some updates for the blinding code; summary:

- possibility of re-creation of the blinding parameters after a
  fixed number of uses (suggested by Bodo)
- calculatition of the rsa::e in case it's absent and p and q
  are present (see bug report #785)
- improve the performance when if one rsa structure is shared by
  more than a thread (see bug report #555)
- fix the problem described in bug report #827
- hide the definition ot the BN_BLINDING structure in bn_blind.c

4 files changed, 160 insertions, 137 deletions

diff --git a/crypto/rsa/rsa.h b/crypto/rsa/rsa.h
index 4bfd51a4bb..4e28bbc39c 100644
--- a/crypto/rsa/rsa.h
+++ b/crypto/rsa/rsa.h
@@ -156,6 +156,7 @@ struct rsa_st
 	 * NULL */
 	char *bignum_data;
 	BN_BLINDING *blinding;
+	BN_BLINDING *mt_blinding;
 	};
 
 #define RSA_3	0x3L
@@ -279,6 +280,7 @@ int RSA_verify_ASN1_OCTET_STRING(int type,
 
 int RSA_blinding_on(RSA *rsa, BN_CTX *ctx);
 void RSA_blinding_off(RSA *rsa);
+BN_BLINDING *RSA_setup_blinding(RSA *rsa, BN_CTX *ctx);
 
 int RSA_padding_add_PKCS1_type_1(unsigned char *to,int tlen,
 	const unsigned char *f,int fl);
@@ -341,6 +343,7 @@ void ERR_load_RSA_strings(void);
 #define RSA_F_RSA_PADDING_CHECK_SSLV23			 114
 #define RSA_F_RSA_PRINT					 115
 #define RSA_F_RSA_PRINT_FP				 116
+#define RSA_F_RSA_SETUP_BLINDING			 125
 #define RSA_F_RSA_SIGN					 117
 #define RSA_F_RSA_SIGN_ASN1_OCTET_STRING		 118
 #define RSA_F_RSA_VERIFY				 119
@@ -367,6 +370,7 @@ void ERR_load_RSA_strings(void);
 #define RSA_R_INVALID_MESSAGE_LENGTH			 131
 #define RSA_R_IQMP_NOT_INVERSE_OF_Q			 126
 #define RSA_R_KEY_SIZE_TOO_SMALL			 120
+#define RSA_R_NO_PUBLIC_EXPONENT			 133
 #define RSA_R_NULL_BEFORE_BLOCK_MISSING			 113
 #define RSA_R_N_DOES_NOT_EQUAL_P_Q			 127
 #define RSA_R_OAEP_DECODING_ERROR			 121
diff --git a/crypto/rsa/rsa_eay.c b/crypto/rsa/rsa_eay.c
index 3ee753ec86..6bf681f1f9 100644
--- a/crypto/rsa/rsa_eay.c
+++ b/crypto/rsa/rsa_eay.c
@@ -212,64 +212,78 @@ err:
 	return(r);
 	}
 
-static int rsa_eay_blinding(RSA *rsa, BN_CTX *ctx)
-	{
-	int ret = 1;
-	CRYPTO_w_lock(CRYPTO_LOCK_RSA);
-	/* Check again inside the lock - the macro's check is racey */
-	if(rsa->blinding == NULL)
-		ret = RSA_blinding_on(rsa, ctx);
-	CRYPTO_w_unlock(CRYPTO_LOCK_RSA);
-	return ret;
-	}
+static BN_BLINDING *rsa_get_blinding(RSA *rsa, BIGNUM **r, int *local, BN_CTX *ctx)
+{
+	BN_BLINDING *ret;
 
-#define BLINDING_HELPER(rsa, ctx, err_instr) \
-	do { \
-		if((!((rsa)->flags & RSA_FLAG_NO_BLINDING)) && \
-		    ((rsa)->blinding == NULL) && \
-		    !rsa_eay_blinding(rsa, ctx)) \
-			err_instr \
-	} while(0)
+	if (rsa->blinding == NULL)
+		{
+		if (rsa->blinding == NULL)
+			{
+			CRYPTO_w_lock(CRYPTO_LOCK_RSA);
+			if (rsa->blinding == NULL)
+				rsa->blinding = RSA_setup_blinding(rsa, ctx);
+			CRYPTO_w_unlock(CRYPTO_LOCK_RSA);
+			}
+		}
 
-static BN_BLINDING *setup_blinding(RSA *rsa, BN_CTX *ctx)
-	{
-	BIGNUM *A, *Ai;
-	BN_BLINDING *ret = NULL;
+	ret = rsa->blinding;
+	if (ret == NULL)
+		return NULL;
 
-	/* added in OpenSSL 0.9.6j and 0.9.7b */
+	if (BN_BLINDING_get_thread_id(ret) != CRYPTO_thread_id())
+		{
+		*local = 0;
+		if (rsa->mt_blinding == NULL)
+			{
+			CRYPTO_w_lock(CRYPTO_LOCK_RSA);
+			if (rsa->mt_blinding == NULL)
+				rsa->mt_blinding = RSA_setup_blinding(rsa, ctx);
+			CRYPTO_w_unlock(CRYPTO_LOCK_RSA);
+			}
+		ret = rsa->mt_blinding;
+		}
+	else
+		*local = 1;
 
-	/* NB: similar code appears in RSA_blinding_on (rsa_lib.c);
-	 * this should be placed in a new function of its own, but for reasons
-	 * of binary compatibility can't */
+	return ret;
+}
 
-	BN_CTX_start(ctx);
-	A = BN_CTX_get(ctx);
-	if ((RAND_status() == 0) && rsa->d != NULL && rsa->d->d != NULL)
+static int rsa_blinding_convert(BN_BLINDING *b, int local, BIGNUM *f,
+	BIGNUM *r, BN_CTX *ctx)
+{
+	if (local)
+		return BN_BLINDING_convert_ex(f, NULL, b, ctx);
+	else
 		{
-		/* if PRNG is not properly seeded, resort to secret exponent as unpredictable seed */
-		RAND_add(rsa->d->d, rsa->d->dmax * sizeof rsa->d->d[0], 0.0);
-		if (!BN_pseudo_rand_range(A,rsa->n)) goto err;
-		}
+		int ret;
+		CRYPTO_w_lock(CRYPTO_LOCK_RSA_BLINDING);
+		ret = BN_BLINDING_convert_ex(f, r, b, ctx);
+		CRYPTO_w_unlock(CRYPTO_LOCK_RSA_BLINDING);
+		return ret;
+		}
+}
+
+static int rsa_blinding_invert(BN_BLINDING *b, int local, BIGNUM *f,
+	BIGNUM *r, BN_CTX *ctx)
+{
+	if (local)
+		return BN_BLINDING_invert_ex(f, NULL, b, ctx);
 	else
 		{
-		if (!BN_rand_range(A,rsa->n)) goto err;
+		int ret;
+		CRYPTO_r_lock(CRYPTO_LOCK_RSA_BLINDING);
+		ret = BN_BLINDING_invert_ex(f, r, b, ctx);
+		CRYPTO_r_unlock(CRYPTO_LOCK_RSA_BLINDING);
+		return ret;
 		}
-	if ((Ai=BN_mod_inverse(NULL,A,rsa->n,ctx)) == NULL) goto err;
-
-	if (!rsa->meth->bn_mod_exp(A,A,rsa->e,rsa->n,ctx,rsa->_method_mod_n))
-		goto err;
-	ret = BN_BLINDING_new(A,Ai,rsa->n);
-	BN_free(Ai);
-err:
-	BN_CTX_end(ctx);
-	return ret;
-	}
+}
 
 /* signing */
 static int RSA_eay_private_encrypt(int flen, const unsigned char *from,
 	     unsigned char *to, RSA *rsa, int padding)
 	{
-	BIGNUM *f,*ret;
+	BIGNUM *f, *ret, *br;
 	int i,j,k,num=0,r= -1;
 	unsigned char *buf=NULL;
 	BN_CTX *ctx=NULL;
@@ -278,9 +292,10 @@ static int RSA_eay_private_encrypt(int flen, const unsigned char *from,
 
 	if ((ctx=BN_CTX_new()) == NULL) goto err;
 	BN_CTX_start(ctx);
-	f = BN_CTX_get(ctx);
+	f   = BN_CTX_get(ctx);
+	br  = BN_CTX_get(ctx);
 	ret = BN_CTX_get(ctx);
-	num=BN_num_bytes(rsa->n);
+	num = BN_num_bytes(rsa->n);
 	buf = OPENSSL_malloc(num);
 	if(!f || !ret || !buf)
 		{
@@ -312,17 +327,9 @@ static int RSA_eay_private_encrypt(int flen, const unsigned char *from,
 		goto err;
 		}
 
-	BLINDING_HELPER(rsa, ctx, goto err;);
-	blinding = rsa->blinding;
-	
-	/* Now unless blinding is disabled, 'blinding' is non-NULL.
-	 * But the BN_BLINDING object may be owned by some other thread
-	 * (we don't want to keep it constant and we don't want to use
-	 * lots of locking to avoid race conditions, so only a single
-	 * thread can use it; other threads have to use local blinding
-	 * factors) */
 	if (!(rsa->flags & RSA_FLAG_NO_BLINDING))
 		{
+		blinding = rsa_get_blinding(rsa, &br, &local_blinding, ctx);
 		if (blinding == NULL)
 			{
 			RSAerr(RSA_F_RSA_EAY_PRIVATE_ENCRYPT, ERR_R_INTERNAL_ERROR);
@@ -331,20 +338,8 @@ static int RSA_eay_private_encrypt(int flen, const unsigned char *from,
 		}
 	
 	if (blinding != NULL)
-		{
-		if (blinding->thread_id != CRYPTO_thread_id())
-			{
-			/* we need a local one-time blinding factor */
-
-			blinding = setup_blinding(rsa, ctx);
-			if (blinding == NULL)
-				goto err;
-			local_blinding = 1;
-			}
-		}
-
-	if (blinding)
-		if (!BN_BLINDING_convert(f, blinding, ctx)) goto err;
+		if (!rsa_blinding_convert(blinding, local_blinding, f, br, ctx))
+			goto err;
 
 	if ( (rsa->flags & RSA_FLAG_EXT_PKEY) ||
 		((rsa->p != NULL) &&
@@ -361,7 +356,8 @@ static int RSA_eay_private_encrypt(int flen, const unsigned char *from,
 		}
 
 	if (blinding)
-		if (!BN_BLINDING_invert(ret, blinding, ctx)) goto err;
+		if (!rsa_blinding_invert(blinding, local_blinding, ret, br, ctx))
+			goto err;
 
 	/* put in leading 0 bytes if the number is less than the
 	 * length of the modulus */
@@ -377,8 +373,6 @@ err:
 		BN_CTX_end(ctx);
 		BN_CTX_free(ctx);
 		}
-	if (local_blinding)
-		BN_BLINDING_free(blinding);
 	if (buf != NULL)
 		{
 		OPENSSL_cleanse(buf,num);
@@ -390,7 +384,7 @@ err:
 static int RSA_eay_private_decrypt(int flen, const unsigned char *from,
 	     unsigned char *to, RSA *rsa, int padding)
 	{
-	BIGNUM *f,*ret;
+	BIGNUM *f, *ret, *br;
 	int j,num=0,r= -1;
 	unsigned char *p;
 	unsigned char *buf=NULL;
@@ -400,9 +394,10 @@ static int RSA_eay_private_decrypt(int flen, const unsigned char *from,
 
 	if((ctx = BN_CTX_new()) == NULL) goto err;
 	BN_CTX_start(ctx);
-	f = BN_CTX_get(ctx);
+	f   = BN_CTX_get(ctx);
+	br  = BN_CTX_get(ctx);
 	ret = BN_CTX_get(ctx);
-	num=BN_num_bytes(rsa->n);
+	num = BN_num_bytes(rsa->n);
 	buf = OPENSSL_malloc(num);
 	if(!f || !ret || !buf)
 		{
@@ -427,39 +422,19 @@ static int RSA_eay_private_decrypt(int flen, const unsigned char *from,
 		goto err;
 		}
 
-	BLINDING_HELPER(rsa, ctx, goto err;);
-	blinding = rsa->blinding;
-	
-	/* Now unless blinding is disabled, 'blinding' is non-NULL.
-	 * But the BN_BLINDING object may be owned by some other thread
-	 * (we don't want to keep it constant and we don't want to use
-	 * lots of locking to avoid race conditions, so only a single
-	 * thread can use it; other threads have to use local blinding
-	 * factors) */
 	if (!(rsa->flags & RSA_FLAG_NO_BLINDING))
 		{
+		blinding = rsa_get_blinding(rsa, &br, &local_blinding, ctx);
 		if (blinding == NULL)
 			{
-			RSAerr(RSA_F_RSA_EAY_PRIVATE_DECRYPT, ERR_R_INTERNAL_ERROR);
+			RSAerr(RSA_F_RSA_EAY_PRIVATE_ENCRYPT, ERR_R_INTERNAL_ERROR);
 			goto err;
 			}
 		}
 	
 	if (blinding != NULL)
-		{
-		if (blinding->thread_id != CRYPTO_thread_id())
-			{
-			/* we need a local one-time blinding factor */
-
-			blinding = setup_blinding(rsa, ctx);
-			if (blinding == NULL)
-				goto err;
-			local_blinding = 1;
-			}
-		}
-
-	if (blinding)
-		if (!BN_BLINDING_convert(f, blinding, ctx)) goto err;
+		if (!rsa_blinding_convert(blinding, local_blinding, f, br, ctx))
+			goto err;
 
 	/* do the decrypt */
 	if ( (rsa->flags & RSA_FLAG_EXT_PKEY) ||
@@ -478,7 +453,8 @@ static int RSA_eay_private_decrypt(int flen, const unsigned char *from,
 		}
 
 	if (blinding)
-		if (!BN_BLINDING_invert(ret, blinding, ctx)) goto err;
+		if (!rsa_blinding_invert(blinding, local_blinding, ret, br, ctx))
+			goto err;
 
 	p=buf;
 	j=BN_bn2bin(ret,p); /* j is only used with no-padding mode */
@@ -512,8 +488,6 @@ err:
 		BN_CTX_end(ctx);
 		BN_CTX_free(ctx);
 		}
-	if (local_blinding)
-		BN_BLINDING_free(blinding);
 	if (buf != NULL)
 		{
 		OPENSSL_cleanse(buf,num);
diff --git a/crypto/rsa/rsa_err.c b/crypto/rsa/rsa_err.c
index 07ef9df0cd..6641e61c7f 100644
--- a/crypto/rsa/rsa_err.c
+++ b/crypto/rsa/rsa_err.c
@@ -91,6 +91,7 @@ static ERR_STRING_DATA RSA_str_functs[]=
 {ERR_FUNC(RSA_F_RSA_PADDING_CHECK_SSLV23),	"RSA_padding_check_SSLv23"},
 {ERR_FUNC(RSA_F_RSA_PRINT),	"RSA_print"},
 {ERR_FUNC(RSA_F_RSA_PRINT_FP),	"RSA_print_fp"},
+{ERR_FUNC(RSA_F_RSA_SETUP_BLINDING),	"RSA_setup_blinding"},
 {ERR_FUNC(RSA_F_RSA_SIGN),	"RSA_sign"},
 {ERR_FUNC(RSA_F_RSA_SIGN_ASN1_OCTET_STRING),	"RSA_sign_ASN1_OCTET_STRING"},
 {ERR_FUNC(RSA_F_RSA_VERIFY),	"RSA_verify"},
@@ -120,6 +121,7 @@ static ERR_STRING_DATA RSA_str_reasons[]=
 {ERR_REASON(RSA_R_INVALID_MESSAGE_LENGTH),"invalid message length"},
 {ERR_REASON(RSA_R_IQMP_NOT_INVERSE_OF_Q) ,"iqmp not inverse of q"},
 {ERR_REASON(RSA_R_KEY_SIZE_TOO_SMALL)    ,"key size too small"},
+{ERR_REASON(RSA_R_NO_PUBLIC_EXPONENT)    ,"no public exponent"},
 {ERR_REASON(RSA_R_NULL_BEFORE_BLOCK_MISSING),"null before block missing"},
 {ERR_REASON(RSA_R_N_DOES_NOT_EQUAL_P_Q)  ,"n does not equal p q"},
 {ERR_REASON(RSA_R_OAEP_DECODING_ERROR)   ,"oaep decoding error"},
diff --git a/crypto/rsa/rsa_lib.c b/crypto/rsa/rsa_lib.c
index cba2dd66cd..0447fd5c70 100644
--- a/crypto/rsa/rsa_lib.c
+++ b/crypto/rsa/rsa_lib.c
@@ -179,6 +179,7 @@ RSA *RSA_new_method(ENGINE *engine)
 	ret->_method_mod_p=NULL;
 	ret->_method_mod_q=NULL;
 	ret->blinding=NULL;
+	ret->mt_blinding=NULL;
 	ret->bignum_data=NULL;
 	ret->flags=ret->meth->flags;
 	CRYPTO_new_ex_data(CRYPTO_EX_INDEX_RSA, ret, &ret->ex_data);
@@ -232,6 +233,7 @@ void RSA_free(RSA *r)
 	if (r->dmq1 != NULL) BN_clear_free(r->dmq1);
 	if (r->iqmp != NULL) BN_clear_free(r->iqmp);
 	if (r->blinding != NULL) BN_BLINDING_free(r->blinding);
+	if (r->mt_blinding != NULL) BN_BLINDING_free(r->mt_blinding);
 	if (r->bignum_data != NULL) OPENSSL_free_locked(r->bignum_data);
 	OPENSSL_free(r);
 	}
@@ -314,59 +316,100 @@ void RSA_blinding_off(RSA *rsa)
 	rsa->flags |= RSA_FLAG_NO_BLINDING;
 	}
 
-int RSA_blinding_on(RSA *rsa, BN_CTX *p_ctx)
+int RSA_blinding_on(RSA *rsa, BN_CTX *ctx)
 	{
-	BIGNUM *A,*Ai = NULL;
-	BN_CTX *ctx;
 	int ret=0;
 
-	if (p_ctx == NULL)
+	if (rsa->blinding != NULL)
+		RSA_blinding_off(rsa);
+
+	rsa->blinding = RSA_setup_blinding(rsa, ctx);
+	if (rsa->blinding == NULL)
+		goto err;
+
+	rsa->flags |= RSA_FLAG_BLINDING;
+	rsa->flags &= ~RSA_FLAG_NO_BLINDING;
+	ret=1;
+err:
+	return(ret);
+	}
+
+static BIGNUM *rsa_get_public_exp(const BIGNUM *d, const BIGNUM *p,
+	const BIGNUM *q, BN_CTX *ctx)
+{
+	BIGNUM *ret = NULL, *r0, *r1, *r2;
+
+	if (d == NULL || p == NULL || q == NULL)
+		return NULL;
+
+	BN_CTX_start(ctx);
+	r0 = BN_CTX_get(ctx);
+	r1 = BN_CTX_get(ctx);
+	r2 = BN_CTX_get(ctx);
+	if (r2 == NULL)
+		goto err;
+
+	if (!BN_sub(r1, p, BN_value_one())) goto err;
+	if (!BN_sub(r2, q, BN_value_one())) goto err;
+	if (!BN_mul(r0, r1, r2, ctx)) goto err;
+
+	ret = BN_mod_inverse(NULL, d, r0, ctx);
+err:
+	BN_CTX_end(ctx);
+	return ret;
+}
+
+BN_BLINDING *RSA_setup_blinding(RSA *rsa, BN_CTX *in_ctx)
+{
+	BIGNUM *e;
+	BN_CTX *ctx;
+	BN_BLINDING *ret = NULL;
+
+	if (in_ctx == NULL)
 		{
-		if ((ctx=BN_CTX_new()) == NULL) goto err;
+		if ((ctx = BN_CTX_new()) == NULL) return 0;
 		}
 	else
-		ctx=p_ctx;
+		ctx = in_ctx;
 
-	/* XXXXX: Shouldn't this be RSA_blinding_off(rsa)? */
-	if (rsa->blinding != NULL)
+	BN_CTX_start(ctx);
+	e  = BN_CTX_get(ctx);
+	if (e == NULL)
 		{
-		BN_BLINDING_free(rsa->blinding);
-		rsa->blinding = NULL;
+		RSAerr(RSA_F_RSA_SETUP_BLINDING, ERR_R_MALLOC_FAILURE);
+		goto err;
 		}
 
-	/* NB: similar code appears in setup_blinding (rsa_eay.c);
-	 * this should be placed in a new function of its own, but for reasons
-	 * of binary compatibility can't */
-
-	BN_CTX_start(ctx);
-	A = BN_CTX_get(ctx);
-	if ((RAND_status() == 0) && rsa->d != NULL && rsa->d->d != NULL)
+	if (rsa->e == NULL)
 		{
-		/* if PRNG is not properly seeded, resort to secret exponent as unpredictable seed */
-		RAND_add(rsa->d->d, rsa->d->dmax * sizeof rsa->d->d[0], 0.0);
-		if (!BN_pseudo_rand_range(A,rsa->n)) goto err;
+		e = rsa_get_public_exp(rsa->d, rsa->p, rsa->q, ctx);
+		if (e == NULL)
+			{
+			RSAerr(RSA_F_RSA_SETUP_BLINDING, RSA_R_NO_PUBLIC_EXPONENT);
+			goto err;
+			}
 		}
 	else
+		e = rsa->e;
+
+	
+	if ((RAND_status() == 0) && rsa->d != NULL && rsa->d->d != NULL)
 		{
-		if (!BN_rand_range(A,rsa->n)) goto err;
+		/* if PRNG is not properly seeded, resort to secret
+		 * exponent as unpredictable seed */
+		RAND_add(rsa->d->d, rsa->d->dmax * sizeof rsa->d->d[0], 0.0);
 		}
-	if ((Ai=BN_mod_inverse(NULL,A,rsa->n,ctx)) == NULL) goto err;
 
-	if (!rsa->meth->bn_mod_exp(A,A,rsa->e,rsa->n,ctx,rsa->_method_mod_n))
-		goto err;
-	if ((rsa->blinding=BN_BLINDING_new(A,Ai,rsa->n)) == NULL) goto err;
-	/* to make things thread-safe without excessive locking,
-	 * rsa->blinding will be used just by the current thread: */
-	rsa->blinding->thread_id = CRYPTO_thread_id();
-	rsa->flags |= RSA_FLAG_BLINDING;
-	rsa->flags &= ~RSA_FLAG_NO_BLINDING;
-	ret=1;
+	ret = BN_BLINDING_create_param(NULL, e, rsa->n, ctx,
+			rsa->meth->bn_mod_exp, rsa->_method_mod_n);
+	BN_BLINDING_set_thread_id(ret, CRYPTO_thread_id());
 err:
-	if (Ai != NULL) BN_free(Ai);
 	BN_CTX_end(ctx);
-	if (ctx != p_ctx) BN_CTX_free(ctx);
-	return(ret);
-	}
+	if (in_ctx == NULL)
+		BN_CTX_free(ctx);
+
+	return ret;
+}
 
 int RSA_memory_lock(RSA *r)
 	{