Address PR review comments
1) update ChangLog to have new feature in Features instead of Changes
2) Change MBEDTLS_ECDSA_ALT to function specific alternative definitions:
MBEDTLS_ECDSA_SIGN_ALT, MBEDTLS_ECDSA_VERIFY_ALT and MBEDTLS_ECDSA_GENKEY_ALT
diff --git a/ChangeLog b/ChangeLog
index 94eba42..040632c 100644
--- a/ChangeLog
+++ b/ChangeLog
@@ -36,10 +36,13 @@
* Clarify ECDSA documentation and improve the sample code to avoid
misunderstandings and potentially dangerous use of the API. Pointed out
by Jean-Philippe Aumasson.
- * Add support for alternative implementation for ECDSA, controlled by new
- configuration flag MBEDTLS_ECDSA_ALT in config.h.
+
+Features
+ * Add support for alternative implementations for ECDSA, controlled by new
+ configuration flags MBEDTLS_ECDSA_SIGN_ALT, MBEDTLS_ECDSA_VERIFY_ALT and
+ MBEDTLS_ECDSDA_GENKEY_AT in config.h.
The following functions from the ECDSA module can be replaced
- with an alternative implementation:
+ with alternative implementation:
mbedtls_ecdsa_sign(), mbedtls_ecdsa_verify() and mbedtls_ecdsa_genkey().
= mbed TLS 2.5.0 branch released 2017-05-17
diff --git a/include/mbedtls/config.h b/include/mbedtls/config.h
index 54dc237..7c06ec4 100644
--- a/include/mbedtls/config.h
+++ b/include/mbedtls/config.h
@@ -238,7 +238,6 @@
//#define MBEDTLS_BLOWFISH_ALT
//#define MBEDTLS_CAMELLIA_ALT
//#define MBEDTLS_DES_ALT
-//#define MBEDTLS_ECDSA_ALT
//#define MBEDTLS_XTEA_ALT
//#define MBEDTLS_MD2_ALT
//#define MBEDTLS_MD4_ALT
@@ -295,6 +294,9 @@
//#define MBEDTLS_AES_SETKEY_DEC_ALT
//#define MBEDTLS_AES_ENCRYPT_ALT
//#define MBEDTLS_AES_DECRYPT_ALT
+//#define MBEDTLS_ECDSA_VERIFY_ALT
+//#define MBEDTLS_ECDSA_SIGN_ALT
+//#define MBEDTLS_ECDSA_GENKEY_ALT
/**
* \def MBEDTLS_ECP_INTERNAL_ALT
diff --git a/library/ecdsa.c b/library/ecdsa.c
index 804884b..a241072 100644
--- a/library/ecdsa.c
+++ b/library/ecdsa.c
@@ -65,8 +65,7 @@
return( ret );
}
-#if !defined(MBEDTLS_ECDSA_ALT)
-
+#if !defined(MBEDTLS_ECDSA_SIGN_ALT)
/*
* Compute ECDSA signature of a hashed message (SEC1 4.1.3)
* Obviously, compared to SEC1 4.1.3, we skip step 4 (hash message)
@@ -155,8 +154,47 @@
return( ret );
}
+#endif /* MBEDTLS_ECDSA_SIGN_ALT */
+#if defined(MBEDTLS_ECDSA_DETERMINISTIC)
+/*
+ * Deterministic signature wrapper
+ */
+int mbedtls_ecdsa_sign_det( mbedtls_ecp_group *grp, mbedtls_mpi *r, mbedtls_mpi *s,
+ const mbedtls_mpi *d, const unsigned char *buf, size_t blen,
+ mbedtls_md_type_t md_alg )
+{
+ int ret;
+ mbedtls_hmac_drbg_context rng_ctx;
+ unsigned char data[2 * MBEDTLS_ECP_MAX_BYTES];
+ size_t grp_len = ( grp->nbits + 7 ) / 8;
+ const mbedtls_md_info_t *md_info;
+ mbedtls_mpi h;
+ if( ( md_info = mbedtls_md_info_from_type( md_alg ) ) == NULL )
+ return( MBEDTLS_ERR_ECP_BAD_INPUT_DATA );
+
+ mbedtls_mpi_init( &h );
+ mbedtls_hmac_drbg_init( &rng_ctx );
+
+ /* Use private key and message hash (reduced) to initialize HMAC_DRBG */
+ MBEDTLS_MPI_CHK( mbedtls_mpi_write_binary( d, data, grp_len ) );
+ MBEDTLS_MPI_CHK( derive_mpi( grp, &h, buf, blen ) );
+ MBEDTLS_MPI_CHK( mbedtls_mpi_write_binary( &h, data + grp_len, grp_len ) );
+ mbedtls_hmac_drbg_seed_buf( &rng_ctx, md_info, data, 2 * grp_len );
+
+ ret = mbedtls_ecdsa_sign( grp, r, s, d, buf, blen,
+ mbedtls_hmac_drbg_random, &rng_ctx );
+
+cleanup:
+ mbedtls_hmac_drbg_free( &rng_ctx );
+ mbedtls_mpi_free( &h );
+
+ return( ret );
+}
+#endif /* MBEDTLS_ECDSA_DETERMINISTIC */
+
+#if !defined(MBEDTLS_ECDSA_VERIFY_ALT)
/*
* Verify ECDSA signature of hashed message (SEC1 4.1.4)
* Obviously, compared to SEC1 4.1.3, we skip step 2 (hash message)
@@ -242,56 +280,7 @@
return( ret );
}
-
-/*
- * Generate key pair
- */
-int mbedtls_ecdsa_genkey( mbedtls_ecdsa_context *ctx, mbedtls_ecp_group_id gid,
- int (*f_rng)(void *, unsigned char *, size_t), void *p_rng )
-{
- return( mbedtls_ecp_group_load( &ctx->grp, gid ) ||
- mbedtls_ecp_gen_keypair( &ctx->grp, &ctx->d, &ctx->Q, f_rng, p_rng ) );
-}
-
-#endif /* MBEDTLS_ECDSA_ALT */
-
-#if defined(MBEDTLS_ECDSA_DETERMINISTIC)
-/*
- * Deterministic signature wrapper
- */
-int mbedtls_ecdsa_sign_det( mbedtls_ecp_group *grp, mbedtls_mpi *r, mbedtls_mpi *s,
- const mbedtls_mpi *d, const unsigned char *buf, size_t blen,
- mbedtls_md_type_t md_alg )
-{
- int ret;
- mbedtls_hmac_drbg_context rng_ctx;
- unsigned char data[2 * MBEDTLS_ECP_MAX_BYTES];
- size_t grp_len = ( grp->nbits + 7 ) / 8;
- const mbedtls_md_info_t *md_info;
- mbedtls_mpi h;
-
- if( ( md_info = mbedtls_md_info_from_type( md_alg ) ) == NULL )
- return( MBEDTLS_ERR_ECP_BAD_INPUT_DATA );
-
- mbedtls_mpi_init( &h );
- mbedtls_hmac_drbg_init( &rng_ctx );
-
- /* Use private key and message hash (reduced) to initialize HMAC_DRBG */
- MBEDTLS_MPI_CHK( mbedtls_mpi_write_binary( d, data, grp_len ) );
- MBEDTLS_MPI_CHK( derive_mpi( grp, &h, buf, blen ) );
- MBEDTLS_MPI_CHK( mbedtls_mpi_write_binary( &h, data + grp_len, grp_len ) );
- mbedtls_hmac_drbg_seed_buf( &rng_ctx, md_info, data, 2 * grp_len );
-
- ret = mbedtls_ecdsa_sign( grp, r, s, d, buf, blen,
- mbedtls_hmac_drbg_random, &rng_ctx );
-
-cleanup:
- mbedtls_hmac_drbg_free( &rng_ctx );
- mbedtls_mpi_free( &h );
-
- return( ret );
-}
-#endif /* MBEDTLS_ECDSA_DETERMINISTIC */
+#endif /* MBEDTLS_ECDSA_VERIFY_ALT */
/*
* Convert a signature (given by context) to ASN.1
@@ -417,6 +406,18 @@
return( ret );
}
+#if !defined(MBEDTLS_ECDSA_GENKEY_ALT)
+/*
+ * Generate key pair
+ */
+int mbedtls_ecdsa_genkey( mbedtls_ecdsa_context *ctx, mbedtls_ecp_group_id gid,
+ int (*f_rng)(void *, unsigned char *, size_t), void *p_rng )
+{
+ return( mbedtls_ecp_group_load( &ctx->grp, gid ) ||
+ mbedtls_ecp_gen_keypair( &ctx->grp, &ctx->d, &ctx->Q, f_rng, p_rng ) );
+}
+#endif /* MBEDTLS_ECDSA_GENKEY_ALT */
+
/*
* Set context from an mbedtls_ecp_keypair
*/
diff --git a/library/version_features.c b/library/version_features.c
index df7f957..2629098 100644
--- a/library/version_features.c
+++ b/library/version_features.c
@@ -93,9 +93,6 @@
#if defined(MBEDTLS_DES_ALT)
"MBEDTLS_DES_ALT",
#endif /* MBEDTLS_DES_ALT */
-#if defined(MBEDTLS_ECDSA_ALT)
- "MBEDTLS_ECDSA_ALT",
-#endif /* MBEDTLS_ECDSA_ALT */
#if defined(MBEDTLS_XTEA_ALT)
"MBEDTLS_XTEA_ALT",
#endif /* MBEDTLS_XTEA_ALT */
@@ -165,6 +162,15 @@
#if defined(MBEDTLS_AES_DECRYPT_ALT)
"MBEDTLS_AES_DECRYPT_ALT",
#endif /* MBEDTLS_AES_DECRYPT_ALT */
+#if defined(MBEDTLS_ECDSA_VERIFY_ALT)
+ "MBEDTLS_ECDSA_VERIFY_ALT",
+#endif /* MBEDTLS_ECDSA_VERIFY_ALT */
+#if defined(MBEDTLS_ECDSA_SIGN_ALT)
+ "MBEDTLS_ECDSA_SIGN_ALT",
+#endif /* MBEDTLS_ECDSA_SIGN_ALT */
+#if defined(MBEDTLS_ECDSA_GENKEY_ALT)
+ "MBEDTLS_ECDSA_GENKEY_ALT",
+#endif /* MBEDTLS_ECDSA_GENKEY_ALT */
#if defined(MBEDTLS_ECP_INTERNAL_ALT)
"MBEDTLS_ECP_INTERNAL_ALT",
#endif /* MBEDTLS_ECP_INTERNAL_ALT */
