pem_lib.c

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/* crypto/pem/pem_lib.c */
/* Copyright (C) 1995-1998 Eric Young ([e-mail])
 * All rights reserved.
 *
 * This package is an SSL implementation written
 * by Eric Young ([e-mail]).
 * 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 ([e-mail]).
 * 
 * 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 ([e-mail])"
 *    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 ([e-mail])"
 * 
 * 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 "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>
#ifndef NO_DES
#include <openssl/des.h>
#endif

const char *PEM_version="PEM" OPENSSL_VERSION_PTEXT;

#define MIN_LENGTH	4

static int def_callback(char *buf, int num, int w, void *userdata);
static int load_iv(unsigned char **fromp,unsigned char *to, int num);
static int check_pem(const char *nm, const char *name);
static int do_pk8pkey(BIO *bp, EVP_PKEY *x, int isder,
				int nid, const EVP_CIPHER *enc,
				char *kstr, int klen,
				pem_password_cb *cb, void *u);
static int do_pk8pkey_fp(FILE *bp, EVP_PKEY *x, int isder,
				int nid, const EVP_CIPHER *enc,
				char *kstr, int klen,
				pem_password_cb *cb, void *u);

static int def_callback(char *buf, int num, int w, void *key)
	{
#ifdef NO_FP_API
	/* We should not ever call the default callback routine from
	 * windows. */
	PEMerr(PEM_F_DEF_CALLBACK,ERR_R_SHOULD_NOT_HAVE_BEEN_CALLED);
	return(-1);
#else
	int i,j;
	const char *prompt;
	if(key) {
		i=strlen(key);
		i=(i > num)?num:i;
		memcpy(buf,key,i);
		return(i);
	}

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

	for (;;)
		{
		i=EVP_read_pw_string(buf,num,prompt,w);
		if (i != 0)
			{
			PEMerr(PEM_F_DEF_CALLBACK,PEM_R_PROBLEMS_GETTING_PASSWORD);
			memset(buf,0,(unsigned int)num);
			return(-1);
			}
		j=strlen(buf);
		if (j < MIN_LENGTH)
			{
			fprintf(stderr,"phrase is too short, needs to be at least %d chars\n",MIN_LENGTH);
			}
		else
			break;
		}
	return(j);
#endif
	}

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

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

	strcat(buf,"DEK-Info: ");
	strcat(buf,type);
	strcat(buf,",");
	j=strlen(buf);
	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 NO_FP_API
char *PEM_ASN1_read(char *(*d2i)(), const char *name, FILE *fp, char **x,
	     pem_password_cb *cb, void *u)
	{
        BIO *b;
        char *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(nm,PEM_STRING_PKCS8) &&
		!strcmp(name,PEM_STRING_EVP_PKEY)) return 1;

	if(!strcmp(nm,PEM_STRING_PKCS8INF) &&
		 !strcmp(name,PEM_STRING_EVP_PKEY)) return 1;

	if(!strcmp(nm,PEM_STRING_RSA) &&
		!strcmp(name,PEM_STRING_EVP_PKEY)) return 1;

	if(!strcmp(nm,PEM_STRING_DSA) &&
		 !strcmp(name,PEM_STRING_EVP_PKEY)) 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;

	return 0;
}

char *PEM_ASN1_read_bio(char *(*d2i)(), const char *name, BIO *bp, char **x,
	     pem_password_cb *cb, void *u)
	{
	EVP_CIPHER_INFO cipher;
	char *nm=NULL,*header=NULL;
	unsigned char *p=NULL,*data=NULL;
	long len;
	char *ret=NULL;

	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(NULL);
		}
		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;
	p=data;
	if (strcmp(name,PEM_STRING_EVP_PKEY) == 0) {
		if (strcmp(nm,PEM_STRING_RSA) == 0)
			ret=d2i(EVP_PKEY_RSA,x,&p,len);
		else if (strcmp(nm,PEM_STRING_DSA) == 0)
			ret=d2i(EVP_PKEY_DSA,x,&p,len);
		else if (strcmp(nm,PEM_STRING_PKCS8INF) == 0) {
			PKCS8_PRIV_KEY_INFO *p8inf;
			p8inf=d2i_PKCS8_PRIV_KEY_INFO(
					(PKCS8_PRIV_KEY_INFO **) x, &p, len);
			ret = (char *)EVP_PKCS82PKEY(p8inf);
			PKCS8_PRIV_KEY_INFO_free(p8inf);
		} else if (strcmp(nm,PEM_STRING_PKCS8) == 0) {
			PKCS8_PRIV_KEY_INFO *p8inf;
			X509_SIG *p8;
			int klen;
			char psbuf[PEM_BUFSIZE];
			p8 = d2i_X509_SIG(NULL, &p, len);
			if(!p8) goto p8err;
			if (cb) klen=cb(psbuf,PEM_BUFSIZE,0,u);
			else klen=def_callback(psbuf,PEM_BUFSIZE,0,u);
			if (klen <= 0) {
				PEMerr(PEM_F_PEM_ASN1_READ_BIO,
						PEM_R_BAD_PASSWORD_READ);
				goto err;
			}
			p8inf = M_PKCS8_decrypt(p8, psbuf, klen);
			X509_SIG_free(p8);
			if(!p8inf) goto p8err;
			ret = (char *)EVP_PKCS82PKEY(p8inf);
			if(x) {
				if(*x) EVP_PKEY_free((EVP_PKEY *)*x);
				*x = ret;
			}
			PKCS8_PRIV_KEY_INFO_free(p8inf);
		}
	} else	ret=d2i(x,&p,len);
p8err:
	if (ret == NULL)
		PEMerr(PEM_F_PEM_ASN1_READ_BIO,ERR_R_ASN1_LIB);
err:
	OPENSSL_free(nm);
	OPENSSL_free(header);
	OPENSSL_free(data);
	return(ret);
	}

#ifndef NO_FP_API
int PEM_ASN1_write(int (*i2d)(), const char *name, FILE *fp, char *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(int (*i2d)(), const char *name, BIO *bp, char *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)
			{
			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_MALLOC_FAILURE);
		dsize=0;
		goto err;
		}
	/* dzise + 8 bytes are needed */
	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=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. */
		if (RAND_pseudo_bytes(iv,8) < 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 */
		EVP_BytesToKey(enc,EVP_md5(),iv,kstr,klen,1,key,NULL);

		if (kstr == (unsigned char *)buf) memset(buf,0,PEM_BUFSIZE);

		buf[0]='\0';
		PEM_proc_type(buf,PEM_TYPE_ENCRYPTED);
		PEM_dek_info(buf,objstr,8,(char *)iv);
		/* k=strlen(buf); */
	
		EVP_EncryptInit(&ctx,enc,key,iv);
		EVP_EncryptUpdate(&ctx,data,&j,data,i);
		EVP_EncryptFinal(&ctx,&(data[j]),&i);
		i+=j;
		ret=1;
		}
	else
		{
		ret=1;
		buf[0]='\0';
		}
	i=PEM_write_bio(bp,name,buf,data,i);
	if (i <= 0) ret=0;
err:
	memset(key,0,sizeof(key));
	memset(iv,0,sizeof(iv));
	memset((char *)&ctx,0,sizeof(ctx));
	memset(buf,0,PEM_BUFSIZE);
	memset(data,0,(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,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=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

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

	j=(int)len;
	EVP_DecryptInit(&ctx,cipher->cipher,key,&(cipher->iv[0]));
	EVP_DecryptUpdate(&ctx,data,&i,data,j);
	o=EVP_DecryptFinal(&ctx,&(data[i]),&j);
	EVP_CIPHER_CTX_cleanup(&ctx);
	memset((char *)buf,0,sizeof(buf));
	memset((char *)key,0,sizeof(key));
	j+=i;
	if (!o)
		{
		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)
	{
	int o;
	const EVP_CIPHER *enc=NULL;
	char *p,c;

	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;