diff -r -u -N --exclude=Makefile.in --exclude=.deps --exclude=Makefile src/auth/password-scheme.c auth/password-scheme.c
--- src/auth/password-scheme.c	2007-02-21 13:30:38.756711250 +0100
+++ auth/password-scheme.c	2007-02-21 14:18:49.645380500 +0100
@@ -10,6 +10,7 @@
 #include "mycrypt.h"
 #include "randgen.h"
 #include "sha1.h"
+#include "sha2.h"
 #include "str.h"
 #include "password-scheme.h"
 
@@ -153,6 +154,17 @@
 	return str_c(str);
 }
 
+static const char *sha256_generate(const char *plaintext,
+                                const char *user __attr_unused__)
+{
+       unsigned char digest[SHA256_RESULTLEN];
+       string_t *str;
+       sha256_get_digest(plaintext, strlen(plaintext), digest);
+       str = t_str_new(MAX_BASE64_ENCODED_SIZE(sizeof(digest)+1));
+       base64_encode(digest, sizeof(digest), str);
+       return str_c(str);
+}
+
 static const void *
 password_decode(const char *password, unsigned int result_len)
 {
@@ -196,6 +208,23 @@
 	return memcmp(sha1_digest, data, SHA1_RESULTLEN) == 0;
 }
 
+static bool sha256_verify(const char *plaintext, const char *password,
+                        const char *user)
+{
+        unsigned char sha256_digest[SHA256_RESULTLEN];
+        const char *data;
+
+        sha256_get_digest(plaintext, strlen(plaintext), sha256_digest);
+
+        data = password_decode(password, SHA256_RESULTLEN);
+        if (data == NULL) {
+                i_error("sha256_verify(%s): Invalid password encoding", user);
+                return 0;
+        }
+
+        return memcmp(sha256_digest, data, SHA256_RESULTLEN) == 0;
+}
+
 static const char *ssha_generate(const char *plaintext,
 				 const char *user __attr_unused__)
 {
@@ -466,6 +495,7 @@
 	{ "MD5-CRYPT", md5_crypt_verify, md5_crypt_generate },
  	{ "SHA", sha1_verify, sha1_generate },
  	{ "SHA1", sha1_verify, sha1_generate },
+	{ "SHA256", sha256_verify, sha256_generate },
 	{ "SMD5", smd5_verify, smd5_generate },
 	{ "SSHA", ssha_verify, ssha_generate },
 	{ "PLAIN", plain_verify, plain_generate },
diff -r -u -N --exclude=Makefile.in --exclude=.deps --exclude=Makefile src/lib/Makefile.am lib/Makefile.am
--- src/lib/Makefile.am	2007-02-21 13:30:38.792713500 +0100
+++ lib/Makefile.am	2007-02-21 14:21:59.437241750 +0100
@@ -73,6 +73,7 @@
 	sendfile-util.c \
 	seq-range-array.c \
 	sha1.c \
+	sha2.c \
 	str.c \
 	str-sanitize.c \
 	strescape.c \
@@ -146,6 +147,7 @@
 	sendfile-util.h \
 	seq-range-array.h \
 	sha1.h \
+	sha2.h \
 	str.h \
 	str-sanitize.h \
 	strescape.h \
diff -r -u -N --exclude=Makefile.in --exclude=.deps --exclude=Makefile src/lib/sha2.c lib/sha2.c
--- src/lib/sha2.c	1970-01-01 01:00:00.000000000 +0100
+++ lib/sha2.c	2007-02-23 14:03:46.857739818 +0100
@@ -0,0 +1,257 @@
+/*
+ * FIPS 180-2 SHA-224/256/384/512 implementation
+ * Last update: 02/02/2007
+ * Issue date:  04/30/2005
+ *
+ * Copyright (C) 2005, 2007 Olivier Gay <olivier.gay@a3.epfl.ch>
+ * All rights reserved.
+ *
+ * Redistribution and use in source and binary forms, with or without
+ * modification, are permitted provided that the following conditions
+ * are met:
+ * 1. Redistributions of source code must retain the above copyright
+ *    notice, this list of conditions and the following disclaimer.
+ * 2. Redistributions in binary form must reproduce the above copyright
+ *    notice, this list of conditions and the following disclaimer in the
+ *    documentation and/or other materials provided with the distribution.
+ * 3. Neither the name of the project nor the names of its contributors
+ *    may be used to endorse or promote products derived from this software
+ *    without specific prior written permission.
+ *
+ * THIS SOFTWARE IS PROVIDED BY THE PROJECT AND CONTRIBUTORS ``AS IS'' AND
+ * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
+ * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
+ * ARE DISCLAIMED.  IN NO EVENT SHALL THE PROJECT OR CONTRIBUTORS BE LIABLE
+ * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
+ * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
+ * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
+ * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
+ * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
+ * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
+ * SUCH DAMAGE.
+ */
+
+#include <string.h>
+
+#include "sha2.h"
+
+#define SHFR(x, n)    (x >> n)
+#define ROTR(x, n)   ((x >> n) | (x << ((sizeof(x) << 3) - n)))
+#define ROTL(x, n)   ((x << n) | (x >> ((sizeof(x) << 3) - n)))
+#define CH(x, y, z)  ((x & y) ^ (~x & z))
+#define MAJ(x, y, z) ((x & y) ^ (x & z) ^ (y & z))
+
+#define SHA256_F1(x) (ROTR(x,  2) ^ ROTR(x, 13) ^ ROTR(x, 22))
+#define SHA256_F2(x) (ROTR(x,  6) ^ ROTR(x, 11) ^ ROTR(x, 25))
+#define SHA256_F3(x) (ROTR(x,  7) ^ ROTR(x, 18) ^ SHFR(x,  3))
+#define SHA256_F4(x) (ROTR(x, 17) ^ ROTR(x, 19) ^ SHFR(x, 10))
+
+#define UNPACK32(x, str)                      \
+{                                             \
+    *((str) + 3) = (uint8) ((x)      );       \
+    *((str) + 2) = (uint8) ((x) >>  8);       \
+    *((str) + 1) = (uint8) ((x) >> 16);       \
+    *((str) + 0) = (uint8) ((x) >> 24);       \
+}
+
+#define PACK32(str, x)                        \
+{                                             \
+    *(x) =   ((uint32) *((str) + 3)      )    \
+           | ((uint32) *((str) + 2) <<  8)    \
+           | ((uint32) *((str) + 1) << 16)    \
+           | ((uint32) *((str) + 0) << 24);   \
+}
+
+#define UNPACK64(x, str)                      \
+{                                             \
+    *((str) + 7) = (uint8) ((x)      );       \
+    *((str) + 6) = (uint8) ((x) >>  8);       \
+    *((str) + 5) = (uint8) ((x) >> 16);       \
+    *((str) + 4) = (uint8) ((x) >> 24);       \
+    *((str) + 3) = (uint8) ((x) >> 32);       \
+    *((str) + 2) = (uint8) ((x) >> 40);       \
+    *((str) + 1) = (uint8) ((x) >> 48);       \
+    *((str) + 0) = (uint8) ((x) >> 56);       \
+}
+
+#define PACK64(str, x)                        \
+{                                             \
+    *(x) =   ((uint64) *((str) + 7)      )    \
+           | ((uint64) *((str) + 6) <<  8)    \
+           | ((uint64) *((str) + 5) << 16)    \
+           | ((uint64) *((str) + 4) << 24)    \
+           | ((uint64) *((str) + 3) << 32)    \
+           | ((uint64) *((str) + 2) << 40)    \
+           | ((uint64) *((str) + 1) << 48)    \
+           | ((uint64) *((str) + 0) << 56);   \
+}
+
+/* Macros used for loops unrolling */
+
+#define SHA256_SCR(i)                         \
+{                                             \
+    w[i] =  SHA256_F4(w[i -  2]) + w[i -  7]  \
+          + SHA256_F3(w[i - 15]) + w[i - 16]; \
+}
+
+
+
+uint32 sha256_h0[8] =
+            {0x6a09e667, 0xbb67ae85, 0x3c6ef372, 0xa54ff53a,
+             0x510e527f, 0x9b05688c, 0x1f83d9ab, 0x5be0cd19};
+
+
+uint32 sha256_k[64] =
+            {0x428a2f98, 0x71374491, 0xb5c0fbcf, 0xe9b5dba5,
+             0x3956c25b, 0x59f111f1, 0x923f82a4, 0xab1c5ed5,
+             0xd807aa98, 0x12835b01, 0x243185be, 0x550c7dc3,
+             0x72be5d74, 0x80deb1fe, 0x9bdc06a7, 0xc19bf174,
+             0xe49b69c1, 0xefbe4786, 0x0fc19dc6, 0x240ca1cc,
+             0x2de92c6f, 0x4a7484aa, 0x5cb0a9dc, 0x76f988da,
+             0x983e5152, 0xa831c66d, 0xb00327c8, 0xbf597fc7,
+             0xc6e00bf3, 0xd5a79147, 0x06ca6351, 0x14292967,
+             0x27b70a85, 0x2e1b2138, 0x4d2c6dfc, 0x53380d13,
+             0x650a7354, 0x766a0abb, 0x81c2c92e, 0x92722c85,
+             0xa2bfe8a1, 0xa81a664b, 0xc24b8b70, 0xc76c51a3,
+             0xd192e819, 0xd6990624, 0xf40e3585, 0x106aa070,
+             0x19a4c116, 0x1e376c08, 0x2748774c, 0x34b0bcb5,
+             0x391c0cb3, 0x4ed8aa4a, 0x5b9cca4f, 0x682e6ff3,
+             0x748f82ee, 0x78a5636f, 0x84c87814, 0x8cc70208,
+             0x90befffa, 0xa4506ceb, 0xbef9a3f7, 0xc67178f2};
+
+
+/* SHA-256 functions */
+
+void sha256_transf(sha256_ctx *ctx, const unsigned char *message,
+                   unsigned int block_nb)
+{
+    uint32 w[64];
+    uint32 wv[8];
+    uint32 t1, t2;
+    const unsigned char *sub_block;
+    int i,j;
+
+
+    for (i = 0; i < (int) block_nb; i++) {
+        sub_block = message + (i << 6);
+
+        for (j = 0; j < 16; j++) {
+            PACK32(&sub_block[j << 2], &w[j]);
+        }
+
+        for (j = 16; j < 64; j++) {
+            SHA256_SCR(j);
+        }
+
+        for (j = 0; j < 8; j++) {
+            wv[j] = ctx->h[j];
+        }
+
+        for (j = 0; j < 64; j++) {
+            t1 = wv[7] + SHA256_F2(wv[4]) + CH(wv[4], wv[5], wv[6])
+                + sha256_k[j] + w[j];
+            t2 = SHA256_F1(wv[0]) + MAJ(wv[0], wv[1], wv[2]);
+            wv[7] = wv[6];
+            wv[6] = wv[5];
+            wv[5] = wv[4];
+            wv[4] = wv[3] + t1;
+            wv[3] = wv[2];
+            wv[2] = wv[1];
+            wv[1] = wv[0];
+            wv[0] = t1 + t2;
+        }
+
+        for (j = 0; j < 8; j++) {
+            ctx->h[j] += wv[j];
+        }
+    }
+}
+
+void sha256(const unsigned char *message, unsigned int len, unsigned char *digest)
+{
+    sha256_ctx ctx;
+
+    sha256_init(&ctx);
+    sha256_loop(&ctx, message, len);
+    sha256_result(&ctx, digest);
+}
+
+void sha256_init(sha256_ctx *ctx)
+{
+    int i;
+    for (i = 0; i < 8; i++) {
+        ctx->h[i] = sha256_h0[i];
+    }
+
+    ctx->len = 0;
+    ctx->tot_len = 0;
+}
+
+void sha256_loop(sha256_ctx *ctx, const unsigned char *message,
+                   unsigned int len)
+{
+    unsigned int block_nb;
+    unsigned int new_len, rem_len, tmp_len;
+    const unsigned char *shifted_message;
+
+    tmp_len = SHA256_BLOCK_SIZE - ctx->len;
+    rem_len = len < tmp_len ? len : tmp_len;
+
+    memcpy(&ctx->block[ctx->len], message, rem_len);
+
+    if (ctx->len + len < SHA256_BLOCK_SIZE) {
+        ctx->len += len;
+        return;
+    }
+
+    new_len = len - rem_len;
+    block_nb = new_len / SHA256_BLOCK_SIZE;
+
+    shifted_message = message + rem_len;
+
+    sha256_transf(ctx, ctx->block, 1);
+    sha256_transf(ctx, shifted_message, block_nb);
+
+    rem_len = new_len % SHA256_BLOCK_SIZE;
+
+    memcpy(ctx->block, &shifted_message[block_nb << 6],
+           rem_len);
+
+    ctx->len = rem_len;
+    ctx->tot_len += (block_nb + 1) << 6;
+}
+
+void sha256_result(sha256_ctx *ctx, unsigned char *digest)
+{
+    unsigned int block_nb;
+    unsigned int pm_len;
+    unsigned int len_b;
+    int i;
+
+    block_nb = (1 + ((SHA256_BLOCK_SIZE - 9)
+                     < (ctx->len % SHA256_BLOCK_SIZE)));
+
+    len_b = (ctx->tot_len + ctx->len) << 3;
+    pm_len = block_nb << 6;
+
+    memset(ctx->block + ctx->len, 0, pm_len - ctx->len);
+    ctx->block[ctx->len] = 0x80;
+    UNPACK32(len_b, ctx->block + pm_len - 4);
+
+    sha256_transf(ctx, ctx->block, block_nb);
+
+    for (i = 0 ; i < 8; i++) {
+        UNPACK32(ctx->h[i], &digest[i << 2]);
+    }
+}
+
+void sha256_get_digest(const void *data, size_t size,
+                     unsigned char result[SHA256_RESULTLEN])
+{
+          sha256_ctx ctx;
+
+        sha256_init(&ctx);
+        sha256_loop(&ctx, data, size);
+        sha256_result(&ctx, result);
+}
+
diff -r -u -N --exclude=Makefile.in --exclude=.deps --exclude=Makefile src/lib/sha2.h lib/sha2.h
--- src/lib/sha2.h	1970-01-01 01:00:00.000000000 +0100
+++ lib/sha2.h	2007-02-23 14:22:32.952116316 +0100
@@ -0,0 +1,72 @@
+/*
+ * FIPS 180-2 SHA-224/256/384/512 implementation
+ * Last update: 02/02/2007
+ * Issue date:  04/30/2005
+ *
+ * Copyright (C) 2005, 2007 Olivier Gay <olivier.gay@a3.epfl.ch>
+ * All rights reserved.
+ *
+ * Redistribution and use in source and binary forms, with or without
+ * modification, are permitted provided that the following conditions
+ * are met:
+ * 1. Redistributions of source code must retain the above copyright
+ *    notice, this list of conditions and the following disclaimer.
+ * 2. Redistributions in binary form must reproduce the above copyright
+ *    notice, this list of conditions and the following disclaimer in the
+ *    documentation and/or other materials provided with the distribution.
+ * 3. Neither the name of the project nor the names of its contributors
+ *    may be used to endorse or promote products derived from this software
+ *    without specific prior written permission.
+ *
+ * THIS SOFTWARE IS PROVIDED BY THE PROJECT AND CONTRIBUTORS ``AS IS'' AND
+ * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
+ * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
+ * ARE DISCLAIMED.  IN NO EVENT SHALL THE PROJECT OR CONTRIBUTORS BE LIABLE
+ * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
+ * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
+ * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
+ * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
+ * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
+ * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
+ * SUCH DAMAGE.
+ */
+
+#ifndef SHA2_H
+#define SHA2_H
+
+#define SHA256_RESULTLEN ( 256 / 8)
+
+#define SHA256_BLOCK_SIZE  ( 512 / 8)
+
+#ifndef SHA2_TYPES
+#define SHA2_TYPES
+typedef unsigned char uint8;
+typedef unsigned int  uint32;
+typedef unsigned long long uint64;
+#endif
+
+
+typedef struct {
+    unsigned int tot_len;
+    unsigned int len;
+    unsigned char block[2 * SHA256_BLOCK_SIZE];
+    uint32 h[8];
+} sha256_ctx;
+
+void sha256_transf(sha256_ctx *ctx, const unsigned char *message,
+                   unsigned int block_nb);
+
+
+void sha256_init(sha256_ctx * ctx);
+void sha256_loop(sha256_ctx *ctx, const unsigned char *message,
+                   unsigned int len);
+void sha256_result(sha256_ctx *ctx, unsigned char *digest);
+void sha256(const unsigned char *message, unsigned int len,
+            unsigned char *digest);
+void sha256_get_digest(const void *data, size_t size,
+                     unsigned char result[SHA256_RESULTLEN]);
+
+
+
+#endif /* !SHA2_H */
+
