/*
 * Copyright 2008 Sun Microsystems, Inc.  All rights reserved.
 * Use is subject to license terms.
 */

/*
 * Copyright (C) 1995-1998 Eric Young (eay@cryptsoft.com)
 * All rights reserved.
 *
 * This package is an SSL implementation written
 * by Eric Young (eay@cryptsoft.com).
 * The implementation was written so as to conform with Netscapes SSL.
 *
 * This library is free for commercial and non-commercial use as long as
 * the following conditions are aheared to.  The following conditions
 * apply to all code found in this distribution, be it the RC4, RSA,
 * lhash, DES, etc., code; not just the SSL code.  The SSL documentation
 * included with this distribution is covered by the same copyright terms
 * except that the holder is Tim Hudson (tjh@cryptsoft.com).
 *
 * Copyright remains Eric Young's, and as such any Copyright notices in
 * the code are not to be removed.
 * If this package is used in a product, Eric Young should be given attribution
 * as the author of the parts of the library used.
 * This can be in the form of a textual message at program startup or
 * in documentation (online or textual) provided with the package.
 *
 * 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 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 acknowledgement:
 *    "This product includes cryptographic software written by
 *     Eric Young (eay@cryptsoft.com)"
 *    The word 'cryptographic' can be left out if the rouines from the library
 *    being used are not cryptographic related :-).
 * 4. If you include any Windows specific code (or a derivative thereof) from
 *    the apps directory (application code) you must include an acknowledgement:
 *    "This product includes software written by Tim Hudson (tjh@cryptsoft.com)"
 *
 * THIS SOFTWARE IS PROVIDED BY ERIC YOUNG ``AS IS'' AND
 * ANY EXPRESS 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 AUTHOR OR 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.
 *
 * The licence and distribution terms for any publically available version or
 * derivative of this code cannot be changed.  i.e. this code cannot simply be
 * copied and put under another distribution licence
 * [including the GNU Public Licence.]
 */

/* pem_encode.c - PEM encoding routines */

#include <stdlib.h>
#include <strings.h>
#include <sys/types.h>
#include <kmfapi.h>
#include <pem_encode.h>

static unsigned char data_bin2ascii[65] = "ABCDEFGHIJKLMNOPQRSTUVWXYZ\
abcdefghijklmnopqrstuvwxyz0123456789+/";

static unsigned char data_ascii2bin[128] = {
        0xFF, 0xFF, 0xFF, 0xFF, 0xFF, 0xFF, 0xFF, 0xFF,
        0xFF, 0xE0, 0xF0, 0xFF, 0xFF, 0xF1, 0xFF, 0xFF,
        0xFF, 0xFF, 0xFF, 0xFF, 0xFF, 0xFF, 0xFF, 0xFF,
        0xFF, 0xFF, 0xFF, 0xFF, 0xFF, 0xFF, 0xFF, 0xFF,
        0xE0, 0xFF, 0xFF, 0xFF, 0xFF, 0xFF, 0xFF, 0xFF,
        0xFF, 0xFF, 0xFF, 0x3E, 0xFF, 0xF2, 0xFF, 0x3F,
        0x34, 0x35, 0x36, 0x37, 0x38, 0x39, 0x3A, 0x3B,
        0x3C, 0x3D, 0xFF, 0xFF, 0xFF, 0x00, 0xFF, 0xFF,
        0xFF, 0x00, 0x01, 0x02, 0x03, 0x04, 0x05, 0x06,
        0x07, 0x08, 0x09, 0x0A, 0x0B, 0x0C, 0x0D, 0x0E,
        0x0F, 0x10, 0x11, 0x12, 0x13, 0x14, 0x15, 0x16,
        0x17, 0x18, 0x19, 0xFF, 0xFF, 0xFF, 0xFF, 0xFF,
        0xFF, 0x1A, 0x1B, 0x1C, 0x1D, 0x1E, 0x1F, 0x20,
        0x21, 0x22, 0x23, 0x24, 0x25, 0x26, 0x27, 0x28,
        0x29, 0x2A, 0x2B, 0x2C, 0x2D, 0x2E, 0x2F, 0x30,
        0x31, 0x32, 0x33, 0xFF, 0xFF, 0xFF, 0xFF, 0xFF,
};

#define conv_bin2ascii(a)       (data_bin2ascii[(a)&0x3f])
#define conv_ascii2bin(a)       (data_ascii2bin[(a)&0x7f])


void
PEM_EncodeInit(PEM_ENCODE_CTX *ctx)
{
        ctx->length = 48;
        ctx->num = 0;
        ctx->line_num = 0;
}

int
PEM_EncodeBlock(unsigned char *t, const unsigned char *f, int dlen)
{
        int i, ret = 0;
        unsigned long l;

        for (i = dlen; i > 0; i -= 3) {
                if (i >= 3) {
                        l = (((unsigned long)f[0])<<16L)|
                            (((unsigned long)f[1])<< 8L)|f[2];
                        *(t++) = conv_bin2ascii(l>>18L);
                        *(t++) = conv_bin2ascii(l>>12L);
                        *(t++) = conv_bin2ascii(l>> 6L);
                        *(t++) = conv_bin2ascii(l);
                } else {
                        l = ((unsigned long)f[0])<<16L;
                        if (i == 2)
                                l |= ((unsigned long)f[1]<<8L);

                        *(t++) = conv_bin2ascii(l>>18L);
                        *(t++) = conv_bin2ascii(l>>12L);
                        *(t++) = (i == 1)?'=':conv_bin2ascii(l>> 6L);
                        *(t++) = '=';
                }
                ret += 4;
                f += 3;
        }

        *t = '\0';
        return (ret);
}

void
PEM_EncodeUpdate(PEM_ENCODE_CTX *ctx, unsigned char *out, int *outl,
        unsigned char *in, int inl)
{
        int i, j;
        unsigned int total = 0;

        *outl = 0;
        if (inl == 0)
                return;
        if ((ctx->num+inl) < ctx->length) {
                (void) memcpy(&(ctx->enc_data[ctx->num]), in, inl);
                ctx->num += inl;
                return;
        }
        if (ctx->num != 0) {
                i = ctx->length-ctx->num;
                (void) memcpy(&(ctx->enc_data[ctx->num]), in, i);
                in += i;
                inl -= i;
                j = PEM_EncodeBlock(out, ctx->enc_data, ctx->length);
                ctx->num = 0;
                out += j;
                *(out++) = '\n';
                *out = '\0';
                total = j+1;
        }

        while (inl >= ctx->length) {
                j = PEM_EncodeBlock(out, in, ctx->length);
                in += ctx->length;
                inl -= ctx->length;
                out += j;
                *(out++) = '\n';
                *out = '\0';
                total += j+1;
        }

        if (inl != 0)
                (void) memcpy(&(ctx->enc_data[0]), in, inl);
        ctx->num = inl;
        *outl = total;
}

void
PEM_EncodeFinal(PEM_ENCODE_CTX *ctx, unsigned char *out, int *outl)
{
        unsigned int ret = 0;

        if (ctx->num != 0) {
                ret = PEM_EncodeBlock(out, ctx->enc_data, ctx->num);
                out[ret++] = '\n';
                out[ret] = '\0';
                ctx->num = 0;
        }
        *outl = ret;
}

KMF_RETURN
Der2Pem(KMF_OBJECT_TYPE type, unsigned char *data,
        int len, unsigned char **out, int *outlen)
{


        int nlen, n, i, j, outl;
        unsigned char *buf = NULL, *p = NULL;
        PEM_ENCODE_CTX ctx;
        char *name = NULL;

        if (data == NULL || len == 0 || out == NULL || outlen == NULL)
                return (KMF_ERR_BAD_PARAMETER);

        if (type == KMF_CERT)
                name = PEM_STRING_X509;
        else if (type == KMF_CSR)
                name = PEM_STRING_X509_REQ;
        else if (type == KMF_CRL)
                name = PEM_STRING_X509_CRL;
        else
                return (KMF_ERR_BAD_OBJECT_TYPE);


        PEM_EncodeInit(&ctx);
        nlen = strlen(name);

        buf = malloc(PEM_BUFSIZE*8);
        if (buf == NULL) {
                return (KMF_ERR_MEMORY);
        }

        p = buf;
        (void) memcpy(p, "-----BEGIN ", 11);
        p += 11;
        (void) memcpy(p, name, nlen);
        p += nlen;
        (void) memcpy(p, "-----\n", 6);
        p += 6;

        i = j = 0;
        while (len > 0) {
                n = (int)((len > (PEM_BUFSIZE*5))?(PEM_BUFSIZE*5):len);
                PEM_EncodeUpdate(&ctx, p, &outl, &(data[j]), n);
                i += outl;
                len -= n;
                j += n;
                p += outl;
        }

        PEM_EncodeFinal(&ctx, p, &outl);

        if (outl > 0)
                p += outl;

        (void) memcpy(p, "-----END ", 9);
        p += 9;
        (void) memcpy(p, name, nlen);
        p += nlen;
        (void) memcpy(p, "-----\n", 6);
        p += 6;

        *out = buf;
        *outlen = i+outl+nlen*2+11+6+9+6;

        return (KMF_OK);

}

int
PEM_DecodeBlock(unsigned char *t, const unsigned char *f, int n)
{
        int i, ret = 0, a, b, c, d;
        unsigned long l;

        /* trim white space from the start of the line. */
        while ((conv_ascii2bin(*f) == B64_WS) && (n > 0)) {
                f++;
                n--;
        }

        /*
         * strip off stuff at the end of the line
         * ascii2bin values B64_WS, B64_EOLN, B64_EOLN and B64_EOF
         */
        while ((n > 3) && (B64_NOT_BASE64(conv_ascii2bin(f[n-1]))))
                n--;

        if (n%4 != 0) {
                return (-1);
        }

        for (i = 0; i < n; i += 4) {
                a = conv_ascii2bin(*(f++));
                b = conv_ascii2bin(*(f++));
                c = conv_ascii2bin(*(f++));
                d = conv_ascii2bin(*(f++));
                if ((a & 0x80) || (b & 0x80) || (c & 0x80) || (d & 0x80))
                        return (-1);
                l = ((((unsigned long)a)<<18L) | (((unsigned long)b)<<12L) |
                    (((unsigned long)c)<< 6L) | (((unsigned long)d)));
                *(t++) = (unsigned char)(l>>16L)&0xff;
                *(t++) = (unsigned char)(l>> 8L)&0xff;
                *(t++) = (unsigned char)(l)&0xff;
                ret += 3;
        }
        return (ret);
}

void
PEM_DecodeInit(PEM_ENCODE_CTX *ctx)
{
        ctx->length = 30;
        ctx->num = 0;
        ctx->line_num = 0;
        ctx->expect_nl = 0;
}

/*
 * -1 for error
 *  0 for last line
 *  1 for full line
 */
int
PEM_DecodeUpdate(PEM_ENCODE_CTX *ctx, unsigned char *out, int *outl,
    unsigned char *in, int inl)
{
        int seof = -1, eof = 0, rv = -1, ret = 0;
        int i, v, tmp, n, ln, exp_nl;
        unsigned char *d;

        n = ctx->num;
        d = ctx->enc_data;
        ln = ctx->line_num;
        exp_nl = ctx->expect_nl;

        /* last line of input. */
        if ((inl == 0) || ((n == 0) && (conv_ascii2bin(in[0]) == B64_EOF))) {
                rv = 0;
                goto end;
        }

        /* We parse the input data */
        for (i = 0; i < inl; i++) {
                /* If the current line is > 80 characters, scream alot */
                if (ln >= 80) {
                        rv = -1;
                        goto end;
                }

                /* Get char and put it into the buffer */
                tmp = *(in++);
                v = conv_ascii2bin(tmp);
                /* only save the good data :-) */
                if (!B64_NOT_BASE64(v)) {
                        d[n++] = tmp;
                        ln++;
                } else if (v == B64_ERROR) {
                        rv = -1;
                        goto end;
                }

                /*
                 * have we seen a '=' which is 'definitly' the last
                 * input line.  seof will point to the character that
                 * holds it. and eof will hold how many characters to
                 * chop off.
                 */
                if (tmp == '=') {
                        if (seof == -1) seof = n;
                        eof++;
                }

                if (v == B64_CR) {
                        ln = 0;
                        if (exp_nl)
                                continue;
                }

                /* eoln */
                if (v == B64_EOLN) {
                        ln = 0;
                        if (exp_nl) {
                                exp_nl = 0;
                                continue;
                        }
                }
                exp_nl = 0;

                /*
                 * If we are at the end of input and it looks like a
                 * line, process it.
                 */
                if (((i+1) == inl) && (((n&3) == 0) || eof)) {
                        v = B64_EOF;
                        /*
                         * In case things were given us in really small
                         * records (so two '=' were given in separate
                         * updates), eof may contain the incorrect number
                         * of ending bytes to skip, so let's redo the count
                         */
                        eof = 0;
                        if (d[n-1] == '=') eof++;
                        if (d[n-2] == '=') eof++;
                        /* There will never be more than two '=' */
                }

                if ((v == B64_EOF) || (n >= 64)) {
                        /*
                         * This is needed to work correctly on 64 byte input
                         * lines.  We process the line and then need to
                         * accept the '\n'
                         */
                        if ((v != B64_EOF) && (n >= 64))
                                exp_nl = 1;
                        if (n > 0) {
                                v = PEM_DecodeBlock(out, d, n);
                                if (v < 0) {
                                        rv = 0;
                                        goto end;
                                }
                                n = 0;
                                ret += (v-eof);
                        } else {
                                eof = 1;
                                v = 0;
                        }

                        /*
                         * This is the case where we have had a short
                         * but valid input line
                         */
                        if ((v < ctx->length) && eof) {
                                rv = 0;
                                goto end;
                        } else
                                ctx->length = v;

                        if (seof >= 0) {
                                rv = 0;
                                goto end;
                        }
                        out += v;
                }
        }
        rv = 1;
end:
        *outl = ret;
        ctx->num = n;
        ctx->line_num = ln;
        ctx->expect_nl = exp_nl;
        return (rv);
}

int
PEM_DecodeFinal(PEM_ENCODE_CTX *ctx, unsigned char *out, int *outl)
{
        int i;

        *outl = 0;
        if (ctx->num != 0) {
                i = PEM_DecodeBlock(out, ctx->enc_data, ctx->num);
                if (i < 0)
                        return (-1);
                ctx->num = 0;
                *outl = i;
                return (1);
        } else
                return (1);
}

static int
get_line(unsigned char *in, int inlen, char *buf, int buflen)
{
        int i = 0;

        while ((i < inlen) && (i < buflen) && (in[i] != '\n')) {
                buf[i] = in[i];
                i++;
        }

        return (i);
}

KMF_RETURN
Pem2Der(unsigned char *in, int inlen,
    unsigned char **out, int *outlen)
{
        int kmf_rv = 0;
        PEM_ENCODE_CTX ctx;
        int i, j, k, bl = 0;
        char buf[2048];
        char *nameB = NULL;
        unsigned char *dataB = NULL;
        int total = 0;

        if (in == NULL || inlen == 0 || out == NULL)
                return (KMF_ERR_BAD_PARAMETER);

        (void) memset(buf, 0, sizeof (buf));

        while (total < inlen) {
                /*
                 * get a line (ended at '\n'), which returns
                 * number of bytes in the line
                 */
                i = get_line(in + total, inlen - total, buf, sizeof (buf));
                if (i == 0) {
                        kmf_rv = KMF_ERR_ENCODING;
                        goto err;
                }

                j = i;
                while ((j >= 0) && (buf[j] <= ' ')) j--;
                buf[++j] = '\n';
                buf[++j] = '\0';

                total += i + 1;

                if (strncmp(buf, "-----BEGIN ", 11) == 0) {
                        i = strlen(&(buf[11]));
                        if (strncmp(&(buf[11+i-6]), "-----\n", 6) != 0) {
                                continue;
                        }

                        if ((nameB = malloc(i+9)) == NULL) {
                                kmf_rv = KMF_ERR_MEMORY;
                                goto err;
                        }

                        (void) memcpy(nameB, &(buf[11]), i-6);
                        nameB[i-6] = '\0';
                        break;
                }
        }

        bl = 0;
        if ((dataB = malloc(2048)) == NULL) {
                kmf_rv = KMF_ERR_MEMORY;
                goto err;
        }

        dataB[0] = '\0';

        while (total < inlen) {
                (void) memset(buf, 0, 1024);
                i = get_line(in+total, inlen - total, buf, sizeof (buf));

                if (i == 0) break;

                j = i;
                while ((j >= 0) && (buf[j] <= ' '))
                        j--;

                buf[++j] = '\n';
                buf[++j] = '\0';
                total += i + 1;

                if (buf[0] == '\n') break;
                if ((dataB = realloc(dataB, bl+j+9)) == NULL) {
                        kmf_rv = KMF_ERR_MEMORY;
                        goto err;
                }

                if (strncmp(buf, "-----END ", 9) == 0) {
                        break;
                }

                (void) memcpy(&(dataB[bl]), buf, j);
                dataB[bl+j] = '\0';
                bl += j;
        }

        if (nameB == NULL)
                goto err;

        i = strlen(nameB);
        if ((strncmp(buf, "-----END ", 9) != 0) ||
            (strncmp(nameB, &(buf[9]), i) != 0) ||
            (strncmp(&(buf[9+i]), "-----", 5) != 0)) {
                kmf_rv = KMF_ERR_ENCODING;
                goto err;
        }

        PEM_DecodeInit(&ctx);
        i = PEM_DecodeUpdate(&ctx,
            (unsigned char *)dataB, &bl, (unsigned char *)dataB, bl);

        if (i < 0) {
                kmf_rv = KMF_ERR_ENCODING;
                goto err;
        }

        i = PEM_DecodeFinal(&ctx, (unsigned char *)&(dataB[bl]), &k);
        if (i < 0) {
                kmf_rv = KMF_ERR_ENCODING;
                goto err;
        }
        bl += k;

        if (bl == 0) goto err;
        *out = (unsigned char *)dataB;
        *outlen = bl;

err:
        if (nameB != NULL)
                free(nameB);
        if (kmf_rv != KMF_OK && dataB != NULL)
                free(dataB);

        return (kmf_rv);
}