/*

 * 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/x509.h>

#include <openssl/asn1.h>

#include <openssl/dsa.h>

#include <openssl/bn.h>

#ifndef OPENSSL_NO_CMS

# include <openssl/cms.h>

#endif

#include "asn1_locl.h"

static int dsa_pub_decode(EVP_PKEY *pkey, X509_PUBKEY *pubkey)

{

    const unsigned char *p, *pm;

    int pklen, pmlen;

    int ptype;

    void *pval;

    ASN1_STRING *pstr;

    X509_ALGOR *palg;

    ASN1_INTEGER *public_key = NULL;

    DSA *dsa = NULL;

    if (!X509_PUBKEY_get0_param(NULL, &p, &pklen, &palg, pubkey))

        return 0;

    X509_ALGOR_get0(NULL, &ptype, &pval, palg);

    if (ptype == V_ASN1_SEQUENCE) {

        pstr = pval;

        pm = pstr->data;

        pmlen = pstr->length;

        if (!(dsa = d2i_DSAparams(NULL, &pm, pmlen))) {

            DSAerr(DSA_F_DSA_PUB_DECODE, DSA_R_DECODE_ERROR);

            goto err;

        }

    } else if ((ptype == V_ASN1_NULL) || (ptype == V_ASN1_UNDEF)) {

        if (!(dsa = DSA_new())) {

            DSAerr(DSA_F_DSA_PUB_DECODE, ERR_R_MALLOC_FAILURE);

            goto err;

        }

    } else {

        DSAerr(DSA_F_DSA_PUB_DECODE, DSA_R_PARAMETER_ENCODING_ERROR);

        goto err;

    }

    if (!(public_key = d2i_ASN1_INTEGER(NULL, &p, pklen))) {

        DSAerr(DSA_F_DSA_PUB_DECODE, DSA_R_DECODE_ERROR);

        goto err;

    }

    if (!(dsa->pub_key = ASN1_INTEGER_to_BN(public_key, NULL))) {

        DSAerr(DSA_F_DSA_PUB_DECODE, DSA_R_BN_DECODE_ERROR);

        goto err;

    }

    ASN1_INTEGER_free(public_key);

    EVP_PKEY_assign_DSA(pkey, dsa);

    return 1;

 err:

    if (public_key)

        ASN1_INTEGER_free(public_key);

    if (dsa)

        DSA_free(dsa);

    return 0;

}

static int dsa_pub_encode(X509_PUBKEY *pk, const EVP_PKEY *pkey)

{

    DSA *dsa;

    int ptype;

    unsigned char *penc = NULL;

    int penclen;

    ASN1_STRING *str = NULL;

    dsa = pkey->pkey.dsa;

    if (pkey->save_parameters && dsa->p && dsa->q && dsa->g) {

        str = ASN1_STRING_new();

        if (!str) {

            DSAerr(DSA_F_DSA_PUB_ENCODE, ERR_R_MALLOC_FAILURE);

            goto err;

        }

        str->length = i2d_DSAparams(dsa, &str->data);

        if (str->length <= 0) {

            DSAerr(DSA_F_DSA_PUB_ENCODE, ERR_R_MALLOC_FAILURE);

            goto err;

        }

        ptype = V_ASN1_SEQUENCE;

    } else

        ptype = V_ASN1_UNDEF;

    dsa->write_params = 0;

    penclen = i2d_DSAPublicKey(dsa, &penc);

    if (penclen <= 0) {

        DSAerr(DSA_F_DSA_PUB_ENCODE, ERR_R_MALLOC_FAILURE);

        goto err;

    }

    if (X509_PUBKEY_set0_param(pk, OBJ_nid2obj(EVP_PKEY_DSA),

                               ptype, str, penc, penclen))

        return 1;

 err:

    if (penc)

        OPENSSL_free(penc);

    if (str)

        ASN1_STRING_free(str);

    return 0;

}

/*

 * In PKCS#8 DSA: you just get a private key integer and parameters in the

 * AlgorithmIdentifier the pubkey must be recalculated.

 */

static int dsa_priv_decode(EVP_PKEY *pkey, PKCS8_PRIV_KEY_INFO *p8)

{

    const unsigned char *p, *pm;

    int pklen, pmlen;

    int ptype;

    void *pval;

    ASN1_STRING *pstr;

    X509_ALGOR *palg;

    ASN1_INTEGER *privkey = NULL;

    BN_CTX *ctx = NULL;

    STACK_OF(ASN1_TYPE) *ndsa = NULL;

    DSA *dsa = NULL;

    int ret = 0;

    if (!PKCS8_pkey_get0(NULL, &p, &pklen, &palg, p8))

        return 0;

    X509_ALGOR_get0(NULL, &ptype, &pval, palg);

    /* Check for broken DSA PKCS#8, UGH! */

    if (*p == (V_ASN1_SEQUENCE | V_ASN1_CONSTRUCTED)) {

        ASN1_TYPE *t1, *t2;

        if (!(ndsa = d2i_ASN1_SEQUENCE_ANY(NULL, &p, pklen)))

            goto decerr;

        if (sk_ASN1_TYPE_num(ndsa) != 2)

            goto decerr;

        /*-

         * Handle Two broken types:

         * SEQUENCE {parameters, priv_key}

         * SEQUENCE {pub_key, priv_key}

         */

        t1 = sk_ASN1_TYPE_value(ndsa, 0);

        t2 = sk_ASN1_TYPE_value(ndsa, 1);

        if (t1->type == V_ASN1_SEQUENCE) {

            p8->broken = PKCS8_EMBEDDED_PARAM;

            pval = t1->value.ptr;

        } else if (ptype == V_ASN1_SEQUENCE)

            p8->broken = PKCS8_NS_DB;

        else

            goto decerr;

        if (t2->type != V_ASN1_INTEGER)

            goto decerr;

        privkey = t2->value.integer;

    } else {

        const unsigned char *q = p;

        if (!(privkey = d2i_ASN1_INTEGER(NULL, &p, pklen)))

            goto decerr;

        if (privkey->type == V_ASN1_NEG_INTEGER) {

            p8->broken = PKCS8_NEG_PRIVKEY;

            ASN1_STRING_clear_free(privkey);

            if (!(privkey = d2i_ASN1_UINTEGER(NULL, &q, pklen)))

                goto decerr;

        }

        if (ptype != V_ASN1_SEQUENCE)

            goto decerr;

    }

    pstr = pval;

    pm = pstr->data;

    pmlen = pstr->length;

    if (!(dsa = d2i_DSAparams(NULL, &pm, pmlen)))

        goto decerr;

    /* We have parameters now set private key */

    if (!(dsa->priv_key = ASN1_INTEGER_to_BN(privkey, NULL))) {

        DSAerr(DSA_F_DSA_PRIV_DECODE, DSA_R_BN_ERROR);

        goto dsaerr;

    }

    /* Calculate public key */

    if (!(dsa->pub_key = BN_new())) {

        DSAerr(DSA_F_DSA_PRIV_DECODE, ERR_R_MALLOC_FAILURE);

        goto dsaerr;

    }

    if (!(ctx = BN_CTX_new())) {

        DSAerr(DSA_F_DSA_PRIV_DECODE, ERR_R_MALLOC_FAILURE);

        goto dsaerr;

    }

    BN_set_flags(dsa->priv_key, BN_FLG_CONSTTIME);

    if (!BN_mod_exp(dsa->pub_key, dsa->g, dsa->priv_key, dsa->p, ctx)) {

        DSAerr(DSA_F_DSA_PRIV_DECODE, DSA_R_BN_ERROR);

        goto dsaerr;

    }

    EVP_PKEY_assign_DSA(pkey, dsa);

    ret = 1;

    goto done;

 decerr:

    DSAerr(DSA_F_DSA_PRIV_DECODE, DSA_R_DECODE_ERROR);

 dsaerr:

    DSA_free(dsa);

 done:

    BN_CTX_free(ctx);

    if (ndsa)

        sk_ASN1_TYPE_pop_free(ndsa, ASN1_TYPE_free);

    else

        ASN1_STRING_clear_free(privkey);

    return ret;

}

static int dsa_priv_encode(PKCS8_PRIV_KEY_INFO *p8, const EVP_PKEY *pkey)

{

    ASN1_STRING *params = NULL;

    ASN1_INTEGER *prkey = NULL;

    unsigned char *dp = NULL;

    int dplen;

    if (!pkey->pkey.dsa || !pkey->pkey.dsa->priv_key) {

        DSAerr(DSA_F_DSA_PRIV_ENCODE, DSA_R_MISSING_PARAMETERS);

        goto err;

    }

    params = ASN1_STRING_new();

    if (!params) {

        DSAerr(DSA_F_DSA_PRIV_ENCODE, ERR_R_MALLOC_FAILURE);

        goto err;

    }

    params->length = i2d_DSAparams(pkey->pkey.dsa, &params->data);

    if (params->length <= 0) {

        DSAerr(DSA_F_DSA_PRIV_ENCODE, ERR_R_MALLOC_FAILURE);

        goto err;

    }

    params->type = V_ASN1_SEQUENCE;

    /* Get private key into integer */

    prkey = BN_to_ASN1_INTEGER(pkey->pkey.dsa->priv_key, NULL);

    if (!prkey) {

        DSAerr(DSA_F_DSA_PRIV_ENCODE, DSA_R_BN_ERROR);

        goto err;

    }

    dplen = i2d_ASN1_INTEGER(prkey, &dp);

    ASN1_STRING_clear_free(prkey);

    prkey = NULL;

    if (!PKCS8_pkey_set0(p8, OBJ_nid2obj(NID_dsa), 0,

                         V_ASN1_SEQUENCE, params, dp, dplen))

        goto err;

    return 1;

 err:

    if (dp != NULL)

        OPENSSL_free(dp);

    if (params != NULL)

        ASN1_STRING_free(params);

    if (prkey != NULL)

        ASN1_STRING_clear_free(prkey);

    return 0;

}

static int int_dsa_size(const EVP_PKEY *pkey)

{

    return (DSA_size(pkey->pkey.dsa));

}

static int dsa_bits(const EVP_PKEY *pkey)

{

    return BN_num_bits(pkey->pkey.dsa->p);

}

static int dsa_missing_parameters(const EVP_PKEY *pkey)

{

    DSA *dsa;

    dsa = pkey->pkey.dsa;

    if (dsa == NULL || dsa->p == NULL || dsa->q == NULL || dsa->g == NULL)

        return 1;

    return 0;

}

static int dsa_copy_parameters(EVP_PKEY *to, const EVP_PKEY *from)

{

    BIGNUM *a;

    if ((a = BN_dup(from->pkey.dsa->p)) == NULL)

        return 0;

    if (to->pkey.dsa->p != NULL)

        BN_free(to->pkey.dsa->p);

    to->pkey.dsa->p = a;

    if ((a = BN_dup(from->pkey.dsa->q)) == NULL)

        return 0;

    if (to->pkey.dsa->q != NULL)

        BN_free(to->pkey.dsa->q);

    to->pkey.dsa->q = a;

    if ((a = BN_dup(from->pkey.dsa->g)) == NULL)

        return 0;

    if (to->pkey.dsa->g != NULL)

        BN_free(to->pkey.dsa->g);

    to->pkey.dsa->g = a;

    return 1;

}

static int dsa_cmp_parameters(const EVP_PKEY *a, const EVP_PKEY *b)

{

    if (BN_cmp(a->pkey.dsa->p, b->pkey.dsa->p) ||

        BN_cmp(a->pkey.dsa->q, b->pkey.dsa->q) ||

        BN_cmp(a->pkey.dsa->g, b->pkey.dsa->g))

        return 0;

    else

        return 1;

}

static int dsa_pub_cmp(const EVP_PKEY *a, const EVP_PKEY *b)

{

    if (BN_cmp(b->pkey.dsa->pub_key, a->pkey.dsa->pub_key) != 0)

        return 0;

    else

        return 1;

}

static void int_dsa_free(EVP_PKEY *pkey)

{

    DSA_free(pkey->pkey.dsa);

}

static void update_buflen(const BIGNUM *b, size_t *pbuflen)

{

    size_t i;

    if (!b)

        return;

    if (*pbuflen < (i = (size_t)BN_num_bytes(b)))

        *pbuflen = i;

}

static int do_dsa_print(BIO *bp, const DSA *x, int off, int ptype)

{

    unsigned char *m = NULL;

    int ret = 0;

    size_t buf_len = 0;

    const char *ktype = NULL;

    const BIGNUM *priv_key, *pub_key;

    if (ptype == 2)

        priv_key = x->priv_key;

    else

        priv_key = NULL;

    if (ptype > 0)

        pub_key = x->pub_key;

    else

        pub_key = NULL;

    if (ptype == 2)

        ktype = "Private-Key";

    else if (ptype == 1)

        ktype = "Public-Key";

    else

        ktype = "DSA-Parameters";

    update_buflen(x->p, &buf_len);

    update_buflen(x->q, &buf_len);

    update_buflen(x->g, &buf_len);

    update_buflen(priv_key, &buf_len);

    update_buflen(pub_key, &buf_len);

    m = (unsigned char *)OPENSSL_malloc(buf_len + 10);

    if (m == NULL) {

        DSAerr(DSA_F_DO_DSA_PRINT, ERR_R_MALLOC_FAILURE);

        goto err;

    }

    if (priv_key) {

        if (!BIO_indent(bp, off, 128))

            goto err;

        if (BIO_printf(bp, "%s: (%d bit)\n", ktype, BN_num_bits(x->p))

            <= 0)

            goto err;

    }

    if (!ASN1_bn_print(bp, "priv:", priv_key, m, off))

        goto err;

    if (!ASN1_bn_print(bp, "pub: ", pub_key, m, off))

        goto err;

    if (!ASN1_bn_print(bp, "P:   ", x->p, m, off))

        goto err;

    if (!ASN1_bn_print(bp, "Q:   ", x->q, m, off))

        goto err;

    if (!ASN1_bn_print(bp, "G:   ", x->g, m, off))

        goto err;

    ret = 1;

 err:

    if (m != NULL)

        OPENSSL_free(m);

    return (ret);

}

static int dsa_param_decode(EVP_PKEY *pkey,

                            const unsigned char **pder, int derlen)

{

    DSA *dsa;

    if (!(dsa = d2i_DSAparams(NULL, pder, derlen))) {

        DSAerr(DSA_F_DSA_PARAM_DECODE, ERR_R_DSA_LIB);

        return 0;

    }

    EVP_PKEY_assign_DSA(pkey, dsa);

    return 1;

}

static int dsa_param_encode(const EVP_PKEY *pkey, unsigned char **pder)

{

    return i2d_DSAparams(pkey->pkey.dsa, pder);

}

static int dsa_param_print(BIO *bp, const EVP_PKEY *pkey, int indent,

                           ASN1_PCTX *ctx)

{

    return do_dsa_print(bp, pkey->pkey.dsa, indent, 0);

}

static int dsa_pub_print(BIO *bp, const EVP_PKEY *pkey, int indent,

                         ASN1_PCTX *ctx)

{

    return do_dsa_print(bp, pkey->pkey.dsa, indent, 1);

}

static int dsa_priv_print(BIO *bp, const EVP_PKEY *pkey, int indent,

                          ASN1_PCTX *ctx)

{

    return do_dsa_print(bp, pkey->pkey.dsa, indent, 2);

}

static int old_dsa_priv_decode(EVP_PKEY *pkey,

                               const unsigned char **pder, int derlen)

{

    DSA *dsa;

    if (!(dsa = d2i_DSAPrivateKey(NULL, pder, derlen))) {

        DSAerr(DSA_F_OLD_DSA_PRIV_DECODE, ERR_R_DSA_LIB);

        return 0;

    }

    EVP_PKEY_assign_DSA(pkey, dsa);

    return 1;

}

static int old_dsa_priv_encode(const EVP_PKEY *pkey, unsigned char **pder)

{

    return i2d_DSAPrivateKey(pkey->pkey.dsa, pder);

}

static int dsa_sig_print(BIO *bp, const X509_ALGOR *sigalg,

                         const ASN1_STRING *sig, int indent, ASN1_PCTX *pctx)

{

    DSA_SIG *dsa_sig;

    const unsigned char *p;

    if (!sig) {

        if (BIO_puts(bp, "\n") <= 0)

            return 0;

        else

            return 1;

    }

    p = sig->data;

    dsa_sig = d2i_DSA_SIG(NULL, &p, sig->length);

    if (dsa_sig) {

        int rv = 0;

        size_t buf_len = 0;

        unsigned char *m = NULL;

        update_buflen(dsa_sig->r, &buf_len);

        update_buflen(dsa_sig->s, &buf_len);

        m = OPENSSL_malloc(buf_len + 10);

        if (m == NULL) {

            DSAerr(DSA_F_DSA_SIG_PRINT, ERR_R_MALLOC_FAILURE);

            goto err;

        }

        if (BIO_write(bp, "\n", 1) != 1)

            goto err;

        if (!ASN1_bn_print(bp, "r:   ", dsa_sig->r, m, indent))

            goto err;

        if (!ASN1_bn_print(bp, "s:   ", dsa_sig->s, m, indent))

            goto err;

        rv = 1;

 err:

        if (m)

            OPENSSL_free(m);

        DSA_SIG_free(dsa_sig);

        return rv;

    }

    return X509_signature_dump(bp, sig, indent);

}

static int dsa_pkey_ctrl(EVP_PKEY *pkey, int op, long arg1, void *arg2)

{

    switch (op) {

    case ASN1_PKEY_CTRL_PKCS7_SIGN:

        if (arg1 == 0) {

            int snid, hnid;

            X509_ALGOR *alg1, *alg2;

            PKCS7_SIGNER_INFO_get0_algs(arg2, NULL, &alg1, &alg2);

            if (alg1 == NULL || alg1->algorithm == NULL)

                return -1;

            hnid = OBJ_obj2nid(alg1->algorithm);

            if (hnid == NID_undef)

                return -1;

            if (!OBJ_find_sigid_by_algs(&snid, hnid, EVP_PKEY_id(pkey)))

                return -1;

            X509_ALGOR_set0(alg2, OBJ_nid2obj(snid), V_ASN1_UNDEF, 0);

        }

        return 1;

#ifndef OPENSSL_NO_CMS

    case ASN1_PKEY_CTRL_CMS_SIGN:

        if (arg1 == 0) {

            int snid, hnid;

            X509_ALGOR *alg1, *alg2;

            CMS_SignerInfo_get0_algs(arg2, NULL, NULL, &alg1, &alg2);

            if (alg1 == NULL || alg1->algorithm == NULL)

                return -1;

            hnid = OBJ_obj2nid(alg1->algorithm);

            if (hnid == NID_undef)

                return -1;

            if (!OBJ_find_sigid_by_algs(&snid, hnid, EVP_PKEY_id(pkey)))

                return -1;

            X509_ALGOR_set0(alg2, OBJ_nid2obj(snid), V_ASN1_UNDEF, 0);

        }

        return 1;

    case ASN1_PKEY_CTRL_CMS_RI_TYPE:

        *(int *)arg2 = CMS_RECIPINFO_NONE;

        return 1;

#endif

    case ASN1_PKEY_CTRL_DEFAULT_MD_NID:

        *(int *)arg2 = NID_sha256;

        return 2;

    default:

        return -2;

    }

}

/* NB these are sorted in pkey_id order, lowest first */

const EVP_PKEY_ASN1_METHOD dsa_asn1_meths[] = {

    {

     EVP_PKEY_DSA2,

     EVP_PKEY_DSA,

     ASN1_PKEY_ALIAS},

    {

     EVP_PKEY_DSA1,

     EVP_PKEY_DSA,

     ASN1_PKEY_ALIAS},

    {

     EVP_PKEY_DSA4,

     EVP_PKEY_DSA,

     ASN1_PKEY_ALIAS},

    {

     EVP_PKEY_DSA3,

     EVP_PKEY_DSA,

     ASN1_PKEY_ALIAS},

    {

     EVP_PKEY_DSA,

     EVP_PKEY_DSA,

     0,

     "DSA",

     "OpenSSL DSA method",

     dsa_pub_decode,

     dsa_pub_encode,

     dsa_pub_cmp,

     dsa_pub_print,

     dsa_priv_decode,

     dsa_priv_encode,

     dsa_priv_print,

     int_dsa_size,

     dsa_bits,

     dsa_param_decode,

     dsa_param_encode,

     dsa_missing_parameters,

     dsa_copy_parameters,

     dsa_cmp_parameters,

     dsa_param_print,

     dsa_sig_print,

     int_dsa_free,

     dsa_pkey_ctrl,

     old_dsa_priv_decode,

     old_dsa_priv_encode}

};