pkwrite: split pk_write_rsa_der() with a dedicated function for non-opaque RSA key
Signed-off-by: Valerio Setti <valerio.setti@nordicsemi.no>
diff --git a/library/pkwrite.c b/library/pkwrite.c
index 1f0d399..8930525 100644
--- a/library/pkwrite.c
+++ b/library/pkwrite.c
@@ -62,13 +62,12 @@
* publicExponent INTEGER -- e
* }
*/
-static int pk_write_rsa_pubkey(unsigned char **p, unsigned char *start,
- const mbedtls_pk_context *pk)
+static int mbedtls_rsa_pubkey_write(unsigned char **p, unsigned char *start,
+ const mbedtls_rsa_context *rsa)
{
int ret = MBEDTLS_ERR_ERROR_CORRUPTION_DETECTED;
size_t len = 0;
mbedtls_mpi T;
- mbedtls_rsa_context *rsa = mbedtls_pk_rsa(*pk);
mbedtls_mpi_init(&T);
@@ -100,16 +99,99 @@
return (int) len;
}
-static int pk_write_rsa_der(unsigned char **p, unsigned char *buf,
- const mbedtls_pk_context *pk)
+static int mbedtls_rsa_key_write(unsigned char **p, unsigned char *start,
+ const mbedtls_rsa_context *rsa)
{
size_t len = 0;
int ret;
+ mbedtls_mpi T; /* Temporary holding the exported parameters */
+
+ /*
+ * Export the parameters one after another to avoid simultaneous copies.
+ */
+
+ mbedtls_mpi_init(&T);
+
+ /* Export QP */
+ if ((ret = mbedtls_rsa_export_crt(rsa, NULL, NULL, &T)) != 0 ||
+ (ret = mbedtls_asn1_write_mpi(p, start, &T)) < 0) {
+ goto end_of_export;
+ }
+ len += ret;
+
+ /* Export DQ */
+ if ((ret = mbedtls_rsa_export_crt(rsa, NULL, &T, NULL)) != 0 ||
+ (ret = mbedtls_asn1_write_mpi(p, start, &T)) < 0) {
+ goto end_of_export;
+ }
+ len += ret;
+
+ /* Export DP */
+ if ((ret = mbedtls_rsa_export_crt(rsa, &T, NULL, NULL)) != 0 ||
+ (ret = mbedtls_asn1_write_mpi(p, start, &T)) < 0) {
+ goto end_of_export;
+ }
+ len += ret;
+
+ /* Export Q */
+ if ((ret = mbedtls_rsa_export(rsa, NULL, NULL, &T, NULL, NULL)) != 0 ||
+ (ret = mbedtls_asn1_write_mpi(p, start, &T)) < 0) {
+ goto end_of_export;
+ }
+ len += ret;
+
+ /* Export P */
+ if ((ret = mbedtls_rsa_export(rsa, NULL, &T, NULL, NULL, NULL)) != 0 ||
+ (ret = mbedtls_asn1_write_mpi(p, start, &T)) < 0) {
+ goto end_of_export;
+ }
+ len += ret;
+
+ /* Export D */
+ if ((ret = mbedtls_rsa_export(rsa, NULL, NULL, NULL, &T, NULL)) != 0 ||
+ (ret = mbedtls_asn1_write_mpi(p, start, &T)) < 0) {
+ goto end_of_export;
+ }
+ len += ret;
+
+ /* Export E */
+ if ((ret = mbedtls_rsa_export(rsa, NULL, NULL, NULL, NULL, &T)) != 0 ||
+ (ret = mbedtls_asn1_write_mpi(p, start, &T)) < 0) {
+ goto end_of_export;
+ }
+ len += ret;
+
+ /* Export N */
+ if ((ret = mbedtls_rsa_export(rsa, &T, NULL, NULL, NULL, NULL)) != 0 ||
+ (ret = mbedtls_asn1_write_mpi(p, start, &T)) < 0) {
+ goto end_of_export;
+ }
+ len += ret;
+
+end_of_export:
+
+ mbedtls_mpi_free(&T);
+ if (ret < 0) {
+ return ret;
+ }
+
+ MBEDTLS_ASN1_CHK_ADD(len, mbedtls_asn1_write_int(p, start, 0));
+ 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_CONSTRUCTED |
+ MBEDTLS_ASN1_SEQUENCE));
+
+ return (int) len;
+}
+
+static int pk_write_rsa_der(unsigned char **p, unsigned char *buf,
+ const mbedtls_pk_context *pk)
+{
#if defined(MBEDTLS_USE_PSA_CRYPTO)
if (mbedtls_pk_get_type(pk) == MBEDTLS_PK_OPAQUE) {
uint8_t tmp[PSA_EXPORT_KEY_PAIR_MAX_SIZE];
- size_t tmp_len = 0;
+ size_t len = 0, tmp_len = 0;
if (psa_export_key(pk->priv_id, tmp, sizeof(tmp), &tmp_len) != PSA_SUCCESS) {
return MBEDTLS_ERR_PK_BAD_INPUT_DATA;
@@ -118,94 +200,11 @@
memcpy(*p, tmp, tmp_len);
len += tmp_len;
mbedtls_platform_zeroize(tmp, sizeof(tmp));
- } else
-#endif /* MBEDTLS_USE_PSA_CRYPTO */
- {
- mbedtls_mpi T; /* Temporary holding the exported parameters */
- mbedtls_rsa_context *rsa = mbedtls_pk_rsa(*pk);
- /*
- * Export the parameters one after another to avoid simultaneous copies.
- */
-
- mbedtls_mpi_init(&T);
-
- /* Export QP */
- if ((ret = mbedtls_rsa_export_crt(rsa, NULL, NULL, &T)) != 0 ||
- (ret = mbedtls_asn1_write_mpi(p, buf, &T)) < 0) {
- goto end_of_export;
- }
- len += ret;
-
- /* Export DQ */
- if ((ret = mbedtls_rsa_export_crt(rsa, NULL, &T, NULL)) != 0 ||
- (ret = mbedtls_asn1_write_mpi(p, buf, &T)) < 0) {
- goto end_of_export;
- }
- len += ret;
-
- /* Export DP */
- if ((ret = mbedtls_rsa_export_crt(rsa, &T, NULL, NULL)) != 0 ||
- (ret = mbedtls_asn1_write_mpi(p, buf, &T)) < 0) {
- goto end_of_export;
- }
- len += ret;
-
- /* Export Q */
- if ((ret = mbedtls_rsa_export(rsa, NULL, NULL,
- &T, NULL, NULL)) != 0 ||
- (ret = mbedtls_asn1_write_mpi(p, buf, &T)) < 0) {
- goto end_of_export;
- }
- len += ret;
-
- /* Export P */
- if ((ret = mbedtls_rsa_export(rsa, NULL, &T,
- NULL, NULL, NULL)) != 0 ||
- (ret = mbedtls_asn1_write_mpi(p, buf, &T)) < 0) {
- goto end_of_export;
- }
- len += ret;
-
- /* Export D */
- if ((ret = mbedtls_rsa_export(rsa, NULL, NULL,
- NULL, &T, NULL)) != 0 ||
- (ret = mbedtls_asn1_write_mpi(p, buf, &T)) < 0) {
- goto end_of_export;
- }
- len += ret;
-
- /* Export E */
- if ((ret = mbedtls_rsa_export(rsa, NULL, NULL,
- NULL, NULL, &T)) != 0 ||
- (ret = mbedtls_asn1_write_mpi(p, buf, &T)) < 0) {
- goto end_of_export;
- }
- len += ret;
-
- /* Export N */
- if ((ret = mbedtls_rsa_export(rsa, &T, NULL,
- NULL, NULL, NULL)) != 0 ||
- (ret = mbedtls_asn1_write_mpi(p, buf, &T)) < 0) {
- goto end_of_export;
- }
- len += ret;
-
-end_of_export:
-
- mbedtls_mpi_free(&T);
- if (ret < 0) {
- return ret;
- }
-
- MBEDTLS_ASN1_CHK_ADD(len, mbedtls_asn1_write_int(p, buf, 0));
- MBEDTLS_ASN1_CHK_ADD(len, mbedtls_asn1_write_len(p, buf, len));
- MBEDTLS_ASN1_CHK_ADD(len, mbedtls_asn1_write_tag(p,
- buf, MBEDTLS_ASN1_CONSTRUCTED |
- MBEDTLS_ASN1_SEQUENCE));
+ return (int) len;
}
-
- return (int) len;
+#endif /* MBEDTLS_USE_PSA_CRYPTO */
+ return mbedtls_rsa_key_write(p, buf, mbedtls_pk_rsa(*pk));
}
#endif /* MBEDTLS_RSA_C */
@@ -543,7 +542,7 @@
#if defined(MBEDTLS_RSA_C)
if (mbedtls_pk_get_type(key) == MBEDTLS_PK_RSA) {
- MBEDTLS_ASN1_CHK_ADD(len, pk_write_rsa_pubkey(p, start, key));
+ MBEDTLS_ASN1_CHK_ADD(len, mbedtls_rsa_pubkey_write(p, start, mbedtls_pk_rsa(*key)));
} else
#endif
#if defined(MBEDTLS_PK_HAVE_ECC_KEYS)