Provide rand_bytes_ex and rand_priv_bytes_ex

We provider internal versions of RAND_bytes() and RAND_priv_bytes() which
have the addition of taking an OPENSSL_CTX as a parameter.

Reviewed-by: Matthias St. Pierre <Matthias.St.Pierre@ncp-e.com>
(Merged from https://github.com/openssl/openssl/pull/9193)

2 files changed, 30 insertions, 8 deletions

diff --git a/crypto/rand/rand_err.c b/crypto/rand/rand_err.c
index 5c0dc3d8e5..d729441ef4 100644
--- a/crypto/rand/rand_err.c
+++ b/crypto/rand/rand_err.c
@@ -20,6 +20,7 @@ static const ERR_STRING_DATA RAND_str_functs[] = {
     {ERR_PACK(ERR_LIB_RAND, RAND_F_DRBG_SETUP, 0), "drbg_setup"},
     {ERR_PACK(ERR_LIB_RAND, RAND_F_GET_ENTROPY, 0), "get_entropy"},
     {ERR_PACK(ERR_LIB_RAND, RAND_F_RAND_BYTES, 0), "RAND_bytes"},
+    {ERR_PACK(ERR_LIB_RAND, RAND_F_RAND_BYTES_EX, 0), "rand_bytes_ex"},
     {ERR_PACK(ERR_LIB_RAND, RAND_F_RAND_DRBG_ENABLE_LOCKING, 0),
      "rand_drbg_enable_locking"},
     {ERR_PACK(ERR_LIB_RAND, RAND_F_RAND_DRBG_GENERATE, 0),
diff --git a/crypto/rand/rand_lib.c b/crypto/rand/rand_lib.c
index 07d2362b04..7768ade8b7 100644
--- a/crypto/rand/rand_lib.c
+++ b/crypto/rand/rand_lib.c
@@ -749,16 +749,16 @@ void RAND_add(const void *buf, int num, double randomness)
  * the default method, then just call RAND_bytes().  Otherwise make
  * sure we're instantiated and use the private DRBG.
  */
-int RAND_priv_bytes(unsigned char *buf, int num)
+int rand_priv_bytes_ex(OPENSSL_CTX *ctx, unsigned char *buf, int num)
 {
     RAND_DRBG *drbg;
     int ret;
     const RAND_METHOD *meth = RAND_get_rand_method();
 
     if (meth != RAND_OpenSSL())
-        return RAND_bytes(buf, num);
+        return meth->bytes(buf, num);
 
-    drbg = RAND_DRBG_get0_private();
+    drbg = OPENSSL_CTX_get0_private_drbg(ctx);
     if (drbg == NULL)
         return 0;
 
@@ -766,14 +766,35 @@ int RAND_priv_bytes(unsigned char *buf, int num)
     return ret;
 }
 
-int RAND_bytes(unsigned char *buf, int num)
+int RAND_priv_bytes(unsigned char *buf, int num)
 {
+    return rand_priv_bytes_ex(NULL, buf, num);
+}
+
+int rand_bytes_ex(OPENSSL_CTX *ctx, unsigned char *buf, int num)
+{
+    RAND_DRBG *drbg;
+    int ret;
     const RAND_METHOD *meth = RAND_get_rand_method();
 
-    if (meth->bytes != NULL)
-        return meth->bytes(buf, num);
-    RANDerr(RAND_F_RAND_BYTES, RAND_R_FUNC_NOT_IMPLEMENTED);
-    return -1;
+    if (meth != RAND_OpenSSL()) {
+        if (meth->bytes != NULL)
+            return meth->bytes(buf, num);
+        RANDerr(RAND_F_RAND_BYTES_EX, RAND_R_FUNC_NOT_IMPLEMENTED);
+        return -1;
+    }
+
+    drbg = OPENSSL_CTX_get0_public_drbg(ctx);
+    if (drbg == NULL)
+        return 0;
+
+    ret = RAND_DRBG_bytes(drbg, buf, num);
+    return ret;
+}
+
+int RAND_bytes(unsigned char *buf, int num)
+{
+    return rand_bytes_ex(NULL, buf, num);
 }
 
 #if !OPENSSL_API_1_1_0 && !defined(FIPS_MODE)