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openssl/crypto/pem/pem_lib.c
Matt Caswell a07dc8167b Fix instances of pointer addition with the NULL pointer 
Addition using the NULL pointer (even when adding 0) is undefined
behaviour. Recent versions of ubsan are now complaining about this, so
we fix various instances.

Reviewed-by: Paul Dale <paul.dale@oracle.com>
Reviewed-by: Richard Levitte <levitte@openssl.org>
(Merged from https://github.com/openssl/openssl/pull/13513)
2020-11-30 10:37:14 +00:00

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/*
* Copyright 1995-2020 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 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 = 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 = 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;
}
static void pem_free(void *p, unsigned int flags, size_t num)
{
if (flags & PEM_FLAG_SECURE)
OPENSSL_secure_clear_free(p, num);
else
OPENSSL_free(p);
}
static void *pem_malloc(int num, unsigned int flags)
{
return (flags & PEM_FLAG_SECURE) ? OPENSSL_secure_malloc(num)
: OPENSSL_malloc(num);
}
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 = OBJ_nid2sn(EVP_CIPHER_nid(enc));
if (objstr == NULL || EVP_CIPHER_iv_length(enc) == 0
|| EVP_CIPHER_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_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) {
ERR_raise(ERR_LIB_PEM, 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) {
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;
}
if (RAND_bytes(iv, EVP_CIPHER_iv_length(enc)) <= 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);
buf[0] = '\0';
PEM_proc_type(buf, PEM_TYPE_ENCRYPTED);
PEM_dek_info(buf, objstr, EVP_CIPHER_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.
*/
int PEM_get_EVP_CIPHER_INFO(char *header, EVP_CIPHER_INFO *cipher)
{
static const char ProcType[] = "Proc-Type:";
static const char ENCRYPTED[] = "ENCRYPTED";
static const char DEKInfo[] = "DEK-Info:";
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 (strncmp(header, ProcType, sizeof(ProcType)-1) != 0) {
ERR_raise(ERR_LIB_PEM, PEM_R_NOT_PROC_TYPE);
return 0;
}
header += sizeof(ProcType)-1;
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 (strncmp(header, ENCRYPTED, sizeof(ENCRYPTED)-1) != 0 ||
strspn(header+sizeof(ENCRYPTED)-1, " \t\r\n") == 0) {
ERR_raise(ERR_LIB_PEM, PEM_R_NOT_ENCRYPTED);
return 0;
}
header += sizeof(ENCRYPTED)-1;
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 (strncmp(header, DEKInfo, sizeof(DEKInfo)-1) != 0) {
ERR_raise(ERR_LIB_PEM, PEM_R_NOT_DEK_INFO);
return 0;
}
header += sizeof(DEKInfo)-1;
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_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_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 = ERR_R_BUF_LIB;
int retval = 0;
if (ctx == NULL) {
reason = ERR_R_MALLOC_FAILURE;
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))
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);
if (!EVP_EncodeUpdate(ctx, buf, &outl, &(data[j]), n))
goto err;
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;
if ((BIO_write(bp, "-----END ", 9) != 9) ||
(BIO_write(bp, name, nlen) != nlen) ||
(BIO_write(bp, "-----\n", 6) != 6))
goto err;
retval = i + outl;
err:
if (retval == 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. */
static const char beginstr[] = "-----BEGIN ";
static const char endstr[] = "-----END ";
static const char 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) {
ERR_raise(ERR_LIB_PEM, ERR_R_MALLOC_FAILURE);
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 (strncmp(linebuf, beginstr, BEGINLEN) != 0
|| len < TAILLEN
|| strncmp(linebuf + len - TAILLEN, tailstr, TAILLEN) != 0);
linebuf[len - TAILLEN] = '\0';
len = len - BEGINLEN - TAILLEN + 1;
*name = pem_malloc(len, flags);
if (*name == NULL) {
ERR_raise(ERR_LIB_PEM, ERR_R_MALLOC_FAILURE);
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, line, 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) {
ERR_raise(ERR_LIB_PEM, ERR_R_MALLOC_FAILURE);
return 0;
}
for (line = 0; ; line++) {
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 (!strncmp(linebuf, endstr, ENDLEN) || 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). */
if (strncmp(linebuf, endstr, ENDLEN) == 0) {
p = linebuf + ENDLEN;
namelen = strlen(name);
if (strncmp(p, name, namelen) != 0 ||
strncmp(p + namelen, tailstr, TAILLEN) != 0) {
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);
goto end;
}
bmeth = (flags & PEM_FLAG_SECURE) ? BIO_s_secmem() : BIO_s_mem();
headerB = BIO_new(bmeth);
dataB = BIO_new(bmeth);
if (headerB == NULL || dataB == NULL) {
ERR_raise(ERR_LIB_PEM, ERR_R_MALLOC_FAILURE);
goto end;
}
if (!get_name(bp, &name, flags))
goto end;
if (!get_header_and_data(bp, &headerB, &dataB, name, flags))
goto end;
BIO_get_mem_ptr(dataB, &buf_mem);
len = buf_mem->length;
/* There was no data in the PEM file */
if (len == 0)
goto end;
ctx = EVP_ENCODE_CTX_new();
if (ctx == NULL) {
ERR_raise(ERR_LIB_PEM, ERR_R_MALLOC_FAILURE);
goto end;
}
EVP_DecodeInit(ctx);
if (EVP_DecodeUpdate(ctx, (unsigned char*)buf_mem->data, &len,
(unsigned char*)buf_mem->data, len) < 0
|| EVP_DecodeFinal(ctx, (unsigned char*)&(buf_mem->data[len]),
&taillen) < 0) {
ERR_raise(ERR_LIB_PEM, PEM_R_BAD_BASE64_DECODE);
goto end;
}
len += taillen;
buf_mem->length = len;
headerlen = BIO_get_mem_data(headerB, NULL);
*header = pem_malloc(headerlen + 1, flags);
*data = pem_malloc(len, flags);
if (*header == NULL || *data == NULL) {
pem_free(*header, flags, 0);
pem_free(*data, flags, 0);
goto end;
}
BIO_read(headerB, *header, headerlen);
(*header)[headerlen] = '\0';
BIO_read(dataB, *data, len);
*len_out = len;
*name_out = name;
name = NULL;
ret = 1;
end:
EVP_ENCODE_CTX_free(ctx);
pem_free(name, flags, 0);
BIO_free(headerB);
BIO_free(dataB);
return ret;
}
int PEM_read_bio(BIO *bp, char **name, char **header, unsigned char **data,
long *len)
{
return PEM_read_bio_ex(bp, name, header, data, len, PEM_FLAG_EAY_COMPATIBLE);
}
/*
* 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;
}
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