--- /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 der_decode_subject_public_key_info.c
+ ASN.1 DER, encode a Subject Public Key structure --nmav
+*/
+
+#ifdef LTC_DER
+
+/* AlgorithmIdentifier := SEQUENCE {
+ * algorithm OBJECT IDENTIFIER,
+ * parameters ANY DEFINED BY algorithm
+ * }
+ *
+ * SubjectPublicKeyInfo := SEQUENCE {
+ * algorithm AlgorithmIdentifier,
+ * subjectPublicKey BIT STRING
+ * }
+ */
+/**
+ Decode a subject public key info
+ @param in The input buffer
+ @param inlen The length of the input buffer
+ @param algorithm One out of the enum #public_key_algorithms
+ @param public_key The buffer for the public key
+ @param public_key_len [in/out] The length of the public key buffer and the written length
+ @param parameters_type The parameters' type out of the enum ltc_asn1_type
+ @param parameters The parameters to include
+ @param parameters_len The number of parameters to include
+ @return CRYPT_OK on success
+*/
+int der_decode_subject_public_key_info(const unsigned char *in, unsigned long inlen,
+ unsigned int algorithm, void* public_key, unsigned long* public_key_len,
+ unsigned long parameters_type, ltc_asn1_list* parameters, unsigned long parameters_len)
+{
+ int err;
+ unsigned long len;
+ oid_st oid;
+ unsigned char *tmpbuf;
+ unsigned long tmpoid[16];
+ ltc_asn1_list alg_id[2];
+ ltc_asn1_list subject_pubkey[2];
+
+ LTC_ARGCHK(in != NULL);
+ LTC_ARGCHK(inlen != 0);
+ LTC_ARGCHK(public_key_len != NULL);
+
+ err = pk_get_oid(algorithm, &oid);
+ if (err != CRYPT_OK) {
+ return err;
+ }
+
+ /* see if the OpenSSL DER format RSA public key will work */
+ tmpbuf = XCALLOC(1, inlen);
+ if (tmpbuf == NULL) {
+ err = CRYPT_MEM;
+ goto LBL_ERR;
+ }
+
+ /* this includes the internal hash ID and optional params (NULL in this case) */
+ LTC_SET_ASN1(alg_id, 0, LTC_ASN1_OBJECT_IDENTIFIER, tmpoid, sizeof(tmpoid)/sizeof(tmpoid[0]));
+ LTC_SET_ASN1(alg_id, 1, (ltc_asn1_type)parameters_type, parameters, parameters_len);
+
+ /* the actual format of the SSL DER key is odd, it stores a RSAPublicKey
+ * in a **BIT** string ... so we have to extract it then proceed to convert bit to octet
+ */
+ LTC_SET_ASN1(subject_pubkey, 0, LTC_ASN1_SEQUENCE, alg_id, 2);
+ LTC_SET_ASN1(subject_pubkey, 1, LTC_ASN1_RAW_BIT_STRING, tmpbuf, inlen*8U);
+
+ err=der_decode_sequence(in, inlen, subject_pubkey, 2UL);
+ if (err != CRYPT_OK) {
+ goto LBL_ERR;
+ }
+
+ if ((alg_id[0].size != oid.OIDlen) ||
+ XMEMCMP(oid.OID, alg_id[0].data, oid.OIDlen * sizeof(oid.OID[0])) != 0) {
+ /* OID mismatch */
+ err = CRYPT_PK_INVALID_TYPE;
+ goto LBL_ERR;
+ }
+
+ len = subject_pubkey[1].size/8;
+ if (*public_key_len > len) {
+ XMEMCPY(public_key, subject_pubkey[1].data, len);
+ *public_key_len = len;
+ } else {
+ *public_key_len = len;
+ err = CRYPT_BUFFER_OVERFLOW;
+ goto LBL_ERR;
+ }
+
+ err = CRYPT_OK;
+
+LBL_ERR:
+
+ XFREE(tmpbuf);
+
+ return err;
+}
+
+#endif
+
+/* ref: $Format:%D$ */
+/* git commit: $Format:%H$ */
+/* commit time: $Format:%ai$ */