diff --git a/ChangeLog.d/ecp_write_key.txt b/ChangeLog.d/ecp_write_key.txt
new file mode 100644
index 000000000..73354c863
--- /dev/null
+++ b/ChangeLog.d/ecp_write_key.txt
@@ -0,0 +1,8 @@
+Features
+ * The new function mbedtls_ecp_write_key_ext() is similar to
+ mbedtls_ecp_write_key(), but can be used without separately calculating
+ the output length.
+
+New deprecations
+ * mbedtls_ecp_write_key() is deprecated in favor of
+ mbedtls_ecp_write_key_ext().
diff --git a/docs/psa-transition.md b/docs/psa-transition.md
index e89128cbd..94b57eba9 100644
--- a/docs/psa-transition.md
+++ b/docs/psa-transition.md
@@ -845,7 +845,6 @@ For an ECC private key (a future version of Mbed TLS [will provide a more direct
```
unsigned char buf[PSA_BITS_TO_BYTES(PSA_VENDOR_ECC_MAX_CURVE_BITS)];
-size_t length = PSA_BITS_TO_BYTES(mbedtls_pk_bitlen(&pk));
mbedtls_ecp_keypair *ec = mbedtls_pk_ec(&pk);
psa_ecc_curve_t curve;
{
@@ -862,7 +861,8 @@ psa_ecc_curve_t curve;
mbedtls_ecp_point_free(&Q);
mbedtls_mpi_free(&d);
}
-mbedtls_ecp_write_key(ec, buf, length);
+size_t length;
+mbedtls_ecp_write_key_ext(ec, &length, buf, sizeof(buf));
psa_key_attributes_t attributes = PSA_KEY_ATTRIBUTES_INIT;
psa_set_key_type(&attributes, PSA_KEY_TYPE_ECC_KEY_PAIR(curve));
psa_set_key_usage_flags(&attributes, PSA_KEY_USAGE_... | ...);
@@ -900,8 +900,8 @@ mbedtls_ecp_keypair_init(&ec);
// Omitted: fill ec with key material
// (the public key will not be used and does not need to be set)
unsigned char buf[PSA_BITS_TO_BYTES(PSA_VENDOR_ECC_MAX_CURVE_BITS)];
-size_t length = PSA_BITS_TO_BYTES(mbedtls_pk_bitlen(&pk));
-mbedtls_ecp_write_key(&ec, buf, length);
+size_t length;
+mbedtls_ecp_write_key_ext(&ec, &length, buf, sizeof(buf));
psa_ecc_curve_t curve = ...; // need to determine the curve family manually
psa_key_attributes_t attributes = PSA_KEY_ATTRIBUTES_INIT;
psa_set_key_attributes(&attributes, PSA_KEY_TYPE_ECC_KEY_PAIR(curve));
@@ -1300,7 +1300,7 @@ There is no PSA equivalent to the types `mbedtls_ecdsa_context` and `mbedtls_ecd
The PSA API is a cryptography API, not an arithmetic API. As a consequence, there is no PSA equivalent for the ECC arithmetic functionality exposed by `ecp.h`:
* Manipulation of point objects and input-output: the type `mbedtls_ecp_point` and functions operating on it (`mbedtls_ecp_point_xxx`, `mbedtls_ecp_copy`, `mbedtls_ecp_{set,is}_zero`, `mbedtls_ecp_tls_{read,write}_point`). Note that the PSA export format for public keys corresponds to the uncompressed point format (`MBEDTLS_ECP_PF_UNCOMPRESSED`), so [`psa_import_key`](https://mbed-tls.readthedocs.io/projects/api/en/development/api/group/group__import__export/#group__import__export_1ga0336ea76bf30587ab204a8296462327b), [`psa_export_key`](https://mbed-tls.readthedocs.io/projects/api/en/development/api/group/group__import__export/#group__import__export_1ga668e35be8d2852ad3feeef74ac6f75bf) and [`psa_export_public_key`](https://mbed-tls.readthedocs.io/projects/api/en/development/api/group/group__import__export/#group__import__export_1gaf22ae73312217aaede2ea02cdebb6062) are equivalent to `mbedtls_ecp_point_read_binary` and `mbedtls_ecp_point_write_binary` for uncompressed points. The PSA API does not currently support compressed points, but it is likely that such support will be added in the future.
-* Manipulation of key pairs as such, with a bridge to bignum arithmetic (`mbedtls_ecp_keypair` type, `mbedtls_ecp_export`). However, the PSA export format for ECC private keys used by [`psa_import_key`](https://mbed-tls.readthedocs.io/projects/api/en/development/api/group/group__import__export/#group__import__export_1ga0336ea76bf30587ab204a8296462327b), [`psa_export_key`](https://mbed-tls.readthedocs.io/projects/api/en/development/api/group/group__import__export/#group__import__export_1ga668e35be8d2852ad3feeef74ac6f75bf) is the same as the format used by `mbedtls_ecp_read_key` and `mbedtls_ecp_write_key`.
+* Manipulation of key pairs as such, with a bridge to bignum arithmetic (`mbedtls_ecp_keypair` type, `mbedtls_ecp_export`). However, the PSA export format for ECC private keys used by [`psa_import_key`](https://mbed-tls.readthedocs.io/projects/api/en/development/api/group/group__import__export/#group__import__export_1ga0336ea76bf30587ab204a8296462327b), [`psa_export_key`](https://mbed-tls.readthedocs.io/projects/api/en/development/api/group/group__import__export/#group__import__export_1ga668e35be8d2852ad3feeef74ac6f75bf) is the same as the format used by `mbedtls_ecp_read_key` and `mbedtls_ecp_write_key_ext`.
* Elliptic curve arithmetic (`mbedtls_ecp_mul`, `mbedtls_ecp_muladd` and their restartable variants).
### Additional information about RSA
diff --git a/include/mbedtls/ecp.h b/include/mbedtls/ecp.h
index 0201963ab..d8f73ae96 100644
--- a/include/mbedtls/ecp.h
+++ b/include/mbedtls/ecp.h
@@ -24,6 +24,7 @@
#include "mbedtls/private_access.h"
#include "mbedtls/build_info.h"
+#include "mbedtls/platform_util.h"
#include "mbedtls/bignum.h"
@@ -1327,10 +1328,11 @@ int mbedtls_ecp_set_public_key(mbedtls_ecp_group_id grp_id,
int mbedtls_ecp_read_key(mbedtls_ecp_group_id grp_id, mbedtls_ecp_keypair *key,
const unsigned char *buf, size_t buflen);
+#if !defined(MBEDTLS_DEPRECATED_REMOVED)
/**
* \brief This function exports an elliptic curve private key.
*
- * \note Note that although this function accepts an output
+ * \deprecated Note that although this function accepts an output
* buffer that is smaller or larger than the key, most key
* import interfaces require the output to have exactly
* key's nominal length. It is generally simplest to
@@ -1338,6 +1340,10 @@ int mbedtls_ecp_read_key(mbedtls_ecp_group_id grp_id, mbedtls_ecp_keypair *key,
* checking that the output buffer is large enough.
* See the description of the \p buflen parameter for
* how to calculate the nominal length.
+ * To avoid this difficulty, use mbedtls_ecp_write_key_ext()
+ * instead.
+ * mbedtls_ecp_write_key() is deprecated and will be
+ * removed in a future version of the library.
*
* \note If the private key was not set in \p key,
* the output is unspecified. Future versions
@@ -1367,8 +1373,31 @@ int mbedtls_ecp_read_key(mbedtls_ecp_group_id grp_id, mbedtls_ecp_keypair *key,
* representation is larger than the available space in \p buf.
* \return Another negative error code on different kinds of failure.
*/
-int mbedtls_ecp_write_key(mbedtls_ecp_keypair *key,
- unsigned char *buf, size_t buflen);
+int MBEDTLS_DEPRECATED mbedtls_ecp_write_key(mbedtls_ecp_keypair *key,
+ unsigned char *buf, size_t buflen);
+#endif /* MBEDTLS_DEPRECATED_REMOVED */
+
+/**
+ * \brief This function exports an elliptic curve private key.
+ *
+ * \param key The private key.
+ * \param olen On success, the length of the private key.
+ * This is always (`grp->nbits` + 7) / 8 bytes
+ * where `grp->nbits` is the private key size in bits.
+ * \param buf The output buffer for containing the binary representation
+ * of the key.
+ * \param buflen The total length of the buffer in bytes.
+ * #MBEDTLS_ECP_MAX_BYTES is always sufficient.
+ *
+ * \return \c 0 on success.
+ * \return #MBEDTLS_ERR_ECP_BUFFER_TOO_SMALL if the \p key
+ * representation is larger than the available space in \p buf.
+ * \return #MBEDTLS_ERR_ECP_BAD_INPUT_DATA if no private key is
+ * set in \p key.
+ * \return Another negative error code on different kinds of failure.
+ */
+int mbedtls_ecp_write_key_ext(const mbedtls_ecp_keypair *key,
+ size_t *olen, unsigned char *buf, size_t buflen);
/**
* \brief This function exports an elliptic curve public key.
diff --git a/library/ecp.c b/library/ecp.c
index 66b3dc1be..427059bb5 100644
--- a/library/ecp.c
+++ b/library/ecp.c
@@ -3302,6 +3302,7 @@ cleanup:
/*
* Write a private key.
*/
+#if !defined MBEDTLS_DEPRECATED_REMOVED
int mbedtls_ecp_write_key(mbedtls_ecp_keypair *key,
unsigned char *buf, size_t buflen)
{
@@ -3332,6 +3333,39 @@ cleanup:
return ret;
}
+#endif /* MBEDTLS_DEPRECATED_REMOVED */
+
+int mbedtls_ecp_write_key_ext(const mbedtls_ecp_keypair *key,
+ size_t *olen, unsigned char *buf, size_t buflen)
+{
+ size_t len = (key->grp.nbits + 7) / 8;
+ if (len > buflen) {
+ /* For robustness, ensure *olen <= buflen even on error. */
+ *olen = 0;
+ return MBEDTLS_ERR_ECP_BUFFER_TOO_SMALL;
+ }
+ *olen = len;
+
+ /* Private key not set */
+ if (key->d.n == 0) {
+ return MBEDTLS_ERR_ECP_BAD_INPUT_DATA;
+ }
+
+#if defined(MBEDTLS_ECP_MONTGOMERY_ENABLED)
+ if (mbedtls_ecp_get_type(&key->grp) == MBEDTLS_ECP_TYPE_MONTGOMERY) {
+ return mbedtls_mpi_write_binary_le(&key->d, buf, len);
+ }
+#endif
+
+#if defined(MBEDTLS_ECP_SHORT_WEIERSTRASS_ENABLED)
+ if (mbedtls_ecp_get_type(&key->grp) == MBEDTLS_ECP_TYPE_SHORT_WEIERSTRASS) {
+ return mbedtls_mpi_write_binary(&key->d, buf, len);
+ }
+#endif
+
+ /* Private key set but no recognized curve type? This shouldn't happen. */
+ return MBEDTLS_ERR_ERROR_CORRUPTION_DETECTED;
+}
/*
* Write a public key.
diff --git a/library/pk.c b/library/pk.c
index 8a5124f26..003ef4aac 100644
--- a/library/pk.c
+++ b/library/pk.c
@@ -675,10 +675,7 @@ static int import_pair_into_psa(const mbedtls_pk_context *pk,
#if defined(MBEDTLS_PK_USE_PSA_EC_DATA)
psa_ecc_family_t from_family = pk->ec_family;
#else /* MBEDTLS_PK_USE_PSA_EC_DATA */
- /* We're only reading the key, but mbedtls_ecp_write_key()
- * is missing a const annotation on its key parameter, so
- * we need the non-const accessor here. */
- mbedtls_ecp_keypair *ec = mbedtls_pk_ec_rw(*pk);
+ const mbedtls_ecp_keypair *ec = mbedtls_pk_ec_ro(*pk);
size_t from_bits = 0;
psa_ecc_family_t from_family = mbedtls_ecc_group_to_psa(ec->grp.id,
&from_bits);
@@ -704,12 +701,9 @@ static int import_pair_into_psa(const mbedtls_pk_context *pk,
return MBEDTLS_ERR_PK_TYPE_MISMATCH;
}
unsigned char key_buffer[PSA_BITS_TO_BYTES(PSA_VENDOR_ECC_MAX_CURVE_BITS)];
- /* Make sure to pass the exact key length to
- * mbedtls_ecp_write_key(), because it writes Montgomery keys
- * at the start of the buffer but Weierstrass keys at the
- * end of the buffer. */
- size_t key_length = PSA_BITS_TO_BYTES(ec->grp.nbits);
- int ret = mbedtls_ecp_write_key(ec, key_buffer, key_length);
+ size_t key_length = 0;
+ int ret = mbedtls_ecp_write_key_ext(ec, &key_length,
+ key_buffer, sizeof(key_buffer));
if (ret < 0) {
return ret;
}
diff --git a/library/pkwrite.c b/library/pkwrite.c
index b9ddcf1d8..5e009c565 100644
--- a/library/pkwrite.c
+++ b/library/pkwrite.c
@@ -202,7 +202,7 @@ static int pk_write_ec_private(unsigned char **p, unsigned char *start,
mbedtls_ecp_keypair *ec = mbedtls_pk_ec_rw(*pk);
byte_length = (ec->grp.pbits + 7) / 8;
- ret = mbedtls_ecp_write_key(ec, tmp, byte_length);
+ ret = mbedtls_ecp_write_key_ext(ec, &byte_length, tmp, sizeof(tmp));
if (ret != 0) {
goto exit;
}
diff --git a/library/psa_crypto_ecp.c b/library/psa_crypto_ecp.c
index 7edea8164..e373ad9f6 100644
--- a/library/psa_crypto_ecp.c
+++ b/library/psa_crypto_ecp.c
@@ -281,20 +281,8 @@ psa_status_t mbedtls_psa_ecp_export_key(psa_key_type_t type,
return status;
} else {
- if (data_size < PSA_BITS_TO_BYTES(ecp->grp.nbits)) {
- return PSA_ERROR_BUFFER_TOO_SMALL;
- }
-
status = mbedtls_to_psa_error(
- mbedtls_ecp_write_key(ecp,
- data,
- PSA_BITS_TO_BYTES(ecp->grp.nbits)));
- if (status == PSA_SUCCESS) {
- *data_length = PSA_BITS_TO_BYTES(ecp->grp.nbits);
- } else {
- memset(data, 0, data_size);
- }
-
+ mbedtls_ecp_write_key_ext(ecp, data_length, data, data_size));
return status;
}
}
@@ -359,14 +347,11 @@ psa_status_t mbedtls_psa_ecp_generate_key(
}
status = mbedtls_to_psa_error(
- mbedtls_ecp_write_key(&ecp, key_buffer, key_buffer_size));
+ mbedtls_ecp_write_key_ext(&ecp, key_buffer_length,
+ key_buffer, key_buffer_size));
mbedtls_ecp_keypair_free(&ecp);
- if (status == PSA_SUCCESS) {
- *key_buffer_length = key_buffer_size;
- }
-
return status;
}
#endif /* MBEDTLS_PSA_BUILTIN_KEY_TYPE_ECC_KEY_PAIR_GENERATE */
diff --git a/library/ssl_tls12_server.c b/library/ssl_tls12_server.c
index 53a9ce206..5bee18823 100644
--- a/library/ssl_tls12_server.c
+++ b/library/ssl_tls12_server.c
@@ -2703,8 +2703,7 @@ static int ssl_get_ecdh_params_from_cert(mbedtls_ssl_context *ssl)
PSA_KEY_TYPE_ECC_KEY_PAIR(ssl->handshake->xxdh_psa_type));
psa_set_key_bits(&key_attributes, ssl->handshake->xxdh_psa_bits);
- key_len = PSA_BITS_TO_BYTES(key->grp.pbits);
- ret = mbedtls_ecp_write_key(key, buf, key_len);
+ ret = mbedtls_ecp_write_key_ext(key, &key_len, buf, sizeof(buf));
if (ret != 0) {
mbedtls_platform_zeroize(buf, sizeof(buf));
break;
diff --git a/tests/suites/test_suite_ecp.data b/tests/suites/test_suite_ecp.data
index 1dd963a23..fd63657aa 100644
--- a/tests/suites/test_suite_ecp.data
+++ b/tests/suites/test_suite_ecp.data
@@ -888,6 +888,109 @@ ECP write key: Curve448, mostly-0 key, output_size=55
depends_on:MBEDTLS_ECP_DP_CURVE448_ENABLED
ecp_write_key:MBEDTLS_ECP_DP_CURVE448:"0000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000080":55:MBEDTLS_ERR_ECP_BUFFER_TOO_SMALL
+ECP write key ext: secp256r1, nominal
+depends_on:MBEDTLS_ECP_DP_SECP256R1_ENABLED
+ecp_write_key_ext:MBEDTLS_ECP_DP_SECP256R1:"f12a1320760270a83cbffd53f6031ef76a5d86c8a204f2c30ca9ebf51f0f0ea7":32:0
+
+ECP write key ext: secp256r1, output longer by 1
+depends_on:MBEDTLS_ECP_DP_SECP256R1_ENABLED
+ecp_write_key_ext:MBEDTLS_ECP_DP_SECP256R1:"f12a1320760270a83cbffd53f6031ef76a5d86c8a204f2c30ca9ebf51f0f0ea7":33:0
+
+ECP write key ext: secp256r1, output short by 1
+depends_on:MBEDTLS_ECP_DP_SECP256R1_ENABLED
+ecp_write_key_ext:MBEDTLS_ECP_DP_SECP256R1:"f12a1320760270a83cbffd53f6031ef76a5d86c8a204f2c30ca9ebf51f0f0ea7":31:MBEDTLS_ERR_ECP_BUFFER_TOO_SMALL
+
+ECP write key ext: secp256r1, output_size=0
+depends_on:MBEDTLS_ECP_DP_SECP256R1_ENABLED
+ecp_write_key_ext:MBEDTLS_ECP_DP_SECP256R1:"f12a1320760270a83cbffd53f6031ef76a5d86c8a204f2c30ca9ebf51f0f0ea7":0:MBEDTLS_ERR_ECP_BUFFER_TOO_SMALL
+
+ECP write key ext: secp256r1, top byte = 0, output_size=32
+depends_on:MBEDTLS_ECP_DP_SECP256R1_ENABLED
+ecp_write_key_ext:MBEDTLS_ECP_DP_SECP256R1:"00ffffffffffffffffffffffffffffffffffffffffffffffffffffffffffffff":32:0
+
+ECP write key ext: secp256r1, top byte = 0, output_size=31
+depends_on:MBEDTLS_ECP_DP_SECP256R1_ENABLED
+ecp_write_key_ext:MBEDTLS_ECP_DP_SECP256R1:"00ffffffffffffffffffffffffffffffffffffffffffffffffffffffffffffff":31:MBEDTLS_ERR_ECP_BUFFER_TOO_SMALL
+
+ECP write key ext: secp256r1, top byte = 0, output_size=30
+depends_on:MBEDTLS_ECP_DP_SECP256R1_ENABLED
+ecp_write_key_ext:MBEDTLS_ECP_DP_SECP256R1:"00ffffffffffffffffffffffffffffffffffffffffffffffffffffffffffffff":30:MBEDTLS_ERR_ECP_BUFFER_TOO_SMALL
+
+ECP write key ext: secp256r1, mostly-0 key, output_size=32
+depends_on:MBEDTLS_ECP_DP_SECP256R1_ENABLED
+ecp_write_key_ext:MBEDTLS_ECP_DP_SECP256R1:"0000000000000000000000000000000000000000000000000000000000000001":32:0
+
+ECP write key ext: secp256r1, mostly-0 key, output_size=1
+depends_on:MBEDTLS_ECP_DP_SECP256R1_ENABLED
+ecp_write_key_ext:MBEDTLS_ECP_DP_SECP256R1:"0000000000000000000000000000000000000000000000000000000000000001":1:MBEDTLS_ERR_ECP_BUFFER_TOO_SMALL
+
+ECP write key ext: secp256r1, private key not set
+depends_on:MBEDTLS_ECP_DP_SECP256R1_ENABLED
+ecp_write_key_ext:MBEDTLS_ECP_DP_SECP256R1:"":32:MBEDTLS_ERR_ECP_BAD_INPUT_DATA
+
+ECP write key ext: secp384r1, nominal
+depends_on:MBEDTLS_ECP_DP_SECP384R1_ENABLED
+ecp_write_key_ext:MBEDTLS_ECP_DP_SECP384R1:"d27335ea71664af244dd14e9fd1260715dfd8a7965571c48d709ee7a7962a156d706a90cbcb5df2986f05feadb9376f1":48:0
+
+ECP write key ext: secp384r1, output longer by 1
+depends_on:MBEDTLS_ECP_DP_SECP384R1_ENABLED
+ecp_write_key_ext:MBEDTLS_ECP_DP_SECP384R1:"d27335ea71664af244dd14e9fd1260715dfd8a7965571c48d709ee7a7962a156d706a90cbcb5df2986f05feadb9376f1":49:0
+
+ECP write key ext: secp384r1, output short by 1
+depends_on:MBEDTLS_ECP_DP_SECP384R1_ENABLED
+ecp_write_key_ext:MBEDTLS_ECP_DP_SECP384R1:"d27335ea71664af244dd14e9fd1260715dfd8a7965571c48d709ee7a7962a156d706a90cbcb5df2986f05feadb9376f1":47:MBEDTLS_ERR_ECP_BUFFER_TOO_SMALL
+
+ECP write key ext: Curve25519, nominal
+depends_on:MBEDTLS_ECP_DP_CURVE25519_ENABLED
+ecp_write_key_ext:MBEDTLS_ECP_DP_CURVE25519:"a046e36bf0527c9d3b16154b82465edd62144c0ac1fc5a18506a2244ba449a44":32:0
+
+ECP write key ext: Curve25519, output longer by 1
+depends_on:MBEDTLS_ECP_DP_CURVE25519_ENABLED
+ecp_write_key_ext:MBEDTLS_ECP_DP_CURVE25519:"a046e36bf0527c9d3b16154b82465edd62144c0ac1fc5a18506a2244ba449a44":33:0
+
+ECP write key ext: Curve25519, output short by 1
+depends_on:MBEDTLS_ECP_DP_CURVE25519_ENABLED
+ecp_write_key_ext:MBEDTLS_ECP_DP_CURVE25519:"a046e36bf0527c9d3b16154b82465edd62144c0ac1fc5a18506a2244ba449a44":31:MBEDTLS_ERR_ECP_BUFFER_TOO_SMALL
+
+ECP write key ext: Curve25519, output_size=0
+depends_on:MBEDTLS_ECP_DP_CURVE25519_ENABLED
+ecp_write_key_ext:MBEDTLS_ECP_DP_CURVE25519:"a046e36bf0527c9d3b16154b82465edd62144c0ac1fc5a18506a2244ba449a44":0:MBEDTLS_ERR_ECP_BUFFER_TOO_SMALL
+
+ECP write key ext: Curve25519, mostly-0 key, output_size=32
+depends_on:MBEDTLS_ECP_DP_CURVE25519_ENABLED
+ecp_write_key_ext:MBEDTLS_ECP_DP_CURVE25519:"0000000000000000000000000000000000000000000000000000000000000040":32:0
+
+ECP write key ext: Curve25519, mostly-0 key, output_size=31
+depends_on:MBEDTLS_ECP_DP_CURVE25519_ENABLED
+ecp_write_key_ext:MBEDTLS_ECP_DP_CURVE25519:"0000000000000000000000000000000000000000000000000000000000000040":31:MBEDTLS_ERR_ECP_BUFFER_TOO_SMALL
+
+ECP write key ext: Curve25519, private key not set
+depends_on:MBEDTLS_ECP_DP_CURVE25519_ENABLED
+ecp_write_key_ext:MBEDTLS_ECP_DP_CURVE25519:"":32:MBEDTLS_ERR_ECP_BAD_INPUT_DATA
+
+ECP write key ext: Curve448, nominal
+depends_on:MBEDTLS_ECP_DP_CURVE448_ENABLED
+ecp_write_key_ext:MBEDTLS_ECP_DP_CURVE448:"3c262fddf9ec8e88495266fea19a34d28882acef045104d0d1aae121700a779c984c24f8cdd78fbff44943eba368f54b29259a4f1c600ad3":56:0
+
+ECP write key ext: Curve448, output longer by 1
+depends_on:MBEDTLS_ECP_DP_CURVE448_ENABLED
+ecp_write_key_ext:MBEDTLS_ECP_DP_CURVE448:"3c262fddf9ec8e88495266fea19a34d28882acef045104d0d1aae121700a779c984c24f8cdd78fbff44943eba368f54b29259a4f1c600ad3":57:0
+
+ECP write key ext: Curve448, output short by 1
+depends_on:MBEDTLS_ECP_DP_CURVE448_ENABLED
+ecp_write_key_ext:MBEDTLS_ECP_DP_CURVE448:"3c262fddf9ec8e88495266fea19a34d28882acef045104d0d1aae121700a779c984c24f8cdd78fbff44943eba368f54b29259a4f1c600ad3":55:MBEDTLS_ERR_ECP_BUFFER_TOO_SMALL
+
+ECP write key ext: Curve448, mostly-0 key, output_size=56
+depends_on:MBEDTLS_ECP_DP_CURVE448_ENABLED
+ecp_write_key_ext:MBEDTLS_ECP_DP_CURVE448:"0000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000080":56:0
+
+ECP write key ext: Curve448, mostly-0 key, output_size=55
+depends_on:MBEDTLS_ECP_DP_CURVE448_ENABLED
+ecp_write_key_ext:MBEDTLS_ECP_DP_CURVE448:"0000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000080":55:MBEDTLS_ERR_ECP_BUFFER_TOO_SMALL
+
+ECP write key ext: group not set
+ecp_write_key_ext:MBEDTLS_ECP_DP_NONE:"":32:MBEDTLS_ERR_ECP_BAD_INPUT_DATA
+
ECP mod p192 small (more than 192 bits, less limbs than 2 * 192 bits)
depends_on:MBEDTLS_ECP_DP_SECP192R1_ENABLED:MBEDTLS_ECP_NIST_OPTIM
ecp_fast_mod:MBEDTLS_ECP_DP_SECP192R1:"0100000000000103010000000000010201000000000001010100000000000100"
diff --git a/tests/suites/test_suite_ecp.function b/tests/suites/test_suite_ecp.function
index 9cf0ce1b7..9b5c86f97 100644
--- a/tests/suites/test_suite_ecp.function
+++ b/tests/suites/test_suite_ecp.function
@@ -1204,29 +1204,46 @@ void mbedtls_ecp_read_key(int grp_id, data_t *in_key, int expected, int canonica
TEST_EQUAL(mbedtls_mpi_cmp_int(&key.Q.Y, 2), 0);
TEST_EQUAL(mbedtls_mpi_cmp_int(&key.Q.Z, 3), 0);
- if (canonical) {
+ if (canonical && in_key->len == (key.grp.nbits + 7) / 8) {
unsigned char buf[MBEDTLS_ECP_MAX_BYTES];
+ size_t length = 0xdeadbeef;
- ret = mbedtls_ecp_write_key(&key, buf, in_key->len);
- TEST_ASSERT(ret == 0);
+ TEST_EQUAL(mbedtls_ecp_write_key_ext(&key,
+ &length, buf, in_key->len), 0);
+ TEST_MEMORY_COMPARE(in_key->x, in_key->len,
+ buf, length);
+#if defined(MBEDTLS_TEST_DEPRECATED)
+ memset(buf, 0, sizeof(buf));
+ TEST_EQUAL(mbedtls_ecp_write_key(&key, buf, in_key->len), 0);
TEST_MEMORY_COMPARE(in_key->x, in_key->len,
buf, in_key->len);
+#endif /* MBEDTLS_TEST_DEPRECATED */
} else {
unsigned char export1[MBEDTLS_ECP_MAX_BYTES];
unsigned char export2[MBEDTLS_ECP_MAX_BYTES];
- ret = mbedtls_ecp_write_key(&key, export1, in_key->len);
- TEST_ASSERT(ret == 0);
-
- ret = mbedtls_ecp_read_key(grp_id, &key2, export1, in_key->len);
- TEST_ASSERT(ret == expected);
-
- ret = mbedtls_ecp_write_key(&key2, export2, in_key->len);
- TEST_ASSERT(ret == 0);
+ size_t length1 = 0xdeadbeef;
+ TEST_EQUAL(mbedtls_ecp_write_key_ext(&key, &length1,
+ export1, sizeof(export1)), 0);
+ TEST_EQUAL(mbedtls_ecp_read_key(grp_id, &key2, export1, length1),
+ expected);
+ size_t length2 = 0xdeadbeef;
+ TEST_EQUAL(mbedtls_ecp_write_key_ext(&key2, &length2,
+ export2, sizeof(export2)), 0);
+ TEST_MEMORY_COMPARE(export1, length1,
+ export2, length2);
+#if defined(MBEDTLS_TEST_DEPRECATED)
+ memset(export1, 0, sizeof(export1));
+ memset(export2, 0, sizeof(export2));
+ TEST_EQUAL(mbedtls_ecp_write_key(&key, export1, in_key->len), 0);
+ TEST_EQUAL(mbedtls_ecp_read_key(grp_id, &key2, export1, in_key->len),
+ expected);
+ TEST_EQUAL(mbedtls_ecp_write_key(&key2, export2, in_key->len), 0);
TEST_MEMORY_COMPARE(export1, in_key->len,
export2, in_key->len);
+#endif /* MBEDTLS_TEST_DEPRECATED */
}
}
@@ -1236,7 +1253,7 @@ exit:
}
/* END_CASE */
-/* BEGIN_CASE */
+/* BEGIN_CASE depends_on:MBEDTLS_TEST_DEPRECATED */
void ecp_write_key(int grp_id, data_t *in_key,
int exported_size, int expected_ret)
{
@@ -1296,6 +1313,42 @@ exit:
}
/* END_CASE */
+/* BEGIN_CASE */
+void ecp_write_key_ext(int grp_id, data_t *in_key,
+ int exported_size, int expected_ret)
+{
+ mbedtls_ecp_keypair key;
+ mbedtls_ecp_keypair_init(&key);
+ unsigned char *exported = NULL;
+
+ if (in_key->len != 0) {
+ TEST_EQUAL(mbedtls_ecp_read_key(grp_id, &key, in_key->x, in_key->len), 0);
+ } else if (grp_id != MBEDTLS_ECP_DP_NONE) {
+ TEST_EQUAL(mbedtls_ecp_group_load(&key.grp, grp_id), 0);
+ }
+
+ TEST_CALLOC(exported, exported_size);
+ size_t olen = 0xdeadbeef;
+ TEST_EQUAL(mbedtls_ecp_write_key_ext(&key, &olen, exported, exported_size),
+ expected_ret);
+
+ if (expected_ret == 0) {
+ TEST_EQUAL(olen, (key.grp.nbits + 7) / 8);
+ TEST_LE_U(olen, MBEDTLS_ECP_MAX_BYTES);
+ TEST_MEMORY_COMPARE(in_key->x, in_key->len,
+ exported, olen);
+ } else {
+ /* Robustness check: even in the error case, insist that olen is less
+ * than the buffer size. */
+ TEST_LE_U(olen, exported_size);
+ }
+
+exit:
+ mbedtls_ecp_keypair_free(&key);
+ mbedtls_free(exported);
+}
+/* END_CASE */
+
/* BEGIN_CASE depends_on:MBEDTLS_TEST_HOOKS:MBEDTLS_ECP_MONTGOMERY_ENABLED:MBEDTLS_ECP_LIGHT */
void genkey_mx_known_answer(int bits, data_t *seed, data_t *expected)
{