call ossl_raise with NULL when no message is passed

28 files changed, 276 insertions, 275 deletions

diff --git a/ChangeLog b/ChangeLog
index fde35d9..41e12b4 100644
--- a/ChangeLog
+++ b/ChangeLog
@@ -1,3 +1,9 @@
+Wed, 09 Jul 2003 12:41:14 +0200 -- Michal Rokos <m.rokos@sh.cvut.cz>
+	* extconf.rb: Start checking for OpenSSL' missing functions...
+
+Wed, 09 Jul 2003 12:38:38 +0200 -- Michal Rokos <m.rokos@sh.cvut.cz>
+	* *.c: When no message is passed, call ossl_raise with NULL
+
 Sun, 09 Jul 2003 01:50:45 +0900 -- NAKAMURA, Hiroshi <nahi@ruby-lang.org>
 	* examples/cert_store_view.rb: Support trust anchor.
 
diff --git a/extconf.rb b/extconf.rb
index d94aed3..89ceb12 100644
--- a/extconf.rb
+++ b/extconf.rb
@@ -96,6 +96,7 @@ result &= have_library(CRYPTOLIB, "OPENSSL_load_builtin_modules")
 result &= have_library(SSLLIB, "SSL_library_init")
 result &= have_openssl_097(includes)
 
+have_func("HMAC_CTX_copy")
 have_func("X509_STORE_set_ex_data")
 
 if result
diff --git a/openssl_missing.c b/openssl_missing.c
index 481244a..c84459d 100644
--- a/openssl_missing.c
+++ b/openssl_missing.c
@@ -8,14 +8,12 @@
  * This program is licenced under the same licence as Ruby.
  * (See the file 'LICENCE'.)
  */
-#include "ossl.h"
 
 #if !defined(OPENSSL_NO_HMAC)
-
-#include <string.h>
+#include <string.h> /* memcpy() */
 #include <openssl/hmac.h>
 
-/* to hmac.[ch] */
+#if !defined(HAVE_HMAC_CTX_COPY)
 int
 HMAC_CTX_copy(HMAC_CTX *out, HMAC_CTX *in)
 {
@@ -36,11 +34,11 @@ HMAC_CTX_copy(HMAC_CTX *out, HMAC_CTX *in)
     }
     return 1;
 }
+#endif /* HAVE_HMAC_CTX_COPY */
 
 #endif /* NO_HMAC */
 
 #if !defined(HAVE_X509_STORE_SET_EX_DATA)
-
 #include <openssl/x509_vfy.h>
 
 int X509_STORE_set_ex_data(X509_STORE *str, int idx, void *data)
@@ -52,4 +50,4 @@ void *X509_STORE_get_ex_data(X509_STORE *str, int idx)
 {
     return CRYPTO_get_ex_data(&str->ex_data,idx);
 }
-#endif
+#endif /* HAVE_X509_STORE_SET_EX_DATA */
diff --git a/openssl_missing.h b/openssl_missing.h
index eaa52ea..de7db8e 100644
--- a/openssl_missing.h
+++ b/openssl_missing.h
@@ -46,9 +46,10 @@ extern "C" {
 #define PKCS7_RECIP_INFO_dup(ri) (PKCS7_RECIP_INFO *)ASN1_dup((int (*)())i2d_PKCS7_RECIP_INFO, \
 	(char *(*)())d2i_PKCS7_RECIP_INFO, (char *)ri)
 
-/* to hmac.[ch] */
 #if !defined(OPENSSL_NO_HMAC)
+#if !defined(HAVE_HMAC_CTX_COPY)
 int HMAC_CTX_copy(HMAC_CTX *out, HMAC_CTX *in);
+#endif /* HAVE_HMAC_CTX_COPY */
 #endif /* NO_HMAC */
 
 #if !defined(HAVE_X509_STORE_SET_EX_DATA)
diff --git a/ossl.c b/ossl.c
index fd39b1f..24cbc87 100644
--- a/ossl.c
+++ b/ossl.c
@@ -98,12 +98,12 @@ asn1integer_to_num(ASN1_INTEGER *ai)
 	ossl_raise(rb_eTypeError, "ASN1_INTEGER is NULL!");
     }
     if (!(bn = ASN1_INTEGER_to_BN(ai, NULL))) {
-	ossl_raise(eOSSLError, "");
+	ossl_raise(eOSSLError, NULL);
     }
 #if DO_IT_VIA_RUBY
     if (!(txt = BN_bn2dec(bn))) {
 	BN_free(bn);
-	ossl_raise(eOSSLError, "");
+	ossl_raise(eOSSLError, NULL);
     }
     num = rb_cstr_to_inum(txt, 10, Qtrue);
     OPENSSL_free(txt);
@@ -125,12 +125,12 @@ ASN1_INTEGER *num_to_asn1integer(VALUE obj, ASN1_INTEGER *ai)
     } else {
 	obj = rb_String(obj);
 	if (!BN_dec2bn(&bn, StringValuePtr(obj))) {
-	    ossl_raise(eOSSLError, "");
+	    ossl_raise(eOSSLError, NULL);
 	}
     }
     if (!(ai = BN_to_ASN1_INTEGER(bn, ai))) {
 	BN_free(bn);
-	ossl_raise(eOSSLError, "");
+	ossl_raise(eOSSLError, NULL);
     }
     BN_free(bn);
     return ai;
@@ -141,7 +141,7 @@ ASN1_INTEGER *num_to_asn1integer(VALUE obj, ASN1_INTEGER *ai)
     BIGNUM *bn = GetBNPtr(obj);
     
     if (!(ai = BN_to_ASN1_INTEGER(bn, ai))) {
-	ossl_raise(eOSSLError, "");
+	ossl_raise(eOSSLError, NULL);
     }
     return ai;
 }
diff --git a/ossl_bn.c b/ossl_bn.c
index e312c6c..92b43bd 100644
--- a/ossl_bn.c
+++ b/ossl_bn.c
@@ -47,7 +47,7 @@ ossl_bn_new(BIGNUM *bn)
 
     newbn = bn ? BN_dup(bn) : BN_new();
     if (!newbn) {
-	ossl_raise(eBNError, "");
+	ossl_raise(eBNError, NULL);
     }
     WrapBN(cBN, obj, newbn);
 
@@ -66,7 +66,7 @@ GetBNPtr(VALUE obj)
     case T_BIGNUM:
 	obj = rb_String(obj);
 	if (!BN_dec2bn(&bn, StringValuePtr(obj))) {
-	    ossl_raise(eBNError, "");
+	    ossl_raise(eBNError, NULL);
 	}
 	WrapBN(cBN, obj, bn); /* Handle potencial mem leaks */
 	break;
@@ -93,7 +93,7 @@ ossl_bn_alloc(VALUE klass)
     VALUE obj;
 	
     if (!(bn = BN_new())) {
-	ossl_raise(eBNError, "");
+	ossl_raise(eBNError, NULL);
     }
     WrapBN(klass, obj, bn);
 
@@ -118,7 +118,7 @@ ossl_bn_initialize(int argc, VALUE *argv, VALUE self)
 
 	GetBN(str, other); /* Safe - we checked kind_of? above */
 	if (!BN_copy(bn, other)) {
-	    ossl_raise(eBNError, "");
+	    ossl_raise(eBNError, NULL);
 	}
 	return self;
     }
@@ -128,22 +128,22 @@ ossl_bn_initialize(int argc, VALUE *argv, VALUE self)
     switch (base) {
     case 0:
 	if (!BN_mpi2bn(RSTRING(str)->ptr, RSTRING(str)->len, bn)) {
-	    ossl_raise(eBNError, "");
+	    ossl_raise(eBNError, NULL);
 	}
 	break;
     case 2:
 	if (!BN_bin2bn(RSTRING(str)->ptr, RSTRING(str)->len, bn)) {
-	    ossl_raise(eBNError, "");
+	    ossl_raise(eBNError, NULL);
 	}
 	break;
     case 10:
 	if (!BN_dec2bn(&bn, RSTRING(str)->ptr)) {
-	    ossl_raise(eBNError, "");
+	    ossl_raise(eBNError, NULL);
 	}
 	break;
     case 16:
 	if (!BN_hex2bn(&bn, RSTRING(str)->ptr)) {
-	    ossl_raise(eBNError, "");
+	    ossl_raise(eBNError, NULL);
 	}
 	break;
     default:
@@ -173,7 +173,7 @@ ossl_bn_to_s(int argc, VALUE *argv, VALUE self)
 	}
 	if (BN_bn2mpi(bn, buf) != len) {
 	    OPENSSL_free(buf);
-	    ossl_raise(eBNError, "");
+	    ossl_raise(eBNError, NULL);
 	}
 	break;
     case 2:
@@ -183,18 +183,18 @@ ossl_bn_to_s(int argc, VALUE *argv, VALUE self)
 	}
 	if (BN_bn2bin(bn, buf) != len) {
 	    OPENSSL_free(buf);
-	    ossl_raise(eBNError, "");
+	    ossl_raise(eBNError, NULL);
 	}
 	break;
     case 10:
 	if (!(buf = BN_bn2dec(bn))) {
-	    ossl_raise(eBNError, "");
+	    ossl_raise(eBNError, NULL);
 	}
 	len = strlen(buf);
 	break;
     case 16:
 	if (!(buf = BN_bn2hex(bn))) {
-	    ossl_raise(eBNError, "");
+	    ossl_raise(eBNError, NULL);
 	}
 	len = strlen(buf);
 	break;
@@ -217,7 +217,7 @@ ossl_bn_to_i(VALUE self)
     GetBN(self, bn);
 
     if (!(txt = BN_bn2dec(bn))) {
-	ossl_raise(eBNError, "");
+	ossl_raise(eBNError, NULL);
     }
     num = rb_cstr_to_inum(txt, 10, Qtrue);
     OPENSSL_free(txt);
@@ -273,11 +273,11 @@ BIGNUM_BOOL1(is_odd);
 	VALUE obj;					\
 	GetBN(self, bn);				\
 	if (!(result = BN_new())) {			\
-	    ossl_raise(eBNError, "");			\
+	    ossl_raise(eBNError, NULL);			\
 	}						\
 	if (!BN_##func(result, bn, ossl_bn_ctx)) {	\
 	    BN_free(result);				\
-	    ossl_raise(eBNError, "");			\
+	    ossl_raise(eBNError, NULL);			\
 	}						\
 	WrapBN(CLASS_OF(self), obj, result);		\
 	return obj;					\
@@ -292,11 +292,11 @@ BIGNUM_1c(sqr);
 	VALUE obj;					\
 	GetBN(self, bn1);				\
 	if (!(result = BN_new())) {			\
-	    ossl_raise(eBNError, "");			\
+	    ossl_raise(eBNError, NULL);			\
 	}						\
 	if (!BN_##func(result, bn1, bn2)) {		\
 	    BN_free(result);				\
-	    ossl_raise(eBNError, "");			\
+	    ossl_raise(eBNError, NULL);			\
 	}						\
 	WrapBN(CLASS_OF(self), obj, result);		\
 	return obj;					\
@@ -312,11 +312,11 @@ BIGNUM_2(sub);
 	VALUE obj;						\
 	GetBN(self, bn1);					\
 	if (!(result = BN_new())) {				\
-	    ossl_raise(eBNError, "");				\
+	    ossl_raise(eBNError, NULL);				\
 	}							\
 	if (!BN_##func(result, bn1, bn2, ossl_bn_ctx)) {	\
 	    BN_free(result);					\
-	    ossl_raise(eBNError, "");				\
+	    ossl_raise(eBNError, NULL);				\
 	}							\
 	WrapBN(CLASS_OF(self), obj, result);			\
 	return obj;						\
@@ -337,16 +337,16 @@ ossl_bn_div(VALUE self, VALUE other)
     GetBN(self, bn1);
 
     if (!(r1 = BN_new())) {
-	ossl_raise(eBNError, "");
+	ossl_raise(eBNError, NULL);
     }
     if (!(r2 = BN_new())) {
 	BN_free(r1);
-	ossl_raise(eBNError, "");
+	ossl_raise(eBNError, NULL);
     }
     if (!BN_div(r1, r2, bn1, bn2, ossl_bn_ctx)) {
 	BN_free(r1);
 	BN_free(r2);
-	ossl_raise(eBNError, "");
+	ossl_raise(eBNError, NULL);
     }
     WrapBN(CLASS_OF(self), obj1, r1);
     WrapBN(CLASS_OF(self), obj2, r2);
@@ -363,11 +363,11 @@ ossl_bn_div(VALUE self, VALUE other)
 	VALUE obj;						\
 	GetBN(self, bn1);					\
 	if (!(result = BN_new())) {				\
-	    ossl_raise(eBNError, "");				\
+	    ossl_raise(eBNError, NULL);				\
 	}							\
 	if (!BN_##func(result, bn1, bn2, bn3, ossl_bn_ctx)) {	\
 	    BN_free(result);					\
-	    ossl_raise(eBNError, "");				\
+	    ossl_raise(eBNError, NULL);				\
 	}							\
 	WrapBN(CLASS_OF(self), obj, result);			\
 	return obj;						\
@@ -384,7 +384,7 @@ BIGNUM_3c(mod_exp);
 	BIGNUM *bn;					\
 	GetBN(self, bn);				\
 	if (!BN_##func(bn, NUM2INT(bit))) {		\
-	    ossl_raise(eBNError, "");			\
+	    ossl_raise(eBNError, NULL);			\
 	}						\
 	return self;					\
     }
@@ -415,11 +415,11 @@ ossl_bn_is_bit_set(VALUE self, VALUE bit)
 	GetBN(self, bn);				\
 	b = NUM2INT(bits);				\
 	if (!(result = BN_new())) {			\
-		ossl_raise(eBNError, "");		\
+		ossl_raise(eBNError, NULL);		\
 	}						\
 	if (!BN_##func(result, bn, b)) {		\
 		BN_free(result);			\
-		ossl_raise(eBNError, "");		\
+		ossl_raise(eBNError, NULL);		\
 	}						\
 	WrapBN(CLASS_OF(self), obj, result);		\
 	return obj;					\
@@ -444,11 +444,11 @@ BIGNUM_SHIFT(rshift);
 	}							\
 	b = NUM2INT(bits);					\
 	if (!(result = BN_new())) {				\
-	    ossl_raise(eBNError, "");				\
+	    ossl_raise(eBNError, NULL);				\
 	}							\
 	if (!BN_##func(result, b, top, bottom)) {		\
 	    BN_free(result);					\
-	    ossl_raise(eBNError, "");				\
+	    ossl_raise(eBNError, NULL);				\
 	}							\
 	WrapBN(klass, obj, result);				\
 	return obj;						\
@@ -463,11 +463,11 @@ BIGNUM_RAND(pseudo_rand);
 	BIGNUM *bn = GetBNPtr(range), *result;			\
 	VALUE obj;						\
 	if (!(result = BN_new())) {				\
-	    ossl_raise(eBNError, "");				\
+	    ossl_raise(eBNError, NULL);				\
 	}							\
 	if (!BN_##func##_range(result, bn)) {			\
 	    BN_free(result);					\
-	    ossl_raise(eBNError, "");				\
+	    ossl_raise(eBNError, NULL);				\
 	}							\
 	WrapBN(klass, obj, result);				\
 	return obj;						\
@@ -498,11 +498,11 @@ ossl_bn_s_generate_prime(int argc, VALUE *argv, VALUE klass)
 	rem = GetBNPtr(vrem);
     }
     if (!(result = BN_new())) {
-	ossl_raise(eBNError, "");
+	ossl_raise(eBNError, NULL);
     }
     if (!BN_generate_prime(result, num, safe, add, rem, NULL, NULL)) {
 	BN_free(result);
-	ossl_raise(eBNError, "");
+	ossl_raise(eBNError, NULL);
     }
     WrapBN(klass, obj, result);
     
@@ -533,7 +533,7 @@ ossl_bn_copy(VALUE self, VALUE other)
     bn2 = GetBNPtr(other);
     
     if (!BN_copy(bn1, bn2)) {
-	ossl_raise(eBNError, "");
+	ossl_raise(eBNError, NULL);
     }
     return self;
 }
@@ -576,7 +576,7 @@ ossl_bn_is_prime(int argc, VALUE *argv, VALUE self)
     case 0:
 	return Qfalse;
     default:
-	ossl_raise(eBNError, "");
+	ossl_raise(eBNError, NULL);
     }
     /* not reachable */
     return Qnil;
@@ -606,7 +606,7 @@ ossl_bn_is_prime_fasttest(int argc, VALUE *argv, VALUE self)
     case 0:
 	return Qfalse;
     default:
-	ossl_raise(eBNError, "");
+	ossl_raise(eBNError, NULL);
     }
     /* not reachable */
     return Qnil;
diff --git a/ossl_cipher.c b/ossl_cipher.c
index 6657f62..c50c6f0 100644
--- a/ossl_cipher.c
+++ b/ossl_cipher.c
@@ -83,7 +83,7 @@ ossl_cipher_initialize(VALUE self, VALUE str)
     }
     EVP_CIPHER_CTX_init(ctx);
     if (EVP_CipherInit(ctx, cipher, NULL, NULL, -1) != 1)
-		ossl_raise(eCipherError, "");
+		ossl_raise(eCipherError, NULL);
 
     return self;
 }
@@ -110,7 +110,7 @@ ossl_cipher_reset(VALUE self)
 
 	GetCipher(self, ctx);
 	if (EVP_CipherInit(ctx, NULL, NULL, NULL, -1) != 1)
-		ossl_raise(eCipherError, "");
+		ossl_raise(eCipherError, NULL);
 		
 	return self;
 }
@@ -135,7 +135,7 @@ ossl_cipher_encrypt(int argc, VALUE *argv, VALUE self)
 	/*
 	  RAND_add(data,i,0); where from take data?
 	  if (RAND_pseudo_bytes(iv, 8) < 0) {
-	  ossl_raise(eCipherError, "");
+	  ossl_raise(eCipherError, NULL);
 	  }
 	*/
     }
@@ -151,7 +151,7 @@ ossl_cipher_encrypt(int argc, VALUE *argv, VALUE self)
     }
 
     if (EVP_CipherInit(ctx, NULL, NULL, NULL, 1) != 1) {
-        ossl_raise(eCipherError, "");
+        ossl_raise(eCipherError, NULL);
     }
 
     if (!NIL_P(pass)) {
@@ -160,7 +160,7 @@ ossl_cipher_encrypt(int argc, VALUE *argv, VALUE self)
         EVP_BytesToKey(EVP_CIPHER_CTX_cipher(ctx), EVP_md5(), iv,
 		   RSTRING(pass)->ptr, RSTRING(pass)->len, 1, key, NULL);
         if (EVP_CipherInit(ctx, NULL, key, iv, -1) != 1) {
-            ossl_raise(eCipherError, "");
+            ossl_raise(eCipherError, NULL);
         }
     }
 
@@ -196,7 +196,7 @@ ossl_cipher_decrypt(int argc, VALUE *argv, VALUE self)
     }
 
     if (EVP_CipherInit(ctx, NULL, NULL, NULL, 0) != 1) {
-        ossl_raise(eCipherError, "");
+        ossl_raise(eCipherError, NULL);
     }
 
     if (!NIL_P(pass)) {
@@ -205,7 +205,7 @@ ossl_cipher_decrypt(int argc, VALUE *argv, VALUE self)
         EVP_BytesToKey(EVP_CIPHER_CTX_cipher(ctx), EVP_md5(), iv,
 		   RSTRING(pass)->ptr, RSTRING(pass)->len, 1, key, NULL);
         if (EVP_CipherInit(ctx, NULL, key, iv, -1) != 1) {
-            ossl_raise(eCipherError, "");
+            ossl_raise(eCipherError, NULL);
         }
     }
 
@@ -227,11 +227,11 @@ ossl_cipher_update(VALUE self, VALUE data)
     in_len = RSTRING(data)->len;
 	
     if (!(out = OPENSSL_malloc(in_len+EVP_CIPHER_CTX_block_size(ctx)))){
-	ossl_raise(eCipherError, "");
+	ossl_raise(eCipherError, NULL);
     }
     if (!EVP_CipherUpdate(ctx, out, &out_len, in, in_len)) {
 	OPENSSL_free(out);
-	ossl_raise(eCipherError, "");
+	ossl_raise(eCipherError, NULL);
     }
     str = rb_str_new(out, out_len);
     OPENSSL_free(out);
@@ -250,11 +250,11 @@ ossl_cipher_final(VALUE self)
     GetCipher(self, ctx);
 	
     if (!(out = OPENSSL_malloc(EVP_CIPHER_CTX_block_size(ctx)))) {
-	ossl_raise(eCipherError, "");
+	ossl_raise(eCipherError, NULL);
     }
     if (!EVP_CipherFinal(ctx, out, &out_len)) {
 	OPENSSL_free(out);
-	ossl_raise(eCipherError, "");
+	ossl_raise(eCipherError, NULL);
     }
 
     str = rb_str_new(out, out_len);
@@ -285,7 +285,7 @@ ossl_cipher_set_key(VALUE self, VALUE key)
         ossl_raise(eCipherError, "key length too short");
 
     if (EVP_CipherInit(ctx, NULL, RSTRING(key)->ptr, NULL, -1) != 1)
-        ossl_raise(eCipherError, "");
+        ossl_raise(eCipherError, NULL);
 
     return Qnil;
 }
@@ -302,7 +302,7 @@ ossl_cipher_set_iv(VALUE self, VALUE iv)
         ossl_raise(eCipherError, "iv length too short");
 
     if (EVP_CipherInit(ctx, NULL, NULL, RSTRING(iv)->ptr, -1) != 1)
-		ossl_raise(eCipherError, "");
+		ossl_raise(eCipherError, NULL);
 
     return Qnil;
 }
@@ -315,7 +315,7 @@ ossl_cipher_set_padding(VALUE self, VALUE padding)
     GetCipher(self, ctx);
 
     if (EVP_CIPHER_CTX_set_padding(ctx, NUM2INT(padding)) != 1)
-		ossl_raise(eCipherError, "");
+		ossl_raise(eCipherError, NULL);
 
     return Qnil;
 }
diff --git a/ossl_config.c b/ossl_config.c
index 1d91409..5109d3d 100644
--- a/ossl_config.c
+++ b/ossl_config.c
@@ -51,7 +51,7 @@ ossl_config_s_load(int argc, VALUE *argv, VALUE klass)
     }
     else {
 	if (!(filename = CONF_get1_default_config_file())) {
-	    ossl_raise(eConfigError, "");
+	    ossl_raise(eConfigError, NULL);
 	}
     }
 /*
@@ -64,7 +64,7 @@ ossl_config_s_load(int argc, VALUE *argv, VALUE klass)
 #endif
  */
     if (!(conf = NCONF_new(NULL))) {
-	ossl_raise(eConfigError, "");
+	ossl_raise(eConfigError, NULL);
     }
     OSSL_Debug("Loading file: %s", filename);
 
@@ -96,7 +96,7 @@ ossl_config_get_value(int argc, VALUE *argv, VALUE self)
 	sect = StringValuePtr(section);
     }
     if (!(str = NCONF_get_string(conf, sect, StringValuePtr(item)))) {
-	ossl_raise(eConfigError, "");
+	ossl_raise(eConfigError, NULL);
     }
     return rb_str_new2(str);
 }
@@ -118,7 +118,7 @@ ossl_config_get_section(VALUE self, VALUE section)
     GetConfig(self, conf);
 	
     if (!(sk = NCONF_get_section(conf, StringValuePtr(section)))) {
-	ossl_raise(eConfigError, "");
+	ossl_raise(eConfigError, NULL);
     }
     hash = rb_hash_new();
     
diff --git a/ossl_digest.c b/ossl_digest.c
index cdec7f2..caca95b 100644
--- a/ossl_digest.c
+++ b/ossl_digest.c
@@ -90,7 +90,7 @@ ossl_digest_copy(VALUE self, VALUE other)
     SafeGetDigest(other, ctx2);
 
     if (!EVP_MD_CTX_copy(ctx1, ctx2)) {
-	ossl_raise(eDigestError, "");
+	ossl_raise(eDigestError, NULL);
     }
     return self;
 }
@@ -124,7 +124,7 @@ digest_final(EVP_MD_CTX *ctx, char **buf, int *buf_len)
     EVP_MD_CTX final;
 
     if (!EVP_MD_CTX_copy(&final, ctx)) {
-	ossl_raise(eDigestError, "");
+	ossl_raise(eDigestError, NULL);
     }
     if (!(*buf = OPENSSL_malloc(EVP_MD_CTX_size(&final)))) {
 	ossl_raise(eDigestError, "Cannot allocate mem for digest");
diff --git a/ossl_hmac.c b/ossl_hmac.c
index 0a0a37b..05b6e81 100644
--- a/ossl_hmac.c
+++ b/ossl_hmac.c
@@ -82,7 +82,7 @@ ossl_hmac_copy(VALUE self, VALUE other)
     SafeGetHMAC(other, ctx2);
 
     if (!HMAC_CTX_copy(ctx1, ctx2)) {
-	ossl_raise(eHMACError, "");
+	ossl_raise(eHMACError, NULL);
     }
     return self;
 }
@@ -105,7 +105,7 @@ hmac_final(HMAC_CTX *ctx, char **buf, int *buf_len)
     HMAC_CTX final;
 
     if (!HMAC_CTX_copy(&final, ctx)) {
-	ossl_raise(eHMACError, "");
+	ossl_raise(eHMACError, NULL);
     }
     if (!(*buf = OPENSSL_malloc(HMAC_size(&final)))) {
 	OSSL_Debug("Allocating %d mem", HMAC_size(&final));
diff --git a/ossl_ns_spki.c b/ossl_ns_spki.c
index 4244659..bcefcbd 100644
--- a/ossl_ns_spki.c
+++ b/ossl_ns_spki.c
@@ -44,7 +44,7 @@ ossl_spki_alloc(VALUE klass)
     VALUE obj;
 	
     if (!(spki = NETSCAPE_SPKI_new())) {
-	ossl_raise(eSPKIError, "");
+	ossl_raise(eSPKIError, NULL);
     }	
     WrapSPKI(klass, obj, spki);
 	
@@ -62,7 +62,7 @@ ossl_spki_initialize(int argc, VALUE *argv, VALUE self)
 	return self;
     }
     if (!(spki = NETSCAPE_SPKI_b64_decode(StringValuePtr(buffer), -1))) {
-	ossl_raise(eSPKIError, "");
+	ossl_raise(eSPKIError, NULL);
     }
     NETSCAPE_SPKI_free(DATA_PTR(self));
     DATA_PTR(self) = spki;
@@ -79,7 +79,7 @@ ossl_spki_to_pem(VALUE self)
 	
     GetSPKI(self, spki);
     if (!(data = NETSCAPE_SPKI_b64_encode(spki))) {
-	ossl_raise(eSPKIError, "");
+	ossl_raise(eSPKIError, NULL);
     }
     str = rb_str_new2(data);
     OPENSSL_free(data);
@@ -97,11 +97,11 @@ ossl_spki_print(VALUE self)
 	
     GetSPKI(self, spki);
     if (!(out = BIO_new(BIO_s_mem()))) {
-	ossl_raise(eSPKIError, "");
+	ossl_raise(eSPKIError, NULL);
     }
     if (!NETSCAPE_SPKI_print(out, spki)) {
 	BIO_free(out);
-	ossl_raise(eSPKIError, "");
+	ossl_raise(eSPKIError, NULL);
     }
     BIO_get_mem_ptr(out, &buf);
     str = rb_str_new(buf->data, buf->length);
@@ -118,7 +118,7 @@ ossl_spki_get_public_key(VALUE self)
 
     GetSPKI(self, spki);
     if (!(pkey = NETSCAPE_SPKI_get_pubkey(spki))) { /* adds an reference */
-	ossl_raise(eSPKIError, "");
+	ossl_raise(eSPKIError, NULL);
     }
 
     return ossl_pkey_new(pkey); /* NO DUP - OK */
@@ -131,7 +131,7 @@ ossl_spki_set_public_key(VALUE self, VALUE key)
 
     GetSPKI(self, spki);
     if (!NETSCAPE_SPKI_set_pubkey(spki, GetPKeyPtr(key))) { /* NO NEED TO DUP */
-	ossl_raise(eSPKIError, "");
+	ossl_raise(eSPKIError, NULL);
     }
 
     return key;
@@ -145,7 +145,7 @@ ossl_spki_get_challenge(VALUE self)
     GetSPKI(self, spki);
     if (spki->spkac->challenge->length <= 0) {
 	OSSL_Debug("Challenge.length <= 0?");
-	return rb_str_new2("");
+	return rb_str_new2(NULL);
     }
 
     return rb_str_new(spki->spkac->challenge->data,
@@ -161,7 +161,7 @@ ossl_spki_set_challenge(VALUE self, VALUE str)
     StringValue(str);
     if (!ASN1_STRING_set(spki->spkac->challenge, RSTRING(str)->ptr,
 			 RSTRING(str)->len)) {
-	ossl_raise(eSPKIError, "");
+	ossl_raise(eSPKIError, NULL);
     }
     
     return str;
@@ -178,7 +178,7 @@ ossl_spki_sign(VALUE self, VALUE key, VALUE digest)
     pkey = GetPrivPKeyPtr(key); /* NO NEED TO DUP */
     md = GetDigestPtr(digest);
     if (!NETSCAPE_SPKI_sign(spki, pkey, md)) {
-	ossl_raise(eSPKIError, "");
+	ossl_raise(eSPKIError, NULL);
     }
 
     return self;
@@ -199,7 +199,7 @@ ossl_spki_verify(VALUE self, VALUE key)
     case 1:
 	return Qtrue;
     default:
-	ossl_raise(eSPKIError, "");
+	ossl_raise(eSPKIError, NULL);
     }
     return Qnil; /* dummy */
 }
diff --git a/ossl_ocsp.c b/ossl_ocsp.c
index 3041d4d..51e598b 100644
--- a/ossl_ocsp.c
+++ b/ossl_ocsp.c
@@ -168,7 +168,6 @@ ossl_ocspreq_add_certid(VALUE self, VALUE certid)
 {
     OCSP_REQUEST *req;
     OCSP_CERTID *id;
-    X509 *issuer;
 
     GetOCSPReq(self, req);
     GetOCSPCertId(certid, id);
diff --git a/ossl_pkcs7.c b/ossl_pkcs7.c
index 30b3793..372f5ed 100644
--- a/ossl_pkcs7.c
+++ b/ossl_pkcs7.c
@@ -70,7 +70,7 @@ ossl_pkcs7si_new(PKCS7_SIGNER_INFO *p7si)
     VALUE obj;
 
     pkcs7 = p7si ? PKCS7_SIGNER_INFO_dup(p7si) : PKCS7_SIGNER_INFO_new();
-    if (!pkcs7) ossl_raise(ePKCS7Error, "");
+    if (!pkcs7) ossl_raise(ePKCS7Error, NULL);
     WrapPKCS7si(cPKCS7Signer, obj, pkcs7);
 
     return obj;
@@ -83,7 +83,7 @@ DupPKCS7SignerPtr(VALUE obj)
 	
     SafeGetPKCS7si(obj, p7si);
     if (!(pkcs7 = PKCS7_SIGNER_INFO_dup(p7si))) {
-	ossl_raise(ePKCS7Error, "");
+	ossl_raise(ePKCS7Error, NULL);
     }
 
     return pkcs7;
@@ -229,7 +229,7 @@ ossl_pkcs7_alloc(VALUE klass)
     VALUE obj;
 
     if (!(pkcs7 = PKCS7_new())) {
-	ossl_raise(ePKCS7Error, "");
+	ossl_raise(ePKCS7Error, NULL);
     }
     WrapPKCS7(klass, obj, pkcs7);
     
@@ -240,7 +240,6 @@ DEFINE_ALLOC_WRAPPER(ossl_pkcs7_alloc)
 static VALUE
 ossl_pkcs7_initialize(int argc, VALUE *argv, VALUE self)
 {
-    PKCS7 *pkcs7;
     BIO *in;
     VALUE s;
 
@@ -248,10 +247,10 @@ ossl_pkcs7_initialize(int argc, VALUE *argv, VALUE self)
 	return self;
     StringValue(s);
     if (!(in = BIO_new_mem_buf(RSTRING(s)->ptr, RSTRING(s)->len)))
-	ossl_raise(ePKCS7Error, "");
+	ossl_raise(ePKCS7Error, NULL);
     if (!PEM_read_bio_PKCS7(in, (PKCS7 **)&DATA_PTR(self), NULL, NULL)) {
 	BIO_free(in);
-	ossl_raise(ePKCS7Error, "");
+	ossl_raise(ePKCS7Error, NULL);
     }
     BIO_free(in);
     ossl_pkcs7_set_data(self, Qnil);
@@ -273,7 +272,7 @@ ossl_pkcs7_copy(VALUE self, VALUE other)
 
     pkcs7 = PKCS7_dup(b);
     if (!pkcs7) {
-	ossl_raise(ePKCS7Error, "");
+	ossl_raise(ePKCS7Error, NULL);
     }
     DATA_PTR(self) = pkcs7;
     PKCS7_free(a);
@@ -382,7 +381,7 @@ ossl_pkcs7_set_cipher(VALUE self, VALUE cipher)
 
     GetPKCS7(self, pkcs7);
     if (!PKCS7_set_cipher(pkcs7, GetCipherPtr(cipher))) {
-	ossl_raise(ePKCS7Error, "");
+	ossl_raise(ePKCS7Error, NULL);
     }
 
     return cipher;
@@ -444,15 +443,15 @@ ossl_pkcs7_add_recipient(VALUE self, VALUE cert)
     GetPKCS7(self, pkcs7);
     x509 = GetX509CertPtr(cert); /* NO NEED TO DUP */
     if (!(ri = PKCS7_RECIP_INFO_new())) {
-	ossl_raise(ePKCS7Error, "");
+	ossl_raise(ePKCS7Error, NULL);
     }
     if (!PKCS7_RECIP_INFO_set(ri, x509)) {
 	PKCS7_RECIP_INFO_free(ri);
-	ossl_raise(ePKCS7Error, "");
+	ossl_raise(ePKCS7Error, NULL);
     }
     if (!PKCS7_add_recipient_info(pkcs7, ri)) {
 	PKCS7_RECIP_INFO_free(ri);
-	ossl_raise(ePKCS7Error, "");
+	ossl_raise(ePKCS7Error, NULL);
     }
 
     return self;
@@ -467,7 +466,7 @@ ossl_pkcs7_add_certificate(VALUE self, VALUE cert)
     GetPKCS7(self, pkcs7);
     x509 = GetX509CertPtr(cert);  /* NO NEED TO DUP */
     if (!PKCS7_add_certificate(pkcs7, x509)){
-	ossl_raise(ePKCS7Error, "");
+	ossl_raise(ePKCS7Error, NULL);
     }
 
     return self;
@@ -482,7 +481,7 @@ ossl_pkcs7_add_crl(VALUE self, VALUE crl)
     GetPKCS7(self, pkcs7); /* NO DUP needed! */
     x509crl = GetX509CRLPtr(crl);
     if (!PKCS7_add_crl(pkcs7, x509crl)) {
-	ossl_raise(ePKCS7Error, "");
+	ossl_raise(ePKCS7Error, NULL);
     }
 
     return self;
@@ -497,7 +496,7 @@ ossl_pkcs7_verify(int argc, VALUE *argv, VALUE self)
     int flg, ok, status = 0;
     BIO *in, *out;
     PKCS7 *p7;
-    VALUE ret, data;
+    VALUE data;
     const char *msg;
 
     GetPKCS7(self, p7);
@@ -621,7 +620,7 @@ ossl_pkcs7_data_verify(int argc, VALUE *argv, VALUE self)
 	StringValue(detached);
 	data = BIO_new_mem_buf(RSTRING(detached)->ptr, RSTRING(detached)->len);
 	if(!data){
-	    ossl_raise(ePKCS7Error, "");
+	    ossl_raise(ePKCS7Error, NULL);
 	}
     }
 	
@@ -637,7 +636,7 @@ ossl_pkcs7_data_verify(int argc, VALUE *argv, VALUE self)
 	if (data) {
 	    BIO_free(data);
 	}
-	ossl_raise(ePKCS7Error, "");
+	ossl_raise(ePKCS7Error, NULL);
     }
 
     /* We have to 'read' from bio to calculate digests etc. */
@@ -702,11 +701,11 @@ ossl_pkcs7_to_pem(VALUE self)
 	
     GetPKCS7(self, pkcs7);
     if (!(out = BIO_new(BIO_s_mem()))) {
-	ossl_raise(ePKCS7Error, "");
+	ossl_raise(ePKCS7Error, NULL);
     }
     if (!PEM_write_bio_PKCS7(out, pkcs7)) {
 	BIO_free(out);
-	ossl_raise(ePKCS7Error, "");
+	ossl_raise(ePKCS7Error, NULL);
     }
     str = ossl_protect_membio2str(out, &status);
     BIO_free(out);
@@ -725,7 +724,7 @@ ossl_pkcs7si_alloc(VALUE klass)
     VALUE obj;
 
     if (!(p7si = PKCS7_SIGNER_INFO_new())) {
-	ossl_raise(ePKCS7Error, "");
+	ossl_raise(ePKCS7Error, NULL);
     }
     WrapPKCS7si(klass, obj, p7si);
 
@@ -746,7 +745,7 @@ ossl_pkcs7si_initialize(VALUE self, VALUE cert, VALUE key, VALUE digest)
     x509 = GetX509CertPtr(cert); /* NO NEED TO DUP */
     md = GetDigestPtr(digest);
     if (!(PKCS7_SIGNER_INFO_set(p7si, x509, pkey, md))) {
-	ossl_raise(ePKCS7Error, "");
+	ossl_raise(ePKCS7Error, NULL);
     }
 
     return self;
@@ -781,7 +780,7 @@ ossl_pkcs7si_get_signed_time(VALUE self)
     GetPKCS7si(self, p7si);
 	
     if (!(asn1obj = PKCS7_get_signed_attribute(p7si, NID_pkcs9_signingTime))) {
-	ossl_raise(ePKCS7Error, "");
+	ossl_raise(ePKCS7Error, NULL);
     }
     if (asn1obj->type == V_ASN1_UTCTIME) {
 	return asn1time_to_time(asn1obj->value.utctime);
diff --git a/ossl_pkey.c b/ossl_pkey.c
index 38d0055..b8c5f87 100644
--- a/ossl_pkey.c
+++ b/ossl_pkey.c
@@ -60,7 +60,7 @@ ossl_pkey_new_from_file(VALUE filename)
     pkey = PEM_read_PrivateKey(fp, NULL, ossl_pem_passwd_cb, NULL);
     fclose(fp);
     if (!pkey) {
-	ossl_raise(ePKeyError, "");
+	ossl_raise(ePKeyError, NULL);
     }
 
     return ossl_pkey_new(pkey);
@@ -113,7 +113,7 @@ ossl_pkey_alloc(VALUE klass)
     VALUE obj;
 
     if (!(pkey = EVP_PKEY_new())) {
-	ossl_raise(ePKeyError, "");
+	ossl_raise(ePKeyError, NULL);
     }
     WrapPKey(klass, obj, pkey);
 
@@ -140,11 +140,11 @@ ossl_pkey_to_der(VALUE self)
     
     GetPKey(self, pkey);
     if (!(key = X509_PUBKEY_new())) {
-	ossl_raise(ePKeyError, "");
+	ossl_raise(ePKeyError, NULL);
     }
     if (!X509_PUBKEY_set(&key, pkey)) {
 	X509_PUBKEY_free(key);
-	ossl_raise(ePKeyError, "");
+	ossl_raise(ePKeyError, NULL);
     }
 
     oc = ASN1_item_pack(key, ASN1_ITEM_rptr(X509_PUBKEY), NULL);
@@ -173,11 +173,11 @@ ossl_pkey_sign(VALUE self, VALUE digest, VALUE data)
     StringValue(data);
     EVP_SignUpdate(&ctx, RSTRING(data)->ptr, RSTRING(data)->len);
     if (!(buf = OPENSSL_malloc(EVP_PKEY_size(pkey) + 16))) {
-	ossl_raise(ePKeyError, "");
+	ossl_raise(ePKeyError, NULL);
     }
     if (!EVP_SignFinal(&ctx, buf, &buf_len, pkey)) {
 	OPENSSL_free(buf);
-	ossl_raise(ePKeyError, "");
+	ossl_raise(ePKeyError, NULL);
     }	
     str = rb_str_new(buf, buf_len);
     OPENSSL_free(buf);
@@ -202,7 +202,7 @@ ossl_pkey_verify(VALUE self, VALUE digest, VALUE sig, VALUE data)
     case 1:
 	return Qtrue;
     default:
-	ossl_raise(ePKeyError, "");
+	ossl_raise(ePKeyError, NULL);
     }
     return Qnil; /* dummy */
 }
diff --git a/ossl_pkey.h b/ossl_pkey.h
index 0f6f668..f3cf20c 100644
--- a/ossl_pkey.h
+++ b/ossl_pkey.h
@@ -83,7 +83,7 @@ static VALUE ossl_##keytype##_get_##name(VALUE self)			\
 static VALUE ossl_##keytype##_set_##name(VALUE self, VALUE bignum)	\
 {									\
 	EVP_PKEY *pkey;							\
-	BIGNUM *bn, *newbn;						\
+	BIGNUM *bn;							\
 									\
 	GetPKey(self, pkey);						\
 	if (NIL_P(bignum)) {						\
@@ -96,9 +96,9 @@ static VALUE ossl_##keytype##_set_##name(VALUE self, VALUE bignum)	\
 	if (pkey->pkey.keytype->name == NULL)				\
 		pkey->pkey.keytype->name = BN_new();			\
 	if (pkey->pkey.keytype->name == NULL)				\
-		ossl_raise(eBNError, "");				\
+		ossl_raise(eBNError, NULL);				\
 	if (BN_copy(pkey->pkey.keytype->name, bn) == NULL)		\
-		ossl_raise(eBNError, "");				\
+		ossl_raise(eBNError, NULL);				\
 	return bignum;							\
 }
 
diff --git a/ossl_pkey_dh.c b/ossl_pkey_dh.c
index f667eb8..9a6bec1 100644
--- a/ossl_pkey_dh.c
+++ b/ossl_pkey_dh.c
@@ -65,7 +65,7 @@ ossl_dh_new(EVP_PKEY *pkey)
 	WrapPKey(cDH, obj, pkey);
     }
     if (obj == Qfalse) {
-	ossl_raise(eDHError, "");
+	ossl_raise(eDHError, NULL);
     }
 
     return obj;
@@ -124,7 +124,7 @@ ossl_dh_s_generate(int argc, VALUE *argv, VALUE klass)
     obj = dh_instance(klass, dh);
     if (obj == Qfalse) {
 	DH_free(dh);
-	ossl_raise(eDHError, "");
+	ossl_raise(eDHError, NULL);
     }
 
     return obj;
@@ -146,23 +146,23 @@ ossl_dh_initialize(int argc, VALUE *argv, VALUE self)
 	    g = FIX2INT(gen);
 	}
 	if (!(dh = dh_generate(FIX2INT(buffer), g))) {
-	    ossl_raise(eDHError, "");
+	    ossl_raise(eDHError, NULL);
 	}
     } else {
 	StringValue(buffer);
 	in = BIO_new_mem_buf(RSTRING(buffer)->ptr, RSTRING(buffer)->len);
 	if (!in){
-	    ossl_raise(eDHError, "");
+	    ossl_raise(eDHError, NULL);
 	}
 	if (!(dh = PEM_read_bio_DHparams(in, NULL, NULL, NULL))) {
 	    BIO_free(in);
-	    ossl_raise(eDHError, "");
+	    ossl_raise(eDHError, NULL);
 	}
 	BIO_free(in);
     }
     if (!EVP_PKEY_assign_DH(pkey, dh)) {
 	DH_free(dh);
-	ossl_raise(eRSAError, "");
+	ossl_raise(eRSAError, NULL);
     }
     return self;
 }
@@ -200,11 +200,11 @@ ossl_dh_export(VALUE self)
 
     GetPKeyDH(self, pkey);
     if (!(out = BIO_new(BIO_s_mem()))) {
-	ossl_raise(eDHError, "");
+	ossl_raise(eDHError, NULL);
     }
     if (!PEM_write_bio_DHparams(out, pkey->pkey.dh)) {
 	BIO_free(out);
-	ossl_raise(eDHError, "");
+	ossl_raise(eDHError, NULL);
     }
     BIO_get_mem_ptr(out, &buf);
     str = rb_str_new(buf->data, buf->length);
@@ -251,11 +251,11 @@ ossl_dh_to_text(VALUE self)
 
     GetPKeyDH(self, pkey);
     if (!(out = BIO_new(BIO_s_mem()))) {
-	ossl_raise(eDHError, "");
+	ossl_raise(eDHError, NULL);
     }
     if (!DHparams_print(out, pkey->pkey.dh)) {
 	BIO_free(out);
-	ossl_raise(eDHError, "");
+	ossl_raise(eDHError, NULL);
     }
     BIO_get_mem_ptr(out, &buf);
     str = rb_str_new(buf->data, buf->length);
@@ -279,7 +279,7 @@ ossl_dh_to_public_key(VALUE self)
     obj = dh_instance(CLASS_OF(self), dh);
     if (obj == Qfalse) {
 	DH_free(dh);
-	ossl_raise(eDHError, "");
+	ossl_raise(eDHError, NULL);
     }
 
     return obj;
@@ -337,7 +337,7 @@ ossl_dh_compute_key(VALUE self, VALUE pub)
 
     if ((len = DH_compute_key(buf, pub_key, dh)) < 0) {
 	OPENSSL_free(buf);
-	ossl_raise(eDHError, "");
+	ossl_raise(eDHError, NULL);
     }
 
     str = rb_str_new(buf, len);
diff --git a/ossl_pkey_dsa.c b/ossl_pkey_dsa.c
index 89271af..73ab47b 100644
--- a/ossl_pkey_dsa.c
+++ b/ossl_pkey_dsa.c
@@ -65,7 +65,7 @@ ossl_dsa_new(EVP_PKEY *pkey)
 	WrapPKey(cDSA, obj, pkey);
     }
     if (obj == Qfalse) {
-	ossl_raise(eDSAError, "");
+	ossl_raise(eDSAError, NULL);
     }
 
     return obj;
@@ -124,7 +124,7 @@ ossl_dsa_s_generate(VALUE klass, VALUE size)
 
     if (obj == Qfalse) {
 	DSA_free(dsa);
-	ossl_raise(eDSAError, "");
+	ossl_raise(eDSAError, NULL);
     }
 
     return obj;
@@ -143,7 +143,7 @@ ossl_dsa_initialize(int argc, VALUE *argv, VALUE self)
     rb_scan_args(argc, argv, "11", &buffer, &pass);
     if (FIXNUM_P(buffer)) {
 	if (!(dsa = dsa_generate(FIX2INT(buffer)))) {
-	    ossl_raise(eDSAError, "");
+	    ossl_raise(eDSAError, NULL);
 	}
     } else {
 	StringValue(buffer);
@@ -152,7 +152,7 @@ ossl_dsa_initialize(int argc, VALUE *argv, VALUE self)
 	}
 	in = BIO_new_mem_buf(RSTRING(buffer)->ptr, RSTRING(buffer)->len);
 	if (!in){
-	    ossl_raise(eDSAError, "");
+	    ossl_raise(eDSAError, NULL);
 	}
 
 	dsa = PEM_read_bio_DSAPrivateKey(in, NULL, ossl_pem_passwd_cb, passwd);
@@ -174,7 +174,7 @@ ossl_dsa_initialize(int argc, VALUE *argv, VALUE self)
     }
     if (!EVP_PKEY_assign_DSA(pkey, dsa)) {
 	DSA_free(dsa);
-	ossl_raise(eDSAError, "");
+	ossl_raise(eDSAError, NULL);
     }
 
     return self;
@@ -223,18 +223,18 @@ ossl_dsa_export(int argc, VALUE *argv, VALUE self)
 	}
     }
     if (!(out = BIO_new(BIO_s_mem()))) {
-	ossl_raise(eDSAError, "");
+	ossl_raise(eDSAError, NULL);
     }
     if (DSA_PRIVATE(pkey->pkey.dsa)) {
 	if (!PEM_write_bio_DSAPrivateKey(out, pkey->pkey.dsa, ciph,
 					 NULL, 0, ossl_pem_passwd_cb, passwd)){
 	    BIO_free(out);
-	    ossl_raise(eDSAError, "");
+	    ossl_raise(eDSAError, NULL);
 	}
     } else {
 	if (!PEM_write_bio_DSAPublicKey(out, pkey->pkey.dsa)) {
 	    BIO_free(out);
-	    ossl_raise(eDSAError, "");
+	    ossl_raise(eDSAError, NULL);
 	}
     }
     BIO_get_mem_ptr(out, &buf);
@@ -283,11 +283,11 @@ ossl_dsa_to_text(VALUE self)
 
     GetPKeyDSA(self, pkey);
     if (!(out = BIO_new(BIO_s_mem()))) {
-	ossl_raise(eDSAError, "");
+	ossl_raise(eDSAError, NULL);
     }
     if (!DSA_print(out, pkey->pkey.dsa, 0)) { //offset = 0
 	BIO_free(out);
-	ossl_raise(eDSAError, "");
+	ossl_raise(eDSAError, NULL);
     }
     BIO_get_mem_ptr(out, &buf);
     str = rb_str_new(buf->data, buf->length);
@@ -312,7 +312,7 @@ ossl_dsa_to_public_key(VALUE self)
     obj = dsa_instance(CLASS_OF(self), dsa);
     if (obj == Qfalse) {
 	DSA_free(dsa);
-	ossl_raise(eDSAError, "");
+	ossl_raise(eDSAError, NULL);
     }
     return obj;
 }
@@ -331,12 +331,12 @@ ossl_dsa_sign(VALUE self, VALUE data)
 	ossl_raise(eDSAError, "Private DSA key needed!");
     }
     if (!(buf = OPENSSL_malloc(DSA_size(pkey->pkey.dsa) + 16))) {
-	ossl_raise(eDSAError, "");
+	ossl_raise(eDSAError, NULL);
     }
     if (!DSA_sign(0, RSTRING(data)->ptr, RSTRING(data)->len, buf,
 		  &buf_len, pkey->pkey.dsa)) { /* type is ignored (0) */
 	OPENSSL_free(buf);
-	ossl_raise(eDSAError, "");
+	ossl_raise(eDSAError, NULL);
     }
     str = rb_str_new(buf, buf_len);
     OPENSSL_free(buf);
@@ -357,7 +357,7 @@ ossl_dsa_verify(VALUE self, VALUE digest, VALUE sig)
     ret = DSA_verify(0, RSTRING(digest)->ptr, RSTRING(digest)->len,
 		     RSTRING(sig)->ptr, RSTRING(sig)->len, pkey->pkey.dsa);
     if (ret < 0) {
-	ossl_raise(eDSAError, "");
+	ossl_raise(eDSAError, NULL);
     }
     else if (ret == 1) {
 	return Qtrue;
diff --git a/ossl_pkey_rsa.c b/ossl_pkey_rsa.c
index 070c69f..d04a22f 100644
--- a/ossl_pkey_rsa.c
+++ b/ossl_pkey_rsa.c
@@ -66,7 +66,7 @@ ossl_rsa_new(EVP_PKEY *pkey)
 	WrapPKey(cRSA, obj, pkey);
     }
     if (obj == Qfalse) {
-	ossl_raise(eRSAError, "");
+	ossl_raise(eRSAError, NULL);
     }
 
     return obj;
@@ -115,7 +115,7 @@ ossl_rsa_s_generate(int argc, VALUE *argv, VALUE klass)
 
     if (obj == Qfalse) {
 	RSA_free(rsa);
-	ossl_raise(eRSAError, "");
+	ossl_raise(eRSAError, NULL);
     }
 
     return obj;
@@ -137,7 +137,7 @@ ossl_rsa_initialize(int argc, VALUE *argv, VALUE self)
     if (FIXNUM_P(buffer)) {
 	rsa = rsa_generate(FIX2INT(buffer), NIL_P(pass) ? RSA_F4 : NUM2INT(pass));
 	if (!rsa) {
-	    ossl_raise(eRSAError, "");
+	    ossl_raise(eRSAError, NULL);
 	}
     }
     else {
@@ -146,7 +146,7 @@ ossl_rsa_initialize(int argc, VALUE *argv, VALUE self)
 	    passwd = StringValuePtr(pass);
 	}
 	if (!(in = BIO_new_mem_buf(RSTRING(buffer)->ptr, RSTRING(buffer)->len))){
-	    ossl_raise(eRSAError, "");
+	    ossl_raise(eRSAError, NULL);
 	}
 
 	rsa = PEM_read_bio_RSAPrivateKey(in, NULL, ossl_pem_passwd_cb, passwd);
@@ -168,7 +168,7 @@ ossl_rsa_initialize(int argc, VALUE *argv, VALUE self)
     }
     if (!EVP_PKEY_assign_RSA(pkey, rsa)) {
 	RSA_free(rsa);
-	ossl_raise(eRSAError, "");
+	ossl_raise(eRSAError, NULL);
     }
 
     return self;
@@ -218,18 +218,18 @@ ossl_rsa_export(int argc, VALUE *argv, VALUE self)
 	}
     }
     if (!(out = BIO_new(BIO_s_mem()))) {
-	ossl_raise(eRSAError, "");
+	ossl_raise(eRSAError, NULL);
     }
     if (RSA_PRIVATE(pkey->pkey.rsa)) {
 	if (!PEM_write_bio_RSAPrivateKey(out, pkey->pkey.rsa, ciph,
 					 NULL, 0, ossl_pem_passwd_cb, passwd)) {
 	    BIO_free(out);
-	    ossl_raise(eRSAError, "");
+	    ossl_raise(eRSAError, NULL);
 	}
     } else {
 	if (!PEM_write_bio_RSAPublicKey(out, pkey->pkey.rsa)) {
 	    BIO_free(out);
-	    ossl_raise(eRSAError, "");
+	    ossl_raise(eRSAError, NULL);
 	}
     }
     BIO_get_mem_ptr(out, &buf);
@@ -252,13 +252,13 @@ ossl_rsa_public_encrypt(VALUE self, VALUE buffer)
     StringValue(buffer);
 	
     if (!(buf = OPENSSL_malloc(RSA_size(pkey->pkey.rsa) + 16))) {
-	ossl_raise(eRSAError, "");
+	ossl_raise(eRSAError, NULL);
     }
     buf_len = RSA_public_encrypt(RSTRING(buffer)->len, RSTRING(buffer)->ptr,
 				 buf, pkey->pkey.rsa, RSA_PKCS1_PADDING);
     if (buf_len < 0){
 	OPENSSL_free(buf);
-	ossl_raise(eRSAError, "");
+	ossl_raise(eRSAError, NULL);
     }
     str = rb_str_new(buf, buf_len);
     OPENSSL_free(buf);
@@ -277,13 +277,13 @@ ossl_rsa_public_decrypt(VALUE self, VALUE buffer)
     GetPKeyRSA(self, pkey);
     StringValue(buffer);
     if (!(buf = OPENSSL_malloc(RSA_size(pkey->pkey.rsa) + 16))) {
-	ossl_raise(eRSAError, "");
+	ossl_raise(eRSAError, NULL);
     }
     buf_len = RSA_public_decrypt(RSTRING(buffer)->len, RSTRING(buffer)->ptr,
 				 buf, pkey->pkey.rsa, RSA_PKCS1_PADDING);
     if(buf_len < 0) {
 	OPENSSL_free(buf);
-	ossl_raise(eRSAError, "");
+	ossl_raise(eRSAError, NULL);
     }
     str = rb_str_new(buf, buf_len);
     OPENSSL_free(buf);
@@ -311,7 +311,7 @@ ossl_rsa_private_encrypt(VALUE self, VALUE buffer)
 				  buf, pkey->pkey.rsa, RSA_PKCS1_PADDING);
     if (buf_len < 0){
 	OPENSSL_free(buf);
-	ossl_raise(eRSAError, "");
+	ossl_raise(eRSAError, NULL);
     }
     str = rb_str_new(buf, buf_len);
     OPENSSL_free(buf);
@@ -339,7 +339,7 @@ ossl_rsa_private_decrypt(VALUE self, VALUE buffer)
 				  buf, pkey->pkey.rsa, RSA_PKCS1_PADDING);
     if(buf_len < 0) {
 	OPENSSL_free(buf);
-	ossl_raise(eRSAError, "");
+	ossl_raise(eRSAError, NULL);
     }
     str = rb_str_new(buf, buf_len);
     OPENSSL_free(buf);
@@ -389,11 +389,11 @@ ossl_rsa_to_text(VALUE self)
 
     GetPKeyRSA(self, pkey);
     if (!(out = BIO_new(BIO_s_mem()))) {
-	ossl_raise(eRSAError, "");
+	ossl_raise(eRSAError, NULL);
     }
     if (!RSA_print(out, pkey->pkey.rsa, 0)) { //offset = 0
 	BIO_free(out);
-	ossl_raise(eRSAError, "");
+	ossl_raise(eRSAError, NULL);
     }
     BIO_get_mem_ptr(out, &buf);
     str = rb_str_new(buf->data, buf->length);
@@ -418,7 +418,7 @@ ossl_rsa_to_public_key(VALUE self)
     obj = rsa_instance(CLASS_OF(self), rsa);
     if (obj == Qfalse) {
 	RSA_free(rsa);
-	ossl_raise(eRSAError, "");
+	ossl_raise(eRSAError, NULL);
     }
     return obj;
 }
@@ -449,11 +449,11 @@ ossl_rsa_sign(VALUE self, VALUE data)
 	ossl_raise(eRSAError, "Private RSA key needed!");
     }
     if (!(buf = OPENSSL_malloc(RSA_size(pkey->pkey.rsa) + 16))) {
-	ossl_raise(eRSAError, "");
+	ossl_raise(eRSAError, NULL);
     }
     if (!RSA_sign(type, m, m_len, buf, &buf_len, pkey->pkey.rsa)) {
 	OPENSSL_free(buf);
-	ossl_raise(eRSAError, "");
+	ossl_raise(eRSAError, NULL);
     }
     str = rb_str_new(buf, buf_len);
     OPENSSL_free(buf);
@@ -474,7 +474,7 @@ ossl_rsa_verify(VALUE self, VALUE sig, VALUE data)
     ret = RSA_verify(0, RSTRING(digest)->ptr, RSTRING(digest)->len,
 		     RSTRING(sig)->ptr, RSTRING(sig)->len, pkey->pkey.rsa);
     if (ret < 0) {
-	ossl_raise(eRSAError, "");
+	ossl_raise(eRSAError, NULL);
     }
     else if (ret == 1) {
 	return Qtrue;
@@ -496,7 +496,7 @@ ossl_rsa_blinding_on(VALUE self)
     GetPKeyRSA(self, pkey);
 
     if (RSA_blinding_on(pkey->pkey.rsa, ossl_bn_ctx) != 1) {
-	ossl_raise(eRSAError, "");
+	ossl_raise(eRSAError, NULL);
     }
     return self;
 }
diff --git a/ossl_rand.c b/ossl_rand.c
index d779df1..c308892 100644
--- a/ossl_rand.c
+++ b/ossl_rand.c
@@ -42,7 +42,7 @@ ossl_rand_load_file(VALUE self, VALUE filename)
     SafeStringValue(filename);
 	
     if(!RAND_load_file(RSTRING(filename)->ptr, -1)) {
-	ossl_raise(eRandomError, "");
+	ossl_raise(eRandomError, NULL);
     }
     return Qtrue;
 }
@@ -52,7 +52,7 @@ ossl_rand_write_file(VALUE self, VALUE filename)
 {
     SafeStringValue(filename);
     if (RAND_write_file(RSTRING(filename)->ptr) == -1) {
-	ossl_raise(eRandomError, "");
+	ossl_raise(eRandomError, NULL);
     }
     return Qtrue;
 }
@@ -64,11 +64,11 @@ ossl_rand_bytes(VALUE self, VALUE len)
     VALUE str;
 	
     if (!(buffer = OPENSSL_malloc(FIX2INT(len) + 1))) {
-	ossl_raise(eRandomError, "");
+	ossl_raise(eRandomError, NULL);
     }
     if (!RAND_bytes(buffer, FIX2INT(len))) {
 	OPENSSL_free(buffer);
-	ossl_raise(eRandomError, "");
+	ossl_raise(eRandomError, NULL);
     }
     str = rb_str_new(buffer, FIX2INT(len));
     OPENSSL_free(buffer);
@@ -83,11 +83,11 @@ ossl_rand_pseudo_bytes(VALUE self, VALUE len)
     VALUE str;
 	
     if (!(buffer = OPENSSL_malloc(FIX2INT(len) + 1))) {
-	ossl_raise(eRandomError, "");
+	ossl_raise(eRandomError, NULL);
     }
     if (!RAND_pseudo_bytes(buffer, FIX2INT(len))) {
 	OPENSSL_free(buffer);
-	ossl_raise(eRandomError, "");
+	ossl_raise(eRandomError, NULL);
     }
     str = rb_str_new(buffer, FIX2INT(len));
     OPENSSL_free(buffer);
@@ -101,7 +101,7 @@ ossl_rand_egd(VALUE self, VALUE filename)
     SafeStringValue(filename);
 	
     if(!RAND_egd(RSTRING(filename)->ptr)) {
-	ossl_raise(eRandomError, "");
+	ossl_raise(eRandomError, NULL);
     }
     return Qtrue;
 }
@@ -112,7 +112,7 @@ ossl_rand_egd_bytes(VALUE self, VALUE filename, VALUE len)
     SafeStringValue(filename);
 
     if (!RAND_egd_bytes(RSTRING(filename)->ptr, FIX2INT(len))) {
-	ossl_raise(eRandomError, "");
+	ossl_raise(eRandomError, NULL);
     }
     return Qtrue;
 }
diff --git a/ossl_ssl.c b/ossl_ssl.c
index 689996b..f864c79 100644
--- a/ossl_ssl.c
+++ b/ossl_ssl.c
@@ -139,7 +139,7 @@ ossl_sslctx_initialize(int argc, VALUE *argv, VALUE self)
 static int
 ossl_ssl_verify_callback(int preverify_ok, X509_STORE_CTX *ctx)
 {
-    VALUE args, cb, result, rctx;
+    VALUE cb;
     SSL *ssl;
 
     ssl = X509_STORE_CTX_get_ex_data(ctx, SSL_get_ex_data_X509_STORE_CTX_idx());
@@ -299,7 +299,7 @@ ossl_sslctx_set_ciphers(VALUE self, VALUE v)
     }
 
     if (TYPE(v) == T_ARRAY) {
-        str = rb_str_new2("");
+        str = rb_str_new2(NULL);
         for (i = 0; i < RARRAY(v)->len; i++) {
             elem = rb_ary_entry(v, i);
             if (TYPE(elem) == T_ARRAY) elem = rb_ary_entry(elem, 0);
diff --git a/ossl_x509attr.c b/ossl_x509attr.c
index 98f4a33..22b5e17 100644
--- a/ossl_x509attr.c
+++ b/ossl_x509attr.c
@@ -48,7 +48,7 @@ ossl_x509attr_new(X509_ATTRIBUTE *attr)
 	new = X509_ATTRIBUTE_dup(attr);
     }
     if (!new) {
-	ossl_raise(eX509AttrError, "");
+	ossl_raise(eX509AttrError, NULL);
     }
     WrapX509Attr(cX509Attr, obj, new);
 
@@ -62,7 +62,7 @@ ossl_x509attr_get_X509_ATTRIBUTE(VALUE obj)
 
     SafeGetX509Attr(obj, attr);
     if (!(new = X509_ATTRIBUTE_dup(attr))) {
-	ossl_raise(eX509AttrError, "");
+	ossl_raise(eX509AttrError, NULL);
     }
 
     return new;
@@ -87,14 +87,14 @@ ossl_x509attr_s_new_from_array(VALUE klass, VALUE ary)
     StringValue(item);
     if (!(nid = OBJ_ln2nid(RSTRING(item)->ptr))) {
 	if (!(nid = OBJ_sn2nid(RSTRING(item)->ptr))) {
-	    ossl_raise(eX509AttrError, "");
+	    ossl_raise(eX509AttrError, NULL);
 	}
     }
     /* data [1] */
     item = RARRAY(ary)->ptr[1];
     StringValuePtr(item);
     if (!(attr = X509_ATTRIBUTE_create(nid, MBSTRING_ASC, RSTRING(item)->ptr))) {
-	ossl_raise(eX509AttrError, "");
+	ossl_raise(eX509AttrError, NULL);
     }
     WrapX509Attr(klass, obj, attr);
     
@@ -120,10 +120,10 @@ ossl_x509attr_to_a(VALUE self)
     nid = OBJ_obj2nid(X509_ATTRIBUTE_get0_object(attrp->attribute));
     rb_ary_push(ary, rb_str_new2(OBJ_nid2sn(nid)));
     if (!(out = BIO_new(BIO_s_mem())))
-	ossl_raise(eX509ExtensionError, "");
+	ossl_raise(eX509ExtensionError, NULL);
     if (!X509V3_???_print(out, extp->extension, 0, 0)) {
 	BIO_free(out);
-	ossl_raise(eX509ExtensionError, "");
+	ossl_raise(eX509ExtensionError, NULL);
     }
     BIO_get_mem_ptr(out, &buf);
     value = rb_str_new(buf->data, buf->length);
diff --git a/ossl_x509cert.c b/ossl_x509cert.c
index fe3c111..6b58c5c 100644
--- a/ossl_x509cert.c
+++ b/ossl_x509cert.c
@@ -48,7 +48,7 @@ ossl_x509_new(X509 *x509)
 	new = X509_dup(x509);
     }
     if (!new) {
-	ossl_raise(eX509CertError, "");
+	ossl_raise(eX509CertError, NULL);
     }
     WrapX509(cX509Cert, obj, new);
 	
@@ -79,7 +79,7 @@ ossl_x509_new_from_file(VALUE filename)
     */
     fclose(fp);
     if (!x509) {
-	ossl_raise(eX509CertError, "");
+	ossl_raise(eX509CertError, NULL);
     }
     WrapX509(cX509Cert, obj, x509);
 
@@ -118,7 +118,7 @@ ossl_x509_alloc(VALUE klass)
     VALUE obj;
 
     if (!(x509 = X509_new())) {
-	ossl_raise(eX509CertError, "");
+	ossl_raise(eX509CertError, NULL);
     }
     WrapX509(klass, obj, x509);
 
@@ -141,7 +141,7 @@ ossl_x509_initialize(int argc, VALUE *argv, VALUE self)
 	
     in = BIO_new_mem_buf(RSTRING(buffer)->ptr, RSTRING(buffer)->len);
     if (!in) {
-	ossl_raise(eX509CertError, "");
+	ossl_raise(eX509CertError, NULL);
     }
 
     /*
@@ -156,7 +156,7 @@ ossl_x509_initialize(int argc, VALUE *argv, VALUE self)
     }
     if (!x509) {
 	BIO_free(in);
-	ossl_raise(eX509CertError, "");
+	ossl_raise(eX509CertError, NULL);
     }
     BIO_free(in);
     
@@ -173,7 +173,7 @@ ossl_x509_copy(VALUE self, VALUE other)
     GetX509(self, a);
     SafeGetX509(other, b);
     if (!(x509 = X509_dup(b))) {
-	ossl_raise(eX509CertError, "");
+	ossl_raise(eX509CertError, NULL);
     }
     DATA_PTR(self) = x509;
     X509_free(a);
@@ -191,11 +191,11 @@ ossl_x509_to_der(VALUE self)
 
     GetX509(self, x509);
     if (!(out = BIO_new(BIO_s_mem()))) {
-	ossl_raise(eX509CertError, "");
+	ossl_raise(eX509CertError, NULL);
     }
     if (!i2d_X509_bio(out, x509)) {
 	BIO_free(out);
-	ossl_raise(eX509CertError, "");
+	ossl_raise(eX509CertError, NULL);
     }
     BIO_get_mem_ptr(out, &buf);
     str = rb_str_new(buf->data, buf->length);
@@ -214,11 +214,11 @@ ossl_x509_to_pem(VALUE self)
 	
     GetX509(self, x509);
     if (!(out = BIO_new(BIO_s_mem()))) {
-	ossl_raise(eX509CertError, "");
+	ossl_raise(eX509CertError, NULL);
     }
     if (!PEM_write_bio_X509(out, x509)) {
 	BIO_free(out);
-	ossl_raise(eX509CertError, "");
+	ossl_raise(eX509CertError, NULL);
     }
     BIO_get_mem_ptr(out, &buf);
     str = rb_str_new(buf->data, buf->length);
@@ -237,11 +237,11 @@ ossl_x509_to_text(VALUE self)
 	
     GetX509(self, x509);
     if (!(out = BIO_new(BIO_s_mem()))) {
-	ossl_raise(eX509CertError, "");
+	ossl_raise(eX509CertError, NULL);
     }
     if (!X509_print(out, x509)) {
 	BIO_free(out);
-	ossl_raise(eX509CertError, "");
+	ossl_raise(eX509CertError, NULL);
     }
     BIO_get_mem_ptr(out, &buf);
     str = rb_str_new(buf->data, buf->length);
@@ -263,7 +263,7 @@ ossl_x509_to_req(VALUE self)
 
     GetX509(self, x509);
     if (!(req = X509_to_X509_REQ(x509, NULL, EVP_md5()))) {
-	ossl_raise(eX509CertError, "");
+	ossl_raise(eX509CertError, NULL);
     }
     obj = ossl_x509req_new(req);
     X509_REQ_free(req);
@@ -293,7 +293,7 @@ ossl_x509_set_version(VALUE self, VALUE version)
 	ossl_raise(eX509CertError, "version must be >= 0!");
     }
     if (!X509_set_version(x509, ver)) {
-	ossl_raise(eX509CertError, "");
+	ossl_raise(eX509CertError, NULL);
     }
 
     return version;
@@ -333,11 +333,11 @@ ossl_x509_get_signature_algorithm(VALUE self)
     GetX509(self, x509);
 	
     if (!(out = BIO_new(BIO_s_mem()))) {
-	ossl_raise(eX509CertError, "");
+	ossl_raise(eX509CertError, NULL);
     }
     if (!i2a_ASN1_OBJECT(out, x509->cert_info->signature->algorithm)) {
 	BIO_free(out);
-	ossl_raise(eX509CertError, "");
+	ossl_raise(eX509CertError, NULL);
     }
     BIO_get_mem_ptr(out, &buf);
     str = rb_str_new(buf->data, buf->length);
@@ -353,7 +353,7 @@ ossl_x509_get_subject(VALUE self)
 	
     GetX509(self, x509);
     if (!(name = X509_get_subject_name(x509))) { /* NO DUP - don't free! */
-	ossl_raise(eX509CertError, "");
+	ossl_raise(eX509CertError, NULL);
     }
 
     return ossl_x509name_new(name);
@@ -366,7 +366,7 @@ ossl_x509_set_subject(VALUE self, VALUE subject)
 	
     GetX509(self, x509);
     if (!X509_set_subject_name(x509, GetX509NamePtr(subject))) { /* DUPs name */
-	ossl_raise(eX509CertError, "");
+	ossl_raise(eX509CertError, NULL);
     }
 
     return subject;
@@ -380,7 +380,7 @@ ossl_x509_get_issuer(VALUE self)
 
     GetX509(self, x509);
     if(!(name = X509_get_issuer_name(x509))) { /* NO DUP - don't free! */
-	ossl_raise(eX509CertError, "");
+	ossl_raise(eX509CertError, NULL);
     }
 
     return ossl_x509name_new(name);
@@ -393,7 +393,7 @@ ossl_x509_set_issuer(VALUE self, VALUE issuer)
 
     GetX509(self, x509);
     if (!X509_set_issuer_name(x509, GetX509NamePtr(issuer))) { /* DUPs name */
-	ossl_raise(eX509CertError, "");
+	ossl_raise(eX509CertError, NULL);
     }
 
     return issuer;
@@ -407,7 +407,7 @@ ossl_x509_get_not_before(VALUE self)
 
     GetX509(self, x509);
     if (!(asn1time = X509_get_notBefore(x509))) { /* NO DUP - don't free! */
-	ossl_raise(eX509CertError, "");
+	ossl_raise(eX509CertError, NULL);
     }
 
     return asn1time_to_time(asn1time);
@@ -422,7 +422,7 @@ ossl_x509_set_not_before(VALUE self, VALUE time)
     GetX509(self, x509);
     sec = time_to_time_t(time);
     if (!X509_time_adj(X509_get_notBefore(x509), 0, &sec)) {
-	ossl_raise(eX509CertError, "");
+	ossl_raise(eX509CertError, NULL);
     }
 
     return time;
@@ -436,7 +436,7 @@ ossl_x509_get_not_after(VALUE self)
 
     GetX509(self, x509);
     if (!(asn1time = X509_get_notAfter(x509))) { /* NO DUP - don't free! */
-	ossl_raise(eX509CertError, "");
+	ossl_raise(eX509CertError, NULL);
     }
 
     return asn1time_to_time(asn1time);
@@ -451,7 +451,7 @@ ossl_x509_set_not_after(VALUE self, VALUE time)
     GetX509(self, x509);
     sec = time_to_time_t(time);
     if (!X509_time_adj(X509_get_notAfter(x509), 0, &sec)) {
-	ossl_raise(eX509CertError, "");
+	ossl_raise(eX509CertError, NULL);
     }
 
     return time;
@@ -465,7 +465,7 @@ ossl_x509_get_public_key(VALUE self)
 
     GetX509(self, x509);
     if (!(pkey = X509_get_pubkey(x509))) { /* adds an reference */
-	ossl_raise(eX509CertError, "");
+	ossl_raise(eX509CertError, NULL);
     }
 
     return ossl_pkey_new(pkey); /* NO DUP - OK */
@@ -478,7 +478,7 @@ ossl_x509_set_public_key(VALUE self, VALUE key)
 
     GetX509(self, x509);
     if (!X509_set_pubkey(x509, GetPKeyPtr(key))) { /* DUPs pkey */
-	ossl_raise(eX509CertError, "");
+	ossl_raise(eX509CertError, NULL);
     }
 
     return key;
@@ -495,7 +495,7 @@ ossl_x509_sign(VALUE self, VALUE key, VALUE digest)
     pkey = GetPrivPKeyPtr(key); /* NO NEED TO DUP */
     md = GetDigestPtr(digest);
     if (!X509_sign(x509, pkey, md)) {
-	ossl_raise(eX509CertError, "");
+	ossl_raise(eX509CertError, NULL);
     }
 
     return self;
@@ -514,7 +514,7 @@ ossl_x509_verify(VALUE self, VALUE key)
     GetX509(self, x509);
     pkey = GetPKeyPtr(key); /* NO NEED TO DUP */
     if ((i = X509_verify(x509, pkey)) < 0) {
-	ossl_raise(eX509CertError, "");
+	ossl_raise(eX509CertError, NULL);
     } 
     if (i > 0) {
 	return Qtrue;
@@ -591,7 +591,7 @@ ossl_x509_set_extensions(VALUE self, VALUE ary)
 	
 	if (!X509_add_ext(x509, ext, -1)) { /* DUPs ext - FREE it */
 	    X509_EXTENSION_free(ext);
-	    ossl_raise(eX509CertError, "");
+	    ossl_raise(eX509CertError, NULL);
 	}
 	X509_EXTENSION_free(ext);
     }
@@ -609,7 +609,7 @@ ossl_x509_add_extension(VALUE self, VALUE extension)
     ext = DupX509ExtPtr(extension);
     if (!X509_add_ext(x509, ext, -1)) { /* DUPs ext - FREE it */
 	X509_EXTENSION_free(ext);
-	ossl_raise(eX509CertError, "");
+	ossl_raise(eX509CertError, NULL);
     }
     X509_EXTENSION_free(ext);
 
diff --git a/ossl_x509crl.c b/ossl_x509crl.c
index f1e3b74..89133f7 100644
--- a/ossl_x509crl.c
+++ b/ossl_x509crl.c
@@ -64,7 +64,7 @@ ossl_x509crl_new(X509_CRL *crl)
     VALUE obj;
 
     tmp = crl ? X509_CRL_dup(crl) : X509_CRL_new();
-    if(!tmp) ossl_raise(eX509CertError, "");
+    if(!tmp) ossl_raise(eX509CertError, NULL);
     WrapX509CRL(cX509CRL, obj, tmp);
         
     return obj;
@@ -80,7 +80,7 @@ ossl_x509crl_alloc(VALUE klass)
     VALUE obj;
 
     if (!(crl = X509_CRL_new())) {
-	ossl_raise(eX509CRLError, "");
+	ossl_raise(eX509CRLError, NULL);
     }
     WrapX509CRL(klass, obj, crl);
 
@@ -102,7 +102,7 @@ ossl_x509crl_initialize(int argc, VALUE *argv, VALUE self)
     
     in = BIO_new_mem_buf(RSTRING(buffer)->ptr, RSTRING(buffer)->len);
     if (!in) {
-	ossl_raise(eX509CRLError, "");
+	ossl_raise(eX509CRLError, NULL);
     }
     /*
      * TODO:
@@ -117,7 +117,7 @@ ossl_x509crl_initialize(int argc, VALUE *argv, VALUE self)
     }
     if (!crl) {
 	BIO_free(in);
-	ossl_raise(eX509CRLError, "");
+	ossl_raise(eX509CRLError, NULL);
     }
     BIO_free(in);
 
@@ -134,7 +134,7 @@ ossl_x509crl_copy(VALUE self, VALUE other)
     GetX509CRL(self, a);
     SafeGetX509CRL(other, b);
     if (!(crl = X509_CRL_dup(b))) {
-	ossl_raise(eX509CRLError, "");
+	ossl_raise(eX509CRLError, NULL);
     }
     X509_CRL_free(a);
     DATA_PTR(self) = crl;
@@ -166,7 +166,7 @@ ossl_x509crl_set_version(VALUE self, VALUE version)
 	ossl_raise(eX509CRLError, "version must be >= 0!");
     }
     if (!X509_CRL_set_version(crl, ver)) {
-	ossl_raise(eX509CRLError, "");
+	ossl_raise(eX509CRLError, NULL);
     }
 
     return version;
@@ -183,11 +183,11 @@ ossl_x509crl_get_signature_algorithm(VALUE self)
     GetX509CRL(self, crl);
 	
     if (!(out = BIO_new(BIO_s_mem()))) {
-	ossl_raise(eX509CertError, "");
+	ossl_raise(eX509CertError, NULL);
     }
     if (!i2a_ASN1_OBJECT(out, crl->sig_alg->algorithm)) {
 	BIO_free(out);
-	ossl_raise(eX509CertError, "");
+	ossl_raise(eX509CertError, NULL);
     }
     BIO_get_mem_ptr(out, &buf);
     str = rb_str_new(buf->data, buf->length);
@@ -213,7 +213,7 @@ ossl_x509crl_set_issuer(VALUE self, VALUE issuer)
     GetX509CRL(self, crl);
 
     if (!X509_CRL_set_issuer_name(crl, GetX509NamePtr(issuer))) { /* DUPs name */
-	ossl_raise(eX509CRLError, "");
+	ossl_raise(eX509CRLError, NULL);
     }
     return issuer;
 }
@@ -237,7 +237,7 @@ ossl_x509crl_set_last_update(VALUE self, VALUE time)
     GetX509CRL(self, crl);
     sec = time_to_time_t(time);
     if (!X509_time_adj(crl->crl->lastUpdate, 0, &sec)) {
-	ossl_raise(eX509CRLError, "");
+	ossl_raise(eX509CRLError, NULL);
     }
 
     return time;
@@ -263,7 +263,7 @@ ossl_x509crl_set_next_update(VALUE self, VALUE time)
     sec = time_to_time_t(time);
     /* This must be some thinko in OpenSSL */
     if (!(crl->crl->nextUpdate = X509_time_adj(crl->crl->nextUpdate, 0, &sec))){
-	ossl_raise(eX509CRLError, "");
+	ossl_raise(eX509CRLError, NULL);
     }
 
     return time;
@@ -312,7 +312,7 @@ ossl_x509crl_set_revoked(VALUE self, VALUE ary)
     for (i=0; i<RARRAY(ary)->len; i++) {
 	rev = ossl_x509revoked_get_X509_REVOKED(RARRAY(ary)->ptr[i]);
 	if (!X509_CRL_add0_revoked(crl, rev)) { /* NO DUP - don't free! */
-	    ossl_raise(eX509CRLError, "");
+	    ossl_raise(eX509CRLError, NULL);
 	}
     }
     X509_CRL_sort(crl);
@@ -329,7 +329,7 @@ ossl_x509crl_add_revoked(VALUE self, VALUE revoked)
     GetX509CRL(self, crl);
     rev = ossl_x509revoked_get_X509_REVOKED(revoked);
     if (!X509_CRL_add0_revoked(crl, rev)) { /* NO DUP - don't free! */
-	ossl_raise(eX509CRLError, "");
+	ossl_raise(eX509CRLError, NULL);
     }
     X509_CRL_sort(crl);
 
@@ -347,7 +347,7 @@ ossl_x509crl_sign(VALUE self, VALUE key, VALUE digest)
     pkey = GetPrivPKeyPtr(key); /* NO NEED TO DUP */
     md = GetDigestPtr(digest);
     if (!X509_CRL_sign(crl, pkey, md)) {
-	ossl_raise(eX509CRLError, "");
+	ossl_raise(eX509CRLError, NULL);
     }
 
     return self;
@@ -361,7 +361,7 @@ ossl_x509crl_verify(VALUE self, VALUE key)
 
     GetX509CRL(self, crl);
     if ((ret = X509_CRL_verify(crl, GetPKeyPtr(key))) < 0) {
-	ossl_raise(eX509CRLError, "");
+	ossl_raise(eX509CRLError, NULL);
     }
     if (ret == 1) {
 	return Qtrue;
@@ -380,11 +380,11 @@ ossl_x509crl_to_der(VALUE self)
 
     GetX509CRL(self, crl);
     if (!(out = BIO_new(BIO_s_mem()))) {
-	ossl_raise(eX509CRLError, "");
+	ossl_raise(eX509CRLError, NULL);
     }
     if (!i2d_X509_CRL_bio(out, crl)) {
 	BIO_free(out);
-	ossl_raise(eX509CRLError, "");
+	ossl_raise(eX509CRLError, NULL);
     }
     BIO_get_mem_ptr(out, &buf);
     str = rb_str_new(buf->data, buf->length);
@@ -403,11 +403,11 @@ ossl_x509crl_to_pem(VALUE self)
 
     GetX509CRL(self, crl);
     if (!(out = BIO_new(BIO_s_mem()))) {
-	ossl_raise(eX509CRLError, "");
+	ossl_raise(eX509CRLError, NULL);
     }
     if (!PEM_write_bio_X509_CRL(out, crl)) {
 	BIO_free(out);
-	ossl_raise(eX509CRLError, "");
+	ossl_raise(eX509CRLError, NULL);
     }
     BIO_get_mem_ptr(out, &buf);
     str = rb_str_new(buf->data, buf->length);
@@ -426,11 +426,11 @@ ossl_x509crl_to_text(VALUE self)
 
     GetX509CRL(self, crl);
     if (!(out = BIO_new(BIO_s_mem()))) {
-	ossl_raise(eX509CRLError, "");
+	ossl_raise(eX509CRLError, NULL);
     }
     if (!X509_CRL_print(out, crl)) {
 	BIO_free(out);
-	ossl_raise(eX509CRLError, "");
+	ossl_raise(eX509CRLError, NULL);
     }
     BIO_get_mem_ptr(out, &buf);
     str = rb_str_new(buf->data, buf->length);
@@ -487,7 +487,7 @@ ossl_x509crl_set_extensions(VALUE self, VALUE ary)
 	ext = DupX509ExtPtr(RARRAY(ary)->ptr[i]);
 	if(!X509_CRL_add_ext(crl, ext, -1)) { /* DUPs ext - FREE it */
 	    X509_EXTENSION_free(ext);
-	    ossl_raise(eX509CRLError, "");
+	    ossl_raise(eX509CRLError, NULL);
 	}
 	X509_EXTENSION_free(ext);
     }
@@ -505,7 +505,7 @@ ossl_x509crl_add_extension(VALUE self, VALUE extension)
     ext = DupX509ExtPtr(extension);
     if (!X509_CRL_add_ext(crl, ext, -1)) { /* DUPs ext - FREE it */
 	X509_EXTENSION_free(ext);
-	ossl_raise(eX509CRLError, "");
+	ossl_raise(eX509CRLError, NULL);
     }
     X509_EXTENSION_free(ext);
 
diff --git a/ossl_x509ext.c b/ossl_x509ext.c
index 1995f79..8b5f75e 100644
--- a/ossl_x509ext.c
+++ b/ossl_x509ext.c
@@ -58,7 +58,7 @@ ossl_x509ext_new(X509_EXTENSION *ext)
 	new = X509_EXTENSION_dup(ext);
     }
     if (!new) {
-	ossl_raise(eX509ExtError, "");
+	ossl_raise(eX509ExtError, NULL);
     }
     WrapX509Ext(cX509Ext, obj, new);
 	
@@ -82,7 +82,7 @@ DupX509ExtPtr(VALUE obj)
 
     SafeGetX509Ext(obj, ext);
     if (!(new = X509_EXTENSION_dup(ext))) {
-	ossl_raise(eX509ExtError, "");
+	ossl_raise(eX509ExtError, NULL);
     }
 
     return new;
@@ -214,7 +214,7 @@ ossl_x509extfactory_create_ext_from_array(VALUE self, VALUE ary)
     StringValue(item);
     if (!(nid = OBJ_ln2nid(RSTRING(item)->ptr))) {
 	if (!(nid = OBJ_sn2nid(RSTRING(item)->ptr))) {
-	    ossl_raise(eX509ExtError, "");
+	    ossl_raise(eX509ExtError, NULL);
 	}
     }
     /* data [1] */
@@ -233,7 +233,7 @@ ossl_x509extfactory_create_ext_from_array(VALUE self, VALUE ary)
     }
     if (!(ext = X509V3_EXT_conf_nid(NULL, ctx, nid, value))) {
 	OPENSSL_free(value);
-	ossl_raise(eX509ExtError, "");
+	ossl_raise(eX509ExtError, NULL);
     }
     OPENSSL_free(value);
     WrapX509Ext(cX509Ext, obj, ext);
@@ -275,7 +275,6 @@ ossl_x509ext_get_value(VALUE obj)
     X509_EXTENSION *ext;
     BIO *out;
     VALUE ret;
-    char *p;
     int status = 0;
 
     GetX509Ext(obj, ext);
diff --git a/ossl_x509name.c b/ossl_x509name.c
index eab3a5c..6be3253 100644
--- a/ossl_x509name.c
+++ b/ossl_x509name.c
@@ -49,7 +49,7 @@ ossl_x509name_new(X509_NAME *name)
 	new = X509_NAME_dup(name);
     }
     if (!new) {
-	ossl_raise(eX509NameError, "");
+	ossl_raise(eX509NameError, NULL);
     }
     WrapX509Name(cX509Name, obj, new);
     
@@ -76,7 +76,7 @@ ossl_x509name_alloc(VALUE klass)
     VALUE obj;
 	
     if (!(name = X509_NAME_new())) {
-	ossl_raise(eX509NameError, "");
+	ossl_raise(eX509NameError, NULL);
     }
     WrapX509Name(klass, obj, name);
 
@@ -109,7 +109,7 @@ ossl_x509name_initialize(int argc, VALUE *argv, VALUE self)
 	type = ASN1_PRINTABLE_type(RSTRING(value)->ptr, -1);
 	if (!X509_NAME_add_entry_by_txt(name, RSTRING(key)->ptr, type,
 			RSTRING(value)->ptr, RSTRING(value)->len, -1, 0)) {
-	    ossl_raise(eX509NameError, "");
+	    ossl_raise(eX509NameError, NULL);
 	}
     }
 
@@ -150,10 +150,10 @@ ossl_x509name_to_a(VALUE self)
     ary = rb_ary_new2(entries);
     for (i=0; i<entries; i++) {
 	if (!(entry = X509_NAME_get_entry(name, i))) {
-	    ossl_raise(eX509NameError, "");
+	    ossl_raise(eX509NameError, NULL);
 	}
 	if (!i2t_ASN1_OBJECT(long_name, sizeof(long_name), entry->object)) {
-	    ossl_raise(eX509NameError, "");
+	    ossl_raise(eX509NameError, NULL);
 	}
 	short_name = OBJ_nid2sn(OBJ_ln2nid(long_name));
 	
@@ -175,7 +175,7 @@ ossl_x509name_digest(VALUE self, VALUE digest)
     md = GetDigestPtr(digest);
     /* ALLOC! */
     if (!X509_NAME_digest(name, md, buf, &buf_len)) {
-	ossl_raise(eX509NameError, "");
+	ossl_raise(eX509NameError, NULL);
     }
     str = rb_str_new(buf, buf_len);
     OPENSSL_free(buf);
diff --git a/ossl_x509req.c b/ossl_x509req.c
index b1842ef..b24ba05 100644
--- a/ossl_x509req.c
+++ b/ossl_x509req.c
@@ -48,7 +48,7 @@ ossl_x509req_new(X509_REQ *req)
 	new = X509_REQ_dup(req);
     }
     if (!new) {
-	ossl_raise(eX509ReqError, "");
+	ossl_raise(eX509ReqError, NULL);
     }
     WrapX509Req(cX509Req, obj, new);
 
@@ -62,7 +62,7 @@ ossl_x509req_get_X509_REQ(VALUE obj)
 
     SafeGetX509Req(obj, req);
     if (!(new = X509_REQ_dup(req))) {
-	ossl_raise(eX509ReqError, "");
+	ossl_raise(eX509ReqError, NULL);
     }
 
     return new;
@@ -78,7 +78,7 @@ ossl_x509req_alloc(VALUE klass)
     VALUE obj;
 
     if (!(req = X509_REQ_new())) {
-	ossl_raise(eX509ReqError, "");
+	ossl_raise(eX509ReqError, NULL);
     }
     WrapX509Req(klass, obj, req);
 
@@ -100,7 +100,7 @@ ossl_x509req_initialize(int argc, VALUE *argv, VALUE self)
     
     in = BIO_new_mem_buf(RSTRING(buffer)->ptr, RSTRING(buffer)->len);
     if (!in) {
-	ossl_raise(eX509ReqError, "");
+	ossl_raise(eX509ReqError, NULL);
     }
     /*
      * TODO:
@@ -115,7 +115,7 @@ ossl_x509req_initialize(int argc, VALUE *argv, VALUE self)
     }
     if (!req) {
 	BIO_free(in);
-	ossl_raise(eX509ReqError, "");
+	ossl_raise(eX509ReqError, NULL);
     }
     BIO_free(in);
 
@@ -132,7 +132,7 @@ ossl_x509req_copy(VALUE self, VALUE other)
     GetX509Req(self, a);
     SafeGetX509Req(other, b);
     if (!(req = X509_REQ_dup(b))) {
-	ossl_raise(eX509ReqError, "");
+	ossl_raise(eX509ReqError, NULL);
     }
     X509_REQ_free(a);
     DATA_PTR(self) = req;
@@ -150,11 +150,11 @@ ossl_x509req_to_pem(VALUE self)
 	
     GetX509Req(self, req);
     if (!(out = BIO_new(BIO_s_mem()))) {
-	ossl_raise(eX509ReqError, "");
+	ossl_raise(eX509ReqError, NULL);
     }
     if (!PEM_write_bio_X509_REQ(out, req)) {
 	BIO_free(out);
-	ossl_raise(eX509ReqError, "");
+	ossl_raise(eX509ReqError, NULL);
     }
     BIO_get_mem_ptr(out, &buf);
     str = rb_str_new(buf->data, buf->length);
@@ -173,11 +173,11 @@ ossl_x509req_to_text(VALUE self)
 
     GetX509Req(self, req);
     if (!(out = BIO_new(BIO_s_mem()))) {
-	ossl_raise(eX509ReqError, "");
+	ossl_raise(eX509ReqError, NULL);
     }
     if (!X509_REQ_print(out, req)) {
 	BIO_free(out);
-	ossl_raise(eX509ReqError, "");
+	ossl_raise(eX509ReqError, NULL);
     }
     BIO_get_mem_ptr(out, &buf);
     str = rb_str_new(buf->data, buf->length);
@@ -199,7 +199,7 @@ ossl_x509req_to_x509(VALUE self, VALUE days, VALUE key)
     GetX509Req(self, req);
     ...
     if (!(x509 = X509_REQ_to_X509(req, d, pkey))) {
-	ossl_raise(eX509ReqError, "");
+	ossl_raise(eX509ReqError, NULL);
     }
 
     return ossl_x509_new(x509);
@@ -229,7 +229,7 @@ ossl_x509req_set_version(VALUE self, VALUE version)
 	ossl_raise(eX509ReqError, "version must be >= 0!");
     }
     if (!X509_REQ_set_version(req, ver)) {
-	ossl_raise(eX509ReqError, "");
+	ossl_raise(eX509ReqError, NULL);
     }
 
     return version;
@@ -243,7 +243,7 @@ ossl_x509req_get_subject(VALUE self)
 
     GetX509Req(self, req);
     if (!(name = X509_REQ_get_subject_name(req))) { /* NO DUP - don't free */
-	ossl_raise(eX509ReqError, "");
+	ossl_raise(eX509ReqError, NULL);
     }
 
     return ossl_x509name_new(name);
@@ -257,7 +257,7 @@ ossl_x509req_set_subject(VALUE self, VALUE subject)
     GetX509Req(self, req);
     /* DUPs name */
     if (!X509_REQ_set_subject_name(req, GetX509NamePtr(subject))) {
-	ossl_raise(eX509ReqError, "");
+	ossl_raise(eX509ReqError, NULL);
     }
 
     return subject;
@@ -271,7 +271,7 @@ ossl_x509req_get_public_key(VALUE self)
 
     GetX509Req(self, req);
     if (!(pkey = X509_REQ_get_pubkey(req))) { /* adds reference */
-	ossl_raise(eX509ReqError, "");
+	ossl_raise(eX509ReqError, NULL);
     }
 
     return ossl_pkey_new(pkey); /* NO DUP - OK */
@@ -286,7 +286,7 @@ ossl_x509req_set_public_key(VALUE self, VALUE key)
     GetX509Req(self, req);
     pkey = GetPKeyPtr(key); /* NO NEED TO DUP */
     if (!X509_REQ_set_pubkey(req, pkey)) {
-	ossl_raise(eX509ReqError, "");
+	ossl_raise(eX509ReqError, NULL);
     }
 
     return key;
@@ -303,7 +303,7 @@ ossl_x509req_sign(VALUE self, VALUE key, VALUE digest)
     pkey = GetPrivPKeyPtr(key); /* NO NEED TO DUP */
     md = GetDigestPtr(digest);
     if (!X509_REQ_sign(req, pkey, md)) {
-	ossl_raise(eX509ReqError, "");
+	ossl_raise(eX509ReqError, NULL);
     }
 
     return self;
@@ -322,7 +322,7 @@ ossl_x509req_verify(VALUE self, VALUE key)
     GetX509Req(self, req);
     pkey = GetPKeyPtr(key); /* NO NEED TO DUP */
     if ((i = X509_REQ_verify(req, pkey)) < 0) {
-	ossl_raise(eX509ReqError, "");
+	ossl_raise(eX509ReqError, NULL);
     }
     if (i > 0) {
 	return Qtrue;
@@ -374,7 +374,7 @@ ossl_x509req_set_attributes(VALUE self, VALUE ary)
 	item = RARRAY(ary)->ptr[i];
 	attr = ossl_x509attr_get_X509_ATTRIBUTE(item);
 	if (!X509_REQ_add1_attr(req, attr)) {
-	    ossl_raise(eX509ReqError, "");
+	    ossl_raise(eX509ReqError, NULL);
 	}
     }
     return ary;
@@ -387,7 +387,7 @@ ossl_x509req_add_attribute(VALUE self, VALUE attr)
 
     GetX509Req(self, req);
     if (!X509_REQ_add1_attr(req, ossl_x509attr_get_X509_ATTRIBUTE(attr))) {
-	ossl_raise(eX509ReqError, "");
+	ossl_raise(eX509ReqError, NULL);
     }
 
     return attr;
diff --git a/ossl_x509revoked.c b/ossl_x509revoked.c
index 39ff53d..e306521 100644
--- a/ossl_x509revoked.c
+++ b/ossl_x509revoked.c
@@ -48,7 +48,7 @@ ossl_x509revoked_new(X509_REVOKED *rev)
 	new = X509_REVOKED_dup(rev);
     }
     if (!new) {
-	ossl_raise(eX509RevError, "");
+	ossl_raise(eX509RevError, NULL);
     }
     WrapX509Rev(cX509Rev, obj, new);
 
@@ -62,7 +62,7 @@ ossl_x509revoked_get_X509_REVOKED(VALUE obj)
 
     SafeGetX509Rev(obj, rev);
     if (!(new = X509_REVOKED_dup(rev))) {
-	ossl_raise(eX509RevError, "");
+	ossl_raise(eX509RevError, NULL);
     }
 
     return new;
@@ -78,7 +78,7 @@ ossl_x509revoked_alloc(VALUE klass)
     VALUE obj;
 
     if (!(rev = X509_REVOKED_new())) {
-	ossl_raise(eX509RevError, "");
+	ossl_raise(eX509RevError, NULL);
     }
     WrapX509Rev(klass, obj, rev);
 
@@ -133,7 +133,7 @@ ossl_x509revoked_set_time(VALUE self, VALUE time)
     GetX509Rev(self, rev);
     sec = time_to_time_t(time);
     if (!X509_time_adj(rev->revocationDate, 0, &sec)) {
-	ossl_raise(eX509RevError, "");
+	ossl_raise(eX509RevError, NULL);
     }
 
     return time;
@@ -186,7 +186,7 @@ ossl_x509revoked_set_extensions(VALUE self, VALUE ary)
 	item = RARRAY(ary)->ptr[i];
 	ext = DupX509ExtPtr(item);
 	if(!X509_REVOKED_add_ext(rev, ext, -1)) {
-	    ossl_raise(eX509RevError, "");
+	    ossl_raise(eX509RevError, NULL);
 	}
     }
 
@@ -200,7 +200,7 @@ ossl_x509revoked_add_extension(VALUE self, VALUE ext)
     
     GetX509Rev(self, rev);
     if(!X509_REVOKED_add_ext(rev, DupX509ExtPtr(ext), -1)) {
-	ossl_raise(eX509RevError, "");
+	ossl_raise(eX509RevError, NULL);
     }
 
     return ext;
diff --git a/ossl_x509store.c b/ossl_x509store.c
index 02884a1..582c2e0 100644
--- a/ossl_x509store.c
+++ b/ossl_x509store.c
@@ -96,7 +96,7 @@ ossl_x509store_alloc(VALUE klass)
     VALUE obj;
 
     if((store = X509_STORE_new()) == NULL){
-        ossl_raise(eX509StoreError, "");
+        ossl_raise(eX509StoreError, NULL);
     }
     WrapX509Store(klass, obj, store);
 
@@ -182,9 +182,9 @@ ossl_x509store_add_file(VALUE self, VALUE file)
     }
     GetX509Store(self, store);
     lookup = X509_STORE_add_lookup(store, X509_LOOKUP_file());
-    if(lookup == NULL) ossl_raise(eX509StoreError, "");
+    if(lookup == NULL) ossl_raise(eX509StoreError, NULL);
     if(X509_LOOKUP_load_file(lookup, path, X509_FILETYPE_PEM) != 1){
-        ossl_raise(eX509StoreError, "");
+        ossl_raise(eX509StoreError, NULL);
     }
 
     return self;
@@ -203,9 +203,9 @@ ossl_x509store_add_path(VALUE self, VALUE dir)
     }
     GetX509Store(self, store);
     lookup = X509_STORE_add_lookup(store, X509_LOOKUP_hash_dir());
-    if(lookup == NULL) ossl_raise(eX509StoreError, "");
+    if(lookup == NULL) ossl_raise(eX509StoreError, NULL);
     if(X509_LOOKUP_add_dir(lookup, path, X509_FILETYPE_PEM) != 1){
-        ossl_raise(eX509StoreError, "");
+        ossl_raise(eX509StoreError, NULL);
     }
 
     return self;
@@ -275,8 +275,6 @@ ossl_x509stctx_new(X509_STORE_CTX *ctx)
 VALUE
 ossl_x509stctx_clear_ptr(VALUE obj)
 {
-    X509_STORE_CTX *ctx;
-
     OSSL_Check_Kind(obj, cX509StoreContext);
     RDATA(obj)->data = NULL;
 
@@ -293,7 +291,7 @@ ossl_x509stctx_alloc(VALUE klass)
     VALUE obj;
 
     if((ctx = X509_STORE_CTX_new()) == NULL){
-        ossl_raise(eX509StoreError, "");
+        ossl_raise(eX509StoreError, NULL);
     }
     WrapX509StCtx(klass, obj, ctx);
 
@@ -314,7 +312,7 @@ ossl_x509stctx_initialize(int argc, VALUE *argv, VALUE self)
     SafeGetX509Store(store, x509st);
     if(!NIL_P(cert)) x509 = GetX509CertPtr(cert);
     if(X509_STORE_CTX_init(ctx, x509st, x509, NULL) != 1){
-        ossl_raise(eX509StoreError, "");
+        ossl_raise(eX509StoreError, NULL);
     }
     rb_iv_set(self, "@verify_callback", rb_iv_get(store, "@verify_callback"));
     rb_iv_set(self, "@cert", cert);