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Diffstat (limited to 'examples/decrypt2.c')
| -rw-r--r-- | examples/decrypt2.c | 293 |
1 files changed, 293 insertions, 0 deletions
diff --git a/examples/decrypt2.c b/examples/decrypt2.c new file mode 100644 index 00000000..49513e12 --- /dev/null +++ b/examples/decrypt2.c @@ -0,0 +1,293 @@ +/** + * XML Security Library example: Decrypting an encrypted file using keys manager. + * + * Decrypts encrypted XML file using keys manager and a list of + * DES key from a binary file + * + * Usage: + * ./decrypt2 <xml-enc> <des-key-file1> [<des-key-file2> [...]] + * + * Example: + * ./decrypt2 encrypt1-res.xml deskey.bin + * ./decrypt2 encrypt2-res.xml deskey.bin + * + * This is free software; see Copyright file in the source + * distribution for preciese wording. + * + * Copyright (C) 2002-2003 Aleksey Sanin <aleksey@aleksey.com> + */ +#include <stdlib.h> +#include <string.h> +#include <assert.h> + +#include <libxml/tree.h> +#include <libxml/xmlmemory.h> +#include <libxml/parser.h> + +#ifndef XMLSEC_NO_XSLT +#include <libxslt/xslt.h> +#include <libxslt/security.h> +#endif /* XMLSEC_NO_XSLT */ + +#include <xmlsec/xmlsec.h> +#include <xmlsec/xmltree.h> +#include <xmlsec/xmlenc.h> +#include <xmlsec/crypto.h> + +xmlSecKeysMngrPtr load_des_keys(char** files, int files_size); +int decrypt_file(xmlSecKeysMngrPtr mngr, const char* enc_file); + +int +main(int argc, char **argv) { + xmlSecKeysMngrPtr mngr; +#ifndef XMLSEC_NO_XSLT + xsltSecurityPrefsPtr xsltSecPrefs = NULL; +#endif /* XMLSEC_NO_XSLT */ + + assert(argv); + + if(argc != 3) { + fprintf(stderr, "Error: wrong number of arguments.\n"); + fprintf(stderr, "Usage: %s <enc-file> <key-file1> [<key-file2> [...]]\n", argv[0]); + return(1); + } + + /* Init libxml and libxslt libraries */ + xmlInitParser(); + LIBXML_TEST_VERSION + xmlLoadExtDtdDefaultValue = XML_DETECT_IDS | XML_COMPLETE_ATTRS; + xmlSubstituteEntitiesDefault(1); +#ifndef XMLSEC_NO_XSLT + xmlIndentTreeOutput = 1; +#endif /* XMLSEC_NO_XSLT */ + + /* Init libxslt */ +#ifndef XMLSEC_NO_XSLT + /* disable everything */ + xsltSecPrefs = xsltNewSecurityPrefs(); + xsltSetSecurityPrefs(xsltSecPrefs, XSLT_SECPREF_READ_FILE, xsltSecurityForbid); + xsltSetSecurityPrefs(xsltSecPrefs, XSLT_SECPREF_WRITE_FILE, xsltSecurityForbid); + xsltSetSecurityPrefs(xsltSecPrefs, XSLT_SECPREF_CREATE_DIRECTORY, xsltSecurityForbid); + xsltSetSecurityPrefs(xsltSecPrefs, XSLT_SECPREF_READ_NETWORK, xsltSecurityForbid); + xsltSetSecurityPrefs(xsltSecPrefs, XSLT_SECPREF_WRITE_NETWORK, xsltSecurityForbid); + xsltSetDefaultSecurityPrefs(xsltSecPrefs); +#endif /* XMLSEC_NO_XSLT */ + + + /* Init xmlsec library */ + if(xmlSecInit() < 0) { + fprintf(stderr, "Error: xmlsec initialization failed.\n"); + return(-1); + } + + /* Check loaded library version */ + if(xmlSecCheckVersion() != 1) { + fprintf(stderr, "Error: loaded xmlsec library version is not compatible.\n"); + return(-1); + } + + /* Load default crypto engine if we are supporting dynamic + * loading for xmlsec-crypto libraries. Use the crypto library + * name ("openssl", "nss", etc.) to load corresponding + * xmlsec-crypto library. + */ +#ifdef XMLSEC_CRYPTO_DYNAMIC_LOADING + if(xmlSecCryptoDLLoadLibrary(BAD_CAST XMLSEC_CRYPTO) < 0) { + fprintf(stderr, "Error: unable to load default xmlsec-crypto library. Make sure\n" + "that you have it installed and check shared libraries path\n" + "(LD_LIBRARY_PATH) envornment variable.\n"); + return(-1); + } +#endif /* XMLSEC_CRYPTO_DYNAMIC_LOADING */ + + /* Init crypto library */ + if(xmlSecCryptoAppInit(NULL) < 0) { + fprintf(stderr, "Error: crypto initialization failed.\n"); + return(-1); + } + + /* Init xmlsec-crypto library */ + if(xmlSecCryptoInit() < 0) { + fprintf(stderr, "Error: xmlsec-crypto initialization failed.\n"); + return(-1); + } + + /* create keys manager and load keys */ + mngr = load_des_keys(&(argv[2]), argc - 2); + if(mngr == NULL) { + return(-1); + } + + if(decrypt_file(mngr, argv[1]) < 0) { + xmlSecKeysMngrDestroy(mngr); + return(-1); + } + + /* destroy keys manager */ + xmlSecKeysMngrDestroy(mngr); + + /* Shutdown xmlsec-crypto library */ + xmlSecCryptoShutdown(); + + /* Shutdown crypto library */ + xmlSecCryptoAppShutdown(); + + /* Shutdown xmlsec library */ + xmlSecShutdown(); + + /* Shutdown libxslt/libxml */ +#ifndef XMLSEC_NO_XSLT + xsltFreeSecurityPrefs(xsltSecPrefs); + xsltCleanupGlobals(); +#endif /* XMLSEC_NO_XSLT */ + xmlCleanupParser(); + + return(0); +} + +/** + * load_des_keys: + * @files: the list of filenames. + * @files_size: the number of filenames in #files. + * + * Creates simple keys manager and load DES keys from #files in it. + * The caller is responsible for destroing returned keys manager using + * @xmlSecKeysMngrDestroy. + * + * Returns the pointer to newly created keys manager or NULL if an error + * occurs. + */ +xmlSecKeysMngrPtr +load_des_keys(char** files, int files_size) { + xmlSecKeysMngrPtr mngr; + xmlSecKeyPtr key; + int i; + + assert(files); + assert(files_size > 0); + + /* create and initialize keys manager, we use a simple list based + * keys manager, implement your own xmlSecKeysStore klass if you need + * something more sophisticated + */ + mngr = xmlSecKeysMngrCreate(); + if(mngr == NULL) { + fprintf(stderr, "Error: failed to create keys manager.\n"); + return(NULL); + } + if(xmlSecCryptoAppDefaultKeysMngrInit(mngr) < 0) { + fprintf(stderr, "Error: failed to initialize keys manager.\n"); + xmlSecKeysMngrDestroy(mngr); + return(NULL); + } + + for(i = 0; i < files_size; ++i) { + assert(files[i]); + + /* load DES key */ + key = xmlSecKeyReadBinaryFile(xmlSecKeyDataDesId, files[i]); + if(key == NULL) { + fprintf(stderr,"Error: failed to load des key from binary file \"%s\"\n", files[i]); + xmlSecKeysMngrDestroy(mngr); + return(NULL); + } + + /* set key name to the file name, this is just an example! */ + if(xmlSecKeySetName(key, BAD_CAST files[i]) < 0) { + fprintf(stderr,"Error: failed to set key name for key from \"%s\"\n", files[i]); + xmlSecKeyDestroy(key); + xmlSecKeysMngrDestroy(mngr); + return(NULL); + } + + /* add key to keys manager, from now on keys manager is responsible + * for destroying key + */ + if(xmlSecCryptoAppDefaultKeysMngrAdoptKey(mngr, key) < 0) { + fprintf(stderr,"Error: failed to add key from \"%s\" to keys manager\n", files[i]); + xmlSecKeyDestroy(key); + xmlSecKeysMngrDestroy(mngr); + return(NULL); + } + } + + return(mngr); +} + +/** + * decrypt_file: + * @mngr: the pointer to keys manager. + * @enc_file: the encrypted XML file name. + * + * Decrypts the XML file #enc_file using DES key from #key_file and + * prints results to stdout. + * + * Returns 0 on success or a negative value if an error occurs. + */ +int +decrypt_file(xmlSecKeysMngrPtr mngr, const char* enc_file) { + xmlDocPtr doc = NULL; + xmlNodePtr node = NULL; + xmlSecEncCtxPtr encCtx = NULL; + int res = -1; + + assert(mngr); + assert(enc_file); + + /* load template */ + doc = xmlParseFile(enc_file); + if ((doc == NULL) || (xmlDocGetRootElement(doc) == NULL)){ + fprintf(stderr, "Error: unable to parse file \"%s\"\n", enc_file); + goto done; + } + + /* find start node */ + node = xmlSecFindNode(xmlDocGetRootElement(doc), xmlSecNodeEncryptedData, xmlSecEncNs); + if(node == NULL) { + fprintf(stderr, "Error: start node not found in \"%s\"\n", enc_file); + goto done; + } + + /* create encryption context */ + encCtx = xmlSecEncCtxCreate(mngr); + if(encCtx == NULL) { + fprintf(stderr,"Error: failed to create encryption context\n"); + goto done; + } + + /* decrypt the data */ + if((xmlSecEncCtxDecrypt(encCtx, node) < 0) || (encCtx->result == NULL)) { + fprintf(stderr,"Error: decryption failed\n"); + goto done; + } + + /* print decrypted data to stdout */ + if(encCtx->resultReplaced != 0) { + fprintf(stdout, "Decrypted XML data:\n"); + xmlDocDump(stdout, doc); + } else { + fprintf(stdout, "Decrypted binary data (%d bytes):\n", xmlSecBufferGetSize(encCtx->result)); + if(xmlSecBufferGetData(encCtx->result) != NULL) { + fwrite(xmlSecBufferGetData(encCtx->result), + 1, + xmlSecBufferGetSize(encCtx->result), + stdout); + } + } + fprintf(stdout, "\n"); + + /* success */ + res = 0; + +done: + /* cleanup */ + if(encCtx != NULL) { + xmlSecEncCtxDestroy(encCtx); + } + + if(doc != NULL) { + xmlFreeDoc(doc); + } + return(res); +} + |