libaacs | branch: master | npzacs <npz...@gmail.com> | Thu Dec 30 16:07:17 2010 +0200| [1f6b5983412652f7f1d1dcc167069ca86b5560c3] | committer: npzacs
Splitted _aacs_sexp_key() from crypto_aacs_sign(). Added support for public keys. > http://git.videolan.org/gitweb.cgi/libaacs.git/?a=commit;h=1f6b5983412652f7f1d1dcc167069ca86b5560c3 --- src/libaacs/crypto.c | 80 +++++++++++++++++++++++++++++++++++--------------- 1 files changed, 56 insertions(+), 24 deletions(-) diff --git a/src/libaacs/crypto.c b/src/libaacs/crypto.c index ef3f1f2..e1324ee 100644 --- a/src/libaacs/crypto.c +++ b/src/libaacs/crypto.c @@ -167,39 +167,47 @@ void crypto_aesg3(const uint8_t *D, uint8_t *lsubk, uint8_t* rsubk, uint8_t *pk) goto error; \ } -void crypto_aacs_sign(const uint8_t *cert, const uint8_t *priv_key, - uint8_t *signature, - const uint8_t *nonce, const uint8_t *point) +/* + * build S-expressions + */ + +static gcry_error_t _aacs_sexp_key(gcry_sexp_t *p_sexp_key, + const uint8_t *q_x, const uint8_t *q_y, + const uint8_t *priv_key) { - gcry_mpi_t mpi_d, mpi_md; - gcry_sexp_t sexp_key = NULL, sexp_data = NULL, sexp_sig = NULL, sexp_r = NULL, sexp_s = NULL; - unsigned char Q[41], block[60], md[20], *r = NULL, *s = NULL; - gcry_error_t err; + gcry_mpi_t mpi_d = NULL; + unsigned char Q[41]; + char str_Q[sizeof(Q) * 2 + 1]; + gcry_error_t err; /* Assign MPI values for ECDSA parameters Q and d. * Values are: * Q.x = c[12]..c[31] * Q.y = c[32]..c[51] - * d = privk + * d = priv_key * * Note: The MPI values for Q are in the form "<format>||Q.x||Q.y". */ - memcpy(&Q[0], "\x04", 1); // format - memcpy(&Q[1], cert + 12, 20); // Q.x - memcpy(&Q[21], cert + 32, 20); // Q.y - gcry_mpi_scan(&mpi_d, GCRYMPI_FMT_USG, priv_key, 20, NULL); + memcpy(&Q[0], "\x04", 1); // format + memcpy(&Q[1], q_x, 20); // Q.x + memcpy(&Q[21], q_y, 20); // Q.y + if (priv_key) { + gcry_mpi_scan(&mpi_d, GCRYMPI_FMT_USG, priv_key, 20, NULL); + } /* Show the values of the MPIs Q.x, Q.y, and d when debugging */ if (GCRYPT_DEBUG) { gcry_mpi_t mpi_Q_x, mpi_Q_y; - gcry_mpi_scan(&mpi_Q_x, GCRYMPI_FMT_USG, cert + 12, 20, NULL); - gcry_mpi_scan(&mpi_Q_y, GCRYMPI_FMT_USG, cert + 32, 20, NULL); + gcry_mpi_scan(&mpi_Q_x, GCRYMPI_FMT_USG, q_x, 20, NULL); + gcry_mpi_scan(&mpi_Q_y, GCRYMPI_FMT_USG, q_y, 20, NULL); gcry_mpi_dump(mpi_Q_x); printf("\n"); gcry_mpi_dump(mpi_Q_y); printf("\n"); - gcry_mpi_dump(mpi_d); - printf("\n"); + if (mpi_d) { + gcry_mpi_dump(mpi_d); + printf("\n"); + } } /* Build the s-expression for the ecdsa private key @@ -217,11 +225,10 @@ void crypto_aacs_sign(const uint8_t *cert, const uint8_t *priv_key, /* Points are currently only supported in standard format, so get a * hexstring out of Q. */ - char str_Q[sizeof(Q)*2 + 1]; hex_array_to_hexstring(str_Q, Q, sizeof(Q)); char *strfmt = str_printf( - "(private-key" + "(%s" "(ecdsa" "(p #"AACS_EC_p"#)" "(a #"AACS_EC_a"#)" @@ -232,19 +239,46 @@ void crypto_aacs_sign(const uint8_t *cert, const uint8_t *priv_key, "#)" "(n #"AACS_EC_n"#)" "(q #%s#)" - "(d %%m)))", - str_Q + "%s))", + mpi_d ? "private-key" : "public-key", + str_Q, + mpi_d ? "(d %m)" : "" ); /* Now build the S-expression */ GCRY_VERIFY("gcry_sexp_build", - gcry_sexp_build(&sexp_key, NULL, strfmt, mpi_d)); + gcry_sexp_build(p_sexp_key, NULL, strfmt, mpi_d)); /* Dump information about the key s-expression when debugging */ if (GCRYPT_DEBUG) { - gcry_sexp_dump(sexp_key); + gcry_sexp_dump(*p_sexp_key); + } + +error: + X_FREE(strfmt); + + if (mpi_d) { + gcry_mpi_release(mpi_d); } + return err; +} + +/* + * + */ + +void crypto_aacs_sign(const uint8_t *cert, const uint8_t *priv_key, uint8_t *signature, + const uint8_t *nonce, const uint8_t *point) +{ + gcry_mpi_t mpi_md = NULL; + gcry_sexp_t sexp_key = NULL, sexp_data = NULL, sexp_sig = NULL, sexp_r = NULL, sexp_s = NULL; + unsigned char block[60], md[20], *r = NULL, *s = NULL; + gcry_error_t err; + + GCRY_VERIFY("_aacs_sexp_key", + _aacs_sexp_key(&sexp_key, cert + 12, cert + 32, priv_key)); + /* Calculate the sha1 hash from the nonce and host key point and covert * the hash into an MPI. */ @@ -307,7 +341,6 @@ void crypto_aacs_sign(const uint8_t *cert, const uint8_t *priv_key, error: /* Free allocated memory */ - gcry_mpi_release(mpi_d); gcry_mpi_release(mpi_md); gcry_sexp_release(sexp_key); gcry_sexp_release(sexp_data); @@ -316,7 +349,6 @@ void crypto_aacs_sign(const uint8_t *cert, const uint8_t *priv_key, gcry_sexp_release(sexp_s); gcry_free(r); gcry_free(s); - X_FREE(strfmt); } void crypto_aacs_title_hash(const uint8_t *ukf, uint64_t len, uint8_t *hash) _______________________________________________ libaacs-devel mailing list libaacs-devel@videolan.org http://mailman.videolan.org/listinfo/libaacs-devel
