1 files changed, 133 insertions, 17 deletions

diff --git a/src/lib/libcrypto/rsa/rsa_eay.c b/src/lib/libcrypto/rsa/rsa_eay.c
index 0eda816081..027b4dc754 100644
--- a/src/lib/libcrypto/rsa/rsa_eay.c
+++ b/src/lib/libcrypto/rsa/rsa_eay.c
@@ -61,7 +61,6 @@
 #include <openssl/bn.h>
 #include <openssl/rsa.h>
 #include <openssl/rand.h>
-#include <openssl/engine.h>
 
 #ifndef RSA_NULL
 
@@ -187,12 +186,65 @@ err:
         BN_clear_free(&ret);
         if (buf != NULL) 
                 {
-                memset(buf,0,num);
+                OPENSSL_cleanse(buf,num);
                 OPENSSL_free(buf);
                 }
         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;
+        }
+
+#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)
+
+static BN_BLINDING *setup_blinding(RSA *rsa, BN_CTX *ctx)
+        {
+        BIGNUM *A, *Ai;
+        BN_BLINDING *ret = NULL;
+
+        /* added in OpenSSL 0.9.6j and 0.9.7b */
+
+        /* 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 */
+
+        BN_CTX_start(ctx);
+        A = BN_CTX_get(ctx);
+        if ((RAND_status() == 0) && rsa->d != NULL && rsa->d->d != 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);
+                if (!BN_pseudo_rand_range(A,rsa->n)) goto err;
+                }
+        else
+                {
+                if (!BN_rand_range(A,rsa->n)) goto err;
+                }
+        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)
@@ -201,6 +253,8 @@ static int RSA_eay_private_encrypt(int flen, const unsigned char *from,
         int i,j,k,num=0,r= -1;
         unsigned char *buf=NULL;
         BN_CTX *ctx=NULL;
+        int local_blinding = 0;
+        BN_BLINDING *blinding = NULL;
 
         BN_init(&f);
         BN_init(&ret);
@@ -237,10 +291,39 @@ static int RSA_eay_private_encrypt(int flen, const unsigned char *from,
                 goto err;
                 }
 
-        if ((rsa->flags & RSA_FLAG_BLINDING) && (rsa->blinding == NULL))
-                RSA_blinding_on(rsa,ctx);
-        if (rsa->flags & RSA_FLAG_BLINDING)
-                if (!BN_BLINDING_convert(&f,rsa->blinding,ctx)) 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))
+                {
+                if (blinding == NULL)
+                        {
+                        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->flags & RSA_FLAG_EXT_PKEY) ||
                 ((rsa->p != NULL) &&
@@ -254,8 +337,8 @@ static int RSA_eay_private_encrypt(int flen, const unsigned char *from,
                 if (!rsa->meth->bn_mod_exp(&ret,&f,rsa->d,rsa->n,ctx,NULL)) goto err;
                 }
 
-        if (rsa->flags & RSA_FLAG_BLINDING)
-                if (!BN_BLINDING_invert(&ret,rsa->blinding,ctx)) goto err;
+        if (blinding)
+                if (!BN_BLINDING_invert(&ret, blinding, ctx)) goto err;
 
         /* put in leading 0 bytes if the number is less than the
          * length of the modulus */
@@ -269,9 +352,11 @@ err:
         if (ctx != NULL) BN_CTX_free(ctx);
         BN_clear_free(&ret);
         BN_clear_free(&f);
+        if (local_blinding)
+                BN_BLINDING_free(blinding);
         if (buf != NULL)
                 {
-                memset(buf,0,num);
+                OPENSSL_cleanse(buf,num);
                 OPENSSL_free(buf);
                 }
         return(r);
@@ -285,6 +370,8 @@ static int RSA_eay_private_decrypt(int flen, const unsigned char *from,
         unsigned char *p;
         unsigned char *buf=NULL;
         BN_CTX *ctx=NULL;
+        int local_blinding = 0;
+        BN_BLINDING *blinding = NULL;
 
         BN_init(&f);
         BN_init(&ret);
@@ -316,10 +403,39 @@ static int RSA_eay_private_decrypt(int flen, const unsigned char *from,
                 goto err;
                 }
 
-        if ((rsa->flags & RSA_FLAG_BLINDING) && (rsa->blinding == NULL))
-                RSA_blinding_on(rsa,ctx);
-        if (rsa->flags & RSA_FLAG_BLINDING)
-                if (!BN_BLINDING_convert(&f,rsa->blinding,ctx)) 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))
+                {
+                if (blinding == NULL)
+                        {
+                        RSAerr(RSA_F_RSA_EAY_PRIVATE_DECRYPT, 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;
 
         /* do the decrypt */
         if ( (rsa->flags & RSA_FLAG_EXT_PKEY) ||
@@ -335,8 +451,8 @@ static int RSA_eay_private_decrypt(int flen, const unsigned char *from,
                         goto err;
                 }
 
-        if (rsa->flags & RSA_FLAG_BLINDING)
-                if (!BN_BLINDING_invert(&ret,rsa->blinding,ctx)) goto err;
+        if (blinding)
+                if (!BN_BLINDING_invert(&ret, blinding, ctx)) goto err;
 
         p=buf;
         j=BN_bn2bin(&ret,p); /* j is only used with no-padding mode */
@@ -370,7 +486,7 @@ err:
         BN_clear_free(&ret);
         if (buf != NULL)
                 {
-                memset(buf,0,num);
+                OPENSSL_cleanse(buf,num);
                 OPENSSL_free(buf);
                 }
         return(r);
@@ -467,7 +583,7 @@ err:
         BN_clear_free(&ret);
         if (buf != NULL)
                 {
-                memset(buf,0,num);
+                OPENSSL_cleanse(buf,num);
                 OPENSSL_free(buf);
                 }
         return(r);