Merge pull request #5188 from rspamd/vstakhov-openssl-provider-message

[Fix] Do not abort when OpenSSL is broken, report that to a user

3 files changed, 56 insertions, 19 deletions

diff --git a/src/libcryptobox/cryptobox.c b/src/libcryptobox/cryptobox.c
index a976653df..190d0e4a3 100644
--- a/src/libcryptobox/cryptobox.c
+++ b/src/libcryptobox/cryptobox.c
@@ -40,6 +40,7 @@
 #include <openssl/opensslv.h>
 #include <openssl/evp.h>
 #include <openssl/rsa.h>
+#include <openssl/err.h>
 #endif
 
 #include <signal.h>
@@ -456,9 +457,10 @@ bool rspamd_cryptobox_verify_evp_rsa(int nid,
 									 gsize siglen,
 									 const unsigned char *digest,
 									 gsize dlen,
-									 EVP_PKEY *pub_key)
+									 EVP_PKEY *pub_key,
+									 GError **err)
 {
-	bool ret = false;
+	bool ret = false, r;
 
 	EVP_PKEY_CTX *pctx = EVP_PKEY_CTX_new(pub_key, NULL);
 	g_assert(pctx != NULL);
@@ -467,7 +469,18 @@ bool rspamd_cryptobox_verify_evp_rsa(int nid,
 
 	g_assert(EVP_PKEY_verify_init(pctx) == 1);
 	g_assert(EVP_PKEY_CTX_set_rsa_padding(pctx, RSA_PKCS1_PADDING) == 1);
-	g_assert(EVP_PKEY_CTX_set_signature_md(pctx, md) == 1);
+
+	if ((r = EVP_PKEY_CTX_set_signature_md(pctx, md)) <= 0) {
+		g_set_error(err, g_quark_from_static_string("OpenSSL"),
+					r,
+					"cannot set digest %s for RSA verification (%s returned from OpenSSL), try use `update-crypto-policies --set LEGACY` on RH",
+					EVP_MD_name(md),
+					ERR_lib_error_string(ERR_get_error()));
+		EVP_PKEY_CTX_free(pctx);
+		EVP_MD_CTX_free(mdctx);
+
+		return false;
+	}
 
 	ret = (EVP_PKEY_verify(pctx, sig, siglen, digest, dlen) == 1);
 
diff --git a/src/libcryptobox/cryptobox.h b/src/libcryptobox/cryptobox.h
index afe9c4f9a..8d1f5669e 100644
--- a/src/libcryptobox/cryptobox.h
+++ b/src/libcryptobox/cryptobox.h
@@ -238,7 +238,8 @@ bool rspamd_cryptobox_verify_evp_rsa(int nid,
 									 gsize siglen,
 									 const unsigned char *digest,
 									 gsize dlen,
-									 EVP_PKEY *pub_key);
+									 EVP_PKEY *pub_key,
+									 GError **err);
 #endif
 
 /**
diff --git a/src/libserver/dkim.c b/src/libserver/dkim.c
index a76ed31ab..0f51c66c0 100644
--- a/src/libserver/dkim.c
+++ b/src/libserver/dkim.c
@@ -2871,25 +2871,48 @@ rspamd_dkim_check(rspamd_dkim_context_t *ctx,
 		nid = NID_sha1;
 	}
 	switch (key->type) {
-	case RSPAMD_DKIM_KEY_RSA:
+	case RSPAMD_DKIM_KEY_RSA: {
+		GError *err = NULL;
+
 		if (!rspamd_cryptobox_verify_evp_rsa(nid, ctx->b, ctx->blen, raw_digest, dlen,
-											 key->specific.key_ssl.key_evp)) {
-			msg_debug_dkim("headers rsa verify failed");
-			ERR_clear_error();
-			res->rcode = DKIM_REJECT;
-			res->fail_reason = "headers rsa verify failed";
+											 key->specific.key_ssl.key_evp, &err)) {
 
-			msg_info_dkim(
-				"%s: headers RSA verification failure; "
-				"body length %d->%d; headers length %d; d=%s; s=%s; key_md5=%*xs; orig header: %s",
-				rspamd_dkim_type_to_string(ctx->common.type),
-				(int) (body_end - body_start), ctx->common.body_canonicalised,
-				ctx->common.headers_canonicalised,
-				ctx->domain, ctx->selector,
-				RSPAMD_DKIM_KEY_ID_LEN, rspamd_dkim_key_id(key),
-				ctx->dkim_header);
+			if (err == NULL) {
+				msg_debug_dkim("headers rsa verify failed");
+				ERR_clear_error();
+				res->rcode = DKIM_REJECT;
+				res->fail_reason = "headers rsa verify failed";
+
+				msg_info_dkim(
+					"%s: headers RSA verification failure; "
+					"body length %d->%d; headers length %d; d=%s; s=%s; key_md5=%*xs; orig header: %s",
+					rspamd_dkim_type_to_string(ctx->common.type),
+					(int) (body_end - body_start), ctx->common.body_canonicalised,
+					ctx->common.headers_canonicalised,
+					ctx->domain, ctx->selector,
+					RSPAMD_DKIM_KEY_ID_LEN, rspamd_dkim_key_id(key),
+					ctx->dkim_header);
+			}
+			else {
+				res->rcode = DKIM_PERM_ERROR;
+				res->fail_reason = "openssl internal error";
+				msg_err_dkim("internal OpenSSL error: %s", err->message);
+				msg_info_dkim(
+					"%s: headers RSA verification failure due to OpenSSL internal error; "
+					"body length %d->%d; headers length %d; d=%s; s=%s; key_md5=%*xs; orig header: %s",
+					rspamd_dkim_type_to_string(ctx->common.type),
+					(int) (body_end - body_start), ctx->common.body_canonicalised,
+					ctx->common.headers_canonicalised,
+					ctx->domain, ctx->selector,
+					RSPAMD_DKIM_KEY_ID_LEN, rspamd_dkim_key_id(key),
+					ctx->dkim_header);
+
+				ERR_clear_error();
+				g_error_free(err);
+			}
 		}
 		break;
+	}
 	case RSPAMD_DKIM_KEY_ECDSA:
 		if (rspamd_cryptobox_verify_evp_ecdsa(nid, ctx->b, ctx->blen, raw_digest, dlen,
 											  key->specific.key_ssl.key_evp) != 1) {