/*

 * asn1rsa.c

 *

 *  Created on: May 16, 2013

 *      Author: ignat

 */



#include "asn1rsa.h"



rsa_parse_error_t rsa_private_key_parse(const u8 *buf, size_t len, struct rsa_private_key * key)

{

    struct asn1_hdr hdr;

    const u8* key_end;

    const u8* pos;



    if (!buf || !len || !key)

        return RSA_PARSE_ERROR;



    if (asn1_get_next(buf, len, &hdr) || hdr.class != ASN1_CLASS_UNIVERSAL || hdr.tag != ASN1_TAG_SEQUENCE)

        return RSA_PARSE_ERROR;



    key_end = hdr.payload + hdr.length;



    // version

    if (asn1_get_next(hdr.payload, hdr.length, &hdr) || hdr.class != ASN1_CLASS_UNIVERSAL || hdr.tag != ASN1_TAG_INTEGER)

        return RSA_PARSE_ERROR;



    pos = hdr.payload + hdr.length;



    // modulus

    if (asn1_get_next(pos, key_end - pos, &hdr) || hdr.class != ASN1_CLASS_UNIVERSAL || hdr.tag != ASN1_TAG_INTEGER)

        return RSA_PARSE_ERROR;



    if (0x00 == hdr.payload[0])

    {

        key->modulus = hdr.payload + 1;

        key->modulus_len = hdr.length - 1;

    }

    else

    {

        key->modulus = hdr.payload;

        key->modulus_len = hdr.length;

    }



    pos = hdr.payload + hdr.length;



    // public exponent

    if (asn1_get_next(pos, key_end - pos, &hdr) || hdr.class != ASN1_CLASS_UNIVERSAL || hdr.tag != ASN1_TAG_INTEGER)

        return RSA_PARSE_ERROR;



    if (0x00 == hdr.payload[0])

    {

        key->public_exponent = hdr.payload + 1;

        key->public_exponent_len = hdr.length - 1;

    }

    else

    {

        key->public_exponent = hdr.payload;

        key->public_exponent_len = hdr.length;

    }



    pos = hdr.payload + hdr.length;



    // private exponent

    if (asn1_get_next(pos, key_end - pos, &hdr) || hdr.class != ASN1_CLASS_UNIVERSAL || hdr.tag != ASN1_TAG_INTEGER)

        return RSA_PARSE_ERROR;



    if (0x00 == hdr.payload[0])

    {

        key->private_exponent = hdr.payload + 1;

        key->private_exponent_len = hdr.length - 1;

    }

    else

    {

        key->private_exponent = hdr.payload;

        key->private_exponent_len = hdr.length;

    }



    pos = hdr.payload + hdr.length;



    if (asn1_get_next(pos, key_end - pos, &hdr) || hdr.class != ASN1_CLASS_UNIVERSAL || hdr.tag != ASN1_TAG_INTEGER)

        return RSA_PARSE_ERROR;



    if (0x00 == hdr.payload[0])

    {

        key->prime1 = hdr.payload + 1;

        key->prime1_len = hdr.length - 1;

    }

    else

    {

        key->prime1 = hdr.payload;

        key->prime1_len = hdr.length;

    }

    pos = hdr.payload + hdr.length;



    if (asn1_get_next(pos, key_end - pos, &hdr) || hdr.class != ASN1_CLASS_UNIVERSAL || hdr.tag != ASN1_TAG_INTEGER)

        return RSA_PARSE_ERROR;



    if (0x00 == hdr.payload[0])

    {

        key->prime2 = hdr.payload + 1;

        key->prime2_len = hdr.length - 1;

    }

    else

    {

        key->prime2 = hdr.payload;

        key->prime2_len = hdr.length;

    }

    pos = hdr.payload + hdr.length;



    if (asn1_get_next(pos, key_end - pos, &hdr) || hdr.class != ASN1_CLASS_UNIVERSAL || hdr.tag != ASN1_TAG_INTEGER)

        return RSA_PARSE_ERROR;



    if (0x00 == hdr.payload[0])

    {

        key->exponent1 = hdr.payload + 1;

        key->exponent1_len = hdr.length - 1;

    }

    else

    {

        key->exponent1 = hdr.payload;

        key->exponent1_len = hdr.length;

    }

    pos = hdr.payload + hdr.length;

    if (asn1_get_next(pos, key_end - pos, &hdr) || hdr.class != ASN1_CLASS_UNIVERSAL || hdr.tag != ASN1_TAG_INTEGER)

        return RSA_PARSE_ERROR;



    if (0x00 == hdr.payload[0])

    {

        key->exponent2 = hdr.payload + 1;

        key->exponent2_len = hdr.length - 1;

    }

    else

    {

        key->exponent2 = hdr.payload;

        key->exponent2_len = hdr.length;

    }

    pos = hdr.payload + hdr.length;



    if (asn1_get_next(pos, key_end - pos, &hdr) || hdr.class != ASN1_CLASS_UNIVERSAL || hdr.tag != ASN1_TAG_INTEGER)

        return RSA_PARSE_ERROR;



    if (0x00 == hdr.payload[0])

    {

        key->coefficient = hdr.payload + 1;

        key->coefficient_len = hdr.length - 1;

    }

    else

    {

        key->coefficient = hdr.payload;

        key->coefficient_len = hdr.length;

    }



    return RSA_PARSE_OK;

}



rsa_parse_error_t rsa_public_key_parse(const u8 *buf, size_t len, struct rsa_public_key * key)

{

    struct asn1_hdr hdr;

    const u8* key_end;



    if (!buf || !len || !key)

        return RSA_PARSE_ERROR;



    if (asn1_get_next(buf, len, &hdr) || hdr.class != ASN1_CLASS_UNIVERSAL || hdr.tag != ASN1_TAG_SEQUENCE)

        return RSA_PARSE_ERROR;



    key_end = hdr.payload + hdr.length;



    if (asn1_get_next(hdr.payload, hdr.length, &hdr) || hdr.class != ASN1_CLASS_UNIVERSAL || hdr.tag != ASN1_TAG_INTEGER)

        return RSA_PARSE_ERROR;



    if (0x00 == hdr.payload[0])

    {

        key->modulus = hdr.payload + 1;

        key->modulus_len = hdr.length - 1;

    }

    else

    {

        key->modulus = hdr.payload;

        key->modulus_len = hdr.length;

    }



    if (asn1_get_next(hdr.payload + hdr.length, key_end - (hdr.payload + hdr.length), &hdr) || hdr.class != ASN1_CLASS_UNIVERSAL || hdr.tag != ASN1_TAG_INTEGER)

        return RSA_PARSE_ERROR;



    key->exponent = hdr.payload;

    key->exponent_len = hdr.length;



    return RSA_PARSE_OK;

}