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Fix set point A.

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mbedtls does not set point A for some curves.
This commit is contained in:
Pol Henarejos
2022-06-01 11:51:33 +02:00
parent 6edeab6f85
commit 299516f576
1 changed files with 21 additions and 2 deletions
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23
src/hsm/cvc.c
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@@ -48,13 +48,22 @@ size_t asn1_cvc_public_key_rsa(mbedtls_rsa_context *rsa, uint8_t *buf, size_t bu
return tot_len;
}
const uint8_t *pointA[] = {
NULL,
(uint8_t *)"\xFF\xFF\xFF\xFF\xFF\xFF\xFF\xFF\xFF\xFF\xFF\xFF\xFF\xFF\xFF\xFE\xFF\xFF\xFF\xFF\xFF\xFF\xFF\xFC",
(uint8_t *)"\xFF\xFF\xFF\xFF\xFF\xFF\xFF\xFF\xFF\xFF\xFF\xFF\xFF\xFF\xFF\xFE\xFF\xFF\xFF\xFF\xFF\xFF\xFF\xFF\xFF\xFF\xFF\xFE"
(uint8_t *)"\xFF\xFF\xFF\xFF\x00\x00\x00\x01\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00\xFF\xFF\xFF\xFF\xFF\xFF\xFF\xFF\xFF\xFF\xFF\xFC",
(uint8_t *)"\xFF\xFF\xFF\xFF\xFF\xFF\xFF\xFF\xFF\xFF\xFF\xFF\xFF\xFF\xFF\xFF\xFF\xFF\xFF\xFF\xFF\xFF\xFF\xFF\xFF\xFF\xFF\xFF\xFF\xFF\xFF\xFE\xFF\xFF\xFF\xFF\x00\x00\x00\x00\x00\x00\x00\x00\xFF\xFF\xFF\xFC",
(uint8_t *)"\x01\xFF\xFF\xFF\xFF\xFF\xFF\xFF\xFF\xFF\xFF\xFF\xFF\xFF\xFF\xFF\xFF\xFF\xFF\xFF\xFF\xFF\xFF\xFF\xFF\xFF\xFF\xFF\xFF\xFF\xFF\xFF\xFF\xFF\xFF\xFF\xFF\xFF\xFF\xFF\xFF\xFF\xFF\xFF\xFF\xFF\xFF\xFF\xFF\xFF\xFF\xFF\xFF\xFF\xFF\xFF\xFF\xFF\xFF\xFF\xFF\xFF\xFF\xFF\xFF\xFC",
};
size_t asn1_cvc_public_key_ecdsa(mbedtls_ecdsa_context *ecdsa, uint8_t *buf, size_t buf_len) {
const uint8_t oid_ecdsa[] = { 0x04, 0x00, 0x7F, 0x00, 0x07, 0x02, 0x02, 0x02, 0x02, 0x03 };
size_t p_size = mbedtls_mpi_size(&ecdsa->grp.P), a_size = mbedtls_mpi_size(&ecdsa->grp.A);
size_t b_size = mbedtls_mpi_size(&ecdsa->grp.B), g_size = 1+mbedtls_mpi_size(&ecdsa->grp.G.X)+mbedtls_mpi_size(&ecdsa->grp.G.X);
size_t o_size = mbedtls_mpi_size(&ecdsa->grp.N), y_size = 1+mbedtls_mpi_size(&ecdsa->Q.X)+mbedtls_mpi_size(&ecdsa->Q.X);
size_t c_size = 1;
size_t ptot_size = asn1_len_tag(0x81, p_size), atot_size = asn1_len_tag(0x82, a_size);
size_t ptot_size = asn1_len_tag(0x81, p_size), atot_size = asn1_len_tag(0x82, a_size ? a_size : (pointA[ecdsa->grp.id] ? p_size : 0));
size_t btot_size = asn1_len_tag(0x83, b_size), gtot_size = asn1_len_tag(0x84, g_size);
size_t otot_size = asn1_len_tag(0x85, o_size), ytot_size = asn1_len_tag(0x86, y_size);
size_t ctot_size = asn1_len_tag(0x87, c_size);
@@ -72,7 +81,17 @@ size_t asn1_cvc_public_key_ecdsa(mbedtls_ecdsa_context *ecdsa, uint8_t *buf, siz
//p
*p++ = 0x81; p += format_tlv_len(p_size, p); mbedtls_mpi_write_binary(&ecdsa->grp.P, p, p_size); p += p_size;
//A
*p++ = 0x82; p += format_tlv_len(a_size, p); mbedtls_mpi_write_binary(&ecdsa->grp.A, p, a_size); p += a_size;
if (a_size) {
*p++ = 0x82; p += format_tlv_len(a_size, p); mbedtls_mpi_write_binary(&ecdsa->grp.A, p, a_size); p += a_size;
}
else { //mbedtls does not set point A for some curves
if (pointA[ecdsa->grp.id]) {
*p++ = 0x82; p += format_tlv_len(p_size, p); memcpy(p, pointA[ecdsa->grp.id], p_size); p += p_size;
}
else {
*p++ = 0x82; p += format_tlv_len(0, p);
}
}
//B
*p++ = 0x83; p += format_tlv_len(b_size, p); mbedtls_mpi_write_binary(&ecdsa->grp.B, p, b_size); p += b_size;
//G