Coverity: hkdf ENV_MD_size() is an int that can be negative
@@ -182,6 +182,8 @@ static int kdf_hkdf_ctrl_str(EVP_KDF_IMPL *impl, const char *type,
static size_t kdf_hkdf_size(EVP_KDF_IMPL *impl)
{
+ int sz;
+
if (impl->mode != EVP_KDF_HKDF_MODE_EXTRACT_ONLY)
return SIZE_MAX;
@@ -189,7 +191,11 @@ static size_t kdf_hkdf_size(EVP_KDF_IMPL *impl)
KDFerr(KDF_F_KDF_HKDF_SIZE, KDF_R_MISSING_MESSAGE_DIGEST);
return 0;
}
- return EVP_MD_size(impl->md);
+ sz = EVP_MD_size(impl->md);
+ if (sz < 0)
+ return 0;
+
+ return sz;
}
static int kdf_hkdf_derive(EVP_KDF_IMPL *impl, unsigned char *key,
@@ -241,8 +247,13 @@ static int HKDF(const EVP_MD *evp_md,
unsigned char *okm, size_t okm_len)
{
unsigned char prk[EVP_MAX_MD_SIZE];
- int ret;
- size_t prk_len = EVP_MD_size(evp_md);
+ int ret, sz;
+ size_t prk_len;
+
+ sz = EVP_MD_size(evp_md);
+ if (sz < 0)
+ return 0;
+ prk_len = (size_t)sz;
if (!HKDF_Extract(evp_md, salt, salt_len, key, key_len, prk, prk_len))
return 0;
@@ -258,7 +269,11 @@ static int HKDF_Extract(const EVP_MD *evp_md,
const unsigned char *key, size_t key_len,
unsigned char *prk, size_t prk_len)
{
- if (prk_len != (size_t)EVP_MD_size(evp_md)) {
+ int sz = EVP_MD_size(evp_md);
+
+ if (sz < 0)
+ return 0;
+ if (prk_len != (size_t)sz) {
KDFerr(KDF_F_HKDF_EXTRACT, KDF_R_WRONG_OUTPUT_BUFFER_SIZE);
return 0;
}
@@ -271,11 +286,16 @@ static int HKDF_Expand(const EVP_MD *evp_md,
unsigned char *okm, size_t okm_len)
{
HMAC_CTX *hmac;
- int ret = 0;
+ int ret = 0, sz;
unsigned int i;
unsigned char prev[EVP_MAX_MD_SIZE];
- size_t done_len = 0, dig_len = EVP_MD_size(evp_md);
- size_t n = okm_len / dig_len;
+ size_t done_len = 0, dig_len, n;
+
+ sz = EVP_MD_size(evp_md);
+ if (sz <= 0)
+ return 0;
+ dig_len = (size_t)sz;
+ n = okm_len / dig_len;
if (okm_len % dig_len)
n++;
