From: J. Nick Koston <nick@cpanel.net>
Date: Wed, 2 Oct 2019 08:18:52 +0000 (-0500)
Subject: Defer loading crypto strings for DKIM until needed to improve startup time
X-Git-Url: https://git.exim.org/users/heiko/exim.git/commitdiff_plain/133f2ed09bdf9988aed1934de650cae0caa40f8d

Defer loading crypto strings for DKIM until needed to improve startup time
---

diff --git a/src/src/pdkim/signing.c b/src/src/pdkim/signing.c
index a47f824b8..b5cb71ecd 100644
--- a/src/src/pdkim/signing.c
+++ b/src/src/pdkim/signing.c
@@ -690,10 +690,12 @@ return NULL;
 #elif defined(SIGN_OPENSSL)
 /******************************************************************************/
 
+/* Defer as much as possible to the exim_dkim_signing_init and
+exim_dkim_verify_init() functions below. This increases startup time if we do
+not need the dkim functions */
 void
 exim_dkim_init(void)
 {
-ERR_load_crypto_strings();
 }
 
 
@@ -714,6 +716,12 @@ exim_dkim_signing_init(const uschar * privkey_pem, es_ctx * sign_ctx)
 {
 BIO * bp = BIO_new_mem_buf(privkey_pem, -1);
 
+/* Load crypto strings only when we need to init signing
+instead of in exim_dkim_init which impacts startup time.
+It is harmless to call it multiple times as it sets a static
+variable which causes it do nothing if called multiple times */
+ERR_load_crypto_strings();
+
 if (!(sign_ctx->key = PEM_read_bio_PrivateKey(bp, NULL, NULL, NULL)))
   return string_sprintf("privkey PEM-block import: %s",
 		       	ERR_error_string(ERR_get_error(), NULL));
@@ -772,7 +780,7 @@ if (  (ctx = EVP_MD_CTX_create())
    && EVP_DigestSignUpdate(ctx, data->data, data->len) > 0
    && EVP_DigestSignFinal(ctx, NULL, &siglen) > 0
    && (sig->data = store_get(siglen))
- 
+
    /* Obtain the signature (slen could change here!) */
    && EVP_DigestSignFinal(ctx, sig->data, &siglen) > 0
    )
@@ -798,6 +806,12 @@ exim_dkim_verify_init(blob * pubkey, keyformat fmt, ev_ctx * verify_ctx)
 const uschar * s = pubkey->data;
 uschar * ret = NULL;
 
+/* Load crypto strings only when we need to init verify
+instead of in exim_dkim_init which impacts startup time.
+It is harmless to call it multiple times as it sets a static
+variable which causes it do nothing if called multiple times */
+ERR_load_crypto_strings();
+
 switch(fmt)
   {
   case KEYFMT_DER: