PKCS#5 v2 PBES2 support and use in PKCS#8 encrypted certificates
The error code POLARSSL_ERR_X509_PASSWORD_MISMATCH is now properly
returned in case of an encryption failure in the padding. The
POLARSSL_ERR_X509_PASSWORD_REQUIRED error code is only returned for PEM
formatted private keys as for DER formatted ones it is impossible to
distinguish if a DER blob is PKCS#8 encrypted or not.
diff --git a/library/error.c b/library/error.c
index 17b414a..cb64d6b 100644
--- a/library/error.c
+++ b/library/error.c
@@ -233,6 +233,17 @@
snprintf( buf, buflen, "PKCS12 - PBE ASN.1 data not as expected" );
#endif /* POLARSSL_PKCS12_C */
+#if defined(POLARSSL_PKCS5_C)
+ if( use_ret == -(POLARSSL_ERR_PKCS5_BAD_INPUT_DATA) )
+ snprintf( buf, buflen, "PKCS5 - Bad input parameters to function" );
+ if( use_ret == -(POLARSSL_ERR_PKCS5_INVALID_FORMAT) )
+ snprintf( buf, buflen, "PKCS5 - Unexpected ASN.1 data" );
+ if( use_ret == -(POLARSSL_ERR_PKCS5_FEATURE_UNAVAILABLE) )
+ snprintf( buf, buflen, "PKCS5 - Requested encryption or digest alg not available" );
+ if( use_ret == -(POLARSSL_ERR_PKCS5_PASSWORD_MISMATCH) )
+ snprintf( buf, buflen, "PKCS5 - Given private key password does not allow for correct decryption" );
+#endif /* POLARSSL_PKCS5_C */
+
#if defined(POLARSSL_RSA_C)
if( use_ret == -(POLARSSL_ERR_RSA_BAD_INPUT_DATA) )
snprintf( buf, buflen, "RSA - Bad input parameters to function" );
@@ -373,6 +384,10 @@
snprintf( buf, buflen, "X509 - Allocation of memory failed" );
if( use_ret == -(POLARSSL_ERR_X509_FILE_IO_ERROR) )
snprintf( buf, buflen, "X509 - Read/write of file failed" );
+ if( use_ret == -(POLARSSL_ERR_X509_PASSWORD_REQUIRED) )
+ snprintf( buf, buflen, "X509 - Private key password can't be empty" );
+ if( use_ret == -(POLARSSL_ERR_X509_PASSWORD_MISMATCH) )
+ snprintf( buf, buflen, "X509 - Given private key password does not allow for correct decryption" );
#endif /* POLARSSL_X509_PARSE_C */
if( strlen( buf ) == 0 )
@@ -548,11 +563,6 @@
snprintf( buf, buflen, "PBKDF2 - Bad input parameters to function" );
#endif /* POLARSSL_PBKDF2_C */
-#if defined(POLARSSL_PKCS5_C)
- if( use_ret == -(POLARSSL_ERR_PKCS5_BAD_INPUT_DATA) )
- snprintf( buf, buflen, "PKCS5 - Bad input parameters to function" );
-#endif /* POLARSSL_PKCS5_C */
-
#if defined(POLARSSL_SHA1_C)
if( use_ret == -(POLARSSL_ERR_SHA1_FILE_IO_ERROR) )
snprintf( buf, buflen, "SHA1 - Read/write error in file" );
diff --git a/library/pkcs5.c b/library/pkcs5.c
index 9e12434..8e55415 100644
--- a/library/pkcs5.c
+++ b/library/pkcs5.c
@@ -38,6 +38,207 @@
#if defined(POLARSSL_PKCS5_C)
#include "polarssl/pkcs5.h"
+#include "polarssl/asn1.h"
+#include "polarssl/cipher.h"
+
+#define OID_CMP(oid_str, oid_buf) \
+ ( ( OID_SIZE(oid_str) == (oid_buf)->len ) && \
+ memcmp( (oid_str), (oid_buf)->p, (oid_buf)->len) == 0)
+
+static int pkcs5_parse_pbkdf2_params( unsigned char **p,
+ const unsigned char *end,
+ asn1_buf *salt, int *iterations,
+ int *keylen, md_type_t *md_type )
+{
+ int ret;
+ size_t len = 0;
+ asn1_buf prf_alg_oid;
+
+ /*
+ * PBKDF2-params ::= SEQUENCE {
+ * salt OCTET STRING,
+ * iterationCount INTEGER,
+ * keyLength INTEGER OPTIONAL
+ * prf AlgorithmIdentifier DEFAULT algid-hmacWithSHA1
+ * }
+ *
+ */
+ if( ( ret = asn1_get_tag( p, end, &len,
+ ASN1_CONSTRUCTED | ASN1_SEQUENCE ) ) != 0 )
+ {
+ return( POLARSSL_ERR_PKCS5_INVALID_FORMAT + ret );
+ }
+
+ end = *p + len;
+
+ if( ( ret = asn1_get_tag( p, end, &salt->len, ASN1_OCTET_STRING ) ) != 0 )
+ return( POLARSSL_ERR_PKCS5_INVALID_FORMAT + ret );
+
+ salt->p = *p;
+ *p += salt->len;
+
+ if( ( ret = asn1_get_int( p, end, iterations ) ) != 0 )
+ return( POLARSSL_ERR_PKCS5_INVALID_FORMAT + ret );
+
+ if( *p == end )
+ return( 0 );
+
+ if( ( ret = asn1_get_int( p, end, keylen ) ) != 0 )
+ {
+ if( ret != POLARSSL_ERR_ASN1_UNEXPECTED_TAG )
+ return( POLARSSL_ERR_PKCS5_INVALID_FORMAT + ret );
+ }
+
+ if( *p == end )
+ return( 0 );
+
+ if( ( ret = asn1_get_tag( p, end, &prf_alg_oid.len, ASN1_OID ) ) != 0 )
+ return( POLARSSL_ERR_PKCS5_INVALID_FORMAT + ret );
+
+ if( !OID_CMP( OID_HMAC_SHA1, &prf_alg_oid ) )
+ return( POLARSSL_ERR_PKCS5_FEATURE_UNAVAILABLE );
+
+ *md_type = POLARSSL_MD_SHA1;
+
+ if( *p != end )
+ return( POLARSSL_ERR_PKCS5_INVALID_FORMAT +
+ POLARSSL_ERR_ASN1_LENGTH_MISMATCH );
+
+ return( 0 );
+}
+
+int pkcs5_pbes2( asn1_buf *pbe_params, int mode,
+ const unsigned char *pwd, size_t pwdlen,
+ const unsigned char *data, size_t datalen,
+ unsigned char *output )
+{
+ int ret, iterations = 0, keylen = 0;
+ unsigned char *p, *end, *end2;
+ asn1_buf kdf_alg_oid, enc_scheme_oid, salt;
+ md_type_t md_type = POLARSSL_MD_SHA1;
+ unsigned char key[32], iv[32];
+ size_t len = 0, olen = 0;
+ const md_info_t *md_info;
+ const cipher_info_t *cipher_info;
+ md_context_t md_ctx;
+ cipher_context_t cipher_ctx;
+
+ p = pbe_params->p;
+ end = p + pbe_params->len;
+
+ /*
+ * PBES2-params ::= SEQUENCE {
+ * keyDerivationFunc AlgorithmIdentifier {{PBES2-KDFs}},
+ * encryptionScheme AlgorithmIdentifier {{PBES2-Encs}}
+ * }
+ */
+ if( ( ret = asn1_get_tag( &p, end, &len,
+ ASN1_CONSTRUCTED | ASN1_SEQUENCE ) ) != 0 )
+ {
+ return( POLARSSL_ERR_PKCS5_INVALID_FORMAT + ret );
+ }
+
+ if( ( ret = asn1_get_tag( &p, end, &len,
+ ASN1_CONSTRUCTED | ASN1_SEQUENCE ) ) != 0 )
+ {
+ return( POLARSSL_ERR_PKCS5_INVALID_FORMAT + ret );
+ }
+
+ end2 = p + len;
+
+ if( ( ret = asn1_get_tag( &p, end2, &kdf_alg_oid.len, ASN1_OID ) ) != 0 )
+ return( POLARSSL_ERR_PKCS5_INVALID_FORMAT + ret );
+
+ kdf_alg_oid.p = p;
+ p += kdf_alg_oid.len;
+
+ // Only PBKDF2 supported at the moment
+ //
+ if( !OID_CMP( OID_PKCS5_PBKDF2, &kdf_alg_oid ) )
+ return( POLARSSL_ERR_PKCS5_FEATURE_UNAVAILABLE );
+
+ if( ( ret = pkcs5_parse_pbkdf2_params( &p, end2,
+ &salt, &iterations, &keylen,
+ &md_type ) ) != 0 )
+ {
+ return( ret );
+ }
+
+ md_info = md_info_from_type( md_type );
+ if( md_info == NULL )
+ return( POLARSSL_ERR_PKCS5_FEATURE_UNAVAILABLE );
+
+ if( ( ret = asn1_get_tag( &p, end, &len,
+ ASN1_CONSTRUCTED | ASN1_SEQUENCE ) ) != 0 )
+ {
+ return( POLARSSL_ERR_PKCS5_INVALID_FORMAT + ret );
+ }
+
+ end2 = p + len;
+
+ if( ( ret = asn1_get_tag( &p, end2, &enc_scheme_oid.len, ASN1_OID ) ) != 0 )
+ return( POLARSSL_ERR_PKCS5_INVALID_FORMAT + ret );
+
+ enc_scheme_oid.p = p;
+ p += enc_scheme_oid.len;
+
+#if defined(POLARSSL_DES_C)
+ // Only DES-CBC and DES-EDE3-CBC supported at the moment
+ //
+ if( OID_CMP( OID_DES_EDE3_CBC, &enc_scheme_oid ) )
+ {
+ cipher_info = cipher_info_from_type( POLARSSL_CIPHER_DES_EDE3_CBC );
+ }
+ else if( OID_CMP( OID_DES_CBC, &enc_scheme_oid ) )
+ {
+ cipher_info = cipher_info_from_type( POLARSSL_CIPHER_DES_CBC );
+ }
+ else
+#endif /* POLARSSL_DES_C */
+ return( POLARSSL_ERR_PKCS5_FEATURE_UNAVAILABLE );
+
+ if( cipher_info == NULL )
+ return( POLARSSL_ERR_PKCS5_FEATURE_UNAVAILABLE );
+
+ keylen = cipher_info->key_length / 8;
+
+ if( ( ret = asn1_get_tag( &p, end2, &len, ASN1_OCTET_STRING ) ) != 0 )
+ return( POLARSSL_ERR_PKCS5_INVALID_FORMAT + ret );
+
+ if( len != cipher_info->iv_size )
+ return( POLARSSL_ERR_PKCS5_INVALID_FORMAT );
+
+ memcpy( iv, p, len );
+
+ if( ( ret = md_init_ctx( &md_ctx, md_info ) ) != 0 )
+ return( ret );
+
+ if( ( ret = cipher_init_ctx( &cipher_ctx, cipher_info ) ) != 0 )
+ return( ret );
+
+ if ( ( ret = pkcs5_pbkdf2_hmac( &md_ctx, pwd, pwdlen, salt.p, salt.len,
+ iterations, keylen, key ) ) != 0 )
+ {
+ return( ret );
+ }
+
+ if( ( ret = cipher_setkey( &cipher_ctx, key, keylen, mode ) ) != 0 )
+ return( ret );
+
+ if( ( ret = cipher_reset( &cipher_ctx, iv ) ) != 0 )
+ return( ret );
+
+ if( ( ret = cipher_update( &cipher_ctx, data, datalen,
+ output, &olen ) ) != 0 )
+ {
+ return( ret );
+ }
+
+ if( ( ret = cipher_finish( &cipher_ctx, output + olen, &olen ) ) != 0 )
+ return( POLARSSL_ERR_PKCS5_PASSWORD_MISMATCH );
+
+ return( 0 );
+}
int pkcs5_pbkdf2_hmac( md_context_t *ctx, const unsigned char *password,
size_t plen, const unsigned char *salt, size_t slen,
diff --git a/library/x509parse.c b/library/x509parse.c
index d2bfddc..25e3b45 100644
--- a/library/x509parse.c
+++ b/library/x509parse.c
@@ -62,6 +62,9 @@
#endif
#include "polarssl/dhm.h"
#include "polarssl/pkcs12.h"
+#if defined(POLARSSL_PKCS5_C)
+#include "polarssl/pkcs5.h"
+#endif
#include <string.h>
#include <stdlib.h>
@@ -2219,6 +2222,9 @@
p = (unsigned char *) key;
end = p + keylen;
+ if( pwdlen == 0 )
+ return( POLARSSL_ERR_X509_PASSWORD_REQUIRED );
+
/*
* This function parses the EncryptedPrivatKeyInfo object (PKCS#8)
*
@@ -2302,6 +2308,19 @@
return( ret );
}
}
+#if defined(POLARSSL_PKCS5_C)
+ else if( OID_CMP( OID_PKCS5_PBES2, &pbe_alg_oid ) )
+ {
+ if( ( ret = pkcs5_pbes2( &pbe_params, PKCS5_DECRYPT, pwd, pwdlen,
+ p, len, buf ) ) != 0 )
+ {
+ if( ret == POLARSSL_ERR_PKCS5_PASSWORD_MISMATCH )
+ return( POLARSSL_ERR_X509_PASSWORD_MISMATCH );
+
+ return( ret );
+ }
+ }
+#endif /* POLARSSL_PKCS5_C */
else
return( POLARSSL_ERR_X509_FEATURE_UNAVAILABLE );
@@ -2401,14 +2420,22 @@
}
rsa_free( rsa );
+
+ if( ret == POLARSSL_ERR_X509_PASSWORD_MISMATCH )
+ {
+ return( ret );
+ }
+
if( ( ret = x509parse_key_pkcs8_unencrypted_der( rsa, key, keylen ) ) == 0 )
return( 0 );
rsa_free( rsa );
+
if( ( ret = x509parse_key_pkcs1_der( rsa, key, keylen ) ) == 0 )
return( 0 );
rsa_free( rsa );
+
return( POLARSSL_ERR_X509_KEY_INVALID_FORMAT );
}