From f02c1a61968e9a9280128a8771dd80fa89c797ef Mon Sep 17 00:00:00 2001 From: Rudolf Polzer Date: Sun, 25 Apr 2010 16:24:55 +0200 Subject: [PATCH] more fixes; always perform DH, perform DH rekeying on a later run --- d0_blind_id.c | 86 ++++++++++++++++++++++++++++++--------------------- d0_blind_id.h | 4 +-- main.c | 2 +- 3 files changed, 54 insertions(+), 38 deletions(-) diff --git a/d0_blind_id.c b/d0_blind_id.c index aa38d45..bdf8023 100644 --- 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 e84d4b8..177682b 100644 --- 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 249e604..3c233e8 100644 --- 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)) -- 2.39.2