From 0336df2fa316a3e08b8f0d2d0e8d4bc175e46634 Mon Sep 17 00:00:00 2001 From: Georg Schmidt Date: Thu, 31 May 2018 01:42:39 +0200 Subject: [PATCH] Issue warnings for large DSA and RSA keys Issue a warning when generating DSA or RSA keys of size greater than OPENSSL_DSA_MAX_MODULUS_BITS resp. OPENSSL_RSA_MAX_MODULUS_BITS. Reviewed-by: Paul Dale Reviewed-by: Rich Salz Reviewed-by: Matthias St. Pierre (Merged from https://github.com/openssl/openssl/pull/6380) --- apps/dsaparam.c | 6 ++++++ apps/gendsa.c | 7 +++++++ apps/genrsa.c | 5 +++++ apps/req.c | 12 ++++++++++++ 4 files changed, 30 insertions(+) diff --git a/apps/dsaparam.c b/apps/dsaparam.c index 341480b818..8e33ffd6b0 100644 --- a/apps/dsaparam.c +++ b/apps/dsaparam.c @@ -128,6 +128,12 @@ int dsaparam_main(int argc, char **argv) goto end; if (numbits > 0) { + if (numbits > OPENSSL_DSA_MAX_MODULUS_BITS) + BIO_printf(bio_err, + "Warning: It is not recommended to use more than %d bit for DSA keys.\n" + " Your key size is %d! Larger key size may behave not as expected.\n", + OPENSSL_DSA_MAX_MODULUS_BITS, numbits); + cb = BN_GENCB_new(); if (cb == NULL) { BIO_printf(bio_err, "Error allocating BN_GENCB object\n"); diff --git a/apps/gendsa.c b/apps/gendsa.c index 06e37924e4..401375420b 100644 --- a/apps/gendsa.c +++ b/apps/gendsa.c @@ -117,6 +117,13 @@ int gendsa_main(int argc, char **argv) goto end2; DSA_get0_pqg(dsa, &p, NULL, NULL); + + if (BN_num_bits(p) > OPENSSL_DSA_MAX_MODULUS_BITS) + BIO_printf(bio_err, + "Warning: It is not recommended to use more than %d bit for DSA keys.\n" + " Your key size is %d! Larger key size may behave not as expected.\n", + OPENSSL_DSA_MAX_MODULUS_BITS, BN_num_bits(p)); + BIO_printf(bio_err, "Generating DSA key, %d bits\n", BN_num_bits(p)); if (!DSA_generate_key(dsa)) goto end; diff --git a/apps/genrsa.c b/apps/genrsa.c index 2bc8fa0827..c17cd14715 100644 --- a/apps/genrsa.c +++ b/apps/genrsa.c @@ -123,6 +123,11 @@ opthelp: if (argc == 1) { if (!opt_int(argv[0], &num) || num <= 0) goto end; + if (num > OPENSSL_RSA_MAX_MODULUS_BITS) + BIO_printf(bio_err, + "Warning: It is not recommended to use more than %d bit for RSA keys.\n" + " Your key size is %d! Larger key size may behave not as expected.\n", + OPENSSL_RSA_MAX_MODULUS_BITS, num); } else if (argc > 0) { BIO_printf(bio_err, "Extra arguments given.\n"); goto opthelp; diff --git a/apps/req.c b/apps/req.c index ca4b7ec891..59baa89bcf 100644 --- a/apps/req.c +++ b/apps/req.c @@ -517,6 +517,18 @@ int req_main(int argc, char **argv) goto end; } + if (pkey_type == EVP_PKEY_RSA && newkey > OPENSSL_RSA_MAX_MODULUS_BITS) + BIO_printf(bio_err, + "Warning: It is not recommended to use more than %d bit for RSA keys.\n" + " Your key size is %ld! Larger key size may behave not as expected.\n", + OPENSSL_RSA_MAX_MODULUS_BITS, newkey); + + if (pkey_type == EVP_PKEY_DSA && newkey > OPENSSL_DSA_MAX_MODULUS_BITS) + BIO_printf(bio_err, + "Warning: It is not recommended to use more than %d bit for DSA keys.\n" + " Your key size is %ld! Larger key size may behave not as expected.\n", + OPENSSL_DSA_MAX_MODULUS_BITS, newkey); + if (genctx == NULL) { genctx = set_keygen_ctx(NULL, &pkey_type, &newkey, &keyalgstr, gen_eng); -- 2.25.1