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src/lib/libkeynote/signature.c

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/* $OpenBSD: signature.c,v 1.30 2022/11/30 10:40:23 bluhm Exp $ */
/*
* The author of this code is Angelos D. Keromytis (angelos@dsl.cis.upenn.edu)
*
* This code was written by Angelos D. Keromytis in Philadelphia, PA, USA,
* in April-May 1998
*
* Copyright (C) 1998, 1999 by Angelos D. Keromytis.
*
* Permission to use, copy, and modify this software with or without fee
* is hereby granted, provided that this entire notice is included in
* all copies of any software which is or includes a copy or
* modification of this software.
*
* THIS SOFTWARE IS BEING PROVIDED "AS IS", WITHOUT ANY EXPRESS OR
* IMPLIED WARRANTY. IN PARTICULAR, THE AUTHORS MAKES NO
* REPRESENTATION OR WARRANTY OF ANY KIND CONCERNING THE
* MERCHANTABILITY OF THIS SOFTWARE OR ITS FITNESS FOR ANY PARTICULAR
* PURPOSE.
*/
/*
* Support for X509 keys and signing added by Ben Laurie <ben@algroup.co.uk>
* 3 May 1999
*/
#include <sys/types.h>
#include <limits.h>
#include <regex.h>
#include <stdlib.h>
#include <stdio.h>
#include <string.h>
#include <openssl/dsa.h>
#include <openssl/md5.h>
#include <openssl/pem.h>
#include <openssl/rsa.h>
#include <openssl/sha.h>
#include <openssl/x509.h>
#include "keynote.h"
#include "assertion.h"
#include "signature.h"
static const char hextab[] = {
'0', '1', '2', '3', '4', '5', '6', '7',
'8', '9', 'a', 'b', 'c', 'd', 'e', 'f'
};
/*
* Actual conversion to hex.
*/
static void
bin2hex(unsigned char *data, unsigned char *buffer, int len)
{
int off = 0;
while(len > 0)
{
buffer[off++] = hextab[*data >> 4];
buffer[off++] = hextab[*data & 0xF];
data++;
len--;
}
}
/*
* Encode a binary string with hex encoding. Return 0 on success.
*/
int
kn_encode_hex(unsigned char *buf, char **dest, int len)
{
keynote_errno = 0;
if (dest == NULL)
{
keynote_errno = ERROR_SYNTAX;
return -1;
}
*dest = calloc(2 * len + 1, sizeof(char));
if (*dest == NULL)
{
keynote_errno = ERROR_MEMORY;
return -1;
}
bin2hex(buf, *dest, len);
return 0;
}
/*
* Decode a hex encoding. Return 0 on success. The second argument
* will be half as large as the first.
*/
int
kn_decode_hex(char *hex, char **dest)
{
int i, decodedlen;
char ptr[3];
keynote_errno = 0;
if (dest == NULL)
{
keynote_errno = ERROR_SYNTAX;
return -1;
}
if (strlen(hex) % 2) /* Should be even */
{
keynote_errno = ERROR_SYNTAX;
return -1;
}
decodedlen = strlen(hex) / 2;
*dest = calloc(decodedlen, sizeof(char));
if (*dest == NULL)
{
keynote_errno = ERROR_MEMORY;
return -1;
}
ptr[2] = '\0';
for (i = 0; i < decodedlen; i++)
{
ptr[0] = hex[2 * i];
ptr[1] = hex[(2 * i) + 1];
(*dest)[i] = (unsigned char) strtoul(ptr, NULL, 16);
}
return 0;
}
void
keynote_free_key(void *key, int type)
{
if (key == NULL)
return;
/* DSA keys */
if (type == KEYNOTE_ALGORITHM_DSA)
{
DSA_free(key);
return;
}
/* RSA keys */
if (type == KEYNOTE_ALGORITHM_RSA)
{
RSA_free(key);
return;
}
/* X509 keys */
if (type == KEYNOTE_ALGORITHM_X509)
{
RSA_free(key); /* RSA-specific */
return;
}
/* BINARY keys */
if (type == KEYNOTE_ALGORITHM_BINARY)
{
free(((struct keynote_binary *) key)->bn_key);
free(key);
return;
}
/* Catch-all case */
if (type == KEYNOTE_ALGORITHM_NONE)
free(key);
}
/*
* Map a signature to an algorithm. Return algorithm number (defined in
* keynote.h), or KEYNOTE_ALGORITHM_NONE if unknown.
* Also return in the second, third and fourth arguments the digest
* algorithm, ASCII and internal encodings respectively.
*/
static int
keynote_get_sig_algorithm(char *sig, int *hash, int *enc, int *internal)
{
if (sig == NULL)
return KEYNOTE_ALGORITHM_NONE;
if (!strncasecmp(SIG_DSA_SHA1_HEX, sig, SIG_DSA_SHA1_HEX_LEN))
{
*hash = KEYNOTE_HASH_SHA1;
*enc = ENCODING_HEX;
*internal = INTERNAL_ENC_ASN1;
return KEYNOTE_ALGORITHM_DSA;
}
if (!strncasecmp(SIG_DSA_SHA1_BASE64, sig, SIG_DSA_SHA1_BASE64_LEN))
{
*hash = KEYNOTE_HASH_SHA1;
*enc = ENCODING_BASE64;
*internal = INTERNAL_ENC_ASN1;
return KEYNOTE_ALGORITHM_DSA;
}
if (!strncasecmp(SIG_RSA_MD5_PKCS1_HEX, sig, SIG_RSA_MD5_PKCS1_HEX_LEN))
{
*hash = KEYNOTE_HASH_MD5;
*enc = ENCODING_HEX;
*internal = INTERNAL_ENC_PKCS1;
return KEYNOTE_ALGORITHM_RSA;
}
if (!strncasecmp(SIG_RSA_SHA1_PKCS1_HEX, sig, SIG_RSA_SHA1_PKCS1_HEX_LEN))
{
*hash = KEYNOTE_HASH_SHA1;
*enc = ENCODING_HEX;
*internal = INTERNAL_ENC_PKCS1;
return KEYNOTE_ALGORITHM_RSA;
}
if (!strncasecmp(SIG_RSA_MD5_PKCS1_BASE64, sig,
SIG_RSA_MD5_PKCS1_BASE64_LEN))
{
*hash = KEYNOTE_HASH_MD5;
*enc = ENCODING_BASE64;
*internal = INTERNAL_ENC_PKCS1;
return KEYNOTE_ALGORITHM_RSA;
}
if (!strncasecmp(SIG_RSA_SHA1_PKCS1_BASE64, sig,
SIG_RSA_SHA1_PKCS1_BASE64_LEN))
{
*hash = KEYNOTE_HASH_SHA1;
*enc = ENCODING_BASE64;
*internal = INTERNAL_ENC_PKCS1;
return KEYNOTE_ALGORITHM_RSA;
}
if (!strncasecmp(SIG_X509_SHA1_BASE64, sig, SIG_X509_SHA1_BASE64_LEN))
{
*hash = KEYNOTE_HASH_SHA1;
*enc = ENCODING_BASE64;
*internal = INTERNAL_ENC_ASN1;
return KEYNOTE_ALGORITHM_X509;
}
if (!strncasecmp(SIG_X509_SHA1_HEX, sig, SIG_X509_SHA1_HEX_LEN))
{
*hash = KEYNOTE_HASH_SHA1;
*enc = ENCODING_HEX;
*internal = INTERNAL_ENC_ASN1;
return KEYNOTE_ALGORITHM_X509;
}
*hash = KEYNOTE_HASH_NONE;
*enc = ENCODING_NONE;
*internal = INTERNAL_ENC_NONE;
return KEYNOTE_ALGORITHM_NONE;
}
/*
* Map a key to an algorithm. Return algorithm number (defined in
* keynote.h), or KEYNOTE_ALGORITHM_NONE if unknown.
* This latter is also a valid algorithm (for logical tags). Also return
* in the second and third arguments the ASCII and internal encodings.
*/
int
keynote_get_key_algorithm(char *key, int *encoding, int *internalencoding)
{
if (!strncasecmp(DSA_HEX, key, DSA_HEX_LEN))
{
*internalencoding = INTERNAL_ENC_ASN1;
*encoding = ENCODING_HEX;
return KEYNOTE_ALGORITHM_DSA;
}
if (!strncasecmp(DSA_BASE64, key, DSA_BASE64_LEN))
{
*internalencoding = INTERNAL_ENC_ASN1;
*encoding = ENCODING_BASE64;
return KEYNOTE_ALGORITHM_DSA;
}
if (!strncasecmp(RSA_PKCS1_HEX, key, RSA_PKCS1_HEX_LEN))
{
*internalencoding = INTERNAL_ENC_PKCS1;
*encoding = ENCODING_HEX;
return KEYNOTE_ALGORITHM_RSA;
}
if (!strncasecmp(RSA_PKCS1_BASE64, key, RSA_PKCS1_BASE64_LEN))
{
*internalencoding = INTERNAL_ENC_PKCS1;
*encoding = ENCODING_BASE64;
return KEYNOTE_ALGORITHM_RSA;
}
if (!strncasecmp(X509_BASE64, key, X509_BASE64_LEN))
{
*internalencoding = INTERNAL_ENC_ASN1;
*encoding = ENCODING_BASE64;
return KEYNOTE_ALGORITHM_X509;
}
if (!strncasecmp(X509_HEX, key, X509_HEX_LEN))
{
*internalencoding = INTERNAL_ENC_ASN1;
*encoding = ENCODING_HEX;
return KEYNOTE_ALGORITHM_X509;
}
if (!strncasecmp(BINARY_HEX, key, BINARY_HEX_LEN))
{
*internalencoding = INTERNAL_ENC_NONE;
*encoding = ENCODING_HEX;
return KEYNOTE_ALGORITHM_BINARY;
}
if (!strncasecmp(BINARY_BASE64, key, BINARY_BASE64_LEN))
{
*internalencoding = INTERNAL_ENC_NONE;
*encoding = ENCODING_BASE64;
return KEYNOTE_ALGORITHM_BINARY;
}
*internalencoding = INTERNAL_ENC_NONE;
*encoding = ENCODING_NONE;
return KEYNOTE_ALGORITHM_NONE;
}
/*
* Same as keynote_get_key_algorithm(), only verify that this is
* a private key (just look at the prefix).
*/
static int
keynote_get_private_key_algorithm(char *key, int *encoding,
int *internalencoding)
{
if (strncasecmp(KEYNOTE_PRIVATE_KEY_PREFIX, key,
KEYNOTE_PRIVATE_KEY_PREFIX_LEN))
{
*internalencoding = INTERNAL_ENC_NONE;
*encoding = ENCODING_NONE;
return KEYNOTE_ALGORITHM_NONE;
}
return keynote_get_key_algorithm(key + KEYNOTE_PRIVATE_KEY_PREFIX_LEN,
encoding, internalencoding);
}
/*
* Decode a string to a key. Return 0 on success.
*/
int
kn_decode_key(struct keynote_deckey *dc, char *key, int keytype)
{
X509 *px509Cert;
EVP_PKEY *pPublicKey;
unsigned char *ptr = NULL, *decoded = NULL;
int encoding, internalencoding;
long len = 0;
keynote_errno = 0;
if (keytype == KEYNOTE_PRIVATE_KEY)
dc->dec_algorithm = keynote_get_private_key_algorithm(key, &encoding,
&internalencoding);
else
dc->dec_algorithm = keynote_get_key_algorithm(key, &encoding,
&internalencoding);
if (dc->dec_algorithm == KEYNOTE_ALGORITHM_NONE)
{
if ((dc->dec_key = strdup(key)) == NULL) {
keynote_errno = ERROR_MEMORY;
return -1;
}
return 0;
}
key = strchr(key, ':'); /* Move forward, to the Encoding. We're guaranteed
* to have a ':' character, since this is a key */
key++;
/* Remove ASCII encoding */
switch (encoding)
{
case ENCODING_NONE:
break;
case ENCODING_HEX:
len = strlen(key) / 2;
if (kn_decode_hex(key, (char **) &decoded) != 0)
return -1;
ptr = decoded;
break;
case ENCODING_BASE64:
len = strlen(key);
if (len % 4) /* Base64 encoding must be a multiple of 4 */
{
keynote_errno = ERROR_SYNTAX;
return -1;
}
len = 3 * (len / 4);
decoded = calloc(len, sizeof(unsigned char));
ptr = decoded;
if (decoded == NULL) {
keynote_errno = ERROR_MEMORY;
return -1;
}
if ((len = kn_decode_base64(key, decoded, len)) == -1)
return -1;
break;
case ENCODING_NATIVE:
decoded = strdup(key);
if (decoded == NULL) {
keynote_errno = ERROR_MEMORY;
return -1;
}
len = strlen(key);
ptr = decoded;
break;
default:
keynote_errno = ERROR_SYNTAX;
return -1;
}
/* DSA-HEX */
if ((dc->dec_algorithm == KEYNOTE_ALGORITHM_DSA) &&
(internalencoding == INTERNAL_ENC_ASN1))
{
if (keytype == KEYNOTE_PRIVATE_KEY)
{
if ((dc->dec_key =
d2i_DSAPrivateKey(NULL, (const unsigned char **) &decoded, len))
== NULL)
{
free(ptr);
keynote_errno = ERROR_SYNTAX; /* Could be a memory error */
return -1;
}
}
else
{
if ((dc->dec_key =
d2i_DSAPublicKey(NULL, (const unsigned char **) &decoded, len))
== NULL)
{
free(ptr);
keynote_errno = ERROR_SYNTAX; /* Could be a memory error */
return -1;
}
}
free(ptr);
return 0;
}
/* RSA-PKCS1-HEX */
if ((dc->dec_algorithm == KEYNOTE_ALGORITHM_RSA) &&
(internalencoding == INTERNAL_ENC_PKCS1))
{
if (keytype == KEYNOTE_PRIVATE_KEY)
{
if ((dc->dec_key =
d2i_RSAPrivateKey(NULL, (const unsigned char **) &decoded, len))
== NULL)
{
free(ptr);
keynote_errno = ERROR_SYNTAX; /* Could be a memory error */
return -1;
}
if (RSA_blinding_on(dc->dec_key, NULL) != 1) {
free(ptr);
RSA_free(dc->dec_key);
keynote_errno = ERROR_MEMORY;
return -1;
}
}
else
{
if ((dc->dec_key =
d2i_RSAPublicKey(NULL, (const unsigned char **) &decoded, len))
== NULL)
{
free(ptr);
keynote_errno = ERROR_SYNTAX; /* Could be a memory error */
return -1;
}
}
free(ptr);
return 0;
}
/* X509 Cert */
if ((dc->dec_algorithm == KEYNOTE_ALGORITHM_X509) &&
(internalencoding == INTERNAL_ENC_ASN1) &&
(keytype == KEYNOTE_PUBLIC_KEY))
{
if((px509Cert =
d2i_X509(NULL, (const unsigned char **)&decoded, len)) == NULL)
{
free(ptr);
keynote_errno = ERROR_SYNTAX;
return -1;
}
if ((pPublicKey = X509_get0_pubkey(px509Cert)) == NULL) {
free(ptr);
X509_free(px509Cert);
keynote_errno = ERROR_SYNTAX;
return -1;
}
/* RSA-specific */
dc->dec_key = EVP_PKEY_get0_RSA(pPublicKey);
RSA_up_ref(dc->dec_key);
free(ptr);
X509_free(px509Cert);
return 0;
}
/* BINARY keys */
if ((dc->dec_algorithm == KEYNOTE_ALGORITHM_BINARY) &&
(internalencoding == INTERNAL_ENC_NONE))
{
dc->dec_key = calloc(1, sizeof(struct keynote_binary));
if (dc->dec_key == NULL)
{
keynote_errno = ERROR_MEMORY;
return -1;
}
((struct keynote_binary *) dc->dec_key)->bn_key = decoded;
((struct keynote_binary *) dc->dec_key)->bn_len = len;
return RESULT_TRUE;
}
/* Add support for more algorithms here */
free(ptr);
/* This shouldn't ever be reached really */
keynote_errno = ERROR_SYNTAX;
return -1;
}
/*
* Compare two keys for equality. Return RESULT_TRUE if equal,
* RESULT_FALSE otherwise.
*/
int
kn_keycompare(void *key1, void *key2, int algorithm)
{
DSA *p1, *p2;
RSA *p3, *p4;
struct keynote_binary *bn1, *bn2;
if (key1 == NULL || key2 == NULL)
return RESULT_FALSE;
switch (algorithm)
{
case KEYNOTE_ALGORITHM_NONE:
if (!strcmp(key1, key2))
return RESULT_TRUE;
else
return RESULT_FALSE;
case KEYNOTE_ALGORITHM_DSA:
p1 = (DSA *) key1;
p2 = (DSA *) key2;
if (!BN_cmp(DSA_get0_p(p1), DSA_get0_p(p2)) &&
!BN_cmp(DSA_get0_q(p1), DSA_get0_q(p2)) &&
!BN_cmp(DSA_get0_g(p1), DSA_get0_g(p2)) &&
!BN_cmp(DSA_get0_pub_key(p1), DSA_get0_pub_key(p2)))
return RESULT_TRUE;
else
return RESULT_FALSE;
case KEYNOTE_ALGORITHM_X509:
p3 = (RSA *) key1;
p4 = (RSA *) key2;
if (!BN_cmp(RSA_get0_n(p3), RSA_get0_n(p4)) &&
!BN_cmp(RSA_get0_e(p3), RSA_get0_e(p4)))
return RESULT_TRUE;
else
return RESULT_FALSE;
case KEYNOTE_ALGORITHM_RSA:
p3 = (RSA *) key1;
p4 = (RSA *) key2;
if (!BN_cmp(RSA_get0_n(p3), RSA_get0_n(p4)) &&
!BN_cmp(RSA_get0_e(p3), RSA_get0_e(p4)))
return RESULT_TRUE;
else
return RESULT_FALSE;
case KEYNOTE_ALGORITHM_ELGAMAL:
/* Not supported yet */
return RESULT_FALSE;
case KEYNOTE_ALGORITHM_PGP:
/* Not supported yet */
return RESULT_FALSE;
case KEYNOTE_ALGORITHM_BINARY:
bn1 = (struct keynote_binary *) key1;
bn2 = (struct keynote_binary *) key2;
if ((bn1->bn_len == bn2->bn_len) &&
!memcmp(bn1->bn_key, bn2->bn_key, bn1->bn_len))
return RESULT_TRUE;
else
return RESULT_FALSE;
default:
return RESULT_FALSE;
}
}
/*
* Verify the signature on an assertion; return SIGRESULT_TRUE is
* success, SIGRESULT_FALSE otherwise.
*/
int
keynote_sigverify_assertion(struct assertion *as)
{
int hashtype, enc, intenc, alg = KEYNOTE_ALGORITHM_NONE, hashlen = 0;
unsigned char *sig, *decoded = NULL, *ptr;
unsigned char res2[20];
SHA_CTX shscontext;
MD5_CTX md5context;
int len = 0;
DSA *dsa;
RSA *rsa;
if (as->as_signature == NULL ||
as->as_startofsignature == NULL ||
as->as_allbutsignature == NULL ||
as->as_allbutsignature - as->as_startofsignature <= 0)
return SIGRESULT_FALSE;
alg = keynote_get_sig_algorithm(as->as_signature, &hashtype, &enc,
&intenc);
if (alg == KEYNOTE_ALGORITHM_NONE)
return SIGRESULT_FALSE;
/* Check for matching algorithms */
if ((alg != as->as_signeralgorithm) &&
!((alg == KEYNOTE_ALGORITHM_RSA) &&
(as->as_signeralgorithm == KEYNOTE_ALGORITHM_X509)) &&
!((alg == KEYNOTE_ALGORITHM_X509) &&
(as->as_signeralgorithm == KEYNOTE_ALGORITHM_RSA)))
return SIGRESULT_FALSE;
sig = strchr(as->as_signature, ':'); /* Move forward to the Encoding. We
* are guaranteed to have a ':'
* character, since this is a valid
* signature */
sig++;
switch (hashtype)
{
case KEYNOTE_HASH_SHA1:
hashlen = 20;
memset(res2, 0, hashlen);
SHA1_Init(&shscontext);
SHA1_Update(&shscontext, as->as_startofsignature,
as->as_allbutsignature - as->as_startofsignature);
SHA1_Update(&shscontext, as->as_signature,
(char *) sig - as->as_signature);
SHA1_Final(res2, &shscontext);
break;
case KEYNOTE_HASH_MD5:
hashlen = 16;
memset(res2, 0, hashlen);
MD5_Init(&md5context);
MD5_Update(&md5context, as->as_startofsignature,
as->as_allbutsignature - as->as_startofsignature);
MD5_Update(&md5context, as->as_signature,
(char *) sig - as->as_signature);
MD5_Final(res2, &md5context);
break;
case KEYNOTE_HASH_NONE:
break;
}
/* Remove ASCII encoding */
switch (enc)
{
case ENCODING_NONE:
ptr = NULL;
break;
case ENCODING_HEX:
len = strlen(sig) / 2;
if (kn_decode_hex(sig, (char **) &decoded) != 0)
return -1;
ptr = decoded;
break;
case ENCODING_BASE64:
len = strlen(sig);
if (len % 4) /* Base64 encoding must be a multiple of 4 */
{
keynote_errno = ERROR_SYNTAX;
return -1;
}
len = 3 * (len / 4);
decoded = calloc(len, sizeof(unsigned char));
ptr = decoded;
if (decoded == NULL) {
keynote_errno = ERROR_MEMORY;
return -1;
}
len = kn_decode_base64(sig, decoded, len);
if ((len == -1) || (len == 0) || (len == 1))
return -1;
break;
case ENCODING_NATIVE:
if ((decoded = strdup(sig)) == NULL) {
keynote_errno = ERROR_MEMORY;
return -1;
}
len = strlen(sig);
ptr = decoded;
break;
default:
keynote_errno = ERROR_SYNTAX;
return -1;
}
/* DSA */
if ((alg == KEYNOTE_ALGORITHM_DSA) && (intenc == INTERNAL_ENC_ASN1))
{
dsa = (DSA *) as->as_authorizer;
if (DSA_verify(0, res2, hashlen, decoded, len, dsa) == 1) {
free(ptr);
return SIGRESULT_TRUE;
}
}
else /* RSA */
if ((alg == KEYNOTE_ALGORITHM_RSA) && (intenc == INTERNAL_ENC_PKCS1))
{
rsa = (RSA *) as->as_authorizer;
if (RSA_verify_ASN1_OCTET_STRING(RSA_PKCS1_PADDING, res2, hashlen,
decoded, len, rsa) == 1) {
free(ptr);
return SIGRESULT_TRUE;
}
}
else
if ((alg == KEYNOTE_ALGORITHM_X509) && (intenc == INTERNAL_ENC_ASN1))
{
/* RSA-specific */
rsa = (RSA *) as->as_authorizer;
if (RSA_verify(NID_shaWithRSAEncryption, res2, hashlen, decoded,
len, rsa) == 1) {
free(ptr);
return SIGRESULT_TRUE;
}
}
/* Handle more algorithms here */
free(ptr);
return SIGRESULT_FALSE;
}
/*
* Sign an assertion.
*/
static char *
keynote_sign_assertion(struct assertion *as, char *sigalg, void *key,
int keyalg, int verifyflag)
{
int slen, i, hashlen = 0, hashtype, alg, encoding, internalenc;
unsigned char *sig = NULL, *finalbuf = NULL;
unsigned char res2[LARGEST_HASH_SIZE], *sbuf = NULL;
BIO *biokey = NULL;
DSA *dsa = NULL;
RSA *rsa = NULL;
SHA_CTX shscontext;
MD5_CTX md5context;
int len;
if (as->as_signature_string_s == NULL ||
as->as_startofsignature == NULL ||
as->as_allbutsignature == NULL ||
as->as_allbutsignature - as->as_startofsignature <= 0 ||
as->as_authorizer == NULL ||
key == NULL ||
as->as_signeralgorithm == KEYNOTE_ALGORITHM_NONE)
{
keynote_errno = ERROR_SYNTAX;
return NULL;
}
alg = keynote_get_sig_algorithm(sigalg, &hashtype, &encoding,
&internalenc);
if (((alg != as->as_signeralgorithm) &&
!((alg == KEYNOTE_ALGORITHM_RSA) &&
(as->as_signeralgorithm == KEYNOTE_ALGORITHM_X509)) &&
!((alg == KEYNOTE_ALGORITHM_X509) &&
(as->as_signeralgorithm == KEYNOTE_ALGORITHM_RSA))) ||
((alg != keyalg) &&
!((alg == KEYNOTE_ALGORITHM_RSA) &&
(keyalg == KEYNOTE_ALGORITHM_X509)) &&
!((alg == KEYNOTE_ALGORITHM_X509) &&
(keyalg == KEYNOTE_ALGORITHM_RSA))))
{
keynote_errno = ERROR_SYNTAX;
return NULL;
}
sig = strchr(sigalg, ':');
if (sig == NULL)
{
keynote_errno = ERROR_SYNTAX;
return NULL;
}
sig++;
switch (hashtype)
{
case KEYNOTE_HASH_SHA1:
hashlen = 20;
memset(res2, 0, hashlen);
SHA1_Init(&shscontext);
SHA1_Update(&shscontext, as->as_startofsignature,
as->as_allbutsignature - as->as_startofsignature);
SHA1_Update(&shscontext, sigalg, (char *) sig - sigalg);
SHA1_Final(res2, &shscontext);
break;
case KEYNOTE_HASH_MD5:
hashlen = 16;
memset(res2, 0, hashlen);
MD5_Init(&md5context);
MD5_Update(&md5context, as->as_startofsignature,
as->as_allbutsignature - as->as_startofsignature);
MD5_Update(&md5context, sigalg, (char *) sig - sigalg);
MD5_Final(res2, &md5context);
break;
case KEYNOTE_HASH_NONE:
break;
}
if ((alg == KEYNOTE_ALGORITHM_DSA) &&
(hashtype == KEYNOTE_HASH_SHA1) &&
(internalenc == INTERNAL_ENC_ASN1) &&
((encoding == ENCODING_HEX) || (encoding == ENCODING_BASE64)))
{
dsa = (DSA *) key;
sbuf = calloc(DSA_size(dsa), sizeof(unsigned char));
if (sbuf == NULL)
{
keynote_errno = ERROR_MEMORY;
return NULL;
}
if (DSA_sign(0, res2, hashlen, sbuf, &slen, dsa) <= 0)
{
free(sbuf);
keynote_errno = ERROR_SYNTAX;
return NULL;
}
}
else
if ((alg == KEYNOTE_ALGORITHM_RSA) &&
((hashtype == KEYNOTE_HASH_SHA1) ||
(hashtype == KEYNOTE_HASH_MD5)) &&
(internalenc == INTERNAL_ENC_PKCS1) &&
((encoding == ENCODING_HEX) || (encoding == ENCODING_BASE64)))
{
rsa = (RSA *) key;
sbuf = calloc(RSA_size(rsa), sizeof(unsigned char));
if (sbuf == NULL)
{
keynote_errno = ERROR_MEMORY;
return NULL;
}
if (RSA_sign_ASN1_OCTET_STRING(RSA_PKCS1_PADDING, res2, hashlen,
sbuf, &slen, rsa) <= 0)
{
free(sbuf);
keynote_errno = ERROR_SYNTAX;
return NULL;
}
}
else
if ((alg == KEYNOTE_ALGORITHM_X509) &&
(hashtype == KEYNOTE_HASH_SHA1) &&
(internalenc == INTERNAL_ENC_ASN1))
{
if ((biokey = BIO_new(BIO_s_mem())) == NULL)
{
keynote_errno = ERROR_SYNTAX;
return NULL;
}
if (BIO_write(biokey, key, strlen(key) + 1) <= 0)
{
BIO_free(biokey);
keynote_errno = ERROR_SYNTAX;
return NULL;
}
/* RSA-specific */
rsa = (RSA *) PEM_read_bio_RSAPrivateKey(biokey, NULL, NULL, NULL);
if (rsa == NULL)
{
BIO_free(biokey);
keynote_errno = ERROR_SYNTAX;
return NULL;
}
sbuf = calloc(RSA_size(rsa), sizeof(char));
if (sbuf == NULL)
{
BIO_free(biokey);
RSA_free(rsa);
keynote_errno = ERROR_MEMORY;
return NULL;
}
if (RSA_sign(NID_shaWithRSAEncryption, res2, hashlen, sbuf, &slen,
rsa) <= 0)
{
BIO_free(biokey);
RSA_free(rsa);
free(sbuf);
keynote_errno = ERROR_SIGN_FAILURE;
return NULL;
}
BIO_free(biokey);
RSA_free(rsa);
}
else /* Other algorithms here */
{
keynote_errno = ERROR_SYNTAX;
return NULL;
}
/* ASCII encoding */
switch (encoding)
{
case ENCODING_HEX:
i = kn_encode_hex(sbuf, (char **) &finalbuf, slen);
free(sbuf);
if (i != 0)
return NULL;
break;
case ENCODING_BASE64:
finalbuf = calloc(2 * slen, sizeof(unsigned char));
if (finalbuf == NULL)
{
keynote_errno = ERROR_MEMORY;
free(sbuf);
return NULL;
}
slen = kn_encode_base64(sbuf, slen, finalbuf, 2 * slen);
free(sbuf);
if (slen == -1) {
free(finalbuf);
return NULL;
}
break;
default:
free(sbuf);
keynote_errno = ERROR_SYNTAX;
return NULL;
}
/* Replace as->as_signature */
len = strlen(sigalg) + strlen(finalbuf) + 1;
as->as_signature = calloc(len, sizeof(char));
if (as->as_signature == NULL)
{
free(finalbuf);
keynote_errno = ERROR_MEMORY;
return NULL;
}
/* Concatenate algorithm name and signature value */
snprintf(as->as_signature, len, "%s%s", sigalg, finalbuf);
free(finalbuf);
finalbuf = as->as_signature;
/* Verify the newly-created signature if requested */
if (verifyflag)
{
/* Do the signature verification */
if (keynote_sigverify_assertion(as) != SIGRESULT_TRUE)
{
as->as_signature = NULL;
free(finalbuf);
if (keynote_errno == 0)
keynote_errno = ERROR_SYNTAX;
return NULL;
}
as->as_signature = NULL;
}
else
as->as_signature = NULL;
/* Everything ok */
return (char *) finalbuf;
}
/*
* Verify the signature on an assertion.
*/
int
kn_verify_assertion(char *buf, int len)
{
struct assertion *as;
int res;
keynote_errno = 0;
as = keynote_parse_assertion(buf, len, ASSERT_FLAG_SIGVER);
if (as == NULL)
return -1;
res = keynote_sigverify_assertion(as);
keynote_free_assertion(as);
return res;
}
/*
* Produce the signature for an assertion.
*/
char *
kn_sign_assertion(char *buf, int buflen, char *key, char *sigalg, int vflag)
{
int i, alg, hashtype, encoding, internalenc;
struct keynote_deckey dc;
struct assertion *as;
char *s, *sig;
keynote_errno = 0;
s = NULL;
if (sigalg == NULL || buf == NULL || key == NULL)
{
keynote_errno = ERROR_NOTFOUND;
return NULL;
}
if (sigalg[0] == '\0' || sigalg[strlen(sigalg) - 1] != ':')
{
keynote_errno = ERROR_SYNTAX;
return NULL;
}
/* We're using a different format for X509 private keys, so... */
alg = keynote_get_sig_algorithm(sigalg, &hashtype, &encoding,
&internalenc);
if (alg != KEYNOTE_ALGORITHM_X509)
{
/* Parse the private key */
s = keynote_get_private_key(key);
if (s == NULL)
return NULL;
/* Decode private key */
i = kn_decode_key(&dc, s, KEYNOTE_PRIVATE_KEY);
if (i == -1)
{
free(s);
return NULL;
}
}
else /* X509 private key */
{
dc.dec_key = key;
dc.dec_algorithm = alg;
}
as = keynote_parse_assertion(buf, buflen, ASSERT_FLAG_SIGGEN);
if (as == NULL)
{
if (alg != KEYNOTE_ALGORITHM_X509)
{
keynote_free_key(dc.dec_key, dc.dec_algorithm);
free(s);
}
return NULL;
}
sig = keynote_sign_assertion(as, sigalg, dc.dec_key, dc.dec_algorithm,
vflag);
if (alg != KEYNOTE_ALGORITHM_X509)
keynote_free_key(dc.dec_key, dc.dec_algorithm);
keynote_free_assertion(as);
if (s != NULL)
free(s);
return sig;
}
/*
* ASCII-encode a key.
*/
char *
kn_encode_key(struct keynote_deckey *dc, int iencoding,
int encoding, int keytype)
{
char *foo, *ptr;
DSA *dsa;
RSA *rsa;
int i;
struct keynote_binary *bn;
char *s;
keynote_errno = 0;
if (dc == NULL || dc->dec_key == NULL)
{
keynote_errno = ERROR_NOTFOUND;
return NULL;
}
/* DSA keys */
if ((dc->dec_algorithm == KEYNOTE_ALGORITHM_DSA) &&
(iencoding == INTERNAL_ENC_ASN1) &&
((encoding == ENCODING_HEX) || (encoding == ENCODING_BASE64)))
{
dsa = (DSA *) dc->dec_key;
if (keytype == KEYNOTE_PUBLIC_KEY)
i = i2d_DSAPublicKey(dsa, NULL);
else
i = i2d_DSAPrivateKey(dsa, NULL);
if (i <= 0)
{
keynote_errno = ERROR_SYNTAX;
return NULL;
}
ptr = foo = calloc(i, sizeof(char));
if (foo == NULL)
{
keynote_errno = ERROR_MEMORY;
return NULL;
}
if (keytype == KEYNOTE_PUBLIC_KEY)
i2d_DSAPublicKey(dsa, (unsigned char **) &foo);
else
i2d_DSAPrivateKey(dsa, (unsigned char **) &foo);
if (encoding == ENCODING_HEX)
{
if (kn_encode_hex(ptr, &s, i) != 0)
{
free(ptr);
return NULL;
}
free(ptr);
return s;
}
else
if (encoding == ENCODING_BASE64)
{
s = calloc(2 * i, sizeof(char));
if (s == NULL)
{
free(ptr);
keynote_errno = ERROR_MEMORY;
return NULL;
}
if (kn_encode_base64(ptr, i, s, 2 * i) == -1)
{
free(s);
free(ptr);
return NULL;
}
free(ptr);
return s;
}
}
/* RSA keys */
if ((dc->dec_algorithm == KEYNOTE_ALGORITHM_RSA) &&
(iencoding == INTERNAL_ENC_PKCS1) &&
((encoding == ENCODING_HEX) || (encoding == ENCODING_BASE64)))
{
rsa = (RSA *) dc->dec_key;
if (keytype == KEYNOTE_PUBLIC_KEY)
i = i2d_RSAPublicKey(rsa, NULL);
else
i = i2d_RSAPrivateKey(rsa, NULL);
if (i <= 0)
{
keynote_errno = ERROR_SYNTAX;
return NULL;
}
ptr = foo = calloc(i, sizeof(char));
if (foo == NULL)
{
keynote_errno = ERROR_MEMORY;
return NULL;
}
if (keytype == KEYNOTE_PUBLIC_KEY)
i2d_RSAPublicKey(rsa, (unsigned char **) &foo);
else
i2d_RSAPrivateKey(rsa, (unsigned char **) &foo);
if (encoding == ENCODING_HEX)
{
if (kn_encode_hex(ptr, &s, i) != 0)
{
free(ptr);
return NULL;
}
free(ptr);
return s;
}
else
if (encoding == ENCODING_BASE64)
{
s = calloc(2 * i, sizeof(char));
if (s == NULL)
{
free(ptr);
keynote_errno = ERROR_MEMORY;
return NULL;
}
if (kn_encode_base64(ptr, i, s, 2 * i) == -1)
{
free(s);
free(ptr);
return NULL;
}
free(ptr);
return s;
}
}
/* BINARY keys */
if ((dc->dec_algorithm == KEYNOTE_ALGORITHM_BINARY) &&
(iencoding == INTERNAL_ENC_NONE) &&
((encoding == ENCODING_HEX) || (encoding == ENCODING_BASE64)))
{
bn = (struct keynote_binary *) dc->dec_key;
if (encoding == ENCODING_HEX)
{
if (kn_encode_hex(bn->bn_key, &s, bn->bn_len) != 0)
return NULL;
return s;
}
else
if (encoding == ENCODING_BASE64)
{
s = calloc(2 * bn->bn_len, sizeof(char));
if (s == NULL)
{
keynote_errno = ERROR_MEMORY;
return NULL;
}
if (kn_encode_base64(bn->bn_key, bn->bn_len, s,
2 * bn->bn_len) == -1)
{
free(s);
return NULL;
}
return s;
}
}
keynote_errno = ERROR_NOTFOUND;
return NULL;
}
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