auth.c: make cast explicit in the crypto API

mbedtls_md_get_size() returns unsigned char, while EVP_MD_size() returns
int. Results coming from both functions are normally in a uint8_t member
of the key_type struct, because it is known that 8bits are enough (also
for EVP_MD_size()).

This unexpected cast can, however, trigger unsolicited warnings.
Make the cast explicit by changing the return value of our crypto API.

Reported-by: Arne Schwabe <arne@rfc2549.org>
Signed-off-by: Antonio Quartulli <a@unstable.cc>
Acked-by: Arne Schwabe <arne@rfc2549.org>
Message-Id: <20191110133525.6069-2-a@unstable.cc>
URL: https://www.mail-archive.com/openvpn-devel@lists.sourceforge.net/msg19093.html
Signed-off-by: Gert Doering <gert@greenie.muc.de>

diff --git a/src/openvpn/crypto_backend.h b/src/openvpn/crypto_backend.h
index d119442f0299ecb14c5f4f06d982c4bd2a8c4a68..1d206a8ce8df6dc390be8ff852b57b9e8f849b9f 100644 (file)
--- a/src/openvpn/crypto_backend.h
+++ b/src/openvpn/crypto_backend.h
@@ -526,7 +526,7 @@ const char *md_kt_name(const md_kt_t *kt);
  *
  * @return              Message digest size, in bytes, or 0 if ctx was NULL.
  */
-int md_kt_size(const md_kt_t *kt);
+unsigned char md_kt_size(const md_kt_t *kt);
 
 
 /*

diff --git a/src/openvpn/crypto_mbedtls.c b/src/openvpn/crypto_mbedtls.c
index 648a988e89dda42a9fbb58d3dd85d807080a2eab..3e77fa9ee66a446c83585a3faa9a4d794139b13c 100644 (file)
--- a/src/openvpn/crypto_mbedtls.c
+++ b/src/openvpn/crypto_mbedtls.c
@@ -823,7 +823,7 @@ md_kt_name(const mbedtls_md_info_t *kt)
     return mbedtls_md_get_name(kt);
 }
 
-int
+unsigned char
 md_kt_size(const mbedtls_md_info_t *kt)
 {
     if (NULL == kt)

diff --git a/src/openvpn/crypto_openssl.c b/src/openvpn/crypto_openssl.c
index 520e40ee304a2244aaa20ec8fcfae0793a4ecb96..a81dcfd8252b9819ee49ca8cbd79a8c210f3235e 100644 (file)
--- a/src/openvpn/crypto_openssl.c
+++ b/src/openvpn/crypto_openssl.c
@@ -930,10 +930,10 @@ md_kt_name(const EVP_MD *kt)
     return EVP_MD_name(kt);
 }
 
-int
+unsigned char
 md_kt_size(const EVP_MD *kt)
 {
-    return EVP_MD_size(kt);
+    return (unsigned char)EVP_MD_size(kt);
 }