--- /dev/null
+/* LibTomCrypt, modular cryptographic library -- Tom St Denis
+ *
+ * LibTomCrypt is a library that provides various cryptographic
+ * algorithms in a highly modular and flexible manner.
+ *
+ * The library is free for all purposes without any express
+ * guarantee it works.
+ */
+#include "tomcrypt.h"
+
+/**
+ @file dsa_export.c
+ DSA implementation, export key, Tom St Denis
+*/
+
+#ifdef LTC_MDSA
+
+/**
+ Export a DSA key to a binary packet
+ @param out [out] Where to store the packet
+ @param outlen [in/out] The max size and resulting size of the packet
+ @param type The type of key to export (PK_PRIVATE or PK_PUBLIC)
+ @param key The key to export
+ @return CRYPT_OK if successful
+*/
+int dsa_export(unsigned char *out, unsigned long *outlen, int type, dsa_key *key)
+{
+ unsigned long zero=0;
+ int err, std;
+
+ LTC_ARGCHK(out != NULL);
+ LTC_ARGCHK(outlen != NULL);
+ LTC_ARGCHK(key != NULL);
+
+ std = type & PK_STD;
+ type &= ~PK_STD;
+
+ /* can we store the static header? */
+ if (type == PK_PRIVATE && key->type != PK_PRIVATE) {
+ return CRYPT_PK_TYPE_MISMATCH;
+ }
+
+ if (type != PK_PUBLIC && type != PK_PRIVATE) {
+ return CRYPT_INVALID_ARG;
+ }
+
+ if (type == PK_PRIVATE) {
+ if (std) {
+ return der_encode_sequence_multi(out, outlen,
+ LTC_ASN1_SHORT_INTEGER, 1UL, &zero,
+ LTC_ASN1_INTEGER, 1UL, key->p,
+ LTC_ASN1_INTEGER, 1UL, key->q,
+ LTC_ASN1_INTEGER, 1UL, key->g,
+ LTC_ASN1_INTEGER, 1UL, key->y,
+ LTC_ASN1_INTEGER, 1UL, key->x,
+ LTC_ASN1_EOL, 0UL, NULL);
+ }
+ else {
+ unsigned char flags[1];
+ flags[0] = 1;
+ return der_encode_sequence_multi(out, outlen,
+ LTC_ASN1_BIT_STRING, 1UL, flags,
+ LTC_ASN1_INTEGER, 1UL, key->g,
+ LTC_ASN1_INTEGER, 1UL, key->p,
+ LTC_ASN1_INTEGER, 1UL, key->q,
+ LTC_ASN1_INTEGER, 1UL, key->y,
+ LTC_ASN1_INTEGER, 1UL, key->x,
+ LTC_ASN1_EOL, 0UL, NULL);
+ }
+ } else {
+ if (std) {
+ unsigned long tmplen = (unsigned long)(mp_count_bits(key->y) / 8) + 8;
+ unsigned char* tmp = XMALLOC(tmplen);
+ ltc_asn1_list int_list[3];
+
+ if (tmp == NULL) {
+ return CRYPT_MEM;
+ }
+
+ err = der_encode_integer(key->y, tmp, &tmplen);
+ if (err != CRYPT_OK) {
+ goto error;
+ }
+
+ LTC_SET_ASN1(int_list, 0, LTC_ASN1_INTEGER, key->p, 1UL);
+ LTC_SET_ASN1(int_list, 1, LTC_ASN1_INTEGER, key->q, 1UL);
+ LTC_SET_ASN1(int_list, 2, LTC_ASN1_INTEGER, key->g, 1UL);
+
+ err = der_encode_subject_public_key_info(out, outlen, PKA_DSA, tmp,
+ tmplen, LTC_ASN1_SEQUENCE, int_list,
+ sizeof(int_list) / sizeof(int_list[0]));
+
+error:
+ XFREE(tmp);
+ return err;
+ }
+ else {
+ unsigned char flags[1];
+ flags[0] = 0;
+ return der_encode_sequence_multi(out, outlen,
+ LTC_ASN1_BIT_STRING, 1UL, flags,
+ LTC_ASN1_INTEGER, 1UL, key->g,
+ LTC_ASN1_INTEGER, 1UL, key->p,
+ LTC_ASN1_INTEGER, 1UL, key->q,
+ LTC_ASN1_INTEGER, 1UL, key->y,
+ LTC_ASN1_EOL, 0UL, NULL);
+ }
+ }
+}
+
+#endif
+
+
+/* ref: $Format:%D$ */
+/* git commit: $Format:%H$ */
+/* commit time: $Format:%ai$ */