/*
 * CDDL HEADER START
 *
 * The contents of this file are subject to the terms of the
 * Common Development and Distribution License (the "License").
 * You may not use this file except in compliance with the License.
 *
 * You can obtain a copy of the license at usr/src/OPENSOLARIS.LICENSE
 * or http://www.opensolaris.org/os/licensing.
 * See the License for the specific language governing permissions
 * and limitations under the License.
 *
 * When distributing Covered Code, include this CDDL HEADER in each
 * file and include the License file at usr/src/OPENSOLARIS.LICENSE.
 * If applicable, add the following below this CDDL HEADER, with the
 * fields enclosed by brackets "[]" replaced with your own identifying
 * information: Portions Copyright [yyyy] [name of copyright owner]
 *
 * CDDL HEADER END
 */

/*
 * Copyright 2007 Sun Microsystems, Inc.  All rights reserved.
 * Use is subject to license terms.
 */

/*
 * Deimos - cryptographic acceleration based upon Broadcom 582x.
 */

#include <sys/types.h>
#include <sys/ddi.h>
#include <sys/sunddi.h>
#include <sys/kmem.h>
#include <sys/note.h>
#include <sys/crypto/spi.h>
#include <sys/crypto/dca.h>


static void dca_rsaverifydone(dca_request_t *, int);
static void dca_rsadone(dca_request_t *, int);

/* Exported function prototypes */
int dca_rsastart(crypto_ctx_t *, crypto_data_t *, crypto_data_t *,
    crypto_req_handle_t, int);
int dca_rsainit(crypto_ctx_t *, crypto_mechanism_t *, crypto_key_t *, int);
void dca_rsactxfree(void *);
int dca_rsaatomic(crypto_provider_handle_t, crypto_session_id_t,
    crypto_mechanism_t *, crypto_key_t *, crypto_data_t *, crypto_data_t *,
    int, crypto_req_handle_t, int);

/* Local function prototypes */
static int dca_pkcs1_padding(dca_t *dca, caddr_t buf, int flen, int tlen,
    int private);
static int dca_pkcs1_unpadding(char *buf, int *tlen, int flen, int mode);
static int dca_x509_padding(caddr_t buf, int flen, int tlen);
static int dca_x509_unpadding(char *buf, int tlen, int flen, int mode);
static int decrypt_error_code(int mode, int decrypt, int verify, int def);


int dca_rsastart(crypto_ctx_t *ctx, crypto_data_t *in, crypto_data_t *out,
    crypto_req_handle_t req, int mode)
{
        dca_request_t           *reqp = ctx->cc_provider_private;
        dca_t                   *dca = ctx->cc_provider;
        caddr_t                 daddr;
        int                     rv = CRYPTO_QUEUED;
        int                     len;

        /* We don't support non-contiguous buffers for RSA */
        if (dca_sgcheck(dca, in, DCA_SG_CONTIG) ||
            dca_sgcheck(dca, out, DCA_SG_CONTIG)) {
                rv = CRYPTO_NOT_SUPPORTED;
                goto errout;
        }

        len = dca_length(in);

        /* Extracting the key attributes is now done in dca_rsainit(). */
        if (mode == DCA_RSA_ENC || mode == DCA_RSA_SIGN ||
            mode == DCA_RSA_SIGNR) {
                /*
                 * Return length needed to store the output.
                 * For sign, sign-recover, and encrypt, the output buffer
                 * should not be smaller than modlen since PKCS or X_509
                 * padding will be applied
                 */
                if (dca_length(out) < reqp->dr_ctx.modlen) {
                        DBG(dca, DWARN,
                            "dca_rsastart: output buffer too short (%d < %d)",
                            dca_length(out), reqp->dr_ctx.modlen);
                        out->cd_length = reqp->dr_ctx.modlen;
                        rv = CRYPTO_BUFFER_TOO_SMALL;
                        goto errout;
                }
        }
        if (out != in && out->cd_length > reqp->dr_ctx.modlen)
                out->cd_length = reqp->dr_ctx.modlen;

        /* The input length should not be bigger than the modulus */
        if (len > reqp->dr_ctx.modlen) {
                rv = decrypt_error_code(mode, CRYPTO_ENCRYPTED_DATA_LEN_RANGE,
                    CRYPTO_SIGNATURE_LEN_RANGE, CRYPTO_DATA_LEN_RANGE);
                goto errout;
        }

        /*
         * For decryption, verify, and verifyRecover, the input length should
         * not be less than the modulus
         */
        if (len < reqp->dr_ctx.modlen && (mode == DCA_RSA_DEC ||
            mode == DCA_RSA_VRFY || mode == DCA_RSA_VRFYR)) {
                rv = decrypt_error_code(mode, CRYPTO_ENCRYPTED_DATA_LEN_RANGE,
                    CRYPTO_SIGNATURE_LEN_RANGE, CRYPTO_DATA_LEN_RANGE);
                goto errout;
        }

        /*
         * For decryption and verifyRecover, the output buffer should not
         * be less than the modulus
         */
        if (out->cd_length < reqp->dr_ctx.modlen && (mode == DCA_RSA_DEC ||
            mode == DCA_RSA_VRFYR) &&
            reqp->dr_ctx.ctx_cm_type == RSA_X_509_MECH_INFO_TYPE) {
                out->cd_length = reqp->dr_ctx.modlen;
                rv = CRYPTO_BUFFER_TOO_SMALL;
                goto errout;
        }

        /* For decrypt and verify, the input should not be less than output */
        if (out && len < out->cd_length) {
                if ((rv = decrypt_error_code(mode,
                    CRYPTO_ENCRYPTED_DATA_LEN_RANGE,
                    CRYPTO_SIGNATURE_LEN_RANGE, CRYPTO_SUCCESS)) !=
                    CRYPTO_SUCCESS)
                        goto errout;
        }

        if ((daddr = dca_bufdaddr(in)) == NULL && len > 0) {
                rv = CRYPTO_ARGUMENTS_BAD;
                goto errout;
        }

        if (dca_numcmp(daddr, len, (char *)reqp->dr_ctx.mod,
            reqp->dr_ctx.modlen) > 0) {
                DBG(dca, DWARN,
                    "dca_rsastart: input larger (numerically) than modulus!");
                rv = decrypt_error_code(mode, CRYPTO_ENCRYPTED_DATA_INVALID,
                    CRYPTO_SIGNATURE_INVALID, CRYPTO_DATA_INVALID);
                goto errout;
        }

        reqp->dr_byte_stat = -1;
        reqp->dr_in = in;
        reqp->dr_out = out;
        reqp->dr_kcf_req = req;
        if (mode == DCA_RSA_VRFY)
                reqp->dr_callback = dca_rsaverifydone;
        else
                reqp->dr_callback = dca_rsadone;

        dca_reverse(daddr, reqp->dr_ibuf_kaddr, len, reqp->dr_pkt_length);
        if (mode == DCA_RSA_ENC || mode == DCA_RSA_SIGN ||
            mode == DCA_RSA_SIGNR) {
                /*
                 * Needs to pad appropriately for encrypt, sign, and
                 * sign_recover
                 */
                if (reqp->dr_ctx.ctx_cm_type == RSA_PKCS_MECH_INFO_TYPE) {
                        if ((rv = dca_pkcs1_padding(dca, reqp->dr_ibuf_kaddr,
                            len, reqp->dr_ctx.modlen, reqp->dr_ctx.pqfix)) !=
                            CRYPTO_QUEUED)
                                goto errout;
                } else if (reqp->dr_ctx.ctx_cm_type ==
                    RSA_X_509_MECH_INFO_TYPE) {
                        if ((rv = dca_x509_padding(reqp->dr_ibuf_kaddr,
                            len, reqp->dr_pkt_length)) != CRYPTO_QUEUED)
                                goto errout;
                }
        }
        reqp->dr_ctx.mode = mode;

        /*
         * Since the max RSA input size is 256 bytes (2048 bits), the firstx
         * page (at least 4096 bytes) in the pre-mapped buffer is large enough.
         * Therefore, we use this first page for RSA.
         */
        reqp->dr_in_paddr = reqp->dr_ibuf_head.dc_buffer_paddr;
        reqp->dr_in_next = 0;
        reqp->dr_in_len = reqp->dr_pkt_length;
        reqp->dr_out_paddr = reqp->dr_obuf_head.dc_buffer_paddr;
        reqp->dr_out_next = 0;
        reqp->dr_out_len = reqp->dr_pkt_length;

        /* schedule the work by doing a submit */
        rv = dca_start(dca, reqp, MCR2, 1);


errout:
        if (rv != CRYPTO_QUEUED && rv != CRYPTO_BUFFER_TOO_SMALL)
                (void) dca_free_context(ctx);

        return (rv);
}

void
dca_rsadone(dca_request_t *reqp, int errno)
{
        if (errno == CRYPTO_SUCCESS) {
                int     outsz = reqp->dr_out->cd_length;
                caddr_t daddr;

                (void) ddi_dma_sync(reqp->dr_obuf_dmah, 0, reqp->dr_out_len,
                    DDI_DMA_SYNC_FORKERNEL);
                if (dca_check_dma_handle(reqp->dr_dca, reqp->dr_obuf_dmah,
                    DCA_FM_ECLASS_NONE) != DDI_SUCCESS) {
                        reqp->destroy = TRUE;
                        errno = CRYPTO_DEVICE_ERROR;
                        goto errout;
                }

                if (reqp->dr_ctx.mode == DCA_RSA_DEC ||
                    reqp->dr_ctx.mode == DCA_RSA_VRFY ||
                    reqp->dr_ctx.mode == DCA_RSA_VRFYR) {
                        /*
                         * Needs to unpad appropriately for decrypt, verify,
                         * and verify_recover
                         */
                        if (reqp->dr_ctx.ctx_cm_type ==
                            RSA_PKCS_MECH_INFO_TYPE) {
                                errno = dca_pkcs1_unpadding(
                                    reqp->dr_obuf_kaddr, &outsz,
                                    reqp->dr_ctx.modlen, reqp->dr_ctx.mode);

                                /* check for bad data errors */
                                if (errno != CRYPTO_SUCCESS &&
                                    errno != CRYPTO_BUFFER_TOO_SMALL) {
                                        goto errout;
                                }
                                if (dca_bufdaddr(reqp->dr_out) == NULL) {
                                        errno = CRYPTO_BUFFER_TOO_SMALL;
                                }
                                if (errno == CRYPTO_BUFFER_TOO_SMALL) {
                                        reqp->dr_out->cd_length = outsz;
                                        goto errout;
                                }
                                /* Reset the output data length */
                                reqp->dr_out->cd_length = outsz;
                        } else if (reqp->dr_ctx.ctx_cm_type ==
                            RSA_X_509_MECH_INFO_TYPE) {
                                if ((errno = dca_x509_unpadding(
                                    reqp->dr_obuf_kaddr, outsz,
                                    reqp->dr_pkt_length, reqp->dr_ctx.mode)) !=
                                    CRYPTO_SUCCESS)
                                        goto errout;
                        }
                }

                if ((daddr = dca_bufdaddr(reqp->dr_out)) == NULL) {
                        DBG(reqp->dr_dca, DINTR,
                            "dca_rsadone: reqp->dr_out is bad");
                        errno = CRYPTO_ARGUMENTS_BAD;
                        goto errout;
                }
                /*
                 * Note that there may be some number of null bytes
                 * at the end of the source (result), but we don't care
                 * about them -- they are place holders only and are
                 * truncated here.
                 */
                dca_reverse(reqp->dr_obuf_kaddr, daddr, outsz, outsz);
        }
errout:
        ASSERT(reqp->dr_kcf_req != NULL);

        /* notify framework that request is completed */
        crypto_op_notification(reqp->dr_kcf_req, errno);
        DBG(reqp->dr_dca, DINTR,
            "dca_rsadone: returning 0x%x to the kef via crypto_op_notification",
            errno);

        /*
         * For non-atomic operations, reqp will be freed in the kCF
         * callback function since it may be needed again if
         * CRYPTO_BUFFER_TOO_SMALL is returned to kCF
         */
        if (reqp->dr_ctx.atomic) {
                crypto_ctx_t ctx;
                ctx.cc_provider_private = reqp;
                dca_rsactxfree(&ctx);
        }
}

void
dca_rsaverifydone(dca_request_t *reqp, int errno)
{
        if (errno == CRYPTO_SUCCESS) {
                char    scratch[RSA_MAX_KEY_LEN];
                int     outsz = reqp->dr_out->cd_length;
                caddr_t daddr;

                /*
                 * ASSUMPTION: the signature length was already
                 * checked on the way in, and it is a valid length.
                 */
                (void) ddi_dma_sync(reqp->dr_obuf_dmah, 0, outsz,
                    DDI_DMA_SYNC_FORKERNEL);
                if (dca_check_dma_handle(reqp->dr_dca, reqp->dr_obuf_dmah,
                    DCA_FM_ECLASS_NONE) != DDI_SUCCESS) {
                        reqp->destroy = TRUE;
                        errno = CRYPTO_DEVICE_ERROR;
                        goto errout;
                }

                if (reqp->dr_ctx.mode == DCA_RSA_DEC ||
                    reqp->dr_ctx.mode == DCA_RSA_VRFY ||
                    reqp->dr_ctx.mode == DCA_RSA_VRFYR) {
                        /*
                         * Needs to unpad appropriately for decrypt, verify,
                         * and verify_recover
                         */
                        if (reqp->dr_ctx.ctx_cm_type ==
                            RSA_PKCS_MECH_INFO_TYPE) {
                                errno = dca_pkcs1_unpadding(
                                    reqp->dr_obuf_kaddr, &outsz,
                                    reqp->dr_ctx.modlen, reqp->dr_ctx.mode);

                                /* check for bad data errors */
                                if (errno != CRYPTO_SUCCESS &&
                                    errno != CRYPTO_BUFFER_TOO_SMALL) {
                                        goto errout;
                                }
                                if (dca_bufdaddr(reqp->dr_out) == NULL) {
                                        errno = CRYPTO_BUFFER_TOO_SMALL;
                                }
                                if (errno == CRYPTO_BUFFER_TOO_SMALL) {
                                        reqp->dr_out->cd_length = outsz;
                                        goto errout;
                                }
                                /* Reset the output data length */
                                reqp->dr_out->cd_length = outsz;
                        } else if (reqp->dr_ctx.ctx_cm_type ==
                            RSA_X_509_MECH_INFO_TYPE) {
                                if ((errno = dca_x509_unpadding(
                                    reqp->dr_obuf_kaddr, outsz,
                                    reqp->dr_pkt_length, reqp->dr_ctx.mode)) !=
                                    CRYPTO_SUCCESS)
                                        goto errout;
                        }
                }

                dca_reverse(reqp->dr_obuf_kaddr, scratch, outsz, outsz);

                if ((daddr = dca_bufdaddr(reqp->dr_out)) == NULL) {
                        errno = CRYPTO_ARGUMENTS_BAD;
                        goto errout;
                }
                if (dca_numcmp(daddr, reqp->dr_out->cd_length, scratch,
                    outsz) != 0) {
                        /* VERIFY FAILED */
                        errno = CRYPTO_SIGNATURE_INVALID;
                }
        }
errout:
        ASSERT(reqp->dr_kcf_req != NULL);

        /* notify framework that request is completed */
        crypto_op_notification(reqp->dr_kcf_req, errno);
        DBG(reqp->dr_dca, DINTR,
            "dca_rsaverifydone: rtn 0x%x to the kef via crypto_op_notification",
            errno);

        /*
         * For non-atomic operations, reqp will be freed in the kCF
         * callback function since it may be needed again if
         * CRYPTO_BUFFER_TOO_SMALL is returned to kCF
         */
        if (reqp->dr_ctx.atomic) {
                crypto_ctx_t ctx;
                ctx.cc_provider_private = reqp;
                dca_rsactxfree(&ctx);
        }
}

/*
 * Setup either a public or a private RSA key for subsequent uses
 */
int
dca_rsainit(crypto_ctx_t *ctx, crypto_mechanism_t *mechanism,
    crypto_key_t *key, int kmflag)
{
        crypto_object_attribute_t       *attr;
        unsigned                        expname = 0;
        void                            *attrdata;
        int rv;

        uchar_t                 *exp;
        uchar_t                 *p;
        uchar_t                 *q;
        uchar_t                 *dp;
        uchar_t                 *dq;
        uchar_t                 *pinv;

        unsigned                explen = 0;
        unsigned                plen = 0;
        unsigned                qlen = 0;
        unsigned                dplen = 0;
        unsigned                dqlen = 0;
        unsigned                pinvlen = 0;

        unsigned                modbits, expbits, pbits, qbits;
        unsigned                modfix, expfix, pqfix = 0;
        uint16_t                ctxlen;
        caddr_t                 kaddr;
        dca_request_t           *reqp = NULL;
        dca_t                   *dca = (dca_t *)ctx->cc_provider;

        DBG(NULL, DENTRY, "dca_rsainit: start");

        if ((reqp = dca_getreq(dca, MCR2, 1)) == NULL) {
                DBG(NULL, DWARN,
                    "dca_rsainit: unable to allocate request for RSA");
                rv = CRYPTO_HOST_MEMORY;
                goto errout;
        }

        reqp->dr_ctx.ctx_cm_type = mechanism->cm_type;
        ctx->cc_provider_private = reqp;

        /*
         * Key type can be either RAW, or REFERENCE, or ATTR_LIST (VALUE).
         * Only ATTR_LIST is supported on Deimos for RSA.
         */
        if ((attr = dca_get_key_attr(key)) == NULL) {
                DBG(NULL, DWARN, "dca_rsainit: key attributes missing");
                rv = CRYPTO_KEY_TYPE_INCONSISTENT;
                goto errout;
        }

        if (dca_find_attribute(attr, key->ck_count, CKA_PUBLIC_EXPONENT))
                expname = CKA_PUBLIC_EXPONENT;

        /*
         * RSA public key has only public exponent. RSA private key must have
         * private exponent. However, it may also have public exponent.
         * Thus, the existance of a private exponent indicates a private key.
         */
        if (dca_find_attribute(attr, key->ck_count, CKA_PRIVATE_EXPONENT))
                expname = CKA_PRIVATE_EXPONENT;

        if (!expname) {
                DBG(NULL, DWARN, "dca_rsainit: no exponent in key");
                rv = CRYPTO_ARGUMENTS_BAD;
                goto errout;
        }

        /* Modulus */
        if ((rv = dca_attr_lookup_uint8_array(attr, key->ck_count, CKA_MODULUS,
            &attrdata, &(reqp->dr_ctx.modlen))) != CRYPTO_SUCCESS) {
                DBG(NULL, DWARN, "dca_rsainit: failed to retrieve modulus");
                goto errout;
        }
        if ((reqp->dr_ctx.modlen == 0) ||
            (reqp->dr_ctx.modlen > RSA_MAX_KEY_LEN)) {
                DBG(NULL, DWARN, "dca_rsainit: bad modulus size");
                rv = CRYPTO_ARGUMENTS_BAD;
                goto errout;
        }
        if ((reqp->dr_ctx.mod = kmem_alloc(reqp->dr_ctx.modlen, kmflag)) ==
            NULL) {
                rv = CRYPTO_HOST_MEMORY;
                goto errout;
        }
        bcopy(attrdata, reqp->dr_ctx.mod, reqp->dr_ctx.modlen);

        /* Exponent */
        if ((rv = dca_attr_lookup_uint8_array(attr, key->ck_count, expname,
            (void **) &exp, &explen)) != CRYPTO_SUCCESS) {
                DBG(NULL, DWARN, "dca_rsainit: failed to retrieve exponent");
                goto errout;
        }
        if ((explen == 0) || (explen > RSA_MAX_KEY_LEN)) {
                DBG(NULL, DWARN, "dca_rsainit: bad exponent size");
                rv = CRYPTO_ARGUMENTS_BAD;
                goto errout;
        }

        /* Lookup private attributes */
        if (expname == CKA_PRIVATE_EXPONENT) {
                /* Prime 1 */
                (void) dca_attr_lookup_uint8_array(attr, key->ck_count,
                    CKA_PRIME_1, (void **)&q, &qlen);

                /* Prime 2 */
                (void) dca_attr_lookup_uint8_array(attr, key->ck_count,
                    CKA_PRIME_2, (void **)&p, &plen);

                /* Exponent 1 */
                (void) dca_attr_lookup_uint8_array(attr, key->ck_count,
                    CKA_EXPONENT_1, (void **)&dq, &dqlen);

                /* Exponent 2 */
                (void) dca_attr_lookup_uint8_array(attr, key->ck_count,
                    CKA_EXPONENT_2, (void **)&dp, &dplen);

                /* Coefficient */
                (void) dca_attr_lookup_uint8_array(attr, key->ck_count,
                    CKA_COEFFICIENT, (void **)&pinv, &pinvlen);
        }

        modbits = dca_bitlen(reqp->dr_ctx.mod, reqp->dr_ctx.modlen);
        expbits = dca_bitlen(exp, explen);

        if ((modfix = dca_padfull(modbits)) == 0) {
                DBG(NULL, DWARN, "dca_rsainit: modulus too long");
                rv = CRYPTO_KEY_SIZE_RANGE;
                goto errout;
        }
        expfix =  ROUNDUP(explen, sizeof (uint32_t));

        if (plen && qlen && dplen && dqlen && pinvlen) {
                unsigned pfix, qfix;
                qbits = dca_bitlen(q, qlen);
                pbits = dca_bitlen(p, plen);
                qfix = dca_padhalf(qbits);
                pfix = dca_padhalf(pbits);
                if (pfix & qfix)
                        pqfix = max(pfix, qfix);
        }

        if (pqfix) {
                reqp->dr_job_stat = DS_RSAPRIVATE;
                reqp->dr_pkt_length = 2 * pqfix;
        } else {
                reqp->dr_job_stat = DS_RSAPUBLIC;
                reqp->dr_pkt_length = modfix;
        }

        if (pqfix) {
                /*
                 * NOTE: chip's notion of p vs. q is reversed from
                 * PKCS#11.  We use the chip's notion in our variable
                 * naming.
                 */
                ctxlen = 8 + pqfix * 5;

                /* write out the context structure */
                PUTCTX16(reqp, CTX_CMD, CMD_RSAPRIVATE);
                PUTCTX16(reqp, CTX_LENGTH, ctxlen);
                /* exponent and modulus length in bits!!! */
                PUTCTX16(reqp, CTX_RSAQLEN, qbits);
                PUTCTX16(reqp, CTX_RSAPLEN, pbits);

                kaddr = reqp->dr_ctx_kaddr + CTX_RSABIGNUMS;

                /* store the bignums */
                dca_reverse(p, kaddr, plen, pqfix);
                kaddr += pqfix;

                dca_reverse(q, kaddr, qlen, pqfix);
                kaddr += pqfix;

                dca_reverse(dp, kaddr, dplen, pqfix);
                kaddr += pqfix;

                dca_reverse(dq, kaddr, dqlen, pqfix);
                kaddr += pqfix;

                dca_reverse(pinv, kaddr, pinvlen, pqfix);
                kaddr += pqfix;
        } else {
                ctxlen = 8 + modfix + expfix;
                /* write out the context structure */
                PUTCTX16(reqp, CTX_CMD, CMD_RSAPUBLIC);
                PUTCTX16(reqp, CTX_LENGTH, (uint16_t)ctxlen);
                /* exponent and modulus length in bits!!! */
                PUTCTX16(reqp, CTX_RSAEXPLEN, expbits);
                PUTCTX16(reqp, CTX_RSAMODLEN, modbits);

                kaddr = reqp->dr_ctx_kaddr + CTX_RSABIGNUMS;

                /* store the bignums */
                dca_reverse(reqp->dr_ctx.mod, kaddr, reqp->dr_ctx.modlen,
                    modfix);
                kaddr += modfix;

                dca_reverse(exp, kaddr, explen, expfix);
                kaddr += expfix;
        }

        reqp->dr_ctx.pqfix = pqfix;

errout:
        if (rv != CRYPTO_SUCCESS)
                dca_rsactxfree(ctx);

        return (rv);
}

void
dca_rsactxfree(void *arg)
{
        crypto_ctx_t    *ctx = (crypto_ctx_t *)arg;
        dca_request_t   *reqp = ctx->cc_provider_private;

        if (reqp == NULL)
                return;

        if (reqp->dr_ctx.mod)
                kmem_free(reqp->dr_ctx.mod, reqp->dr_ctx.modlen);

        reqp->dr_ctx.mode = 0;
        reqp->dr_ctx.ctx_cm_type = 0;
        reqp->dr_ctx.mod = NULL;
        reqp->dr_ctx.modlen = 0;
        reqp->dr_ctx.pqfix = 0;
        reqp->dr_ctx.atomic = 0;

        if (reqp->destroy)
                dca_destroyreq(reqp);
        else
                dca_freereq(reqp);

        ctx->cc_provider_private = NULL;
}

int
dca_rsaatomic(crypto_provider_handle_t provider,
    crypto_session_id_t session_id, crypto_mechanism_t *mechanism,
    crypto_key_t *key, crypto_data_t *input, crypto_data_t *output,
    int kmflag, crypto_req_handle_t req, int mode)
{
        crypto_ctx_t    ctx;    /* on the stack */
        int             rv;

        ctx.cc_provider = provider;
        ctx.cc_session = session_id;

        rv = dca_rsainit(&ctx, mechanism, key, kmflag);
        if (rv != CRYPTO_SUCCESS) {
                DBG(NULL, DWARN, "dca_rsaatomic: dca_rsainit() failed");
                /* The content of ctx should have been freed already */
                return (rv);
        }

        /*
         * Set the atomic flag so that the hardware callback function
         * will free the context.
         */
        ((dca_request_t *)ctx.cc_provider_private)->dr_ctx.atomic = 1;

        /* check for inplace ops */
        if (input == output) {
                ((dca_request_t *)ctx.cc_provider_private)->dr_flags
                    |= DR_INPLACE;
        }

        rv = dca_rsastart(&ctx, input, output, req, mode);

        /*
         * The context will be freed in the hardware callback function if it
         * is queued
         */
        if (rv != CRYPTO_QUEUED)
                dca_rsactxfree(&ctx);

        return (rv);
}


/*
 * For RSA_PKCS padding and unpadding:
 * 1. The minimum padding is 11 bytes.
 * 2. The first and the last bytes must 0.
 * 3. The second byte is 1 for private and 2 for public keys.
 * 4. Pad with 0xff for private and non-zero random for public keys.
 */
static int
dca_pkcs1_padding(dca_t *dca, caddr_t buf, int flen, int tlen, int private)
{
        int i;

        DBG(NULL, DENTRY,
            "dca_pkcs1_padding: tlen: %d, flen: %d: private: %d\n",
            tlen, flen, private);

        if (flen > tlen - 11)
                return (CRYPTO_DATA_LEN_RANGE);

        if (private) {
                /* Padding for private encrypt */
                buf[flen] = '\0';
                for (i = flen + 1; i < tlen - 2; i++) {
                        buf[i] = (unsigned char) 0xff;
                }
                buf[tlen - 2] = 1;
                buf[tlen - 1] = 0;
        } else {
                /* Padding for public encrypt */
                buf[flen] = '\0';

                if (dca_random_buffer(dca, &buf[flen+1], tlen - flen - 3) !=
                    CRYPTO_SUCCESS)
                        return (CRYPTO_RANDOM_NO_RNG);

                buf[tlen - 2] = 2;
                buf[tlen - 1] = 0;
        }

        return (CRYPTO_QUEUED);
}

static int
dca_pkcs1_unpadding(char *buf, int *tlen, int flen, int mode)
{
        int i;
        const unsigned char *p;
        unsigned char type;

        DBG(NULL, DENTRY, "dca_pkcs1_unpadding: tlen: %d, flen: %d\n",
            *tlen, flen);

        p = (unsigned char *) buf + (flen-1);
        if (*(p--) != 0)
                return decrypt_error_code(mode, CRYPTO_ENCRYPTED_DATA_INVALID,
                    CRYPTO_SIGNATURE_INVALID, CRYPTO_DATA_INVALID);

        /* It is ok if the data length is 0 after removing the padding */
        type = *(p--);
        if (type == 01) {
                for (i = flen - 3; i >= 0; i--) {
                        if (*p != 0xff) {
                                if (*p == '\0') {
                                        p--;
                                        break;
                                } else {
                                        return decrypt_error_code(mode,
                                            CRYPTO_ENCRYPTED_DATA_INVALID,
                                            CRYPTO_SIGNATURE_INVALID,
                                            CRYPTO_DATA_INVALID);
                                }
                        }
                        p--;
                }
        } else if (type == 02) {
                for (i = flen - 3; i >= 0; i--) {
                        if (*p == '\0') {
                                p--;
                                break;
                        }
                        p--;
                }
        } else {
                return decrypt_error_code(mode, CRYPTO_ENCRYPTED_DATA_INVALID,
                    CRYPTO_SIGNATURE_INVALID, CRYPTO_DATA_INVALID);
        }

        /* i < 0 means did not find the end of the padding */
        if (i < 0)
                return decrypt_error_code(mode, CRYPTO_ENCRYPTED_DATA_INVALID,
                    CRYPTO_SIGNATURE_INVALID, CRYPTO_DATA_INVALID);

        if (i > *tlen) {
                *tlen = i;
                return (CRYPTO_BUFFER_TOO_SMALL);
        }

        if (flen - i < 11)
                return decrypt_error_code(mode,
                    CRYPTO_ENCRYPTED_DATA_LEN_RANGE,
                    CRYPTO_SIGNATURE_LEN_RANGE, CRYPTO_DATA_LEN_RANGE);

        /* Return the unpadded length to the caller */
        *tlen = i;

        return (CRYPTO_SUCCESS);
}

/*
 * For RSA_X_509 padding and unpadding, pad all 0s before actual data.
 * Note that the data will be in reverse order.
 */
static int
dca_x509_padding(caddr_t buf, int flen, int tlen)
{
        DBG(NULL, DENTRY, "dca_x509_padding: tlen: %d, flen: %d\n",
            tlen, flen);

        bzero(buf+tlen, tlen - flen);

        return (CRYPTO_QUEUED);
}

/* ARGSUSED */
static int
dca_x509_unpadding(char *buf, int tlen, int flen, int mode)
{
        int i;
        const unsigned char *p;

        DBG(NULL, DENTRY, "dca_x509_unpadding: tlen: %d, flen: %d\n",
            tlen, flen);

        p = (unsigned char *) buf + flen;
        for (i = tlen; i < flen; i++) {
                if (*(--p) != 0)
                        return (CRYPTO_SIGNATURE_INVALID);
        }

        return (CRYPTO_SUCCESS);
}

static int decrypt_error_code(int mode, int decrypt, int verify, int def)
{
        switch (mode) {
        case DCA_RSA_DEC:
                return (decrypt);
        case DCA_RSA_VRFY:
        case DCA_RSA_VRFYR:
                return (verify);
        default:
                return (def);
        }
}