In cases where we ask PEM_def_callback for minimum 0 length, accept 0 length

[thirdparty/openssl.git] / crypto / pem / pem_lib.c

/* crypto/pem/pem_lib.c */
/* 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.]
 */

#include <stdio.h>
#include <ctype.h>
#include "cryptlib.h"
#include <openssl/buffer.h>
#include <openssl/objects.h>
#include <openssl/evp.h>
#include <openssl/rand.h>
#include <openssl/x509.h>
#include <openssl/pem.h>
#include <openssl/pkcs12.h>
#include "asn1_locl.h"
#ifndef OPENSSL_NO_DES
# include <openssl/des.h>
#endif
#ifndef OPENSSL_NO_ENGINE
# include <openssl/engine.h>
#endif

const char PEM_version[] = "PEM" OPENSSL_VERSION_PTEXT;

#define MIN_LENGTH      4

static int load_iv(char **fromp, unsigned char *to, int num);
static int check_pem(const char *nm, const char *name);
int pem_check_suffix(const char *pem_str, const char *suffix);

int PEM_def_callback(char *buf, int num, int rwflag, void *userdata)
{
    int i, min_len;
    const char *prompt;

    /* We assume that the user passes a default password as userdata */
    if (userdata) {
        i = strlen(userdata);
        i = (i > num) ? num : i;
        memcpy(buf, userdata, i);
        return i;
    }

    prompt = EVP_get_pw_prompt();
    if (prompt == NULL)
        prompt = "Enter PEM pass phrase:";

    /*
     * rwflag == 0 means decryption
     * rwflag == 1 means encryption
     *
     * We assume that for encryption, we want a minimum length, while for
     * decryption, we cannot know any minimum length, so we assume zero.
     */
    min_len = rwflag ? MIN_LENGTH : 0;

    i = EVP_read_pw_string_min(buf, min_len, num, prompt, rwflag);
    if (i != 0) {
        PEMerr(PEM_F_PEM_DEF_CALLBACK, PEM_R_PROBLEMS_GETTING_PASSWORD);
        memset(buf, 0, (unsigned int)num);
        return -1;
    }
    return strlen(buf);
}

void PEM_proc_type(char *buf, int type)
{
    const char *str;

    if (type == PEM_TYPE_ENCRYPTED)
        str = "ENCRYPTED";
    else if (type == PEM_TYPE_MIC_CLEAR)
        str = "MIC-CLEAR";
    else if (type == PEM_TYPE_MIC_ONLY)
        str = "MIC-ONLY";
    else
        str = "BAD-TYPE";

    BUF_strlcat(buf, "Proc-Type: 4,", PEM_BUFSIZE);
    BUF_strlcat(buf, str, PEM_BUFSIZE);
    BUF_strlcat(buf, "\n", PEM_BUFSIZE);
}

void PEM_dek_info(char *buf, const char *type, int len, char *str)
{
    static const unsigned char map[17] = "0123456789ABCDEF";
    long i;
    int j;

    BUF_strlcat(buf, "DEK-Info: ", PEM_BUFSIZE);
    BUF_strlcat(buf, type, PEM_BUFSIZE);
    BUF_strlcat(buf, ",", PEM_BUFSIZE);
    j = strlen(buf);
    if (j + (len * 2) + 1 > PEM_BUFSIZE)
        return;
    for (i = 0; i < len; i++) {
        buf[j + i * 2] = map[(str[i] >> 4) & 0x0f];
        buf[j + i * 2 + 1] = map[(str[i]) & 0x0f];
    }
    buf[j + i * 2] = '\n';
    buf[j + i * 2 + 1] = '\0';
}

#ifndef OPENSSL_NO_FP_API
void *PEM_ASN1_read(d2i_of_void *d2i, const char *name, FILE *fp, void **x,
                    pem_password_cb *cb, void *u)
{
    BIO *b;
    void *ret;

    if ((b = BIO_new(BIO_s_file())) == NULL) {
        PEMerr(PEM_F_PEM_ASN1_READ, ERR_R_BUF_LIB);
        return (0);
    }
    BIO_set_fp(b, fp, BIO_NOCLOSE);
    ret = PEM_ASN1_read_bio(d2i, name, b, x, cb, u);
    BIO_free(b);
    return (ret);
}
#endif

static int check_pem(const char *nm, const char *name)
{
    /* Normal matching nm and name */
    if (!strcmp(nm, name))
        return 1;

    /* Make PEM_STRING_EVP_PKEY match any private key */

    if (!strcmp(name, PEM_STRING_EVP_PKEY)) {
        int slen;
        const EVP_PKEY_ASN1_METHOD *ameth;
        if (!strcmp(nm, PEM_STRING_PKCS8))
            return 1;
        if (!strcmp(nm, PEM_STRING_PKCS8INF))
            return 1;
        slen = pem_check_suffix(nm, "PRIVATE KEY");
        if (slen > 0) {
            /*
             * NB: ENGINE implementations wont contain a deprecated old
             * private key decode function so don't look for them.
             */
            ameth = EVP_PKEY_asn1_find_str(NULL, nm, slen);
            if (ameth && ameth->old_priv_decode)
                return 1;
        }
        return 0;
    }

    if (!strcmp(name, PEM_STRING_PARAMETERS)) {
        int slen;
        const EVP_PKEY_ASN1_METHOD *ameth;
        slen = pem_check_suffix(nm, "PARAMETERS");
        if (slen > 0) {
            ENGINE *e;
            ameth = EVP_PKEY_asn1_find_str(&e, nm, slen);
            if (ameth) {
                int r;
                if (ameth->param_decode)
                    r = 1;
                else
                    r = 0;
#ifndef OPENSSL_NO_ENGINE
                if (e)
                    ENGINE_finish(e);
#endif
                return r;
            }
        }
        return 0;
    }
    /* If reading DH parameters handle X9.42 DH format too */
    if (!strcmp(nm, PEM_STRING_DHXPARAMS) &&
        !strcmp(name, PEM_STRING_DHPARAMS))
        return 1;

    /* Permit older strings */

    if (!strcmp(nm, PEM_STRING_X509_OLD) && !strcmp(name, PEM_STRING_X509))
        return 1;

    if (!strcmp(nm, PEM_STRING_X509_REQ_OLD) &&
        !strcmp(name, PEM_STRING_X509_REQ))
        return 1;

    /* Allow normal certs to be read as trusted certs */
    if (!strcmp(nm, PEM_STRING_X509) &&
        !strcmp(name, PEM_STRING_X509_TRUSTED))
        return 1;

    if (!strcmp(nm, PEM_STRING_X509_OLD) &&
        !strcmp(name, PEM_STRING_X509_TRUSTED))
        return 1;

    /* Some CAs use PKCS#7 with CERTIFICATE headers */
    if (!strcmp(nm, PEM_STRING_X509) && !strcmp(name, PEM_STRING_PKCS7))
        return 1;

    if (!strcmp(nm, PEM_STRING_PKCS7_SIGNED) &&
        !strcmp(name, PEM_STRING_PKCS7))
        return 1;

#ifndef OPENSSL_NO_CMS
    if (!strcmp(nm, PEM_STRING_X509) && !strcmp(name, PEM_STRING_CMS))
        return 1;
    /* Allow CMS to be read from PKCS#7 headers */
    if (!strcmp(nm, PEM_STRING_PKCS7) && !strcmp(name, PEM_STRING_CMS))
        return 1;
#endif

    return 0;
}

int PEM_bytes_read_bio(unsigned char **pdata, long *plen, char **pnm,
                       const char *name, BIO *bp, pem_password_cb *cb,
                       void *u)
{
    EVP_CIPHER_INFO cipher;
    char *nm = NULL, *header = NULL;
    unsigned char *data = NULL;
    long len;
    int ret = 0;

    for (;;) {
        if (!PEM_read_bio(bp, &nm, &header, &data, &len)) {
            if (ERR_GET_REASON(ERR_peek_error()) == PEM_R_NO_START_LINE)
                ERR_add_error_data(2, "Expecting: ", name);
            return 0;
        }
        if (check_pem(nm, name))
            break;
        OPENSSL_free(nm);
        OPENSSL_free(header);
        OPENSSL_free(data);
    }
    if (!PEM_get_EVP_CIPHER_INFO(header, &cipher))
        goto err;
    if (!PEM_do_header(&cipher, data, &len, cb, u))
        goto err;

    *pdata = data;
    *plen = len;

    if (pnm)
        *pnm = nm;

    ret = 1;

 err:
    if (!ret || !pnm)
        OPENSSL_free(nm);
    OPENSSL_free(header);
    if (!ret)
        OPENSSL_free(data);
    return ret;
}

#ifndef OPENSSL_NO_FP_API
int PEM_ASN1_write(i2d_of_void *i2d, const char *name, FILE *fp,
                   void *x, const EVP_CIPHER *enc, unsigned char *kstr,
                   int klen, pem_password_cb *callback, void *u)
{
    BIO *b;
    int ret;

    if ((b = BIO_new(BIO_s_file())) == NULL) {
        PEMerr(PEM_F_PEM_ASN1_WRITE, ERR_R_BUF_LIB);
        return (0);
    }
    BIO_set_fp(b, fp, BIO_NOCLOSE);
    ret = PEM_ASN1_write_bio(i2d, name, b, x, enc, kstr, klen, callback, u);
    BIO_free(b);
    return (ret);
}
#endif

int PEM_ASN1_write_bio(i2d_of_void *i2d, const char *name, BIO *bp,
                       void *x, const EVP_CIPHER *enc, unsigned char *kstr,
                       int klen, pem_password_cb *callback, void *u)
{
    EVP_CIPHER_CTX ctx;
    int dsize = 0, i, j, ret = 0;
    unsigned char *p, *data = NULL;
    const char *objstr = NULL;
    char buf[PEM_BUFSIZE];
    unsigned char key[EVP_MAX_KEY_LENGTH];
    unsigned char iv[EVP_MAX_IV_LENGTH];

    if (enc != NULL) {
        objstr = OBJ_nid2sn(EVP_CIPHER_nid(enc));
        if (objstr == NULL || EVP_CIPHER_iv_length(enc) == 0) {
            PEMerr(PEM_F_PEM_ASN1_WRITE_BIO, PEM_R_UNSUPPORTED_CIPHER);
            goto err;
        }
    }

    if ((dsize = i2d(x, NULL)) < 0) {
        PEMerr(PEM_F_PEM_ASN1_WRITE_BIO, ERR_R_ASN1_LIB);
        dsize = 0;
        goto err;
    }
    /* dzise + 8 bytes are needed */
    /* actually it needs the cipher block size extra... */
    data = (unsigned char *)OPENSSL_malloc((unsigned int)dsize + 20);
    if (data == NULL) {
        PEMerr(PEM_F_PEM_ASN1_WRITE_BIO, ERR_R_MALLOC_FAILURE);
        goto err;
    }
    p = data;
    i = i2d(x, &p);

    if (enc != NULL) {
        if (kstr == NULL) {
            if (callback == NULL)
                klen = PEM_def_callback(buf, PEM_BUFSIZE, 1, u);
            else
                klen = (*callback) (buf, PEM_BUFSIZE, 1, u);
            if (klen <= 0) {
                PEMerr(PEM_F_PEM_ASN1_WRITE_BIO, PEM_R_READ_KEY);
                goto err;
            }
#ifdef CHARSET_EBCDIC
            /* Convert the pass phrase from EBCDIC */
            ebcdic2ascii(buf, buf, klen);
#endif
            kstr = (unsigned char *)buf;
        }
        RAND_add(data, i, 0);   /* put in the RSA key. */
        OPENSSL_assert(enc->iv_len <= (int)sizeof(iv));
        if (RAND_bytes(iv, enc->iv_len) <= 0) /* Generate a salt */
            goto err;
        /*
         * The 'iv' is used as the iv and as a salt.  It is NOT taken from
         * the BytesToKey function
         */
        if (!EVP_BytesToKey(enc, EVP_md5(), iv, kstr, klen, 1, key, NULL))
            goto err;

        if (kstr == (unsigned char *)buf)
            OPENSSL_cleanse(buf, PEM_BUFSIZE);

        OPENSSL_assert(strlen(objstr) + 23 + 2 * enc->iv_len + 13 <=
                       sizeof(buf));

        buf[0] = '\0';
        PEM_proc_type(buf, PEM_TYPE_ENCRYPTED);
        PEM_dek_info(buf, objstr, enc->iv_len, (char *)iv);
        /* k=strlen(buf); */

        EVP_CIPHER_CTX_init(&ctx);
        ret = 1;
        if (!EVP_EncryptInit_ex(&ctx, enc, NULL, key, iv)
            || !EVP_EncryptUpdate(&ctx, data, &j, data, i)
            || !EVP_EncryptFinal_ex(&ctx, &(data[j]), &i))
            ret = 0;
        EVP_CIPHER_CTX_cleanup(&ctx);
        if (ret == 0)
            goto err;
        i += j;
    } else {
        ret = 1;
        buf[0] = '\0';
    }
    i = PEM_write_bio(bp, name, buf, data, i);
    if (i <= 0)
        ret = 0;
 err:
    OPENSSL_cleanse(key, sizeof(key));
    OPENSSL_cleanse(iv, sizeof(iv));
    OPENSSL_cleanse((char *)&ctx, sizeof(ctx));
    OPENSSL_cleanse(buf, PEM_BUFSIZE);
    if (data != NULL) {
        OPENSSL_cleanse(data, (unsigned int)dsize);
        OPENSSL_free(data);
    }
    return (ret);
}

int PEM_do_header(EVP_CIPHER_INFO *cipher, unsigned char *data, long *plen,
                  pem_password_cb *callback, void *u)
{
    int i = 0, j, o, klen;
    long len;
    EVP_CIPHER_CTX ctx;
    unsigned char key[EVP_MAX_KEY_LENGTH];
    char buf[PEM_BUFSIZE];

    len = *plen;

    if (cipher->cipher == NULL)
        return (1);
    if (callback == NULL)
        klen = PEM_def_callback(buf, PEM_BUFSIZE, 0, u);
    else
        klen = callback(buf, PEM_BUFSIZE, 0, u);
    if (klen < 0) {
        PEMerr(PEM_F_PEM_DO_HEADER, PEM_R_BAD_PASSWORD_READ);
        return (0);
    }
#ifdef CHARSET_EBCDIC
    /* Convert the pass phrase from EBCDIC */
    ebcdic2ascii(buf, buf, klen);
#endif

    if (!EVP_BytesToKey(cipher->cipher, EVP_md5(), &(cipher->iv[0]),
                        (unsigned char *)buf, klen, 1, key, NULL))
        return 0;

    j = (int)len;
    EVP_CIPHER_CTX_init(&ctx);
    o = EVP_DecryptInit_ex(&ctx, cipher->cipher, NULL, key, &(cipher->iv[0]));
    if (o)
        o = EVP_DecryptUpdate(&ctx, data, &i, data, j);
    if (o)
        o = EVP_DecryptFinal_ex(&ctx, &(data[i]), &j);
    EVP_CIPHER_CTX_cleanup(&ctx);
    OPENSSL_cleanse((char *)buf, sizeof(buf));
    OPENSSL_cleanse((char *)key, sizeof(key));
    if (o)
        j += i;
    else {
        PEMerr(PEM_F_PEM_DO_HEADER, PEM_R_BAD_DECRYPT);
        return (0);
    }
    *plen = j;
    return (1);
}

int PEM_get_EVP_CIPHER_INFO(char *header, EVP_CIPHER_INFO *cipher)
{
    const EVP_CIPHER *enc = NULL;
    char *p, c;
    char **header_pp = &header;

    cipher->cipher = NULL;
    if ((header == NULL) || (*header == '\0') || (*header == '\n'))
        return (1);
    if (strncmp(header, "Proc-Type: ", 11) != 0) {
        PEMerr(PEM_F_PEM_GET_EVP_CIPHER_INFO, PEM_R_NOT_PROC_TYPE);
        return (0);
    }
    header += 11;
    if (*header != '4')
        return (0);
    header++;
    if (*header != ',')
        return (0);
    header++;
    if (strncmp(header, "ENCRYPTED", 9) != 0) {
        PEMerr(PEM_F_PEM_GET_EVP_CIPHER_INFO, PEM_R_NOT_ENCRYPTED);
        return (0);
    }
    for (; (*header != '\n') && (*header != '\0'); header++) ;
    if (*header == '\0') {
        PEMerr(PEM_F_PEM_GET_EVP_CIPHER_INFO, PEM_R_SHORT_HEADER);
        return (0);
    }
    header++;
    if (strncmp(header, "DEK-Info: ", 10) != 0) {
        PEMerr(PEM_F_PEM_GET_EVP_CIPHER_INFO, PEM_R_NOT_DEK_INFO);
        return (0);
    }
    header += 10;

    p = header;
    for (;;) {
        c = *header;
#ifndef CHARSET_EBCDIC
        if (!(((c >= 'A') && (c <= 'Z')) || (c == '-') ||
              ((c >= '0') && (c <= '9'))))
            break;
#else
        if (!(isupper((unsigned char)c) || (c == '-')
            || isdigit((unsigned char)c)))
            break;
#endif
        header++;
    }
    *header = '\0';
    cipher->cipher = enc = EVP_get_cipherbyname(p);
    *header = c;
    header++;

    if (enc == NULL) {
        PEMerr(PEM_F_PEM_GET_EVP_CIPHER_INFO, PEM_R_UNSUPPORTED_ENCRYPTION);
        return (0);
    }
    if (!load_iv(header_pp, &(cipher->iv[0]), enc->iv_len))
        return (0);

    return (1);
}

static int load_iv(char **fromp, unsigned char *to, int num)
{
    int v, i;
    char *from;

    from = *fromp;
    for (i = 0; i < num; i++)
        to[i] = 0;
    num *= 2;
    for (i = 0; i < num; i++) {
        if ((*from >= '0') && (*from <= '9'))
            v = *from - '0';
        else if ((*from >= 'A') && (*from <= 'F'))
            v = *from - 'A' + 10;
        else if ((*from >= 'a') && (*from <= 'f'))
            v = *from - 'a' + 10;
        else {
            PEMerr(PEM_F_LOAD_IV, PEM_R_BAD_IV_CHARS);
            return (0);
        }
        from++;
        to[i / 2] |= v << (long)((!(i & 1)) * 4);
    }

    *fromp = from;
    return (1);
}

#ifndef OPENSSL_NO_FP_API
int PEM_write(FILE *fp, const char *name, const char *header,
              const unsigned char *data, long len)
{
    BIO *b;
    int ret;

    if ((b = BIO_new(BIO_s_file())) == NULL) {
        PEMerr(PEM_F_PEM_WRITE, ERR_R_BUF_LIB);
        return (0);
    }
    BIO_set_fp(b, fp, BIO_NOCLOSE);
    ret = PEM_write_bio(b, name, header, data, len);
    BIO_free(b);
    return (ret);
}
#endif

int PEM_write_bio(BIO *bp, const char *name, const char *header,
                  const unsigned char *data, long len)
{
    int nlen, n, i, j, outl;
    unsigned char *buf = NULL;
    EVP_ENCODE_CTX ctx;
    int reason = ERR_R_BUF_LIB;

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

    if ((BIO_write(bp, "-----BEGIN ", 11) != 11) ||
        (BIO_write(bp, name, nlen) != nlen) ||
        (BIO_write(bp, "-----\n", 6) != 6))
        goto err;

    i = strlen(header);
    if (i > 0) {
        if ((BIO_write(bp, header, i) != i) || (BIO_write(bp, "\n", 1) != 1))
            goto err;
    }

    buf = OPENSSL_malloc(PEM_BUFSIZE * 8);
    if (buf == NULL) {
        reason = ERR_R_MALLOC_FAILURE;
        goto err;
    }

    i = j = 0;
    while (len > 0) {
        n = (int)((len > (PEM_BUFSIZE * 5)) ? (PEM_BUFSIZE * 5) : len);
        EVP_EncodeUpdate(&ctx, buf, &outl, &(data[j]), n);
        if ((outl) && (BIO_write(bp, (char *)buf, outl) != outl))
            goto err;
        i += outl;
        len -= n;
        j += n;
    }
    EVP_EncodeFinal(&ctx, buf, &outl);
    if ((outl > 0) && (BIO_write(bp, (char *)buf, outl) != outl))
        goto err;
    OPENSSL_cleanse(buf, PEM_BUFSIZE * 8);
    OPENSSL_free(buf);
    buf = NULL;
    if ((BIO_write(bp, "-----END ", 9) != 9) ||
        (BIO_write(bp, name, nlen) != nlen) ||
        (BIO_write(bp, "-----\n", 6) != 6))
        goto err;
    return (i + outl);
 err:
    if (buf) {
        OPENSSL_cleanse(buf, PEM_BUFSIZE * 8);
        OPENSSL_free(buf);
    }
    PEMerr(PEM_F_PEM_WRITE_BIO, reason);
    return (0);
}

#ifndef OPENSSL_NO_FP_API
int PEM_read(FILE *fp, char **name, char **header, unsigned char **data,
             long *len)
{
    BIO *b;
    int ret;

    if ((b = BIO_new(BIO_s_file())) == NULL) {
        PEMerr(PEM_F_PEM_READ, ERR_R_BUF_LIB);
        return (0);
    }
    BIO_set_fp(b, fp, BIO_NOCLOSE);
    ret = PEM_read_bio(b, name, header, data, len);
    BIO_free(b);
    return (ret);
}
#endif

int PEM_read_bio(BIO *bp, char **name, char **header, unsigned char **data,
                 long *len)
{
    EVP_ENCODE_CTX ctx;
    int end = 0, i, k, bl = 0, hl = 0, nohead = 0;
    char buf[256];
    BUF_MEM *nameB;
    BUF_MEM *headerB;
    BUF_MEM *dataB, *tmpB;

    nameB = BUF_MEM_new();
    headerB = BUF_MEM_new();
    dataB = BUF_MEM_new();
    if ((nameB == NULL) || (headerB == NULL) || (dataB == NULL)) {
        BUF_MEM_free(nameB);
        BUF_MEM_free(headerB);
        BUF_MEM_free(dataB);
        PEMerr(PEM_F_PEM_READ_BIO, ERR_R_MALLOC_FAILURE);
        return (0);
    }

    buf[254] = '\0';
    for (;;) {
        i = BIO_gets(bp, buf, 254);

        if (i <= 0) {
            PEMerr(PEM_F_PEM_READ_BIO, PEM_R_NO_START_LINE);
            goto err;
        }

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

        if (strncmp(buf, "-----BEGIN ", 11) == 0) {
            i = strlen(&(buf[11]));

            if (strncmp(&(buf[11 + i - 6]), "-----\n", 6) != 0)
                continue;
            if (!BUF_MEM_grow(nameB, i + 9)) {
                PEMerr(PEM_F_PEM_READ_BIO, ERR_R_MALLOC_FAILURE);
                goto err;
            }
            memcpy(nameB->data, &(buf[11]), i - 6);
            nameB->data[i - 6] = '\0';
            break;
        }
    }
    hl = 0;
    if (!BUF_MEM_grow(headerB, 256)) {
        PEMerr(PEM_F_PEM_READ_BIO, ERR_R_MALLOC_FAILURE);
        goto err;
    }
    headerB->data[0] = '\0';
    for (;;) {
        i = BIO_gets(bp, buf, 254);
        if (i <= 0)
            break;

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

        if (buf[0] == '\n')
            break;
        if (!BUF_MEM_grow(headerB, hl + i + 9)) {
            PEMerr(PEM_F_PEM_READ_BIO, ERR_R_MALLOC_FAILURE);
            goto err;
        }
        if (strncmp(buf, "-----END ", 9) == 0) {
            nohead = 1;
            break;
        }
        memcpy(&(headerB->data[hl]), buf, i);
        headerB->data[hl + i] = '\0';
        hl += i;
    }

    bl = 0;
    if (!BUF_MEM_grow(dataB, 1024)) {
        PEMerr(PEM_F_PEM_READ_BIO, ERR_R_MALLOC_FAILURE);
        goto err;
    }
    dataB->data[0] = '\0';
    if (!nohead) {
        for (;;) {
            i = BIO_gets(bp, buf, 254);
            if (i <= 0)
                break;

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

            if (i != 65)
                end = 1;
            if (strncmp(buf, "-----END ", 9) == 0)
                break;
            if (i > 65)
                break;
            if (!BUF_MEM_grow_clean(dataB, i + bl + 9)) {
                PEMerr(PEM_F_PEM_READ_BIO, ERR_R_MALLOC_FAILURE);
                goto err;
            }
            memcpy(&(dataB->data[bl]), buf, i);
            dataB->data[bl + i] = '\0';
            bl += i;
            if (end) {
                buf[0] = '\0';
                i = BIO_gets(bp, buf, 254);
                if (i <= 0)
                    break;

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

                break;
            }
        }
    } else {
        tmpB = headerB;
        headerB = dataB;
        dataB = tmpB;
        bl = hl;
    }
    i = strlen(nameB->data);
    if ((strncmp(buf, "-----END ", 9) != 0) ||
        (strncmp(nameB->data, &(buf[9]), i) != 0) ||
        (strncmp(&(buf[9 + i]), "-----\n", 6) != 0)) {
        PEMerr(PEM_F_PEM_READ_BIO, PEM_R_BAD_END_LINE);
        goto err;
    }

    EVP_DecodeInit(&ctx);
    i = EVP_DecodeUpdate(&ctx,
                         (unsigned char *)dataB->data, &bl,
                         (unsigned char *)dataB->data, bl);
    if (i < 0) {
        PEMerr(PEM_F_PEM_READ_BIO, PEM_R_BAD_BASE64_DECODE);
        goto err;
    }
    i = EVP_DecodeFinal(&ctx, (unsigned char *)&(dataB->data[bl]), &k);
    if (i < 0) {
        PEMerr(PEM_F_PEM_READ_BIO, PEM_R_BAD_BASE64_DECODE);
        goto err;
    }
    bl += k;

    if (bl == 0)
        goto err;
    *name = nameB->data;
    *header = headerB->data;
    *data = (unsigned char *)dataB->data;
    *len = bl;
    OPENSSL_free(nameB);
    OPENSSL_free(headerB);
    OPENSSL_free(dataB);
    return (1);
 err:
    BUF_MEM_free(nameB);
    BUF_MEM_free(headerB);
    BUF_MEM_free(dataB);
    return (0);
}

/*
 * Check pem string and return prefix length. If for example the pem_str ==
 * "RSA PRIVATE KEY" and suffix = "PRIVATE KEY" the return value is 3 for the
 * string "RSA".
 */

int pem_check_suffix(const char *pem_str, const char *suffix)
{
    int pem_len = strlen(pem_str);
    int suffix_len = strlen(suffix);
    const char *p;
    if (suffix_len + 1 >= pem_len)
        return 0;
    p = pem_str + pem_len - suffix_len;
    if (strcmp(p, suffix))
        return 0;
    p--;
    if (*p != ' ')
        return 0;
    return p - pem_str;
}