more fixes; always perform DH, perform DH rekeying on a later run

diff --git a/d0_blind_id.c b/d0_blind_id.c
index aa38d4535246e421404298d5d01a99891b778606..bdf8023a7df946c224cfdc3a5d7eccd03e75fec8 100644 (file)
--- a/d0_blind_id.c
+++ b/d0_blind_id.c
@@ -66,6 +66,9 @@ struct d0_blind_id_s
 #define CHECK(x) do { if(!(x)) goto fail; } while(0)
 #define CHECK_ASSIGN(var, value) do { d0_bignum_t *val; val = value; if(!val) goto fail; var = val; } while(0)
 
+#define USING(x) if(!(ctx->x)) return 0
+#define REPLACING(x)
+
 static d0_bignum_t *zero, *one, *four, *temp0, *temp1, *temp2, *temp3, *temp4;
 
 void d0_blind_id_INITIALIZE(void)
@@ -205,6 +208,7 @@ void d0_blind_id_clear(d0_blind_id_t *ctx)
        if(ctx->rn) d0_bignum_free(ctx->rn);
        if(ctx->r) d0_bignum_free(ctx->r);
        if(ctx->e) d0_bignum_free(ctx->e);
+       if(ctx->other_4_to_r) d0_bignum_free(ctx->other_4_to_r);
        memset(ctx, 0, sizeof(*ctx));
 }
 
@@ -222,12 +226,15 @@ void d0_blind_id_copy(d0_blind_id_t *ctx, const d0_blind_id_t *src)
        if(src->r) ctx->r = d0_bignum_mov(NULL, src->r);
        if(src->e) ctx->e = d0_bignum_mov(NULL, src->e);
        if(src->other_4_to_r) ctx->other_4_to_r = d0_bignum_mov(NULL, src->other_4_to_r);
-       // TODO xnbh, msg, msglen?
+       memcpy(ctx->msg, src->msg, sizeof(ctx->msg));
+       ctx->msglen = src->msglen;
+       memcpy(ctx->xnbh, src->xnbh, sizeof(ctx->xnbh));
 }
 
 WARN_UNUSED_RESULT BOOL d0_blind_id_generate_private_key(d0_blind_id_t *ctx, int k)
 {
-       d0_blind_id_clear(ctx);
+       REPLACING(rsa_e); REPLACING(rsa_d); REPLACING(rsa_n);
+
        CHECK_ASSIGN(ctx->rsa_e, d0_bignum_int(ctx->rsa_e, 65537));
        CHECK_ASSIGN(ctx->rsa_d, d0_bignum_zero(ctx->rsa_d));
        CHECK_ASSIGN(ctx->rsa_n, d0_bignum_zero(ctx->rsa_n));
@@ -239,7 +246,12 @@ fail:
 
 WARN_UNUSED_RESULT BOOL d0_blind_id_read_private_key(d0_blind_id_t *ctx, const char *inbuf, size_t inbuflen)
 {
-       d0_iobuf_t *in = d0_iobuf_open_read(inbuf, inbuflen);
+       d0_iobuf_t *in = NULL;
+
+       REPLACING(rsa_n); REPLACING(rsa_e); REPLACING(rsa_d);
+
+       in = d0_iobuf_open_read(inbuf, inbuflen);
+
        CHECK_ASSIGN(ctx->rsa_n, d0_iobuf_read_bignum(in, ctx->rsa_n));
        CHECK_ASSIGN(ctx->rsa_e, d0_iobuf_read_bignum(in, ctx->rsa_e));
        CHECK_ASSIGN(ctx->rsa_d, d0_iobuf_read_bignum(in, ctx->rsa_d));
@@ -252,7 +264,11 @@ fail:
 
 WARN_UNUSED_RESULT BOOL d0_blind_id_read_public_key(d0_blind_id_t *ctx, const char *inbuf, size_t inbuflen)
 {
-       d0_iobuf_t *in = d0_iobuf_open_read(inbuf, inbuflen);
+       d0_iobuf_t *in = NULL;
+
+       REPLACING(rsa_n); REPLACING(rsa_e);
+
+       in = d0_iobuf_open_read(inbuf, inbuflen);
        CHECK_ASSIGN(ctx->rsa_n, d0_iobuf_read_bignum(in, ctx->rsa_n));
        CHECK_ASSIGN(ctx->rsa_e, d0_iobuf_read_bignum(in, ctx->rsa_e));
        return d0_iobuf_close(in, NULL);
@@ -262,9 +278,6 @@ fail:
        return 0;
 }
 
-#define USING(x) if(!(ctx->x)) return 0
-#define REPLACING(x)
-
 WARN_UNUSED_RESULT BOOL d0_blind_id_write_private_key(d0_blind_id_t *ctx, char *outbuf, size_t *outbuflen)
 {
        d0_iobuf_t *out = NULL;
@@ -313,7 +326,11 @@ fail:
 
 WARN_UNUSED_RESULT BOOL d0_blind_id_read_private_id_modulus(d0_blind_id_t *ctx, const char *inbuf, size_t inbuflen)
 {
-       d0_iobuf_t *in = d0_iobuf_open_read(inbuf, inbuflen);
+       d0_iobuf_t *in = NULL;
+
+       REPLACING(schnorr_G);
+
+       in = d0_iobuf_open_read(inbuf, inbuflen);
        CHECK_ASSIGN(ctx->schnorr_G, d0_iobuf_read_bignum(in, ctx->schnorr_G));
        return d0_iobuf_close(in, NULL);
 
@@ -339,7 +356,7 @@ fail:
 
 WARN_UNUSED_RESULT BOOL d0_blind_id_generate_private_id_start(d0_blind_id_t *ctx)
 {
-       // temps: temp0 order
+       // temps: temp0 = order
        USING(schnorr_G);
        REPLACING(schnorr_s); REPLACING(schnorr_4_to_s);
 
@@ -357,7 +374,7 @@ WARN_UNUSED_RESULT BOOL d0_blind_id_generate_private_id_request(d0_blind_id_t *c
 {
        d0_iobuf_t *out = NULL;
 
-       // temps: temp0 temp1
+       // temps: temp0 rn^e, temp1 (4^s)*rn^e
        USING(rsa_n); USING(rsa_e); USING(schnorr_4_to_s);
        REPLACING(rn);
 
@@ -379,7 +396,7 @@ WARN_UNUSED_RESULT BOOL d0_blind_id_answer_private_id_request(d0_blind_id_t *ctx
        d0_iobuf_t *in = NULL;
        d0_iobuf_t *out = NULL;
 
-       // temps: temp0 temp1
+       // temps: temp0 input, temp1 temp0^d
        USING(rsa_d); USING(rsa_n);
 
        in = d0_iobuf_open_read(inbuf, inbuflen);
@@ -402,7 +419,7 @@ WARN_UNUSED_RESULT BOOL d0_blind_id_finish_private_id_request(d0_blind_id_t *ctx
 {
        d0_iobuf_t *in = NULL;
 
-       // temps: temp0 temp1
+       // temps: temp0 input, temp1 rn^-1
        USING(rn); USING(rsa_n);
        REPLACING(schnorr_4_to_s_signature);
 
@@ -501,8 +518,9 @@ WARN_UNUSED_RESULT BOOL d0_blind_id_authenticate_with_private_id_start(d0_blind_
        d0_iobuf_t *out = NULL;
        static unsigned char convbuf[1024];
        d0_iobuf_t *conv = NULL;
-       size_t sz;
+       size_t sz = 0;
 
+       // temps: temp0 order, temp0 4^r
        if(is_first)
        {
                USING(schnorr_4_to_s); USING(schnorr_4_to_s_signature);
@@ -553,20 +571,22 @@ WARN_UNUSED_RESULT BOOL d0_blind_id_authenticate_with_private_id_challenge(d0_bl
        d0_iobuf_t *in = NULL;
        d0_iobuf_t *out = NULL;
 
+       // temps: temp0 order, temp0 signature check
        if(is_first)
        {
-               REPLACING(schnorr_4_to_s); REPLACING(k); REPLACING(schnorr_4_to_s_signature);
-               USING(rsa_n);
-               if(!recv_modulus)
+               REPLACING(schnorr_4_to_s); REPLACING(schnorr_4_to_s_signature);
+               if(recv_modulus)
+                       REPLACING(schnorr_G);
+               else
                        USING(schnorr_G);
        }
        else
        {
-               USING(schnorr_4_to_s_signature); USING(schnorr_4_to_s);
+               USING(schnorr_4_to_s); USING(schnorr_4_to_s_signature);
                USING(schnorr_G);
        }
        USING(rsa_e); USING(rsa_n);
-       REPLACING(e); REPLACING(msg); REPLACING(msglen);
+       REPLACING(e); REPLACING(msg); REPLACING(msglen); REPLACING(xnbh); REPLACING(r);
 
        in = d0_iobuf_open_read(inbuf, inbuflen);
        out = d0_iobuf_open_write(outbuf, *outbuflen);
@@ -604,14 +624,11 @@ WARN_UNUSED_RESULT BOOL d0_blind_id_authenticate_with_private_id_challenge(d0_bl
 
        CHECK(d0_iobuf_write_bignum(out, ctx->e));
 
-       if(is_first)
-       {
-               // Diffie Hellmann
-               CHECK(d0_dl_get_order(temp0, ctx->schnorr_G));
-               CHECK_ASSIGN(ctx->r, d0_bignum_rand_range(ctx->r, zero, temp0));
-               CHECK(d0_bignum_mod_pow(temp0, four, ctx->r, ctx->schnorr_G));
-               CHECK(d0_iobuf_write_bignum(out, temp0));
-       }
+       // Diffie Hellmann
+       CHECK(d0_dl_get_order(temp0, ctx->schnorr_G));
+       CHECK_ASSIGN(ctx->r, d0_bignum_rand_range(ctx->r, zero, temp0));
+       CHECK(d0_bignum_mod_pow(temp0, four, ctx->r, ctx->schnorr_G));
+       CHECK(d0_iobuf_write_bignum(out, temp0));
 
        if(status)
                *status = !!d0_bignum_cmp(ctx->schnorr_4_to_s_signature, zero);
@@ -625,7 +642,7 @@ fail:
        return 0;
 }
 
-WARN_UNUSED_RESULT BOOL d0_blind_id_authenticate_with_private_id_response(d0_blind_id_t *ctx, BOOL is_first, const char *inbuf, size_t inbuflen, char *outbuf, size_t *outbuflen)
+WARN_UNUSED_RESULT BOOL d0_blind_id_authenticate_with_private_id_response(d0_blind_id_t *ctx, const char *inbuf, size_t inbuflen, char *outbuf, size_t *outbuflen)
 //   1. read challenge e of SCHNORR_BITS
 //   2. reply with r + s * e mod order
 {
@@ -633,6 +650,7 @@ WARN_UNUSED_RESULT BOOL d0_blind_id_authenticate_with_private_id_response(d0_bli
        d0_iobuf_t *out = NULL;
 
        // temps: 0 order, 1 prod, 2 y, 3 e
+       REPLACING(other_4_to_r);
        USING(schnorr_G); USING(schnorr_s); USING(r);
 
        in = d0_iobuf_open_read(inbuf, inbuflen);
@@ -642,13 +660,10 @@ WARN_UNUSED_RESULT BOOL d0_blind_id_authenticate_with_private_id_response(d0_bli
        CHECK(d0_bignum_cmp(temp3, zero) >= 0);
        CHECK(d0_bignum_size(temp3) <= SCHNORR_BITS);
 
-       if(is_first)
-       {
-               // Diffie Hellmann
-               CHECK_ASSIGN(ctx->other_4_to_r, d0_iobuf_read_bignum(in, ctx->other_4_to_r));
-               CHECK(d0_bignum_cmp(ctx->other_4_to_r, zero) > 0);
-               CHECK(d0_bignum_cmp(ctx->other_4_to_r, ctx->schnorr_G) < 0);
-       }
+       // Diffie Hellmann
+       CHECK_ASSIGN(ctx->other_4_to_r, d0_iobuf_read_bignum(in, ctx->other_4_to_r));
+       CHECK(d0_bignum_cmp(ctx->other_4_to_r, zero) > 0);
+       CHECK(d0_bignum_cmp(ctx->other_4_to_r, ctx->schnorr_G) < 0);
 
        // send response for schnorr ID scheme
        // i.e. r + ctx->schnorr_s * temp3
@@ -678,6 +693,7 @@ WARN_UNUSED_RESULT BOOL d0_blind_id_authenticate_with_private_id_verify(d0_blind
 
        // temps: 0 y 1 order
        USING(e); USING(schnorr_G);
+       REPLACING(other_4_to_r);
 
        in = d0_iobuf_open_read(inbuf, inbuflen);
 
@@ -762,7 +778,7 @@ BOOL d0_blind_id_sessionkey_public_id(d0_blind_id_t *ctx, char *outbuf, size_t *
        d0_iobuf_t *conv = NULL;
        size_t n, sz;
 
-       USING(r); USING(other_4_to_r);
+       USING(r); USING(other_4_to_r); USING(schnorr_G);
 
        out = d0_iobuf_open_write(outbuf, *outbuflen);
        conv = d0_iobuf_open_write(convbuf, sizeof(convbuf));

diff --git a/d0_blind_id.h b/d0_blind_id.h
index e84d4b80e0944f7e0e53e3f309d2dd805be3573b..177682b0f1466615c5ccd7fa9086219e03b4405b 100644 (file)
--- a/d0_blind_id.h
+++ b/d0_blind_id.h
@@ -27,10 +27,10 @@ EXPORT WARN_UNUSED_RESULT BOOL d0_blind_id_write_private_id(d0_blind_id_t *ctx,
 EXPORT WARN_UNUSED_RESULT BOOL d0_blind_id_write_public_id(d0_blind_id_t *ctx, char *outbuf, size_t *outbuflen);
 EXPORT WARN_UNUSED_RESULT BOOL d0_blind_id_authenticate_with_private_id_start(d0_blind_id_t *ctx, BOOL is_first, BOOL send_modulus, char *message, size_t msglen, char *outbuf, size_t *outbuflen);
 EXPORT WARN_UNUSED_RESULT BOOL d0_blind_id_authenticate_with_private_id_challenge(d0_blind_id_t *ctx, BOOL is_first, BOOL recv_modulus, const char *inbuf, size_t inbuflen, char *outbuf, size_t *outbuflen, BOOL *status);
-EXPORT WARN_UNUSED_RESULT BOOL d0_blind_id_authenticate_with_private_id_response(d0_blind_id_t *ctx, BOOL is_first, const char *inbuf, size_t inbuflen, char *outbuf, size_t *outbuflen);
+EXPORT WARN_UNUSED_RESULT BOOL d0_blind_id_authenticate_with_private_id_response(d0_blind_id_t *ctx, const char *inbuf, size_t inbuflen, char *outbuf, size_t *outbuflen);
 EXPORT WARN_UNUSED_RESULT BOOL d0_blind_id_authenticate_with_private_id_verify(d0_blind_id_t *ctx, const char *inbuf, size_t inbuflen, char *msg, size_t *msglen, BOOL *status);
 EXPORT WARN_UNUSED_RESULT BOOL d0_blind_id_fingerprint64_public_id(d0_blind_id_t *ctx, char *outbuf, size_t *outbuflen);
-EXPORT WARN_UNUSED_RESULT BOOL d0_blind_id_sessionkey_public_id(d0_blind_id_t *ctx, char *outbuf, size_t *outbuflen); // can only be done after successful key exchange, this performs a modpow; key length is limited by SHA_DIGESTSIZE for now
+EXPORT WARN_UNUSED_RESULT BOOL d0_blind_id_sessionkey_public_id(d0_blind_id_t *ctx, char *outbuf, size_t *outbuflen); // can only be done after successful key exchange, this performs a modpow; key length is limited by SHA_DIGESTSIZE for now; also ONLY valid after successful d0_blind_id_authenticate_with_private_id_verify/d0_blind_id_fingerprint64_public_id
 
 EXPORT void d0_blind_id_INITIALIZE(void);
 EXPORT void d0_blind_id_SHUTDOWN(void);

diff --git a/main.c b/main.c
index 249e60471c51b0bebe2297be1a2496985a677c62..3c233e8e5a7fed2068b69ae882da1df082daeb06 100644 (file)
--- a/main.c
+++ b/main.c
@@ -117,7 +117,7 @@ int main(int argc, char **argv)
                buf2size = sizeof(buf2); if(!d0_blind_id_authenticate_with_private_id_challenge(ctx_self, 1, 1, buf, bufsize, buf2, &buf2size, NULL))
                        errx(10, "challenge fail");
                bench(&bench_resp);
-               bufsize = sizeof(buf); if(!d0_blind_id_authenticate_with_private_id_response(ctx_other, 1, buf2, buf2size, buf, &bufsize))
+               bufsize = sizeof(buf); if(!d0_blind_id_authenticate_with_private_id_response(ctx_other, buf2, buf2size, buf, &bufsize))
                        errx(11, "response fail");
                bench(&bench_verify);
                buf2size = sizeof(buf2); if(!d0_blind_id_authenticate_with_private_id_verify(ctx_self, buf, bufsize, buf2, &buf2size, &status))