one specific digest, then
don't ask it to perform a different one.

Fixes: #7348

(cherry picked from commit 2d263a4a
 and reworked for 1.0.2)

Reviewed-by: default avatarMatt Caswell <matt@openssl.org>
Reviewed-by: default avatarNicola Tuveri <nic.tuv@gmail.com>
(Merged from https://github.com/openssl/openssl/pull/7610)
parent cf68eb36

ssl/t1_lib.c

+20 −0
Original line number Diff line number Diff line
@@ -3697,6 +3697,12 @@ int tls12_get_sigid(const EVP_PKEY *pk) 
                         sizeof(tls12_sig) / sizeof(tls12_lookup));

}



static int tls12_get_hash_nid(unsigned char hash_alg)

{

    return tls12_find_nid(hash_alg, tls12_md,

                          sizeof(tls12_md) / sizeof(tls12_lookup));

}



const EVP_MD *tls12_get_hash(unsigned char hash_alg)

{

    switch (hash_alg) {
@@ -3887,6 +3893,8 @@ int tls1_process_sigalgs(SSL *s) 
    const EVP_MD *md;

    CERT *c = s->cert;

    TLS_SIGALGS *sigptr;

    int mandatory_mdnid;



    if (!tls1_set_shared_sigalgs(s))

        return 0;
@@ -3918,6 +3926,18 @@ int tls1_process_sigalgs(SSL *s) 
    for (i = 0, sigptr = c->shared_sigalgs;

         i < c->shared_sigalgslen; i++, sigptr++) {

        idx = tls12_get_pkey_idx(sigptr->rsign);

        if (s->cert->pkeys[idx].privatekey) {

            ERR_set_mark();

            if (EVP_PKEY_get_default_digest_nid(s->cert->pkeys[idx].privatekey,

                                                &mandatory_mdnid) == 2 &&

                mandatory_mdnid != tls12_get_hash_nid(sigptr->rhash))

                continue;

            /*

             * If EVP_PKEY_get_default_digest_nid() failed, don't pollute

             * the error stack.

             */

            ERR_pop_to_mark();

        }

        if (idx > 0 && c->pkeys[idx].digest == NULL) {

            md = tls12_get_hash(sigptr->rhash);

            c->pkeys[idx].digest = md;