Re: [PATCH] lib: rsa: Extract public key from private key if keyfile argument is used

On Sun, Jul 18, 2021 at 09:52:03AM -0700, Chan, Donald wrote:

If the 'keyfile' (-G) argument is used, there is little value to require 'keydir' (-k) argument since the public key can also be extracted from the private key itself.

Signed-off-by: Donald Chan hoiho@lab126.com

lib/rsa/rsa-sign.c | 28 +++++++++++++++++++++------- 1 file changed, 21 insertions(+), 7 deletions(-)

diff --git a/lib/rsa/rsa-sign.c b/lib/rsa/rsa-sign.c index f4ed11e74a..f70f352311 100644 --- a/lib/rsa/rsa-sign.c +++ b/lib/rsa/rsa-sign.c @@ -49,16 +49,16 @@ static int rsa_err(const char *msg) }

/**

• • rsa_pem_get_pub_key() - read a public key from a .crt file

• • rsa_pem_get_pub_key() - read a public key from a private key file or

.crt file

• • @keydir: Directory containins the key
• • @name Name of key file (will have a .crt extension)

• • @keydir: Directory containing the key, can be NULL
• • @name Name of key file (will apply a .crt extension if keydir is not

NULL)

• @evpp Returns EVP_PKEY object, or NULL on failure
• @return 0 if ok, -ve on error (in which case *evpp will be set to NULL)

*/ static int rsa_pem_get_pub_key(const char *keydir, const char *name, EVP_PKEY **evpp) {

• char path[1024];

• char path[1024] = {0}; EVP_PKEY *key = NULL; X509 *cert; FILE *f;

@@ -68,7 +68,10 @@ static int rsa_pem_get_pub_key(const char *keydir, const char *name, EVP_PKEY ** return -EINVAL;

*evpp = NULL;

• snprintf(path, sizeof(path), "%s/%s.crt", keydir, name);

• if (keydir && name)

• snprintf(path, sizeof(path), "%s/%s.crt", keydir, name);
  

• else if (name)

• snprintf(path, sizeof(path), "%s", name);
  

  f = fopen(path, "r"); if (!f) { fprintf(stderr, "Couldn't open RSA certificate: '%s': %s\n",

@@ -76,7 +79,13 @@ static int rsa_pem_get_pub_key(const char *keydir, const char *name, EVP_PKEY ** return -EACCES; }

• /* Read the certificate */

• /* See if it contains a PEM private key? */
• if (PEM_read_PrivateKey(f, evpp, NULL, path)) {

• fclose(f);
  

• return 0;
  

• }
• /* Not a PEM private key, read the certificate */ cert = NULL; if (!PEM_read_X509(f, &cert, NULL, NULL)) { rsa_err("Couldn't read certificate");

@@ -672,7 +681,12 @@ int rsa_add_verify_data(struct image_sign_info *info, void *keydest) if (ret) return ret; }

• ret = rsa_get_pub_key(info->keydir, info->keyname, e, &pkey);

• if (info->keydir && info->keyname)

• ret = rsa_get_pub_key(info->keydir, info->keyname, e, &pkey);
  

• else if (info->keyfile)

• ret = rsa_get_pub_key(NULL, info->keyfile, e, &pkey);
  

• else

• ret = -EINVAL;
  

  if (ret) goto err_get_pub_key;

#if OPENSSL_VERSION_NUMBER < 0x10100000L || \

This seems reasonable, but the formatting of the patch was destroyed somewhere along the way, can you please resend? Thanks.