/*

 * Copyright 1995-2023 The OpenSSL Project Authors. All Rights Reserved.

 *

 * Licensed under the Apache License 2.0 (the "License").  You may not use

 * this file except in compliance with the License.  You can obtain a copy

 * in the file LICENSE in the source distribution or at

 * https://www.openssl.org/source/license.html

 */

/* We need to use some engine deprecated APIs */

#define OPENSSL_SUPPRESS_DEPRECATED

#include <stdio.h>

#include "crypto/ctype.h"

#include <string.h>

#include "internal/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 "crypto/asn1.h"

#include <openssl/des.h>

#include <openssl/engine.h>

#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 ossl_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) {

        ERR_raise(ERR_LIB_PEM, 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;

    char *p = buf + strlen(buf);

    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";

    BIO_snprintf(p, PEM_BUFSIZE - (size_t)(p - buf), "Proc-Type: 4,%s\n", str);

}

void PEM_dek_info(char *buf, const char *type, int len, const char *str)

{

    long i;

    char *p = buf + strlen(buf);

    int j = PEM_BUFSIZE - (size_t)(p - buf), n;

    n = BIO_snprintf(p, j, "DEK-Info: %s,", type);

    if (n > 0) {

        j -= n;

        p += n;

        for (i = 0; i < len; i++) {

            n = BIO_snprintf(p, j, "%02X", 0xff & str[i]);

            if (n <= 0)

                return;

            j -= n;

            p += n;

        }

        if (j > 1)

            strcpy(p, "\n");

    }

}

#ifndef OPENSSL_NO_STDIO

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) {

        ERR_raise(ERR_LIB_PEM, 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) == 0)

        return 1;

    /* Make PEM_STRING_EVP_PKEY match any private key */

    if (strcmp(name, PEM_STRING_EVP_PKEY) == 0) {

        int slen;

        const EVP_PKEY_ASN1_METHOD *ameth;

        if (strcmp(nm, PEM_STRING_PKCS8) == 0)

            return 1;

        if (strcmp(nm, PEM_STRING_PKCS8INF) == 0)

            return 1;

        slen = ossl_pem_check_suffix(nm, "PRIVATE KEY");

        if (slen > 0) {

            /*

             * NB: ENGINE implementations won't 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) == 0) {

        int slen;

        const EVP_PKEY_ASN1_METHOD *ameth;

        slen = ossl_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

                ENGINE_finish(e);

#endif

                return r;

            }

        }

        return 0;

    }

    /* If reading DH parameters handle X9.42 DH format too */

    if (strcmp(nm, PEM_STRING_DHXPARAMS) == 0

        && strcmp(name, PEM_STRING_DHPARAMS) == 0)

        return 1;

    /* Permit older strings */

    if (strcmp(nm, PEM_STRING_X509_OLD) == 0

        && strcmp(name, PEM_STRING_X509) == 0)

        return 1;

    if (strcmp(nm, PEM_STRING_X509_REQ_OLD) == 0

        && strcmp(name, PEM_STRING_X509_REQ) == 0)

        return 1;

    /* Allow normal certs to be read as trusted certs */

    if (strcmp(nm, PEM_STRING_X509) == 0

        && strcmp(name, PEM_STRING_X509_TRUSTED) == 0)

        return 1;

    if (strcmp(nm, PEM_STRING_X509_OLD) == 0

        && strcmp(name, PEM_STRING_X509_TRUSTED) == 0)

        return 1;

    /* Some CAs use PKCS#7 with CERTIFICATE headers */

    if (strcmp(nm, PEM_STRING_X509) == 0

        && strcmp(name, PEM_STRING_PKCS7) == 0)

        return 1;

    if (strcmp(nm, PEM_STRING_PKCS7_SIGNED) == 0

        && strcmp(name, PEM_STRING_PKCS7) == 0)

        return 1;

#ifndef OPENSSL_NO_CMS

    if (strcmp(nm, PEM_STRING_X509) == 0

        && strcmp(name, PEM_STRING_CMS) == 0)

        return 1;

    /* Allow CMS to be read from PKCS#7 headers */

    if (strcmp(nm, PEM_STRING_PKCS7) == 0

        && strcmp(name, PEM_STRING_CMS) == 0)

        return 1;

#endif

    return 0;

}

#define PEM_FREE(p, flags, num) \

    pem_free((p), (flags), (num), OPENSSL_FILE, OPENSSL_LINE)

static void pem_free(void *p, unsigned int flags, size_t num,

    const char *file, int line)

{

    if (flags & PEM_FLAG_SECURE)

        CRYPTO_secure_clear_free(p, num, file, line);

    else

        CRYPTO_free(p, file, line);

}

#define PEM_MALLOC(num, flags) \

    pem_malloc((num), (flags), OPENSSL_FILE, OPENSSL_LINE)

static void *pem_malloc(int num, unsigned int flags,

    const char *file, int line)

{

    return (flags & PEM_FLAG_SECURE) ? CRYPTO_secure_malloc(num, file, line)

                                     : CRYPTO_malloc(num, file, line);

}

static int pem_bytes_read_bio_flags(unsigned char **pdata, long *plen,

    char **pnm, const char *name, BIO *bp,

    pem_password_cb *cb, void *u,

    unsigned int flags)

{

    EVP_CIPHER_INFO cipher;

    char *nm = NULL, *header = NULL;

    unsigned char *data = NULL;

    long len = 0;

    int ret = 0;

    do {

        PEM_FREE(nm, flags, 0);

        PEM_FREE(header, flags, 0);

        PEM_FREE(data, flags, len);

        if (!PEM_read_bio_ex(bp, &nm, &header, &data, &len, flags)) {

            if (ERR_GET_REASON(ERR_peek_error()) == PEM_R_NO_START_LINE)

                ERR_add_error_data(2, "Expecting: ", name);

            return 0;

        }

    } while (!check_pem(nm, name));

    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 != NULL)

        *pnm = nm;

    ret = 1;

err:

    if (!ret || pnm == NULL)

        PEM_FREE(nm, flags, 0);

    PEM_FREE(header, flags, 0);

    if (!ret)

        PEM_FREE(data, flags, len);

    return ret;

}

int PEM_bytes_read_bio(unsigned char **pdata, long *plen, char **pnm,

    const char *name, BIO *bp, pem_password_cb *cb,

    void *u)

{

    return pem_bytes_read_bio_flags(pdata, plen, pnm, name, bp, cb, u,

        PEM_FLAG_EAY_COMPATIBLE);

}

int PEM_bytes_read_bio_secmem(unsigned char **pdata, long *plen, char **pnm,

    const char *name, BIO *bp, pem_password_cb *cb,

    void *u)

{

    return pem_bytes_read_bio_flags(pdata, plen, pnm, name, bp, cb, u,

        PEM_FLAG_SECURE | PEM_FLAG_EAY_COMPATIBLE);

}

#ifndef OPENSSL_NO_STDIO

int PEM_ASN1_write(i2d_of_void *i2d, const char *name, FILE *fp,

    const void *x, const EVP_CIPHER *enc,

    const unsigned char *kstr, int klen,

    pem_password_cb *callback, void *u)

{

    BIO *b;

    int ret;

    if ((b = BIO_new(BIO_s_file())) == NULL) {

        ERR_raise(ERR_LIB_PEM, 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,

    const void *x, const EVP_CIPHER *enc,

    const unsigned char *kstr, int klen,

    pem_password_cb *callback, void *u)

{

    EVP_CIPHER_CTX *ctx = NULL;

    int dsize = 0, i = 0, j = 0, 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 = EVP_CIPHER_get0_name(enc);

        if (objstr == NULL || EVP_CIPHER_get_iv_length(enc) == 0

            || EVP_CIPHER_get_iv_length(enc) > (int)sizeof(iv)

            /*

             * Check "Proc-Type: 4,Encrypted\nDEK-Info: objstr,hex-iv\n"

             * fits into buf

             */

            || strlen(objstr) + 23 + 2 * EVP_CIPHER_get_iv_length(enc) + 13

                > sizeof(buf)) {

            ERR_raise(ERR_LIB_PEM, PEM_R_UNSUPPORTED_CIPHER);

            goto err;

        }

    }

    if ((dsize = i2d(x, NULL)) <= 0) {

        ERR_raise(ERR_LIB_PEM, ERR_R_ASN1_LIB);

        dsize = 0;

        goto err;

    }

    /* dsize + 8 bytes are needed */

    /* actually it needs the cipher block size extra... */

    data = OPENSSL_malloc((unsigned int)dsize + 20);

    if (data == NULL)

        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) {

                ERR_raise(ERR_LIB_PEM, PEM_R_READ_KEY);

                goto err;

            }

#ifdef CHARSET_EBCDIC

            /* Convert the pass phrase from EBCDIC */

            ebcdic2ascii(buf, buf, klen);

#endif

            kstr = (unsigned char *)buf;

        }

        /* Generate a salt */

        if (RAND_bytes(iv, EVP_CIPHER_get_iv_length(enc)) <= 0)

            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);

        buf[0] = '\0';

        PEM_proc_type(buf, PEM_TYPE_ENCRYPTED);

        PEM_dek_info(buf, objstr, EVP_CIPHER_get_iv_length(enc), (char *)iv);

        /* k=strlen(buf); */

        ret = 1;

        if ((ctx = EVP_CIPHER_CTX_new()) == NULL

            || !EVP_EncryptInit_ex(ctx, enc, NULL, key, iv)

            || !EVP_EncryptUpdate(ctx, data, &j, data, i)

            || !EVP_EncryptFinal_ex(ctx, &(data[j]), &i))

            ret = 0;

        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));

    EVP_CIPHER_CTX_free(ctx);

    OPENSSL_cleanse(buf, PEM_BUFSIZE);

    OPENSSL_clear_free(data, (unsigned int)dsize);

    return ret;

}

int PEM_do_header(EVP_CIPHER_INFO *cipher, unsigned char *data, long *plen,

    pem_password_cb *callback, void *u)

{

    int ok;

    int keylen;

    long len = *plen;

    int ilen = (int)len; /* EVP_DecryptUpdate etc. take int lengths */

    EVP_CIPHER_CTX *ctx;

    unsigned char key[EVP_MAX_KEY_LENGTH];

    char buf[PEM_BUFSIZE];

#if LONG_MAX > INT_MAX

    /* Check that we did not truncate the length */

    if (len > INT_MAX) {

        ERR_raise(ERR_LIB_PEM, PEM_R_HEADER_TOO_LONG);

        return 0;

    }

#endif

    if (cipher->cipher == NULL)

        return 1;

    if (callback == NULL)

        keylen = PEM_def_callback(buf, PEM_BUFSIZE, 0, u);

    else

        keylen = callback(buf, PEM_BUFSIZE, 0, u);

    if (keylen < 0) {

        ERR_raise(ERR_LIB_PEM, PEM_R_BAD_PASSWORD_READ);

        return 0;

    }

#ifdef CHARSET_EBCDIC

    /* Convert the pass phrase from EBCDIC */

    ebcdic2ascii(buf, buf, keylen);

#endif

    if (!EVP_BytesToKey(cipher->cipher, EVP_md5(), &(cipher->iv[0]),

            (unsigned char *)buf, keylen, 1, key, NULL))

        return 0;

    ctx = EVP_CIPHER_CTX_new();

    if (ctx == NULL)

        return 0;

    ok = EVP_DecryptInit_ex(ctx, cipher->cipher, NULL, key, &(cipher->iv[0]));

    if (ok)

        ok = EVP_DecryptUpdate(ctx, data, &ilen, data, ilen);

    if (ok) {

        /* Squirrel away the length of data decrypted so far. */

        *plen = ilen;

        ok = EVP_DecryptFinal_ex(ctx, &(data[ilen]), &ilen);

    }

    if (ok)

        *plen += ilen;

    else

        ERR_raise(ERR_LIB_PEM, PEM_R_BAD_DECRYPT);

    EVP_CIPHER_CTX_free(ctx);

    OPENSSL_cleanse((char *)buf, sizeof(buf));

    OPENSSL_cleanse((char *)key, sizeof(key));

    return ok;

}

/*

 * This implements a very limited PEM header parser that does not support the

 * full grammar of rfc1421.  In particular, folded headers are not supported,

 * nor is additional whitespace.

 *

 * A robust implementation would make use of a library that turns the headers

 * into a BIO from which one folded line is read at a time, and is then split

 * into a header label and content.  We would then parse the content of the

 * headers we care about.  This is overkill for just this limited use-case, but

 * presumably we also parse rfc822-style headers for S/MIME, so a common

 * abstraction might well be more generally useful.

 */

#define PROC_TYPE "Proc-Type:"

#define ENCRYPTED "ENCRYPTED"

#define DEK_INFO "DEK-Info:"

int PEM_get_EVP_CIPHER_INFO(char *header, EVP_CIPHER_INFO *cipher)

{

    const EVP_CIPHER *enc = NULL;

    int ivlen;

    char *dekinfostart, c;

    cipher->cipher = NULL;

    memset(cipher->iv, 0, sizeof(cipher->iv));

    if ((header == NULL) || (*header == '\0') || (*header == '\n'))

        return 1;

    if (!CHECK_AND_SKIP_PREFIX(header, PROC_TYPE)) {

        ERR_raise(ERR_LIB_PEM, PEM_R_NOT_PROC_TYPE);

        return 0;

    }

    header += strspn(header, " \t");

    if (*header++ != '4' || *header++ != ',')

        return 0;

    header += strspn(header, " \t");

    /* We expect "ENCRYPTED" followed by optional white-space + line break */

    if (!CHECK_AND_SKIP_PREFIX(header, ENCRYPTED) || strspn(header, " \t\r\n") == 0) {

        ERR_raise(ERR_LIB_PEM, PEM_R_NOT_ENCRYPTED);

        return 0;

    }

    header += strspn(header, " \t\r");

    if (*header++ != '\n') {

        ERR_raise(ERR_LIB_PEM, PEM_R_SHORT_HEADER);

        return 0;

    }

    /*-

     * https://tools.ietf.org/html/rfc1421#section-4.6.1.3

     * We expect "DEK-Info: algo[,hex-parameters]"

     */

    if (!CHECK_AND_SKIP_PREFIX(header, DEK_INFO)) {

        ERR_raise(ERR_LIB_PEM, PEM_R_NOT_DEK_INFO);

        return 0;

    }

    header += strspn(header, " \t");

    /*

     * DEK-INFO is a comma-separated combination of algorithm name and optional

     * parameters.

     */

    dekinfostart = header;

    header += strcspn(header, " \t,");

    c = *header;

    *header = '\0';

    cipher->cipher = enc = EVP_get_cipherbyname(dekinfostart);

    *header = c;

    header += strspn(header, " \t");

    if (enc == NULL) {

        ERR_raise(ERR_LIB_PEM, PEM_R_UNSUPPORTED_ENCRYPTION);

        return 0;

    }

    ivlen = EVP_CIPHER_get_iv_length(enc);

    if (ivlen > 0 && *header++ != ',') {

        ERR_raise(ERR_LIB_PEM, PEM_R_MISSING_DEK_IV);

        return 0;

    } else if (ivlen == 0 && *header == ',') {

        ERR_raise(ERR_LIB_PEM, PEM_R_UNEXPECTED_DEK_IV);

        return 0;

    }

    if (!load_iv(&header, cipher->iv, EVP_CIPHER_get_iv_length(enc)))

        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++) {

        v = OPENSSL_hexchar2int(*from);

        if (v < 0) {

            ERR_raise(ERR_LIB_PEM, PEM_R_BAD_IV_CHARS);

            return 0;

        }

        from++;

        to[i / 2] |= v << (long)((!(i & 1)) * 4);

    }

    *fromp = from;

    return 1;

}

#ifndef OPENSSL_NO_STDIO

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) {

        ERR_raise(ERR_LIB_PEM, 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 = EVP_ENCODE_CTX_new();

    int reason = 0;

    int retval = 0;

    if (ctx == NULL) {

        reason = ERR_R_EVP_LIB;

        goto err;

    }

    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)) {

        reason = ERR_R_BIO_LIB;

        goto err;

    }

    i = header != NULL ? strlen(header) : 0;

    if (i > 0) {

        if ((BIO_write(bp, header, i) != i) || (BIO_write(bp, "\n", 1) != 1)) {

            reason = ERR_R_BIO_LIB;

            goto err;

        }

    }

    buf = OPENSSL_malloc(PEM_BUFSIZE * 8);

    if (buf == NULL)

        goto err;

    i = j = 0;

    while (len > 0) {

        n = (int)((len > (PEM_BUFSIZE * 5)) ? (PEM_BUFSIZE * 5) : len);

        if (!EVP_EncodeUpdate(ctx, buf, &outl, &(data[j]), n)) {

            reason = ERR_R_EVP_LIB;

            goto err;

        }

        if ((outl) && (BIO_write(bp, (char *)buf, outl) != outl)) {

            reason = ERR_R_BIO_LIB;

            goto err;

        }

        i += outl;

        len -= n;

        j += n;

    }

    EVP_EncodeFinal(ctx, buf, &outl);

    if ((outl > 0) && (BIO_write(bp, (char *)buf, outl) != outl)) {

        reason = ERR_R_BIO_LIB;

        goto err;

    }

    if ((BIO_write(bp, "-----END ", 9) != 9) || (BIO_write(bp, name, nlen) != nlen) || (BIO_write(bp, "-----\n", 6) != 6)) {

        reason = ERR_R_BIO_LIB;

        goto err;

    }

    retval = i + outl;

err:

    if (retval == 0 && reason != 0)

        ERR_raise(ERR_LIB_PEM, reason);

    EVP_ENCODE_CTX_free(ctx);

    OPENSSL_clear_free(buf, PEM_BUFSIZE * 8);

    return retval;

}

#ifndef OPENSSL_NO_STDIO

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) {

        ERR_raise(ERR_LIB_PEM, 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

/* Some helpers for PEM_read_bio_ex(). */

static int sanitize_line(char *linebuf, int len, unsigned int flags, int first_call)

{

    int i;

    if (first_call) {

        /* Other BOMs imply unsupported multibyte encoding,

         * so don't strip them and let the error raise */

        const unsigned char utf8_bom[3] = { 0xEF, 0xBB, 0xBF };

        if (len > 3 && memcmp(linebuf, utf8_bom, 3) == 0) {

            memmove(linebuf, linebuf + 3, len - 3);

            linebuf[len - 3] = 0;

            len -= 3;

        }

    }

    if (flags & PEM_FLAG_EAY_COMPATIBLE) {

        /* Strip trailing whitespace */

        while ((len >= 0) && (linebuf[len] <= ' '))

            len--;

        /* Go back to whitespace before applying uniform line ending. */

        len++;

    } else if (flags & PEM_FLAG_ONLY_B64) {

        for (i = 0; i < len; ++i) {

            if (!ossl_isbase64(linebuf[i]) || linebuf[i] == '\n'

                || linebuf[i] == '\r')

                break;

        }

        len = i;

    } else {

        /* EVP_DecodeBlock strips leading and trailing whitespace, so just strip

         * control characters in-place and let everything through. */

        for (i = 0; i < len; ++i) {

            if (linebuf[i] == '\n' || linebuf[i] == '\r')

                break;

            if (ossl_iscntrl(linebuf[i]))

                linebuf[i] = ' ';

        }

        len = i;

    }

    /* The caller allocated LINESIZE+1, so this is safe. */

    linebuf[len++] = '\n';

    linebuf[len] = '\0';

    return len;

}

#define LINESIZE 255

/* Note trailing spaces for begin and end. */

#define BEGINSTR "-----BEGIN "

#define ENDSTR "-----END "

#define TAILSTR "-----\n"

#define BEGINLEN ((int)(sizeof(BEGINSTR) - 1))

#define ENDLEN ((int)(sizeof(ENDSTR) - 1))

#define TAILLEN ((int)(sizeof(TAILSTR) - 1))

static int get_name(BIO *bp, char **name, unsigned int flags)

{

    char *linebuf;

    int ret = 0;

    int len;

    int first_call = 1;

    /*

     * Need to hold trailing NUL (accounted for by BIO_gets() and the newline

     * that will be added by sanitize_line() (the extra '1').

     */

    linebuf = PEM_MALLOC(LINESIZE + 1, flags);

    if (linebuf == NULL)

        return 0;

    do {

        len = BIO_gets(bp, linebuf, LINESIZE);

        if (len <= 0) {

            ERR_raise(ERR_LIB_PEM, PEM_R_NO_START_LINE);

            goto err;

        }

        /* Strip trailing garbage and standardize ending. */

        len = sanitize_line(linebuf, len, flags & ~PEM_FLAG_ONLY_B64, first_call);

        first_call = 0;

        /* Allow leading empty or non-matching lines. */

    } while (!HAS_PREFIX(linebuf, BEGINSTR)

        || len < TAILLEN

        || !HAS_PREFIX(linebuf + len - TAILLEN, TAILSTR));

    linebuf[len - TAILLEN] = '\0';

    len = len - BEGINLEN - TAILLEN + 1;

    *name = PEM_MALLOC(len, flags);

    if (*name == NULL)

        goto err;

    memcpy(*name, linebuf + BEGINLEN, len);

    ret = 1;

err:

    PEM_FREE(linebuf, flags, LINESIZE + 1);

    return ret;

}

/* Keep track of how much of a header we've seen. */

enum header_status {

    MAYBE_HEADER,

    IN_HEADER,

    POST_HEADER

};

/**

 * Extract the optional PEM header, with details on the type of content and

 * any encryption used on the contents, and the bulk of the data from the bio.

 * The end of the header is marked by a blank line; if the end-of-input marker

 * is reached prior to a blank line, there is no header.

 *

 * The header and data arguments are BIO** since we may have to swap them

 * if there is no header, for efficiency.

 *

 * We need the name of the PEM-encoded type to verify the end string.

 */

static int get_header_and_data(BIO *bp, BIO **header, BIO **data, char *name,

    unsigned int flags)

{

    BIO *tmp = *header;

    char *linebuf, *p;

    int len, ret = 0, end = 0, prev_partial_line_read = 0, partial_line_read = 0;

    /* 0 if not seen (yet), 1 if reading header, 2 if finished header */

    enum header_status got_header = MAYBE_HEADER;

    unsigned int flags_mask;

    size_t namelen;

    /* Need to hold trailing NUL (accounted for by BIO_gets() and the newline

     * that will be added by sanitize_line() (the extra '1'). */

    linebuf = PEM_MALLOC(LINESIZE + 1, flags);

    if (linebuf == NULL)

        return 0;

    while (1) {

        flags_mask = ~0u;

        len = BIO_gets(bp, linebuf, LINESIZE);

        if (len <= 0) {

            ERR_raise(ERR_LIB_PEM, PEM_R_BAD_END_LINE);

            goto err;

        }

        /*

         * Check if line has been read completely or if only part of the line

         * has been read. Keep the previous value to ignore newlines that

         * appear due to reading a line up until the char before the newline.

         */

        prev_partial_line_read = partial_line_read;

        partial_line_read = len == LINESIZE - 1 && linebuf[LINESIZE - 2] != '\n';

        if (got_header == MAYBE_HEADER) {

            if (memchr(linebuf, ':', len) != NULL)

                got_header = IN_HEADER;

        }

        if (HAS_PREFIX(linebuf, ENDSTR) || got_header == IN_HEADER)

            flags_mask &= ~PEM_FLAG_ONLY_B64;

        len = sanitize_line(linebuf, len, flags & flags_mask, 0);

        /* Check for end of header. */

        if (linebuf[0] == '\n') {

            /*

             * If previous line has been read only partially this newline is a

             * regular newline at the end of a line and not an empty line.

             */

            if (!prev_partial_line_read) {

                if (got_header == POST_HEADER) {

                    /* Another blank line is an error. */

                    ERR_raise(ERR_LIB_PEM, PEM_R_BAD_END_LINE);

                    goto err;

                }

                got_header = POST_HEADER;

                tmp = *data;

            }

            continue;

        }

        /* Check for end of stream (which means there is no header). */

        p = linebuf;

        if (CHECK_AND_SKIP_PREFIX(p, ENDSTR)) {

            namelen = strlen(name);

            if (strncmp(p, name, namelen) != 0 || !HAS_PREFIX(p + namelen, TAILSTR)) {

                ERR_raise(ERR_LIB_PEM, PEM_R_BAD_END_LINE);

                goto err;

            }

            if (got_header == MAYBE_HEADER) {

                *header = *data;

                *data = tmp;

            }

            break;

        } else if (end) {

            /* Malformed input; short line not at end of data. */

            ERR_raise(ERR_LIB_PEM, PEM_R_BAD_END_LINE);

            goto err;

        }

        /*

         * Else, a line of text -- could be header or data; we don't

         * know yet.  Just pass it through.

         */

        if (BIO_puts(tmp, linebuf) < 0)

            goto err;

        /*

         * Only encrypted files need the line length check applied.

         */

        if (got_header == POST_HEADER) {

            /* 65 includes the trailing newline */

            if (len > 65)

                goto err;

            if (len < 65)

                end = 1;

        }

    }

    ret = 1;

err:

    PEM_FREE(linebuf, flags, LINESIZE + 1);

    return ret;

}

/**

 * Read in PEM-formatted data from the given BIO.

 *

 * By nature of the PEM format, all content must be printable ASCII (except

 * for line endings).  Other characters are malformed input and will be rejected.

 */

int PEM_read_bio_ex(BIO *bp, char **name_out, char **header,

    unsigned char **data, long *len_out, unsigned int flags)

{

    EVP_ENCODE_CTX *ctx = NULL;

    const BIO_METHOD *bmeth;

    BIO *headerB = NULL, *dataB = NULL;

    char *name = NULL;

    int len, taillen, headerlen, ret = 0;

    BUF_MEM *buf_mem;

    *len_out = 0;

    *name_out = *header = NULL;

    *data = NULL;

    if ((flags & PEM_FLAG_EAY_COMPATIBLE) && (flags & PEM_FLAG_ONLY_B64)) {

        /* These two are mutually incompatible; bail out. */

        ERR_raise(ERR_LIB_PEM, ERR_R_PASSED_INVALID_ARGUMENT);