/*

 * Written by Dr Stephen N Henson (steve@openssl.org) for the OpenSSL project

 * 2006.

 */

/* ====================================================================

 * Copyright (c) 2006 The OpenSSL Project.  All rights reserved.

 *

 * Redistribution and use in source and binary forms, with or without

 * modification, are permitted provided that the following conditions

 * are met:

 *

 * 1. Redistributions of source code must retain the above copyright

 *    notice, this list of conditions and the following disclaimer.

 *

 * 2. Redistributions in binary form must reproduce the above copyright

 *    notice, this list of conditions and the following disclaimer in

 *    the documentation and/or other materials provided with the

 *    distribution.

 *

 * 3. All advertising materials mentioning features or use of this

 *    software must display the following acknowledgment:

 *    "This product includes software developed by the OpenSSL Project

 *    for use in the OpenSSL Toolkit. (http://www.OpenSSL.org/)"

 *

 * 4. The names "OpenSSL Toolkit" and "OpenSSL Project" must not be used to

 *    endorse or promote products derived from this software without

 *    prior written permission. For written permission, please contact

 *    licensing@OpenSSL.org.

 *

 * 5. Products derived from this software may not be called "OpenSSL"

 *    nor may "OpenSSL" appear in their names without prior written

 *    permission of the OpenSSL Project.

 *

 * 6. Redistributions of any form whatsoever must retain the following

 *    acknowledgment:

 *    "This product includes software developed by the OpenSSL Project

 *    for use in the OpenSSL Toolkit (http://www.OpenSSL.org/)"

 *

 * THIS SOFTWARE IS PROVIDED BY THE OpenSSL PROJECT ``AS IS'' AND ANY

 * EXPRESSED OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE

 * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR

 * PURPOSE ARE DISCLAIMED.  IN NO EVENT SHALL THE OpenSSL PROJECT OR

 * ITS CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL,

 * SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT

 * NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES;

 * LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)

 * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT,

 * STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE)

 * ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED

 * OF THE POSSIBILITY OF SUCH DAMAGE.

 * ====================================================================

 *

 * This product includes cryptographic software written by Eric Young

 * (eay@cryptsoft.com).  This product includes software written by Tim

 * Hudson (tjh@cryptsoft.com).

 *

 */

#include <stdio.h>

#include "cryptlib.h"

#include <openssl/asn1t.h>

#include <openssl/x509.h>

#include <openssl/evp.h>

#include <openssl/bn.h>

#include "evp_locl.h"

#include "dsa_locl.h"

/* DSA pkey context structure */

typedef struct {

    /* Parameter gen parameters */

    int nbits;                  /* size of p in bits (default: 1024) */

    int qbits;                  /* size of q in bits (default: 160) */

    const EVP_MD *pmd;          /* MD for parameter generation */

    /* Keygen callback info */

    int gentmp[2];

    /* message digest */

    const EVP_MD *md;           /* MD for the signature */

} DSA_PKEY_CTX;

static int pkey_dsa_init(EVP_PKEY_CTX *ctx)

{

    DSA_PKEY_CTX *dctx;

    dctx = OPENSSL_malloc(sizeof(DSA_PKEY_CTX));

    if (!dctx)

        return 0;

    dctx->nbits = 1024;

    dctx->qbits = 160;

    dctx->pmd = NULL;

    dctx->md = NULL;

    ctx->data = dctx;

    ctx->keygen_info = dctx->gentmp;

    ctx->keygen_info_count = 2;

    return 1;

}

static int pkey_dsa_copy(EVP_PKEY_CTX *dst, EVP_PKEY_CTX *src)

{

    DSA_PKEY_CTX *dctx, *sctx;

    if (!pkey_dsa_init(dst))

        return 0;

    sctx = src->data;

    dctx = dst->data;

    dctx->nbits = sctx->nbits;

    dctx->qbits = sctx->qbits;

    dctx->pmd = sctx->pmd;

    dctx->md = sctx->md;

    return 1;

}

static void pkey_dsa_cleanup(EVP_PKEY_CTX *ctx)

{

    DSA_PKEY_CTX *dctx = ctx->data;

    if (dctx)

        OPENSSL_free(dctx);

}

static int pkey_dsa_sign(EVP_PKEY_CTX *ctx, unsigned char *sig,

                         size_t *siglen, const unsigned char *tbs,

                         size_t tbslen)

{

    int ret, type;

    unsigned int sltmp;

    DSA_PKEY_CTX *dctx = ctx->data;

    DSA *dsa = ctx->pkey->pkey.dsa;

    if (dctx->md)

        type = EVP_MD_type(dctx->md);

    else

        type = NID_sha1;

    ret = DSA_sign(type, tbs, tbslen, sig, &sltmp, dsa);

    if (ret <= 0)

        return ret;

    *siglen = sltmp;

    return 1;

}

static int pkey_dsa_verify(EVP_PKEY_CTX *ctx,

                           const unsigned char *sig, size_t siglen,

                           const unsigned char *tbs, size_t tbslen)

{

    int ret, type;

    DSA_PKEY_CTX *dctx = ctx->data;

    DSA *dsa = ctx->pkey->pkey.dsa;

    if (dctx->md)

        type = EVP_MD_type(dctx->md);

    else

        type = NID_sha1;

    ret = DSA_verify(type, tbs, tbslen, sig, siglen, dsa);

    return ret;

}

static int pkey_dsa_ctrl(EVP_PKEY_CTX *ctx, int type, int p1, void *p2)

{

    DSA_PKEY_CTX *dctx = ctx->data;

    switch (type) {

    case EVP_PKEY_CTRL_DSA_PARAMGEN_BITS:

        if (p1 < 256)

            return -2;

        dctx->nbits = p1;

        return 1;

    case EVP_PKEY_CTRL_DSA_PARAMGEN_Q_BITS:

        if (p1 != 160 && p1 != 224 && p1 && p1 != 256)

            return -2;

        dctx->qbits = p1;

        return 1;

    case EVP_PKEY_CTRL_DSA_PARAMGEN_MD:

        if (EVP_MD_type((const EVP_MD *)p2) != NID_sha1 &&

            EVP_MD_type((const EVP_MD *)p2) != NID_sha224 &&

            EVP_MD_type((const EVP_MD *)p2) != NID_sha256) {

            DSAerr(DSA_F_PKEY_DSA_CTRL, DSA_R_INVALID_DIGEST_TYPE);

            return 0;

        }

        dctx->pmd = p2;

        return 1;

    case EVP_PKEY_CTRL_MD:

        if (EVP_MD_type((const EVP_MD *)p2) != NID_sha1 &&

            EVP_MD_type((const EVP_MD *)p2) != NID_dsa &&

            EVP_MD_type((const EVP_MD *)p2) != NID_dsaWithSHA &&

            EVP_MD_type((const EVP_MD *)p2) != NID_sha224 &&

            EVP_MD_type((const EVP_MD *)p2) != NID_sha256 &&

            EVP_MD_type((const EVP_MD *)p2) != NID_sha384 &&

            EVP_MD_type((const EVP_MD *)p2) != NID_sha512) {

            DSAerr(DSA_F_PKEY_DSA_CTRL, DSA_R_INVALID_DIGEST_TYPE);

            return 0;

        }

        dctx->md = p2;

        return 1;

    case EVP_PKEY_CTRL_GET_MD:

        *(const EVP_MD **)p2 = dctx->md;

        return 1;

    case EVP_PKEY_CTRL_DIGESTINIT:

    case EVP_PKEY_CTRL_PKCS7_SIGN:

    case EVP_PKEY_CTRL_CMS_SIGN:

        return 1;

    case EVP_PKEY_CTRL_PEER_KEY:

        DSAerr(DSA_F_PKEY_DSA_CTRL,

               EVP_R_OPERATION_NOT_SUPPORTED_FOR_THIS_KEYTYPE);

        return -2;

    default:

        return -2;

    }

}

static int pkey_dsa_ctrl_str(EVP_PKEY_CTX *ctx,

                             const char *type, const char *value)

{

    if (!strcmp(type, "dsa_paramgen_bits")) {

        int nbits;

        nbits = atoi(value);

        return EVP_PKEY_CTX_set_dsa_paramgen_bits(ctx, nbits);

    }

    if (!strcmp(type, "dsa_paramgen_q_bits")) {

        int qbits = atoi(value);

        return EVP_PKEY_CTX_ctrl(ctx, EVP_PKEY_DSA, EVP_PKEY_OP_PARAMGEN,

                                 EVP_PKEY_CTRL_DSA_PARAMGEN_Q_BITS, qbits,

                                 NULL);

    }

    if (!strcmp(type, "dsa_paramgen_md")) {

        return EVP_PKEY_CTX_ctrl(ctx, EVP_PKEY_DSA, EVP_PKEY_OP_PARAMGEN,

                                 EVP_PKEY_CTRL_DSA_PARAMGEN_MD, 0,

                                 (void *)EVP_get_digestbyname(value));

    }

    return -2;

}

static int pkey_dsa_paramgen(EVP_PKEY_CTX *ctx, EVP_PKEY *pkey)

{

    DSA *dsa = NULL;

    DSA_PKEY_CTX *dctx = ctx->data;

    BN_GENCB *pcb, cb;

    int ret;

    if (ctx->pkey_gencb) {

        pcb = &cb;

        evp_pkey_set_cb_translate(pcb, ctx);

    } else

        pcb = NULL;

    dsa = DSA_new();

    if (!dsa)

        return 0;

    ret = dsa_builtin_paramgen(dsa, dctx->nbits, dctx->qbits, dctx->pmd,

                               NULL, 0, NULL, NULL, NULL, pcb);

    if (ret)

        EVP_PKEY_assign_DSA(pkey, dsa);

    else

        DSA_free(dsa);

    return ret;

}

static int pkey_dsa_keygen(EVP_PKEY_CTX *ctx, EVP_PKEY *pkey)

{

    DSA *dsa = NULL;

    if (ctx->pkey == NULL) {

        DSAerr(DSA_F_PKEY_DSA_KEYGEN, DSA_R_NO_PARAMETERS_SET);

        return 0;

    }

    dsa = DSA_new();

    if (!dsa)

        return 0;

    EVP_PKEY_assign_DSA(pkey, dsa);

    /* Note: if error return, pkey is freed by parent routine */

    if (!EVP_PKEY_copy_parameters(pkey, ctx->pkey))

        return 0;

    return DSA_generate_key(pkey->pkey.dsa);

}

const EVP_PKEY_METHOD dsa_pkey_meth = {

    EVP_PKEY_DSA,

    EVP_PKEY_FLAG_AUTOARGLEN,

    pkey_dsa_init,

    pkey_dsa_copy,

    pkey_dsa_cleanup,

    0,

    pkey_dsa_paramgen,

    0,

    pkey_dsa_keygen,

    0,

    pkey_dsa_sign,

    0,

    pkey_dsa_verify,

    0, 0,

    0, 0, 0, 0,

    0, 0,

    0, 0,

    0, 0,

    pkey_dsa_ctrl,

    pkey_dsa_ctrl_str

};