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diff --git a/doc/rst/legacy/nss_sample_code/nss_sample_code_sample_1_hashing/index.rst b/doc/rst/legacy/nss_sample_code/nss_sample_code_sample_1_hashing/index.rst new file mode 100644 index 000000000..9435e0b8a --- /dev/null +++ b/doc/rst/legacy/nss_sample_code/nss_sample_code_sample_1_hashing/index.rst @@ -0,0 +1,253 @@ +.. _mozilla_projects_nss_nss_sample_code_nss_sample_code_sample_1_hashing: + +NSS Sample Code Sample_1_Hashing +================================ + +.. _nss_sample_code_1_hashing_a_file.: + +`NSS Sample Code 1: Hashing a file. <#nss_sample_code_1_hashing_a_file.>`__ +--------------------------------------------------------------------------- + +.. container:: + + This is an example program that demonstrates how to compute the hash of a file and save it to + another file. This program illustrates the use of NSS message APIs. + +.. _sample_code_1: + +`Sample Code 1 <#sample_code_1>`__ +~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~ + +.. container:: + + .. code:: brush: + + /* NSPR Headers */ + #include <prprf.h> + #include <prtypes.h> + #include <plgetopt.h> + #include <prio.h> + + /* NSS headers */ + #include <secoid.h> + #include <secmodt.h> + #include <sechash.h> + + typedef struct { + const char *hashName; + SECOidTag oid; + } NameTagPair; + + /* The hash algorithms supported */ + static const NameTagPair HASH_NAMES[] = { + { "MD2", SEC_OID_MD2 }, + { "MD5", SEC_OID_MD5 }, + { "SHA1", SEC_OID_SHA1 }, + { "SHA256", SEC_OID_SHA256 }, + { "SHA384", SEC_OID_SHA384 }, + { "SHA512", SEC_OID_SHA512 } + }; + + /* + * Maps a hash name to a SECOidTag. + * Returns NULL if the name is not a supported algorithm + */ + static SECOidTag HashNameToOIDTag(const char *hashName) + { + int i, nhashes = sizeof(HASH_NAMES); + SECOidTag hashtag = SEC_OID_UNKNOWN; + + for (i = 0; i < nhashes; i++) { + if (PORT_Strcasecmp(hashName, HASH_NAMES[i].hashName) == 0) { + hashtag = HASH_NAMES[i].oid; + break; + } + } + return hashtag; + } + + /* + * Newline + */ + static void Newline(PRFileDesc* out) { PR_fprintf(out, "\n"); } + + /* + * PrintAsHex + */ + void PrintAsHex(PRFileDesc* out, unsigned char *data, unsigned int len) + { + unsigned i; + int column; + unsigned int limit = 15; + unsigned int level = 1; + + column = level; + if (!len) { + PR_fprintf(out, "(empty)\n"); + return; + } + + for (i = 0; i < len; i++) { + if (i != len - 1) { + PR_fprintf(out, "%02x:", data[i]); + column += 3; + } else { + PR_fprintf(out, "%02x", data[i]); + column += 2; + break; + } + if (column > 76 || (i % 16 == limit)) { + Newline(out); + column = level; + limit = i % 16; + } + } + if (column != level) { + Newline(out); + } + } + + /* + * Prints a usage message and exits + */ + static void Usage(const char *progName) + { + int htype; + int HASH_AlgTOTAL = sizeof(HASH_NAMES) / sizeof(HASH_NAMES[0]); + + fprintf(stderr, "Usage: %s -t type [ < input ] [ > output ]\n", progName); + fprintf(stderr, "%-20s Specify the digest method (must be one of\n", + "-t type"); + fprintf(stderr, "%-20s ", ""); + for (htype = 0; htype < HASH_AlgTOTAL; htype++) { + fprintf(stderr, HASH_NAMES[htype].hashName); + if (htype == (HASH_AlgTOTAL - 2)) + fprintf(stderr, " or "); + else if (htype != (HASH_AlgTOTAL - 1)) + fprintf(stderr, ", "); + } + fprintf(stderr, " (case ignored))\n"); + fprintf(stderr, "%-20s Define an input file to use (default is stdin)\n", + "< input"); + fprintf(stderr, "%-20s Define an output file to use (default is stdout)\n", + "> output"); + exit(-1); + } + + /* + * Check for the missing arguments + */ + static void PrintMsgAndExit(const char *progName, char opt) + { + fprintf(stderr, "%s: option -%c requires an argument\n", progName, opt); + Usage(progName); + } + + #define REQUIRE_ARG(opt,value) if (!(value)) PrintMsgAndExit(progName, opt) + + /* + * Digests a file according to the specified algorithm. + * It writes out the digest as a hexadecimal string. + */ + static int DigestFile(PRFileDesc *outFile, PRFileDesc *inFile, SECOidTag hashOIDTag) + { + unsigned int nb; + unsigned char ibuf[4096]; + unsigned char digest[64]; + unsigned int len; + unsigned int digestLen; + HASH_HashType hashType; + HASHContext *hashContext = NULL; + + hashType = HASH_GetHashTypeByOidTag(hashOIDTag); + hashContext = HASH_Create(hashType); + if (hashContext == NULL) { + return SECFailure; + } + + do { + + HASH_Begin(hashContext); + + /* Incrementally hash the file contents */ + while ((nb = PR_Read(inFile, ibuf, sizeof(ibuf))) > 0) { + HASH_Update(hashContext, ibuf, nb); + } + + HASH_End(hashContext, digest, &len, 64); + + /* Normally we would write it out in binary with + * nb = PR_Write(outFile, digest, len); + * but for illustration let's print it in hex. + */ + PrintAsHex(outFile, digest, len); + + } while (0); + + /* cleanup */ + if (hashContext != NULL) + HASH_Destroy(hashContext); + + return SECSuccess; + } + + /* + * This sample computes the hash of a file and saves it + * to another file. It illustrates the use of NSS message + * APIs. + */ + int main(int argc, char **argv) + { + SECOidTag hashOIDTag; + PLOptState *optstate; + PLOptStatus status; + SECStatus rv; + char *hashName = NULL; + char *progName = strrchr(argv[0], '/'); + + progName = progName ? progName + 1 : argv[0]; + + rv = NSS_NoDB_Init("/tmp"); + if (rv != SECSuccess) { + fprintf(stderr, "%s: NSS_Init failed in directory %s\n", + progName, "/tmp"); + return -1; + } + + /* Parse command line arguments */ + optstate = PL_CreateOptState(argc, argv, "t:"); + while ((status = PL_GetNextOpt(optstate)) == PL_OPT_OK) { + switch (optstate->option) { + case 't': + REQUIRE_ARG(optstate->option, optstate->value); + hashName = strdup(optstate->value); + break; + } + } + + if (!hashName) + Usage(progName); + + /* convert and validate */ + hashOIDTag = HashNameToOIDTag(hashName); + if (hashOIDTag == SEC_OID_UNKNOWN) { + fprintf(stderr, "%s: invalid digest type - %s\n", progName, hashName); + Usage(progName); + } + + /* Digest it and print the result */ + rv = DigestFile(PR_STDOUT, PR_STDIN, hashOIDTag); + if (rv != SECSuccess) { + fprintf(stderr, "%s: problem digesting data (%d)\n", + progName, PORT_GetError()); + } + + rv = NSS_Shutdown(); + if (rv != SECSuccess) { + exit(-1); + } + + return 0; + } + + </sechash.h></secmodt.h></secoid.h></prio.h></plgetopt.h></prtypes.h></prprf.h>
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