From 0ccd545dd434f54e80992095e85da98871b8361d Mon Sep 17 00:00:00 2001
From: Maarten Billemont <lhunath@lyndir.com>
Date: Sat, 20 Dec 2014 14:30:34 -0500
Subject: [PATCH] More restructuring and rewriting of the C code.

---
 .idea/inspectionProfiles/Project_Default.xml  |   2 +
 MasterPassword/C/build                        |  15 +-
 MasterPassword/C/{mpw.c => mpw-algorithm.c}   |  73 +++----
 MasterPassword/C/mpw-algorithm.h              |  18 ++
 MasterPassword/C/mpw-bench.c                  | 196 +++++-------------
 MasterPassword/C/mpw-cli.c                    |  59 +++---
 MasterPassword/C/{types.c => mpw-types.c}     | 102 +--------
 MasterPassword/C/{types.h => mpw-types.h}     |  53 ++---
 MasterPassword/C/mpw-util.c                   | 155 ++++++++++++++
 MasterPassword/C/mpw-util.h                   |  46 ++++
 MasterPassword/C/mpw.h                        |   6 -
 .../project.pbxproj                           |  26 ++-
 12 files changed, 392 insertions(+), 359 deletions(-)
 rename MasterPassword/C/{mpw.c => mpw-algorithm.c} (58%)
 create mode 100644 MasterPassword/C/mpw-algorithm.h
 rename MasterPassword/C/{types.c => mpw-types.c} (62%)
 rename MasterPassword/C/{types.h => mpw-types.h} (56%)
 create mode 100644 MasterPassword/C/mpw-util.c
 create mode 100644 MasterPassword/C/mpw-util.h
 delete mode 100644 MasterPassword/C/mpw.h

diff --git a/.idea/inspectionProfiles/Project_Default.xml b/.idea/inspectionProfiles/Project_Default.xml
index a84efcb2..d72e0862 100644
--- a/.idea/inspectionProfiles/Project_Default.xml
+++ b/.idea/inspectionProfiles/Project_Default.xml
@@ -2,6 +2,7 @@
   <profile version="1.0" is_locked="false">
     <option name="myName" value="Project Default" />
     <option name="myLocal" value="false" />
+    <inspection_tool class="Convert to string" enabled="true" level="WEAK WARNING" enabled_by_default="true" />
     <inspection_tool class="FunctionImplicitDeclarationInspection" enabled="false" level="WARNING" enabled_by_default="false" />
     <inspection_tool class="ImplicitIntegerAndEnumConversion" enabled="false" level="WARNING" enabled_by_default="false" />
     <inspection_tool class="LossyEncoding" enabled="true" level="WARNING" enabled_by_default="true" />
@@ -9,6 +10,7 @@
     <inspection_tool class="OCNotLocalizedStringInspection" enabled="false" level="WARNING" enabled_by_default="false" />
     <inspection_tool class="OCUnusedMacroInspection" enabled="false" level="WARNING" enabled_by_default="false" />
     <inspection_tool class="OCUnusedMethodInspection" enabled="false" level="WARNING" enabled_by_default="false" />
+    <inspection_tool class="Replace with subshell" enabled="true" level="INFO" enabled_by_default="true" />
     <inspection_tool class="SignednessMismatch" enabled="false" level="WARNING" enabled_by_default="false" />
     <inspection_tool class="UnavailableInDeploymentTarget" enabled="true" level="INFO" enabled_by_default="true" />
     <inspection_tool class="UnusedLocalVariable" enabled="false" level="WARNING" enabled_by_default="false" />
diff --git a/MasterPassword/C/build b/MasterPassword/C/build
index b2b48523..f01e4a0d 100755
--- a/MasterPassword/C/build
+++ b/MasterPassword/C/build
@@ -216,9 +216,11 @@ mpw() {
     # optional features
     (( mpw_color )) && CFLAGS+=( -DCOLOR ) LDFLAGS+=( -l"curses" )
 
-    cc "${CFLAGS[@]}"                 -c types.c -o types.o "$@"
-    cc "${CFLAGS[@]}"                 -c mpw.c -o mpw.o "$@"
-    cc "${CFLAGS[@]}" "${LDFLAGS[@]}" "types.o" "mpw.o" mpw-cli.c -o mpw "$@"
+    cc "${CFLAGS[@]}" "$@"                  -c mpw-algorithm.c    -o mpw-algorithm.o
+    cc "${CFLAGS[@]}" "$@"                  -c mpw-types.c        -o mpw-types.o
+    cc "${CFLAGS[@]}" "$@"                  -c mpw-util.c         -o mpw-util.o
+    cc "${CFLAGS[@]}" "${LDFLAGS[@]}" "$@" "mpw-algorithm.o" "mpw-types.o" "mpw-util.o" \
+                                               mpw-cli.c          -o mpw
     echo "done!  Now run ./install or use ./mpw"
 }
 
@@ -254,8 +256,11 @@ mpw-bench() {
         -l"crypto"
     )
 
-    cc "${CFLAGS[@]}"                 -c types.c -o types.o "$@"
-    cc "${CFLAGS[@]}" "${LDFLAGS[@]}" "types.o" mpw-bench.c -o mpw-bench "$@"
+    cc "${CFLAGS[@]}" "$@"                  -c mpw-algorithm.c    -o mpw-algorithm.o
+    cc "${CFLAGS[@]}" "$@"                  -c mpw-types.c        -o mpw-types.o
+    cc "${CFLAGS[@]}" "$@"                  -c mpw-util.c         -o mpw-util.o
+    cc "${CFLAGS[@]}" "${LDFLAGS[@]}" "$@" "mpw-algorithm.o" "mpw-types.o" "mpw-util.o" \
+                                               mpw-bench.c        -o mpw-bench
     echo "done!  Now use ./mpw-bench"
 }
 
diff --git a/MasterPassword/C/mpw.c b/MasterPassword/C/mpw-algorithm.c
similarity index 58%
rename from MasterPassword/C/mpw.c
rename to MasterPassword/C/mpw-algorithm.c
index ec229e7f..dca0a0ea 100644
--- a/MasterPassword/C/mpw.c
+++ b/MasterPassword/C/mpw-algorithm.c
@@ -1,14 +1,18 @@
-#define _GNU_SOURCE
+//
+//  mpw-algorithm.c
+//  MasterPassword
+//
+//  Created by Maarten Billemont on 2014-12-20.
+//  Copyright (c) 2014 Lyndir. All rights reserved.
+//
 
 #include <stdio.h>
-#include <sys/types.h>
 #include <stdlib.h>
 #include <string.h>
 #include <errno.h>
 
-#include <scrypt/sha256.h>
-#include <scrypt/crypto_scrypt.h>
-#include "types.h"
+#include "mpw-types.h"
+#include "mpw-util.h"
 
 #define MP_N                32768
 #define MP_r                8
@@ -16,33 +20,9 @@
 #define MP_dkLen            64
 #define MP_hash             PearlHashSHA256
 
-static void mpw_pushBuf(uint8_t **const buffer, size_t *const bufferSize, const void *pushBuffer, const size_t pushSize) {
-
-    *bufferSize += pushSize;
-    *buffer = realloc( *buffer, *bufferSize );
-    uint8_t *pushDst = *buffer + *bufferSize - pushSize;
-    memcpy( pushDst, pushBuffer, pushSize );
-}
-
-static void mpw_pushString(uint8_t **buffer, size_t *const bufferSize, const char *pushString) {
-
-    mpw_pushBuf( buffer, bufferSize, pushString, strlen( pushString ) );
-}
-
-static void mpw_pushInt(uint8_t **const buffer, size_t *const bufferSize, const uint32_t pushInt) {
-
-    mpw_pushBuf( buffer, bufferSize, &pushInt, sizeof( pushInt ) );
-}
-
-static void mpw_free(void *const buffer, const size_t bufferSize) {
-
-    memset( buffer, 0, bufferSize );
-    free( buffer );
-}
-
 const uint8_t *mpw_masterKeyForUser(const char *fullName, const char *masterPassword) {
 
-    const char *mpKeyScope = ScopeForVariant( MPSiteVariantPassword );
+    const char *mpKeyScope = mpw_scopeForVariant( MPSiteVariantPassword );
     trc( "fullName: %s\n", fullName );
     trc( "masterPassword: %s\n", masterPassword );
     trc( "key scope: %s\n", mpKeyScope );
@@ -56,18 +36,15 @@ const uint8_t *mpw_masterKeyForUser(const char *fullName, const char *masterPass
     mpw_pushString( &masterKeySalt, &masterKeySaltSize, fullName );
     if (!masterKeySalt)
         ftl( "Could not allocate master key salt: %d\n", errno );
-    trc( "masterKeySalt ID: %s\n", IDForBuf( masterKeySalt, masterKeySaltSize ) );
+    trc( "masterKeySalt ID: %s\n", mpw_idForBuf( masterKeySalt, masterKeySaltSize ) );
 
     // Calculate the master key.
     // masterKey = scrypt( masterPassword, masterKeySalt )
-    uint8_t *masterKey = (uint8_t *)malloc( MP_dkLen );
+    const uint8_t *masterKey = mpw_scrypt( MP_dkLen, masterPassword, masterKeySalt, masterKeySaltSize, MP_N, MP_r, MP_p );
+    mpw_free( masterKeySalt, masterKeySaltSize );
     if (!masterKey)
         ftl( "Could not allocate master key: %d\n", errno );
-    if (crypto_scrypt( (const uint8_t *)masterPassword, strlen( masterPassword ),
-            masterKeySalt, masterKeySaltSize, MP_N, MP_r, MP_p, masterKey, MP_dkLen ) < 0)
-        ftl( "Could not generate master key: %d\n", errno );
-    mpw_free( masterKeySalt, masterKeySaltSize );
-    trc( "masterKey ID: %s\n", IDForBuf( masterKey, MP_dkLen ) );
+    trc( "masterKey ID: %s\n", mpw_idForBuf( masterKey, MP_dkLen ) );
 
     return masterKey;
 }
@@ -75,7 +52,7 @@ const uint8_t *mpw_masterKeyForUser(const char *fullName, const char *masterPass
 const char *mpw_passwordForSite(const uint8_t *masterKey, const char *siteName, const MPSiteType siteType, const uint32_t siteCounter,
         const MPSiteVariant siteVariant, const char *siteContext) {
 
-    const char *siteScope = ScopeForVariant( siteVariant );
+    const char *siteScope = mpw_scopeForVariant( siteVariant );
     trc( "siteName: %s\n", siteName );
     trc( "siteCounter: %d\n", siteCounter );
     trc( "siteVariant: %d\n", siteVariant );
@@ -95,28 +72,28 @@ const char *mpw_passwordForSite(const uint8_t *masterKey, const char *siteName,
         mpw_pushString( &sitePasswordInfo, &sitePasswordInfoSize, siteContext );
     }
     if (!sitePasswordInfo)
-        ftl( "Could not allocate site seed: %d\n", errno );
-    trc( "sitePasswordInfo ID: %s\n", IDForBuf( sitePasswordInfo, sitePasswordInfoSize ) );
+        ftl( "Could not allocate site seed info: %d\n", errno );
+    trc( "sitePasswordInfo ID: %s\n", mpw_idForBuf( sitePasswordInfo, sitePasswordInfoSize ) );
 
-    uint8_t sitePasswordSeed[32];
-    HMAC_SHA256_Buf( masterKey, MP_dkLen, sitePasswordInfo, sitePasswordInfoSize, sitePasswordSeed );
-    mpw_free( sitePasswordInfo, sitePasswordInfoSize );
-    trc( "sitePasswordSeed ID: %s\n", IDForBuf( sitePasswordSeed, 32 ) );
+    const uint8_t *sitePasswordSeed = mpw_hmac_sha256( masterKey, MP_dkLen, sitePasswordInfo, sitePasswordInfoSize );
+    if (!sitePasswordSeed)
+        ftl( "Could not allocate site seed: %d\n", errno );
+    trc( "sitePasswordSeed ID: %s\n", mpw_idForBuf( sitePasswordSeed, 32 ) );
 
     // Determine the template.
-    const char *template = TemplateForType( siteType, sitePasswordSeed[0] );
+    const char *template = mpw_templateForType( siteType, sitePasswordSeed[0] );
     trc( "type %d, template: %s\n", siteType, template );
     if (strlen( template ) > 32)
-        ftl( "Template too long for password seed: %d", strlen( template ) );
+        ftl( "Template too long for password seed: %lu", strlen( template ) );
 
     // Encode the password from the seed using the template.
     char *const sitePassword = calloc( strlen( template ) + 1, sizeof( char ) );
     for (int c = 0; c < strlen( template ); ++c) {
-        sitePassword[c] = CharacterFromClass( template[c], sitePasswordSeed[c + 1] );
+        sitePassword[c] = mpw_characterFromClass( template[c], sitePasswordSeed[c + 1] );
         trc( "class %c, index %u (0x%02X) -> character: %c\n", template[c], sitePasswordSeed[c + 1], sitePasswordSeed[c + 1],
                 sitePassword[c] );
     }
-    memset( sitePasswordSeed, 0, sizeof( sitePasswordSeed ) );
+    mpw_free( sitePasswordSeed, sizeof( sitePasswordSeed ) );
 
     return sitePassword;
 }
diff --git a/MasterPassword/C/mpw-algorithm.h b/MasterPassword/C/mpw-algorithm.h
new file mode 100644
index 00000000..33f3ce93
--- /dev/null
+++ b/MasterPassword/C/mpw-algorithm.h
@@ -0,0 +1,18 @@
+//
+//  mpw-algorithm.h
+//  MasterPassword
+//
+//  Created by Maarten Billemont on 2014-12-20.
+//  Copyright (c) 2014 Lyndir. All rights reserved.
+//
+
+/** Derive the master key for a user based on their name and master password.
+  * @return A new 64-byte allocated buffer. */
+const uint8_t *mpw_masterKeyForUser(
+        const char *fullName, const char *masterPassword);
+
+/** Encode a password for the site from the given master key and site parameters.
+  * @return A newly allocated string. */
+const char *mpw_passwordForSite(
+        const uint8_t *masterKey, const char *siteName, const MPSiteType siteType, const uint32_t siteCounter,
+        const MPSiteVariant siteVariant, const char *siteContext);
diff --git a/MasterPassword/C/mpw-bench.c b/MasterPassword/C/mpw-bench.c
index 66e1c4c9..be64de13 100644
--- a/MasterPassword/C/mpw-bench.c
+++ b/MasterPassword/C/mpw-bench.c
@@ -1,20 +1,22 @@
-#include <sys/time.h>
+//
+//  mpw-bench.c
+//  MasterPassword
+//
+//  Created by Maarten Billemont on 2014-12-20.
+//  Copyright (c) 2014 Lyndir. All rights reserved.
+//
+
 #include <stdio.h>
-#include <sys/ioctl.h>
-#include <sys/types.h>
-#include <fcntl.h>
-#include <unistd.h>
-#include <math.h>
-#include <pwd.h>
-#include <netinet/in.h>
 #include <stdlib.h>
 #include <string.h>
 #include <errno.h>
+#include <sys/time.h>
 
 #include <scrypt/sha256.h>
-#include <scrypt/crypto_scrypt.h>
 #include <bcrypt/ow-crypt.h>
-#include "types.h"
+
+#include "mpw-types.h"
+#include "mpw-algorithm.h"
 
 #define MP_N                32768
 #define MP_r                8
@@ -22,166 +24,82 @@
 #define MP_dkLen            64
 #define MP_hash             PearlHashSHA256
 
+static void mpw_getTime(struct timeval *time) {
+
+    if (gettimeofday( time, NULL ) != 0)
+        ftl( "Could not get time: %d\n", errno );
+}
+
+static const double mpw_showSpeed(struct timeval startTime, const unsigned int iterations, const char *operation) {
+
+    struct timeval endTime;
+    mpw_getTime( &endTime );
+
+    const time_t dsec = (endTime.tv_sec - startTime.tv_sec);
+    const suseconds_t dusec = (endTime.tv_usec - startTime.tv_usec);
+    const double elapsed = dsec + dusec / 1000000.;
+    const double speed = iterations / elapsed;
+
+    fprintf( stderr, " done.  " );
+    fprintf( stdout, "%d %s iterations in %llds %lldµs -> %.2f/s\n", iterations, operation, (long long)dsec, (long long)dusec, speed );
+
+    return speed;
+}
 
 int main(int argc, char *const argv[]) {
 
-    char *fullName = "Robert Lee Mitchel";
-    char *masterPassword = "banana colored duckling";
-    char *siteName = "masterpasswordapp.com";
-    uint32_t siteCounter = 1;
-    MPSiteType siteType = MPSiteTypeGeneratedLong;
-
-    // Start MP
+    const char *fullName = "Robert Lee Mitchel";
+    const char *masterPassword = "banana colored duckling";
+    const char *siteName = "masterpasswordapp.com";
+    const uint32_t siteCounter = 1;
+    const MPSiteType siteType = MPSiteTypeGeneratedLong;
+    const MPSiteVariant siteVariant = MPSiteVariantPassword;
+    const char *siteContext = NULL;
     struct timeval startTime;
-    if (gettimeofday(&startTime, NULL) != 0) {
-        fprintf(stderr, "Could not get time: %d\n", errno);
-        return 1;
-    }
 
-    int iterations = 100;
+    // Start MPW
+    unsigned int iterations = 100;
+    mpw_getTime( &startTime );
     for (int i = 0; i < iterations; ++i) {
-        // Calculate the master key salt.
-        char *mpNameSpace = "com.lyndir.masterpassword";
-        const uint32_t n_fullNameLength = htonl(strlen(fullName));
-        const size_t masterKeySaltLength = strlen(mpNameSpace) + sizeof(n_fullNameLength) + strlen(fullName);
-        char *masterKeySalt = malloc( masterKeySaltLength );
-        if (!masterKeySalt) {
-            fprintf(stderr, "Could not allocate master key salt: %d\n", errno);
-            return 1;
-        }
-
-        char *mKS = masterKeySalt;
-        memcpy(mKS, mpNameSpace, strlen(mpNameSpace)); mKS += strlen(mpNameSpace);
-        memcpy(mKS, &n_fullNameLength, sizeof(n_fullNameLength)); mKS += sizeof(n_fullNameLength);
-        memcpy(mKS, fullName, strlen(fullName)); mKS += strlen(fullName);
-        if (mKS - masterKeySalt != masterKeySaltLength)
-            abort();
-        trc("masterKeySalt ID: %s\n", IDForBuf(masterKeySalt, masterKeySaltLength));
-
-        // Calculate the master key.
-        uint8_t *masterKey = malloc( MP_dkLen );
-        if (!masterKey) {
-            fprintf(stderr, "Could not allocate master key: %d\n", errno);
-            return 1;
-        }
-        if (crypto_scrypt( (const uint8_t *)masterPassword, strlen(masterPassword), (const uint8_t *)masterKeySalt, masterKeySaltLength, MP_N, MP_r, MP_p, masterKey, MP_dkLen ) < 0) {
-            fprintf(stderr, "Could not generate master key: %d\n", errno);
-            return 1;
-        }
-        memset(masterKeySalt, 0, masterKeySaltLength);
-        free(masterKeySalt);
-
-        // Calculate the site seed.
-        const uint32_t n_siteNameLength = htonl(strlen(siteName));
-        const uint32_t n_siteCounter = htonl(siteCounter);
-        const size_t sitePasswordInfoLength = strlen(mpNameSpace) + sizeof(n_siteNameLength) + strlen(siteName) + sizeof(n_siteCounter);
-        char *sitePasswordInfo = malloc( sitePasswordInfoLength );
-        if (!sitePasswordInfo) {
-            fprintf(stderr, "Could not allocate site seed: %d\n", errno);
-            return 1;
-        }
-
-        char *sPI = sitePasswordInfo;
-        memcpy(sPI, mpNameSpace, strlen(mpNameSpace)); sPI += strlen(mpNameSpace);
-        memcpy(sPI, &n_siteNameLength, sizeof(n_siteNameLength)); sPI += sizeof(n_siteNameLength);
-        memcpy(sPI, siteName, strlen(siteName)); sPI += strlen(siteName);
-        memcpy(sPI, &n_siteCounter, sizeof(n_siteCounter)); sPI += sizeof(n_siteCounter);
-        if (sPI - sitePasswordInfo != sitePasswordInfoLength)
-            abort();
-
-        uint8_t sitePasswordSeed[32];
-        HMAC_SHA256_Buf(masterKey, MP_dkLen, sitePasswordInfo, sitePasswordInfoLength, sitePasswordSeed);
-        memset(masterKey, 0, MP_dkLen);
-        memset(sitePasswordInfo, 0, sitePasswordInfoLength);
-        free(masterKey);
-        free(sitePasswordInfo);
-
-        // Determine the template.
-        const char *template = TemplateForType(siteType, sitePasswordSeed[0]);
-        trc("type %d, template: %s\n", siteType, template);
-        if (strlen(template) > 32)
-            abort();
-
-        // Encode the password from the seed using the template.
-        char *sitePassword = calloc(strlen(template) + 1, sizeof(char));
-        for (int c = 0; c < strlen(template); ++c) {
-            sitePassword[c] = CharacterFromClass(template[c], sitePasswordSeed[c + 1]);
-            trc("class %c, character: %c\n", template[c], sitePassword[c]);
-        }
-        memset(sitePasswordSeed, 0, sizeof(sitePasswordSeed));
+        const uint8_t *masterKey = mpw_masterKeyForUser( fullName, masterPassword );
+        if (!masterKey)
+            ftl( "Could not allocate master key: %d\n", errno );
+        free( (void *)mpw_passwordForSite( masterKey, siteName, siteType, siteCounter, siteVariant, siteContext ) );
+        free( (void *)masterKey );
 
         if (i % 1 == 0)
             fprintf( stderr, "\rmpw: iteration %d / %d..", i, iterations );
     }
-
-    // Output timing results.
-    struct timeval endTime;
-    if (gettimeofday(&endTime, NULL) != 0) {
-        fprintf(stderr, "Could not get time: %d\n", errno);
-        return 1;
-    }
-    long long secs = (endTime.tv_sec - startTime.tv_sec);
-    long long usecs = (endTime.tv_usec - startTime.tv_usec);
-    double elapsed = secs + usecs / 1000000.0;
-    double mpwSpeed = iterations / elapsed;
-    fprintf( stdout, " done.  %d iterations in %llds %lldµs -> %.2f/s\n", iterations, secs, usecs, mpwSpeed );
+    const double mpwSpeed = mpw_showSpeed( startTime, iterations, "mpw" );
 
     // Start SHA-256
-    if (gettimeofday(&startTime, NULL) != 0) {
-        fprintf(stderr, "Could not get time: %d\n", errno);
-        return 1;
-    }
-
     iterations = 50000000;
     uint8_t hash[32];
+    mpw_getTime( &startTime );
     for (int i = 0; i < iterations; ++i) {
-        SHA256_Buf(masterPassword, strlen(masterPassword), hash);
+        SHA256_Buf( masterPassword, strlen( masterPassword ), hash );
 
         if (i % 1000 == 0)
             fprintf( stderr, "\rsha256: iteration %d / %d..", i, iterations );
     }
-
-    // Output timing results.
-    if (gettimeofday(&endTime, NULL) != 0) {
-        fprintf(stderr, "Could not get time: %d\n", errno);
-        return 1;
-    }
-    secs = (endTime.tv_sec - startTime.tv_sec);
-    usecs = (endTime.tv_usec - startTime.tv_usec);
-    elapsed = secs + usecs / 1000000.0;
-    double sha256Speed = iterations / elapsed;
-    fprintf( stdout, " done.  %d iterations in %llds %lldµs -> %.2f/s\n", iterations, secs, usecs, sha256Speed );
+    const double sha256Speed = mpw_showSpeed( startTime, iterations, "sha256" );
 
     // Start BCrypt
-    if (gettimeofday(&startTime, NULL) != 0) {
-        fprintf(stderr, "Could not get time: %d\n", errno);
-        return 1;
-    }
-
     int bcrypt_cost = 9;
     iterations = 600;
+    mpw_getTime( &startTime );
     for (int i = 0; i < iterations; ++i) {
-        crypt(masterPassword, crypt_gensalt("$2b$", bcrypt_cost, fullName, strlen(fullName)));
+        crypt( masterPassword, crypt_gensalt( "$2b$", bcrypt_cost, fullName, strlen( fullName ) ) );
 
         if (i % 10 == 0)
             fprintf( stderr, "\rbcrypt (cost %d): iteration %d / %d..", bcrypt_cost, i, iterations );
     }
-
-    // Output timing results.
-    if (gettimeofday(&endTime, NULL) != 0) {
-        fprintf(stderr, "Could not get time: %d\n", errno);
-        return 1;
-    }
-    secs = (endTime.tv_sec - startTime.tv_sec);
-    usecs = (endTime.tv_usec - startTime.tv_usec);
-    elapsed = secs + usecs / 1000000.0;
-    double bcrypt9Speed = iterations / elapsed;
-    fprintf( stdout, " done.  %d iterations in %llds %lldµs -> %.2f/s\n", iterations, secs, usecs, bcrypt9Speed );
+    const double bcrypt9Speed = mpw_showSpeed( startTime, iterations, "bcrypt9" );
 
     // Summarize.
     fprintf( stdout, "\n== SUMMARY ==\nOn this machine,\n" );
-    fprintf( stdout, "mpw is %f times slower than sha256\n", sha256Speed / mpwSpeed );
-    fprintf( stdout, "mpw is %f times slower than bcrypt (cost 9)\n", bcrypt9Speed / mpwSpeed );
+    fprintf( stdout, " - mpw is %f times slower than sha256.\n", sha256Speed / mpwSpeed );
+    fprintf( stdout, " - mpw is %f times slower than bcrypt (cost 9).\n", bcrypt9Speed / mpwSpeed );
 
     return 0;
 }
diff --git a/MasterPassword/C/mpw-cli.c b/MasterPassword/C/mpw-cli.c
index 6cce2806..b45c2ff1 100644
--- a/MasterPassword/C/mpw-cli.c
+++ b/MasterPassword/C/mpw-cli.c
@@ -1,22 +1,24 @@
 #define _GNU_SOURCE
 
 #include <stdio.h>
-#include <sys/types.h>
 #include <unistd.h>
 #include <pwd.h>
 #include <stdlib.h>
 #include <string.h>
 #include <errno.h>
 
-#include "types.h"
-#include "mpw.h"
-
 #if defined(READLINE)
 #include <readline/readline.h>
 #elif defined(EDITLINE)
 #include <histedit.h>
 #endif
 
+#define ftl(...) do { fprintf( stderr, __VA_ARGS__ ); exit(2); } while (0)
+
+#include "mpw-types.h"
+#include "mpw-algorithm.h"
+#include "mpw-util.h"
+
 #define MP_env_fullname     "MP_FULLNAME"
 #define MP_env_sitetype     "MP_SITETYPE"
 #define MP_env_sitecounter  "MP_SITECOUNTER"
@@ -125,18 +127,17 @@ int main(int argc, char *const argv[]) {
             case '?':
                 switch (optopt) {
                     case 'u':
-                        fprintf( stderr, "Missing full name to option: -%c\n", optopt );
+                        ftl( "Missing full name to option: -%c\n", optopt );
                         break;
                     case 't':
-                        fprintf( stderr, "Missing type name to option: -%c\n", optopt );
+                        ftl( "Missing type name to option: -%c\n", optopt );
                         break;
                     case 'c':
-                        fprintf( stderr, "Missing counter value to option: -%c\n", optopt );
+                        ftl( "Missing counter value to option: -%c\n", optopt );
                         break;
                     default:
-                        fprintf( stderr, "Unknown option: -%c\n", optopt );
+                        ftl( "Unknown option: -%c\n", optopt );
                 }
-                return 1;
             default:
                 ftl("Unexpected option: %c", opt);
         }
@@ -144,39 +145,27 @@ int main(int argc, char *const argv[]) {
         siteName = argv[optind];
 
     // Convert and validate input.
-    if (!fullName) {
-        if (!(fullName = getlinep( "Your full name:" ))) {
-            fprintf( stderr, "Missing full name.\n" );
-            return 1;
-        }
-    }
-    if (!siteName) {
-        if (!(siteName = getlinep( "Site name:" ))) {
-            fprintf( stderr, "Missing site name.\n" );
-            return 1;
-        }
-    }
+    if (!fullName && !(fullName = getlinep( "Your full name:" )))
+        ftl( "Missing full name.\n" );
+    if (!siteName && !(siteName = getlinep( "Site name:" )))
+        ftl( "Missing site name.\n" );
     if (siteCounterString)
         siteCounter = atoi( siteCounterString );
-    if (siteCounter < 1) {
-        fprintf( stderr, "Invalid site counter: %d\n", siteCounter );
-        return 1;
-    }
+    if (siteCounter < 1)
+        ftl( "Invalid site counter: %d\n", siteCounter );
     if (siteVariantString)
-        siteVariant = VariantWithName( siteVariantString );
+        siteVariant = mpw_variantWithName( siteVariantString );
     if (siteVariant == MPSiteVariantLogin)
         siteType = MPSiteTypeGeneratedName;
     if (siteVariant == MPSiteVariantAnswer)
         siteType = MPSiteTypeGeneratedPhrase;
     if (siteTypeString)
-        siteType = TypeWithName( siteTypeString );
+        siteType = mpw_typeWithName( siteTypeString );
 
     // Read the master password.
     char *mpwConfigPath = homedir( ".mpw" );
-    if (!mpwConfigPath) {
-        fprintf( stderr, "Couldn't resolve path for configuration file: %d\n", errno );
-        return 1;
-    }
+    if (!mpwConfigPath)
+        ftl( "Couldn't resolve path for configuration file: %d\n", errno );
     trc( "mpwConfigPath: %s\n", mpwConfigPath );
     FILE *mpwConfig = fopen( mpwConfigPath, "r" );
     free( mpwConfigPath );
@@ -190,16 +179,18 @@ int main(int argc, char *const argv[]) {
                 break;
             }
         }
-        free( line );
+        mpw_free( line, linecap );
     }
-    while (!masterPassword)
+    while (!masterPassword || !strlen(masterPassword))
         masterPassword = getpass( "Your master password: " );
 
     // Summarize operation.
-    fprintf( stderr, "%s's password for %s:\n[ %s ]: ", fullName, siteName, Identicon( fullName, masterPassword ) );
+    fprintf( stderr, "%s's password for %s:\n[ %s ]: ", fullName, siteName, mpw_identicon( fullName, masterPassword ) );
 
     // Output the password.
     const uint8_t *masterKey = mpw_masterKeyForUser( fullName, masterPassword );
+    mpw_free( masterPassword, strlen( masterPassword ) );
+
     const char *sitePassword = mpw_passwordForSite( masterKey, siteName, siteType, siteCounter, siteVariant, siteContextString );
     fprintf( stdout, "%s\n", sitePassword );
 
diff --git a/MasterPassword/C/types.c b/MasterPassword/C/mpw-types.c
similarity index 62%
rename from MasterPassword/C/types.c
rename to MasterPassword/C/mpw-types.c
index f2f7a1b7..4f19bdd3 100644
--- a/MasterPassword/C/types.c
+++ b/MasterPassword/C/mpw-types.c
@@ -1,29 +1,24 @@
 //
-//  MPTypes.h
+//  mpw-types.c
 //  MasterPassword
 //
-//  Created by Maarten Billemont on 02/01/12.
-//  Copyright (c) 2012 Lyndir. All rights reserved.
+//  Created by Maarten Billemont on 2012-02-01.
+//  Copyright (c) 2014 Lyndir. All rights reserved.
 //
 
-#include <stdbool.h>
 #include <stdlib.h>
 #include <stdio.h>
 #include <string.h>
 #include <ctype.h>
-#include <errno.h>
-#include <unistd.h>
-
-#include <scrypt/sha256.h>
 
 #ifdef COLOR
 #include <curses.h>
 #include <term.h>
 #endif
 
-#include "types.h"
+#include "mpw-types.h"
 
-const MPSiteType TypeWithName(const char *typeName) {
+const MPSiteType mpw_typeWithName(const char *typeName) {
     char lowerTypeName[strlen(typeName)];
     strcpy(lowerTypeName, typeName);
     for (char *tN = lowerTypeName; *tN; ++tN)
@@ -50,7 +45,7 @@ const MPSiteType TypeWithName(const char *typeName) {
     abort();
 }
 
-const char *TemplateForType(MPSiteType type, uint8_t seedByte) {
+const char *mpw_templateForType(MPSiteType type, uint8_t seedByte) {
     if (!(type & MPSiteTypeClassGenerated)) {
         fprintf(stderr, "Not a generated type: %d", type);
         abort();
@@ -93,7 +88,7 @@ const char *TemplateForType(MPSiteType type, uint8_t seedByte) {
     }
 }
 
-const MPSiteVariant VariantWithName(const char *variantName) {
+const MPSiteVariant mpw_variantWithName(const char *variantName) {
     char lowerVariantName[strlen(variantName)];
     strcpy(lowerVariantName, variantName);
     for (char *vN = lowerVariantName; *vN; ++vN)
@@ -110,7 +105,7 @@ const MPSiteVariant VariantWithName(const char *variantName) {
     abort();
 }
 
-const char *ScopeForVariant(MPSiteVariant variant) {
+const char *mpw_scopeForVariant(MPSiteVariant variant) {
     switch (variant) {
         case MPSiteVariantPassword: {
             return "com.lyndir.masterpassword";
@@ -128,7 +123,7 @@ const char *ScopeForVariant(MPSiteVariant variant) {
     }
 }
 
-const char CharacterFromClass(char characterClass, uint8_t seedByte) {
+const char mpw_characterFromClass(char characterClass, uint8_t seedByte) {
     const char *classCharacters;
     switch (characterClass) {
         case 'V': {
@@ -179,82 +174,3 @@ const char CharacterFromClass(char characterClass, uint8_t seedByte) {
 
     return classCharacters[seedByte % strlen(classCharacters)];
 }
-
-const char *IDForBuf(const void *buf, size_t length) {
-    uint8_t hash[32];
-    SHA256_Buf(buf, length, hash);
-
-    char *id = (char *)calloc(65, sizeof(char));
-    for (int kH = 0; kH < 32; kH++)
-        sprintf(&(id[kH * 2]), "%02X", hash[kH]);
-
-    return id;
-}
-
-const char *Hex(const void *buf, size_t length) {
-    char *id = (char *)calloc(length*2+1, sizeof(char));
-    for (int kH = 0; kH < length; kH++)
-        sprintf(&(id[kH * 2]), "%02X", ((const uint8_t*)buf)[kH]);
-
-    return id;
-}
-
-#ifdef COLOR
-int putvari;
-char *putvarc = NULL;
-bool istermsetup = false;
-static void initputvar() {
-    if (putvarc)
-        free(putvarc);
-    putvarc=(char *)calloc(256, sizeof(char));
-    putvari=0;
-
-    if (!istermsetup)
-        istermsetup = (OK == setupterm(NULL, STDERR_FILENO, NULL));
-}
-static int putvar(int c) {
-    putvarc[putvari++]=c;
-    return 0;
-}
-#endif
-
-const char *Identicon(const char *fullName, const char *masterPassword) {
-    const char *leftArm[]   = { "╔", "╚", "╰", "═" };
-    const char *rightArm[]  = { "╗", "╝", "╯", "═" };
-    const char *body[]      = { "█", "░", "▒", "▓", "☺", "☻" };
-    const char *accessory[] = { "◈", "◎", "◐", "◑", "◒", "◓", "☀", "☁", "☂", "☃", "☄", "★", "☆", "☎", "☏", "⎈", "⌂", "☘", "☢", "☣", "☕", "⌚", "⌛", "⏰", "⚡", "⛄", "⛅", "☔", "♔", "♕", "♖", "♗", "♘", "♙", "♚", "♛", "♜", "♝", "♞", "♟", "♨", "♩", "♪", "♫", "⚐", "⚑", "⚔", "⚖", "⚙", "⚠", "⌘", "⏎", "✄", "✆", "✈", "✉", "✌" };
-
-    uint8_t identiconSeed[32];
-    HMAC_SHA256_Buf(masterPassword, strlen(masterPassword), fullName, strlen(fullName), identiconSeed);
-
-    char *colorString, *resetString;
-#ifdef COLOR
-    if (isatty( STDERR_FILENO )) {
-        uint8_t colorIdentifier = (uint8_t)(identiconSeed[4] % 7 + 1);
-        initputvar();
-        tputs(tparm(tgetstr("AF", NULL), colorIdentifier), 1, putvar);
-        colorString = calloc(strlen(putvarc) + 1, sizeof(char));
-        strcpy(colorString, putvarc);
-        tputs(tgetstr("me", NULL), 1, putvar);
-        resetString = calloc(strlen(putvarc) + 1, sizeof(char));
-        strcpy(resetString, putvarc);
-    } else
-#endif
-    {
-        colorString = calloc(1, sizeof(char));
-        resetString = calloc(1, sizeof(char));
-    }
-
-    char *identicon = (char *)calloc(256, sizeof(char));
-    snprintf(identicon, 256, "%s%s%s%s%s%s",
-             colorString,
-             leftArm[identiconSeed[0] % (sizeof(leftArm) / sizeof(leftArm[0]))],
-             body[identiconSeed[1] % (sizeof(body) / sizeof(body[0]))],
-             rightArm[identiconSeed[2] % (sizeof(rightArm) / sizeof(rightArm[0]))],
-             accessory[identiconSeed[3] % (sizeof(accessory) / sizeof(accessory[0]))],
-             resetString);
-
-    free(colorString);
-    free(resetString);
-    return identicon;
-}
diff --git a/MasterPassword/C/types.h b/MasterPassword/C/mpw-types.h
similarity index 56%
rename from MasterPassword/C/types.h
rename to MasterPassword/C/mpw-types.h
index ec6bd83c..14334b82 100644
--- a/MasterPassword/C/types.h
+++ b/MasterPassword/C/mpw-types.h
@@ -1,32 +1,45 @@
 //
-//  MPTypes.h
+//  mpw-types.h
 //  MasterPassword
 //
-//  Created by Maarten Billemont on 02/01/12.
-//  Copyright (c) 2012 Lyndir. All rights reserved.
+//  Created by Maarten Billemont on 2012-02-01.
+//  Copyright (c) 2014 Lyndir. All rights reserved.
 //
 
+//// Logging.
+
+#ifdef DEBUG
+#define trc(...) fprintf( stderr, __VA_ARGS__ )
+#else
+#define trc(...) do {} while (0)
+#endif
+#ifndef ftl
+#define ftl(...) do { fprintf( stderr, __VA_ARGS__ ); abort(); } while (0)
+#endif
+
+//// Types.
+
 typedef enum {
     /** Generate the password to log in with. */
-    MPSiteVariantPassword,
+            MPSiteVariantPassword,
     /** Generate the login name to log in as. */
-    MPSiteVariantLogin,
+            MPSiteVariantLogin,
     /** Generate the answer to a security question. */
-    MPSiteVariantAnswer,
+            MPSiteVariantAnswer,
 } MPSiteVariant;
 
 typedef enum {
     /** Generate the password. */
-    MPSiteTypeClassGenerated = 1 << 4,
+            MPSiteTypeClassGenerated = 1 << 4,
     /** Store the password. */
-    MPSiteTypeClassStored = 1 << 5,
+            MPSiteTypeClassStored = 1 << 5,
 } MPSiteTypeClass;
 
 typedef enum {
     /** Export the key-protected content data. */
-    MPSiteFeatureExportContent = 1 << 10,
+            MPSiteFeatureExportContent = 1 << 10,
     /** Never export content. */
-    MPSiteFeatureDevicePrivate = 1 << 11,
+            MPSiteFeatureDevicePrivate = 1 << 11,
 } MPSiteFeature;
 
 typedef enum {
@@ -43,19 +56,11 @@ typedef enum {
     MPSiteTypeStoredDevicePrivate = 0x1 | MPSiteTypeClassStored | MPSiteFeatureDevicePrivate,
 } MPSiteType;
 
-#ifdef DEBUG
-#define trc(...) fprintf(stderr, __VA_ARGS__)
-#else
-#define trc(...) do {} while (0)
-#endif
-#define ftl(...) do { fprintf( stderr, "Could not allocate master key salt: %d\n", errno ); abort(); } while (0)
+//// Type utilities.
 
-const MPSiteVariant VariantWithName(const char *variantName);
-const char *ScopeForVariant(MPSiteVariant variant);
-const MPSiteType TypeWithName(const char *typeName);
-const char *TemplateForType(MPSiteType type, uint8_t seedByte);
-const char CharacterFromClass(char characterClass, uint8_t seedByte);
-const char *IDForBuf(const void *buf, size_t length);
-const char *Hex(const void *buf, size_t length);
-const char *Identicon(const char *fullName, const char *masterPassword);
+const MPSiteVariant mpw_variantWithName(const char *variantName);
+const char *mpw_scopeForVariant(MPSiteVariant variant);
+const MPSiteType mpw_typeWithName(const char *typeName);
+const char *mpw_templateForType(MPSiteType type, uint8_t seedByte);
+const char mpw_characterFromClass(char characterClass, uint8_t seedByte);
 
diff --git a/MasterPassword/C/mpw-util.c b/MasterPassword/C/mpw-util.c
new file mode 100644
index 00000000..cb9f0638
--- /dev/null
+++ b/MasterPassword/C/mpw-util.c
@@ -0,0 +1,155 @@
+//
+//  mpw-util.c
+//  MasterPassword
+//
+//  Created by Maarten Billemont on 2014-12-20.
+//  Copyright (c) 2014 Lyndir. All rights reserved.
+//
+
+#include <stdio.h>
+#include <stdlib.h>
+#include <string.h>
+
+#include <scrypt/sha256.h>
+#include <scrypt/crypto_scrypt.h>
+
+#include "mpw-util.h"
+
+void mpw_pushBuf(uint8_t **const buffer, size_t *const bufferSize, const void *pushBuffer, const size_t pushSize) {
+
+    if (*bufferSize == (size_t)-1)
+        return;
+
+    *bufferSize += pushSize;
+    *buffer = realloc( *buffer, *bufferSize );
+    if (!*buffer) {
+        *bufferSize = -1;
+        return;
+    }
+
+    uint8_t *pushDst = *buffer + *bufferSize - pushSize;
+    memcpy( pushDst, pushBuffer, pushSize );
+}
+
+void mpw_pushString(uint8_t **buffer, size_t *const bufferSize, const char *pushString) {
+
+    mpw_pushBuf( buffer, bufferSize, pushString, strlen( pushString ) );
+}
+
+void mpw_pushInt(uint8_t **const buffer, size_t *const bufferSize, const uint32_t pushInt) {
+
+    mpw_pushBuf( buffer, bufferSize, &pushInt, sizeof( pushInt ) );
+}
+
+void mpw_free(const void *buffer, const size_t bufferSize) {
+
+    memset( (void *)buffer, 0, bufferSize );
+    free( (void *)buffer );
+}
+
+uint8_t const *mpw_scrypt(const size_t keySize, const char *secret, const uint8_t *salt, const size_t saltSize,
+        uint64_t N, uint32_t r, uint32_t p) {
+
+    uint8_t *key = malloc( keySize );
+    if (!key)
+        return NULL;
+
+    if (crypto_scrypt( (const uint8_t *)secret, strlen( secret ), salt, saltSize, N, r, p, key, keySize ) < 0) {
+        mpw_free( key, keySize );
+        return NULL;
+    }
+
+    return key;
+}
+
+uint8_t const *mpw_hmac_sha256(const uint8_t *key, const size_t keySize, const uint8_t *salt, const size_t saltSize) {
+
+    uint8_t *const buffer = malloc(32);
+    if (!buffer)
+        return NULL;
+
+    HMAC_SHA256_Buf( key, keySize, salt, saltSize, buffer );
+    return buffer;
+}
+
+const char *mpw_idForBuf(const void *buf, size_t length) {
+
+    uint8_t hash[32];
+    SHA256_Buf( buf, length, hash );
+
+    return mpw_hex( hash, 32 );
+}
+
+static char *mpw_hex_buf = NULL;
+const char *mpw_hex(const void *buf, size_t length) {
+
+    mpw_hex_buf = realloc( mpw_hex_buf, length * 2 + 1 );
+    for (int kH = 0; kH < length; kH++)
+        sprintf( &(mpw_hex_buf[kH * 2]), "%02X", ((const uint8_t *)buf)[kH] );
+
+    return mpw_hex_buf;
+}
+
+#ifdef COLOR
+static int putvari;
+static char *putvarc = NULL;
+static bool istermsetup = false;
+static void initputvar() {
+    if (putvarc)
+        free(putvarc);
+    putvarc=(char *)calloc(256, sizeof(char));
+    putvari=0;
+
+    if (!istermsetup)
+        istermsetup = (OK == setupterm(NULL, STDERR_FILENO, NULL));
+}
+static int putvar(int c) {
+    putvarc[putvari++]=c;
+    return 0;
+}
+#endif
+
+const char *mpw_identicon(const char *fullName, const char *masterPassword) {
+
+    const char *leftArm[] = { "╔", "╚", "╰", "═" };
+    const char *rightArm[] = { "╗", "╝", "╯", "═" };
+    const char *body[] = { "█", "░", "▒", "▓", "☺", "☻" };
+    const char *accessory[] = {
+            "◈", "◎", "◐", "◑", "◒", "◓", "☀", "☁", "☂", "☃", "☄", "★", "☆", "☎", "☏", "⎈", "⌂", "☘", "☢", "☣",
+            "☕", "⌚", "⌛", "⏰", "⚡", "⛄", "⛅", "☔", "♔", "♕", "♖", "♗", "♘", "♙", "♚", "♛", "♜", "♝", "♞", "♟",
+            "♨", "♩", "♪", "♫", "⚐", "⚑", "⚔", "⚖", "⚙", "⚠", "⌘", "⏎", "✄", "✆", "✈", "✉", "✌" };
+
+    uint8_t identiconSeed[32];
+    HMAC_SHA256_Buf( masterPassword, strlen( masterPassword ), fullName, strlen( fullName ), identiconSeed );
+
+    char *colorString, *resetString;
+#ifdef COLOR
+    if (isatty( STDERR_FILENO )) {
+        uint8_t colorIdentifier = (uint8_t)(identiconSeed[4] % 7 + 1);
+        initputvar();
+        tputs(tparm(tgetstr("AF", NULL), colorIdentifier), 1, putvar);
+        colorString = calloc(strlen(putvarc) + 1, sizeof(char));
+        strcpy(colorString, putvarc);
+        tputs(tgetstr("me", NULL), 1, putvar);
+        resetString = calloc(strlen(putvarc) + 1, sizeof(char));
+        strcpy(resetString, putvarc);
+    } else
+#endif
+    {
+        colorString = calloc( 1, sizeof( char ) );
+        resetString = calloc( 1, sizeof( char ) );
+    }
+
+    char *identicon = (char *)calloc( 256, sizeof( char ) );
+    snprintf( identicon, 256, "%s%s%s%s%s%s",
+            colorString,
+            leftArm[identiconSeed[0] % (sizeof( leftArm ) / sizeof( leftArm[0] ))],
+            body[identiconSeed[1] % (sizeof( body ) / sizeof( body[0] ))],
+            rightArm[identiconSeed[2] % (sizeof( rightArm ) / sizeof( rightArm[0] ))],
+            accessory[identiconSeed[3] % (sizeof( accessory ) / sizeof( accessory[0] ))],
+            resetString );
+
+    free( colorString );
+    free( resetString );
+    return identicon;
+}
diff --git a/MasterPassword/C/mpw-util.h b/MasterPassword/C/mpw-util.h
new file mode 100644
index 00000000..27adf206
--- /dev/null
+++ b/MasterPassword/C/mpw-util.h
@@ -0,0 +1,46 @@
+//
+//  mpw-util.h
+//  MasterPassword
+//
+//  Created by Maarten Billemont on 2014-12-20.
+//  Copyright (c) 2014 Lyndir. All rights reserved.
+//
+
+//// Buffers and memory.
+
+/** Push a buffer onto a buffer.  reallocs the given buffer and appends the given buffer. */
+void mpw_pushBuf(
+        uint8_t **const buffer, size_t *const bufferSize, const void *pushBuffer, const size_t pushSize);
+/** Push a string onto a buffer.  reallocs the given buffer and appends the given string. */
+void mpw_pushString(
+        uint8_t **buffer, size_t *const bufferSize, const char *pushString);
+/** Push an integer onto a buffer.  reallocs the given buffer and appends the given integer. */
+void mpw_pushInt(
+        uint8_t **const buffer, size_t *const bufferSize, const uint32_t pushInt);
+/** Free a buffer after zero'ing its contents. */
+void mpw_free(
+        const void *buffer, const size_t bufferSize);
+
+//// Cryptographic functions.
+
+/** Perform a scrypt-based key derivation on the given key using the given salt and scrypt parameters.
+  * @return A new keySize-size allocated buffer. */
+uint8_t const *mpw_scrypt(
+        const size_t keySize, const char *secret, const uint8_t *salt, const size_t saltSize,
+        uint64_t N, uint32_t r, uint32_t p);
+/** Calculate a SHA256-based HMAC by encrypting the given salt with the given key.
+  * @return A new 32-byte allocated buffer. */
+uint8_t const *mpw_hmac_sha256(
+        const uint8_t *key, const size_t keySize, const uint8_t *salt, const size_t saltSize);
+
+//// Visualizers.
+
+/** Encode a buffer as a string of hexadecimal characters.
+  * @return A reused buffer, do not free or store it. */
+const char *mpw_hex(const void *buf, size_t length);
+/** Encode a fingerprint for a buffer.
+  * @return A reused buffer, do not free or store it. */
+const char *mpw_idForBuf(const void *buf, size_t length);
+/** Encode a visual fingerprint for a user.
+  * @return A newly allocated string. */
+const char *mpw_identicon(const char *fullName, const char *masterPassword);
diff --git a/MasterPassword/C/mpw.h b/MasterPassword/C/mpw.h
deleted file mode 100644
index 2d333fd2..00000000
--- a/MasterPassword/C/mpw.h
+++ /dev/null
@@ -1,6 +0,0 @@
-const uint8_t *mpw_masterKeyForUser(
-        const char *fullName, const char *masterPassword);
-
-const char *mpw_passwordForSite(
-        const uint8_t *masterKey, const char *siteName, const MPSiteType siteType, const uint32_t siteCounter,
-        const MPSiteVariant siteVariant, const char *siteContext);
diff --git a/MasterPassword/ObjC/iOS/MasterPassword-iOS.xcodeproj/project.pbxproj b/MasterPassword/ObjC/iOS/MasterPassword-iOS.xcodeproj/project.pbxproj
index 734e0eba..ee4b3735 100644
--- a/MasterPassword/ObjC/iOS/MasterPassword-iOS.xcodeproj/project.pbxproj
+++ b/MasterPassword/ObjC/iOS/MasterPassword-iOS.xcodeproj/project.pbxproj
@@ -27,7 +27,7 @@
 		93D3954FCE045A3CC7E804B7 /* MPUsersViewController.m in Sources */ = {isa = PBXBuildFile; fileRef = 93D399E571F61E50A9BF8FAF /* MPUsersViewController.m */; };
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 		93D3958C13B557F60F63C72B /* distribute in Resources */ = {isa = PBXBuildFile; fileRef = 93D3979016BF0C5B29D1340D /* distribute */; };
-		93D395B715D15F2B56F2A2EE /* types.c in Sources */ = {isa = PBXBuildFile; fileRef = 93D392C5A6572DB0EB5B82C8 /* types.c */; };
+		93D395B715D15F2B56F2A2EE /* mpw-types.c in Sources */ = {isa = PBXBuildFile; fileRef = 93D392C5A6572DB0EB5B82C8 /* mpw-types.c */; };
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 		93D396AA30690B256F30378A /* PearlNavigationController.m in Sources */ = {isa = PBXBuildFile; fileRef = 93D3956915634581E737B38C /* PearlNavigationController.m */; };
@@ -40,6 +40,7 @@
 		93D399246DC90F50913A1287 /* UIResponder+PearlFirstResponder.m in Sources */ = {isa = PBXBuildFile; fileRef = 93D39A1DDFA09AE2E14D26DC /* UIResponder+PearlFirstResponder.m */; };
 		93D3992FA1546E01F498F665 /* PearlNavigationController.h in Headers */ = {isa = PBXBuildFile; fileRef = 93D398567FD02DB2647B8CF3 /* PearlNavigationController.h */; };
 		93D399433EA75E50656040CB /* Twitter.framework in Frameworks */ = {isa = PBXBuildFile; fileRef = 93D394077F8FAB8167647187 /* Twitter.framework */; };
+		93D39943D01E70DAC3B0DF76 /* mpw-util.c in Sources */ = {isa = PBXBuildFile; fileRef = 93D396C311C3725870343EE0 /* mpw-util.c */; };
 		93D399D7E08A142776A74CB8 /* MPOverlayViewController.m in Sources */ = {isa = PBXBuildFile; fileRef = 93D395105935859D71679931 /* MPOverlayViewController.m */; };
 		93D39A27F2506C6FEEF9C588 /* MPAlgorithmV2.m in Sources */ = {isa = PBXBuildFile; fileRef = 93D399A8E3181B442D347CD7 /* MPAlgorithmV2.m */; };
 		93D39A53D76CA70786423458 /* UICollectionView+PearlReloadFromArray.h in Headers */ = {isa = PBXBuildFile; fileRef = 93D39246FC21C6E63E35D615 /* UICollectionView+PearlReloadFromArray.h */; };
@@ -477,7 +478,7 @@
 		93D3924D6F77E6BF41AC32D3 /* MPRootSegue.h */ = {isa = PBXFileReference; fileEncoding = 4; lastKnownFileType = sourcecode.c.h; path = MPRootSegue.h; sourceTree = "<group>"; };
 		93D3924EE15017F8A12CB436 /* MPPasswordsViewController.m */ = {isa = PBXFileReference; fileEncoding = 4; lastKnownFileType = sourcecode.c.objc; path = MPPasswordsViewController.m; sourceTree = "<group>"; };
 		93D392876BE5C011DE73B43F /* MPPopdownSegue.h */ = {isa = PBXFileReference; fileEncoding = 4; lastKnownFileType = sourcecode.c.h; path = MPPopdownSegue.h; sourceTree = "<group>"; };
-		93D392C5A6572DB0EB5B82C8 /* types.c */ = {isa = PBXFileReference; fileEncoding = 4; lastKnownFileType = sourcecode.c.c; path = types.c; sourceTree = "<group>"; };
+		93D392C5A6572DB0EB5B82C8 /* mpw-types.c */ = {isa = PBXFileReference; fileEncoding = 4; lastKnownFileType = sourcecode.c.c; path = "mpw-types.c"; sourceTree = "<group>"; };
 		93D393310223DDB35218467A /* MPCombinedViewController.m */ = {isa = PBXFileReference; fileEncoding = 4; lastKnownFileType = sourcecode.c.objc; path = MPCombinedViewController.m; sourceTree = "<group>"; };
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 		93D393BB973253D4BAAC84AA /* PearlEMail.m */ = {isa = PBXFileReference; fileEncoding = 4; lastKnownFileType = sourcecode.c.objc; path = PearlEMail.m; sourceTree = "<group>"; };
@@ -490,7 +491,8 @@
 		93D395105935859D71679931 /* MPOverlayViewController.m */ = {isa = PBXFileReference; fileEncoding = 4; lastKnownFileType = sourcecode.c.objc; path = MPOverlayViewController.m; sourceTree = "<group>"; };
 		93D3956915634581E737B38C /* PearlNavigationController.m */ = {isa = PBXFileReference; fileEncoding = 4; lastKnownFileType = sourcecode.c.objc; path = PearlNavigationController.m; sourceTree = "<group>"; };
 		93D3957D76F71A652716EECC /* MPStoreViewController.m */ = {isa = PBXFileReference; fileEncoding = 4; lastKnownFileType = sourcecode.c.objc; path = MPStoreViewController.m; sourceTree = "<group>"; };
-		93D3969393A3A46BD27D7078 /* mpw.c */ = {isa = PBXFileReference; fileEncoding = 4; lastKnownFileType = sourcecode.c.c; path = mpw.c; sourceTree = "<group>"; };
+		93D3969393A3A46BD27D7078 /* mpw-algorithm.c */ = {isa = PBXFileReference; fileEncoding = 4; lastKnownFileType = sourcecode.c.c; path = "mpw-algorithm.c"; sourceTree = "<group>"; };
+		93D396C311C3725870343EE0 /* mpw-util.c */ = {isa = PBXFileReference; fileEncoding = 4; lastKnownFileType = sourcecode.c.c; path = "mpw-util.c"; sourceTree = "<group>"; };
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@@ -502,7 +504,7 @@
 		93D398121C8F063A3637144E /* mpw-cli.c */ = {isa = PBXFileReference; fileEncoding = 4; lastKnownFileType = sourcecode.c.c; path = "mpw-cli.c"; sourceTree = "<group>"; };
 		93D398567FD02DB2647B8CF3 /* PearlNavigationController.h */ = {isa = PBXFileReference; fileEncoding = 4; lastKnownFileType = sourcecode.c.h; path = PearlNavigationController.h; sourceTree = "<group>"; };
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-		93D3990D850D76A94C6B7A4D /* mpw.h */ = {isa = PBXFileReference; fileEncoding = 4; lastKnownFileType = sourcecode.c.h; path = mpw.h; sourceTree = "<group>"; };
+		93D3990D850D76A94C6B7A4D /* mpw-algorithm.h */ = {isa = PBXFileReference; fileEncoding = 4; lastKnownFileType = sourcecode.c.h; path = "mpw-algorithm.h"; sourceTree = "<group>"; };
 		93D3990E0CD1B5CF9FBB2C07 /* MPWebViewController.m */ = {isa = PBXFileReference; fileEncoding = 4; lastKnownFileType = sourcecode.c.objc; path = MPWebViewController.m; sourceTree = "<group>"; };
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 		93D3995B1D4DCE5A30D882BA /* MPCoachmarkViewController.m */ = {isa = PBXFileReference; fileEncoding = 4; lastKnownFileType = sourcecode.c.objc; path = MPCoachmarkViewController.m; sourceTree = "<group>"; };
@@ -521,7 +523,7 @@
 		93D39AA1EE2E1E7B81372240 /* NSDictionary+Indexing.m */ = {isa = PBXFileReference; fileEncoding = 4; lastKnownFileType = sourcecode.c.objc; path = "NSDictionary+Indexing.m"; sourceTree = "<group>"; };
 		93D39ACBA9F4878B6A1CC33B /* MPEmergencyViewController.m */ = {isa = PBXFileReference; fileEncoding = 4; lastKnownFileType = sourcecode.c.objc; path = MPEmergencyViewController.m; sourceTree = "<group>"; };
 		93D39ACD33E79386E6F33601 /* install */ = {isa = PBXFileReference; fileEncoding = 4; lastKnownFileType = text; path = install; sourceTree = "<group>"; };
-		93D39AFD17CBE324D745DAB0 /* types.h */ = {isa = PBXFileReference; fileEncoding = 4; lastKnownFileType = sourcecode.c.h; path = types.h; sourceTree = "<group>"; };
+		93D39AFD17CBE324D745DAB0 /* mpw-types.h */ = {isa = PBXFileReference; fileEncoding = 4; lastKnownFileType = sourcecode.c.h; path = "mpw-types.h"; sourceTree = "<group>"; };
 		93D39B050DD5F55E9794EFD4 /* MPPopdownSegue.m */ = {isa = PBXFileReference; fileEncoding = 4; lastKnownFileType = sourcecode.c.objc; path = MPPopdownSegue.m; sourceTree = "<group>"; };
 		93D39B1D8177A86C5B9EDDE3 /* PearlUICollectionView.h */ = {isa = PBXFileReference; fileEncoding = 4; lastKnownFileType = sourcecode.c.h; path = PearlUICollectionView.h; sourceTree = "<group>"; };
 		93D39B381350802A194BF332 /* MPAvatarCell.m */ = {isa = PBXFileReference; fileEncoding = 4; lastKnownFileType = sourcecode.c.objc; path = MPAvatarCell.m; sourceTree = "<group>"; };
@@ -536,6 +538,7 @@
 		93D39CC01630D0421205C4C4 /* MPNavigationController.m */ = {isa = PBXFileReference; fileEncoding = 4; lastKnownFileType = sourcecode.c.objc; path = MPNavigationController.m; sourceTree = "<group>"; };
 		93D39CDD434AFD6E1B0DA359 /* MPEmergencyViewController.h */ = {isa = PBXFileReference; fileEncoding = 4; lastKnownFileType = sourcecode.c.h; path = MPEmergencyViewController.h; sourceTree = "<group>"; };
 		93D39CECA10BCCB0BA581BF1 /* MPAppDelegate_InApp.h */ = {isa = PBXFileReference; fileEncoding = 4; lastKnownFileType = sourcecode.c.h; path = MPAppDelegate_InApp.h; sourceTree = "<group>"; };
+		93D39CF7DB942C69D1C5D6BE /* mpw-util.h */ = {isa = PBXFileReference; fileEncoding = 4; lastKnownFileType = sourcecode.c.h; path = "mpw-util.h"; sourceTree = "<group>"; };
 		93D39CF8ADF4542CDC4CD385 /* MPCombinedViewController.h */ = {isa = PBXFileReference; fileEncoding = 4; lastKnownFileType = sourcecode.c.h; path = MPCombinedViewController.h; sourceTree = "<group>"; };
 		93D39D6604447D7708039155 /* MPAnswersViewController.h */ = {isa = PBXFileReference; fileEncoding = 4; lastKnownFileType = sourcecode.c.h; path = MPAnswersViewController.h; sourceTree = "<group>"; };
 		93D39D8A953779B35403AF6E /* PearlUICollectionView.m */ = {isa = PBXFileReference; fileEncoding = 4; lastKnownFileType = sourcecode.c.objc; path = PearlUICollectionView.m; sourceTree = "<group>"; };
@@ -1606,17 +1609,19 @@
 			isa = PBXGroup;
 			children = (
 				93D39B573E4DE98BAE518215 /* build */,
-				93D3969393A3A46BD27D7078 /* mpw.c */,
+				93D3969393A3A46BD27D7078 /* mpw-algorithm.c */,
 				93D39E71D6BAECEC4CD886F4 /* bashlib */,
 				93D39ACD33E79386E6F33601 /* install */,
-				93D392C5A6572DB0EB5B82C8 /* types.c */,
-				93D39AFD17CBE324D745DAB0 /* types.h */,
+				93D392C5A6572DB0EB5B82C8 /* mpw-types.c */,
+				93D39AFD17CBE324D745DAB0 /* mpw-types.h */,
 				93D3944F4D55D2A37EF6021B /* VERSION */,
 				93D3979016BF0C5B29D1340D /* distribute */,
 				93D39245A478883C672818F3 /* mpw.bashrc */,
 				93D39B70138D0E28F7D5E86B /* mpw-bench.c */,
 				93D398121C8F063A3637144E /* mpw-cli.c */,
-				93D3990D850D76A94C6B7A4D /* mpw.h */,
+				93D3990D850D76A94C6B7A4D /* mpw-algorithm.h */,
+				93D39CF7DB942C69D1C5D6BE /* mpw-util.h */,
+				93D396C311C3725870343EE0 /* mpw-util.c */,
 			);
 			name = C;
 			path = ../../C;
@@ -3630,8 +3635,9 @@
 				93D39A27F2506C6FEEF9C588 /* MPAlgorithmV2.m in Sources */,
 				93D39B429C67A62E29DC02DA /* MPRootSegue.m in Sources */,
 				93D392FD5E2052F7D7DB3774 /* NSString+MPMarkDown.m in Sources */,
-				93D395B715D15F2B56F2A2EE /* types.c in Sources */,
+				93D395B715D15F2B56F2A2EE /* mpw-types.c in Sources */,
 				93D39B35D4B8E87ADEC05246 /* mpw-cli.c in Sources */,
+				93D39943D01E70DAC3B0DF76 /* mpw-util.c in Sources */,
 			);
 			runOnlyForDeploymentPostprocessing = 0;
 		};