Merge pull request #5518 from superna9999/5274-ecdsa-signing
PK: ECDSA signing
diff --git a/library/pk_wrap.c b/library/pk_wrap.c
index 215606d..92e9bf4 100644
--- a/library/pk_wrap.c
+++ b/library/pk_wrap.c
@@ -947,6 +947,206 @@
}
#endif /* MBEDTLS_USE_PSA_CRYPTO */
+#if defined(MBEDTLS_USE_PSA_CRYPTO)
+/*
+ * Simultaneously convert and move raw MPI from the beginning of a buffer
+ * to an ASN.1 MPI at the end of the buffer.
+ * See also mbedtls_asn1_write_mpi().
+ *
+ * p: pointer to the end of the output buffer
+ * start: start of the output buffer, and also of the mpi to write at the end
+ * n_len: length of the mpi to read from start
+ */
+static int asn1_write_mpibuf( unsigned char **p, unsigned char *start,
+ size_t n_len )
+{
+ int ret = MBEDTLS_ERR_ERROR_CORRUPTION_DETECTED;
+ size_t len = 0;
+
+ if( (size_t)( *p - start ) < n_len )
+ return( MBEDTLS_ERR_ASN1_BUF_TOO_SMALL );
+
+ len = n_len;
+ *p -= len;
+ memmove( *p, start, len );
+
+ /* ASN.1 DER encoding requires minimal length, so skip leading 0s.
+ * Neither r nor s should be 0, but as a failsafe measure, still detect
+ * that rather than overflowing the buffer in case of a PSA error. */
+ while( len > 0 && **p == 0x00 )
+ {
+ ++(*p);
+ --len;
+ }
+
+ /* this is only reached if the signature was invalid */
+ if( len == 0 )
+ return( MBEDTLS_ERR_PLATFORM_HW_ACCEL_FAILED );
+
+ /* if the msb is 1, ASN.1 requires that we prepend a 0.
+ * Neither r nor s can be 0, so we can assume len > 0 at all times. */
+ if( **p & 0x80 )
+ {
+ if( *p - start < 1 )
+ return( MBEDTLS_ERR_ASN1_BUF_TOO_SMALL );
+
+ *--(*p) = 0x00;
+ len += 1;
+ }
+
+ MBEDTLS_ASN1_CHK_ADD( len, mbedtls_asn1_write_len( p, start, len ) );
+ MBEDTLS_ASN1_CHK_ADD( len, mbedtls_asn1_write_tag( p, start,
+ MBEDTLS_ASN1_INTEGER ) );
+
+ return( (int) len );
+}
+
+/* Transcode signature from PSA format to ASN.1 sequence.
+ * See ecdsa_signature_to_asn1 in ecdsa.c, but with byte buffers instead of
+ * MPIs, and in-place.
+ *
+ * [in/out] sig: the signature pre- and post-transcoding
+ * [in/out] sig_len: signature length pre- and post-transcoding
+ * [int] buf_len: the available size the in/out buffer
+ */
+static int pk_ecdsa_sig_asn1_from_psa( unsigned char *sig, size_t *sig_len,
+ size_t buf_len )
+{
+ int ret = MBEDTLS_ERR_ERROR_CORRUPTION_DETECTED;
+ size_t len = 0;
+ const size_t rs_len = *sig_len / 2;
+ unsigned char *p = sig + buf_len;
+
+ MBEDTLS_ASN1_CHK_ADD( len, asn1_write_mpibuf( &p, sig + rs_len, rs_len ) );
+ MBEDTLS_ASN1_CHK_ADD( len, asn1_write_mpibuf( &p, sig, rs_len ) );
+
+ MBEDTLS_ASN1_CHK_ADD( len, mbedtls_asn1_write_len( &p, sig, len ) );
+ MBEDTLS_ASN1_CHK_ADD( len, mbedtls_asn1_write_tag( &p, sig,
+ MBEDTLS_ASN1_CONSTRUCTED | MBEDTLS_ASN1_SEQUENCE ) );
+
+ memmove( sig, p, len );
+ *sig_len = len;
+
+ return( 0 );
+}
+
+/* Locate an ECDSA privateKey in a RFC 5915, or SEC1 Appendix C.4 ASN.1 buffer
+ *
+ * [in/out] buf: ASN.1 buffer start as input - ECDSA privateKey start as output
+ * [in] end: ASN.1 buffer end
+ * [out] key_len: the ECDSA privateKey length in bytes
+ */
+static int find_ecdsa_private_key( unsigned char **buf, unsigned char *end,
+ size_t *key_len )
+{
+ size_t len;
+ int ret;
+
+ /*
+ * RFC 5915, or SEC1 Appendix C.4
+ *
+ * ECPrivateKey ::= SEQUENCE {
+ * version INTEGER { ecPrivkeyVer1(1) } (ecPrivkeyVer1),
+ * privateKey OCTET STRING,
+ * parameters [0] ECParameters {{ NamedCurve }} OPTIONAL,
+ * publicKey [1] BIT STRING OPTIONAL
+ * }
+ */
+
+ if( ( ret = mbedtls_asn1_get_tag( buf, end, &len,
+ MBEDTLS_ASN1_CONSTRUCTED |
+ MBEDTLS_ASN1_SEQUENCE ) ) != 0 )
+ return( ret );
+
+ /* version */
+ if( ( ret = mbedtls_asn1_get_tag( buf, end, &len,
+ MBEDTLS_ASN1_INTEGER ) ) != 0 )
+ return( ret );
+
+ *buf += len;
+
+ /* privateKey */
+ if( ( ret = mbedtls_asn1_get_tag( buf, end, &len,
+ MBEDTLS_ASN1_OCTET_STRING ) ) != 0 )
+ return( ret );
+
+ *key_len = len;
+
+ return 0;
+}
+
+static int ecdsa_sign_wrap( void *ctx_arg, mbedtls_md_type_t md_alg,
+ const unsigned char *hash, size_t hash_len,
+ unsigned char *sig, size_t sig_size, size_t *sig_len,
+ int (*f_rng)(void *, unsigned char *, size_t), void *p_rng )
+{
+ mbedtls_ecdsa_context *ctx = ctx_arg;
+ int ret = MBEDTLS_ERR_ERROR_CORRUPTION_DETECTED;
+ psa_key_attributes_t attributes = PSA_KEY_ATTRIBUTES_INIT;
+ mbedtls_svc_key_id_t key_id = MBEDTLS_SVC_KEY_ID_INIT;
+ psa_status_t status;
+ mbedtls_pk_context key;
+ size_t key_len;
+ unsigned char buf[MBEDTLS_PK_ECP_PRV_DER_MAX_BYTES];
+ unsigned char *p;
+ psa_algorithm_t psa_sig_md =
+ PSA_ALG_ECDSA( mbedtls_psa_translate_md( md_alg ) );
+ size_t curve_bits;
+ psa_ecc_family_t curve =
+ mbedtls_ecc_group_to_psa( ctx->grp.id, &curve_bits );
+
+ /* PSA has its own RNG */
+ ((void) f_rng);
+ ((void) p_rng);
+
+ if( curve == 0 )
+ return( MBEDTLS_ERR_PK_BAD_INPUT_DATA );
+
+ /* mbedtls_pk_write_key_der() expects a full PK context;
+ * re-construct one to make it happy */
+ key.pk_info = &mbedtls_eckey_info;
+ key.pk_ctx = ctx;
+ key_len = mbedtls_pk_write_key_der( &key, buf, sizeof( buf ) );
+ if( key_len <= 0 )
+ return( MBEDTLS_ERR_PK_BAD_INPUT_DATA );
+
+ p = buf + sizeof( buf ) - key_len;
+ ret = find_ecdsa_private_key( &p, buf + sizeof( buf ), &key_len );
+ if( ret != 0 )
+ goto cleanup;
+
+ psa_set_key_type( &attributes, PSA_KEY_TYPE_ECC_KEY_PAIR( curve ) );
+ psa_set_key_usage_flags( &attributes, PSA_KEY_USAGE_SIGN_HASH );
+ psa_set_key_algorithm( &attributes, psa_sig_md );
+
+ status = psa_import_key( &attributes,
+ p, key_len,
+ &key_id );
+ if( status != PSA_SUCCESS )
+ {
+ ret = mbedtls_pk_error_from_psa( status );
+ goto cleanup;
+ }
+
+ status = psa_sign_hash( key_id, psa_sig_md, hash, hash_len,
+ sig, sig_size, sig_len );
+ if( status != PSA_SUCCESS )
+ {
+ ret = mbedtls_pk_error_from_psa_ecdca( status );
+ goto cleanup;
+ }
+
+ ret = pk_ecdsa_sig_asn1_from_psa( sig, sig_len, sig_size );
+
+cleanup:
+ mbedtls_platform_zeroize( buf, sizeof( buf ) );
+ status = psa_destroy_key( key_id );
+ if( ret == 0 && status != PSA_SUCCESS )
+ ret = mbedtls_pk_error_from_psa( status );
+
+ return( ret );
+}
+#else
static int ecdsa_sign_wrap( void *ctx, mbedtls_md_type_t md_alg,
const unsigned char *hash, size_t hash_len,
unsigned char *sig, size_t sig_size, size_t *sig_len,
@@ -957,6 +1157,7 @@
sig, sig_size, sig_len,
f_rng, p_rng ) );
}
+#endif
#if defined(MBEDTLS_ECP_RESTARTABLE)
static int ecdsa_verify_rs_wrap( void *ctx, mbedtls_md_type_t md_alg,
@@ -1224,92 +1425,6 @@
type == MBEDTLS_PK_ECDSA );
}
-#if defined(MBEDTLS_ECDSA_C)
-
-/*
- * Simultaneously convert and move raw MPI from the beginning of a buffer
- * to an ASN.1 MPI at the end of the buffer.
- * See also mbedtls_asn1_write_mpi().
- *
- * p: pointer to the end of the output buffer
- * start: start of the output buffer, and also of the mpi to write at the end
- * n_len: length of the mpi to read from start
- */
-static int asn1_write_mpibuf( unsigned char **p, unsigned char *start,
- size_t n_len )
-{
- int ret = MBEDTLS_ERR_ERROR_CORRUPTION_DETECTED;
- size_t len = 0;
-
- if( (size_t)( *p - start ) < n_len )
- return( MBEDTLS_ERR_ASN1_BUF_TOO_SMALL );
-
- len = n_len;
- *p -= len;
- memmove( *p, start, len );
-
- /* ASN.1 DER encoding requires minimal length, so skip leading 0s.
- * Neither r nor s should be 0, but as a failsafe measure, still detect
- * that rather than overflowing the buffer in case of a PSA error. */
- while( len > 0 && **p == 0x00 )
- {
- ++(*p);
- --len;
- }
-
- /* this is only reached if the signature was invalid */
- if( len == 0 )
- return( MBEDTLS_ERR_PLATFORM_HW_ACCEL_FAILED );
-
- /* if the msb is 1, ASN.1 requires that we prepend a 0.
- * Neither r nor s can be 0, so we can assume len > 0 at all times. */
- if( **p & 0x80 )
- {
- if( *p - start < 1 )
- return( MBEDTLS_ERR_ASN1_BUF_TOO_SMALL );
-
- *--(*p) = 0x00;
- len += 1;
- }
-
- MBEDTLS_ASN1_CHK_ADD( len, mbedtls_asn1_write_len( p, start, len ) );
- MBEDTLS_ASN1_CHK_ADD( len, mbedtls_asn1_write_tag( p, start,
- MBEDTLS_ASN1_INTEGER ) );
-
- return( (int) len );
-}
-
-/* Transcode signature from PSA format to ASN.1 sequence.
- * See ecdsa_signature_to_asn1 in ecdsa.c, but with byte buffers instead of
- * MPIs, and in-place.
- *
- * [in/out] sig: the signature pre- and post-transcoding
- * [in/out] sig_len: signature length pre- and post-transcoding
- * [int] buf_len: the available size the in/out buffer
- */
-static int pk_ecdsa_sig_asn1_from_psa( unsigned char *sig, size_t *sig_len,
- size_t buf_len )
-{
- int ret = MBEDTLS_ERR_ERROR_CORRUPTION_DETECTED;
- size_t len = 0;
- const size_t rs_len = *sig_len / 2;
- unsigned char *p = sig + buf_len;
-
- MBEDTLS_ASN1_CHK_ADD( len, asn1_write_mpibuf( &p, sig + rs_len, rs_len ) );
- MBEDTLS_ASN1_CHK_ADD( len, asn1_write_mpibuf( &p, sig, rs_len ) );
-
- MBEDTLS_ASN1_CHK_ADD( len, mbedtls_asn1_write_len( &p, sig, len ) );
- MBEDTLS_ASN1_CHK_ADD( len, mbedtls_asn1_write_tag( &p, sig,
- MBEDTLS_ASN1_CONSTRUCTED | MBEDTLS_ASN1_SEQUENCE ) );
-
- memmove( sig, p, len );
- *sig_len = len;
-
- return( 0 );
-}
-
-#endif /* MBEDTLS_ECDSA_C */
-
static int pk_opaque_sign_wrap( void *ctx, mbedtls_md_type_t md_alg,
const unsigned char *hash, size_t hash_len,
unsigned char *sig, size_t sig_size, size_t *sig_len,
diff --git a/tests/suites/test_suite_x509write.function b/tests/suites/test_suite_x509write.function
index 1e88191..947fcc4 100644
--- a/tests/suites/test_suite_x509write.function
+++ b/tests/suites/test_suite_x509write.function
@@ -83,11 +83,14 @@
mbedtls_pk_context key;
mbedtls_x509write_csr req;
unsigned char buf[4096];
- unsigned char check_buf[4000];
int ret;
- size_t olen = 0, pem_len = 0, buf_index;
- int der_len = -1;
+#if !defined(MBEDTLS_USE_PSA_CRYPTO)
+ unsigned char check_buf[4000];
FILE *f;
+ size_t olen = 0;
+#endif /* !MBEDTLS_USE_PSA_CRYPTO */
+ size_t pem_len = 0, buf_index;
+ int der_len = -1;
const char *subject_name = "C=NL,O=PolarSSL,CN=PolarSSL Server 1";
mbedtls_test_rnd_pseudo_info rnd_info;
@@ -119,6 +122,12 @@
TEST_ASSERT( buf[buf_index] == 0 );
}
+#if defined(MBEDTLS_USE_PSA_CRYPTO)
+ // When using PSA crypto, RNG isn't controllable, so cert_req_check_file can't be used
+ (void)cert_req_check_file;
+ buf[pem_len] = '\0';
+ TEST_ASSERT( x509_crt_verifycsr( buf, pem_len + 1 ) == 0 );
+#else
f = fopen( cert_req_check_file, "r" );
TEST_ASSERT( f != NULL );
olen = fread( check_buf, 1, sizeof( check_buf ), f );
@@ -126,6 +135,7 @@
TEST_ASSERT( olen >= pem_len - 1 );
TEST_ASSERT( memcmp( buf, check_buf, pem_len - 1 ) == 0 );
+#endif /* MBEDTLS_USE_PSA_CRYPTO */
der_len = mbedtls_x509write_csr_der( &req, buf, sizeof( buf ),
mbedtls_test_rnd_pseudo_rand,
@@ -135,7 +145,15 @@
if( der_len == 0 )
goto exit;
- ret = mbedtls_x509write_csr_der( &req, buf, (size_t)( der_len - 1 ),
+#if defined(MBEDTLS_USE_PSA_CRYPTO)
+ // When using PSA crypto, RNG isn't controllable, result length isn't
+ // deterministic over multiple runs, removing a single byte isn't enough to
+ // go into the MBEDTLS_ERR_ASN1_BUF_TOO_SMALL error case
+ der_len /= 2;
+#else
+ der_len -= 1;
+#endif
+ ret = mbedtls_x509write_csr_der( &req, buf, (size_t)( der_len ),
mbedtls_test_rnd_pseudo_rand, &rnd_info );
TEST_ASSERT( ret == MBEDTLS_ERR_ASN1_BUF_TOO_SMALL );