lib/crypto/md5.c - linux - Git at Google


            
            // SPDX-License-Identifier: GPL-2.0-or-later

            
            /*

            
             * MD5 and HMAC-MD5 library functions

            
             *

            
             * md5_block() is derived from cryptoapi implementation, originally based on the

            
             * public domain implementation written by Colin Plumb in 1993.

            
             *

            
             * Copyright (c) Cryptoapi developers.

            
             * Copyright (c) 2002 James Morris <jmorris@intercode.com.au>

            
             * Copyright 2025 Google LLC

            
             */


            #include <crypto/hmac.h>

            
            #include <crypto/md5.h>

            
            #include <linux/export.h>

            
            #include <linux/kernel.h>

            
            #include <linux/module.h>

            
            #include <linux/string.h>

            
            #include <linux/unaligned.h>

            
            #include <linux/wordpart.h>


            static const struct md5_block_state md5_iv = {

            
            	.h = { MD5_H0, MD5_H1, MD5_H2, MD5_H3 },

            
            };


            #define F1(x, y, z) (z ^ (x & (y ^ z)))

            
            #define F2(x, y, z) F1(z, x, y)

            
            #define F3(x, y, z) (x ^ y ^ z)

            
            #define F4(x, y, z) (y ^ (x | ~z))


            #define MD5STEP(f, w, x, y, z, in, s) \

            
            	(w += f(x, y, z) + in, w = rol32(w, s) + x)


            static void md5_block(struct md5_block_state *state,

            
            		      const u8 data[MD5_BLOCK_SIZE])

            
            {

            
            	u32 in[MD5_BLOCK_WORDS];

            
            	u32 a, b, c, d;


            	memcpy(in, data, MD5_BLOCK_SIZE);

            
            	le32_to_cpu_array(in, ARRAY_SIZE(in));


            	a = state->h[0];

            
            	b = state->h[1];

            
            	c = state->h[2];

            
            	d = state->h[3];


            	MD5STEP(F1, a, b, c, d, in[0] + 0xd76aa478, 7);

            
            	MD5STEP(F1, d, a, b, c, in[1] + 0xe8c7b756, 12);

            
            	MD5STEP(F1, c, d, a, b, in[2] + 0x242070db, 17);

            
            	MD5STEP(F1, b, c, d, a, in[3] + 0xc1bdceee, 22);

            
            	MD5STEP(F1, a, b, c, d, in[4] + 0xf57c0faf, 7);

            
            	MD5STEP(F1, d, a, b, c, in[5] + 0x4787c62a, 12);

            
            	MD5STEP(F1, c, d, a, b, in[6] + 0xa8304613, 17);

            
            	MD5STEP(F1, b, c, d, a, in[7] + 0xfd469501, 22);

            
            	MD5STEP(F1, a, b, c, d, in[8] + 0x698098d8, 7);

            
            	MD5STEP(F1, d, a, b, c, in[9] + 0x8b44f7af, 12);

            
            	MD5STEP(F1, c, d, a, b, in[10] + 0xffff5bb1, 17);

            
            	MD5STEP(F1, b, c, d, a, in[11] + 0x895cd7be, 22);

            
            	MD5STEP(F1, a, b, c, d, in[12] + 0x6b901122, 7);

            
            	MD5STEP(F1, d, a, b, c, in[13] + 0xfd987193, 12);

            
            	MD5STEP(F1, c, d, a, b, in[14] + 0xa679438e, 17);

            
            	MD5STEP(F1, b, c, d, a, in[15] + 0x49b40821, 22);


            	MD5STEP(F2, a, b, c, d, in[1] + 0xf61e2562, 5);

            
            	MD5STEP(F2, d, a, b, c, in[6] + 0xc040b340, 9);

            
            	MD5STEP(F2, c, d, a, b, in[11] + 0x265e5a51, 14);

            
            	MD5STEP(F2, b, c, d, a, in[0] + 0xe9b6c7aa, 20);

            
            	MD5STEP(F2, a, b, c, d, in[5] + 0xd62f105d, 5);

            
            	MD5STEP(F2, d, a, b, c, in[10] + 0x02441453, 9);

            
            	MD5STEP(F2, c, d, a, b, in[15] + 0xd8a1e681, 14);

            
            	MD5STEP(F2, b, c, d, a, in[4] + 0xe7d3fbc8, 20);

            
            	MD5STEP(F2, a, b, c, d, in[9] + 0x21e1cde6, 5);

            
            	MD5STEP(F2, d, a, b, c, in[14] + 0xc33707d6, 9);

            
            	MD5STEP(F2, c, d, a, b, in[3] + 0xf4d50d87, 14);

            
            	MD5STEP(F2, b, c, d, a, in[8] + 0x455a14ed, 20);

            
            	MD5STEP(F2, a, b, c, d, in[13] + 0xa9e3e905, 5);

            
            	MD5STEP(F2, d, a, b, c, in[2] + 0xfcefa3f8, 9);

            
            	MD5STEP(F2, c, d, a, b, in[7] + 0x676f02d9, 14);

            
            	MD5STEP(F2, b, c, d, a, in[12] + 0x8d2a4c8a, 20);


            	MD5STEP(F3, a, b, c, d, in[5] + 0xfffa3942, 4);

            
            	MD5STEP(F3, d, a, b, c, in[8] + 0x8771f681, 11);

            
            	MD5STEP(F3, c, d, a, b, in[11] + 0x6d9d6122, 16);

            
            	MD5STEP(F3, b, c, d, a, in[14] + 0xfde5380c, 23);

            
            	MD5STEP(F3, a, b, c, d, in[1] + 0xa4beea44, 4);

            
            	MD5STEP(F3, d, a, b, c, in[4] + 0x4bdecfa9, 11);

            
            	MD5STEP(F3, c, d, a, b, in[7] + 0xf6bb4b60, 16);

            
            	MD5STEP(F3, b, c, d, a, in[10] + 0xbebfbc70, 23);

            
            	MD5STEP(F3, a, b, c, d, in[13] + 0x289b7ec6, 4);

            
            	MD5STEP(F3, d, a, b, c, in[0] + 0xeaa127fa, 11);

            
            	MD5STEP(F3, c, d, a, b, in[3] + 0xd4ef3085, 16);

            
            	MD5STEP(F3, b, c, d, a, in[6] + 0x04881d05, 23);

            
            	MD5STEP(F3, a, b, c, d, in[9] + 0xd9d4d039, 4);

            
            	MD5STEP(F3, d, a, b, c, in[12] + 0xe6db99e5, 11);

            
            	MD5STEP(F3, c, d, a, b, in[15] + 0x1fa27cf8, 16);

            
            	MD5STEP(F3, b, c, d, a, in[2] + 0xc4ac5665, 23);


            	MD5STEP(F4, a, b, c, d, in[0] + 0xf4292244, 6);

            
            	MD5STEP(F4, d, a, b, c, in[7] + 0x432aff97, 10);

            
            	MD5STEP(F4, c, d, a, b, in[14] + 0xab9423a7, 15);

            
            	MD5STEP(F4, b, c, d, a, in[5] + 0xfc93a039, 21);

            
            	MD5STEP(F4, a, b, c, d, in[12] + 0x655b59c3, 6);

            
            	MD5STEP(F4, d, a, b, c, in[3] + 0x8f0ccc92, 10);

            
            	MD5STEP(F4, c, d, a, b, in[10] + 0xffeff47d, 15);

            
            	MD5STEP(F4, b, c, d, a, in[1] + 0x85845dd1, 21);

            
            	MD5STEP(F4, a, b, c, d, in[8] + 0x6fa87e4f, 6);

            
            	MD5STEP(F4, d, a, b, c, in[15] + 0xfe2ce6e0, 10);

            
            	MD5STEP(F4, c, d, a, b, in[6] + 0xa3014314, 15);

            
            	MD5STEP(F4, b, c, d, a, in[13] + 0x4e0811a1, 21);

            
            	MD5STEP(F4, a, b, c, d, in[4] + 0xf7537e82, 6);

            
            	MD5STEP(F4, d, a, b, c, in[11] + 0xbd3af235, 10);

            
            	MD5STEP(F4, c, d, a, b, in[2] + 0x2ad7d2bb, 15);

            
            	MD5STEP(F4, b, c, d, a, in[9] + 0xeb86d391, 21);


            	state->h[0] += a;

            
            	state->h[1] += b;

            
            	state->h[2] += c;

            
            	state->h[3] += d;

            
            }


            static void md5_blocks(struct md5_block_state *state,

            
            		       const u8 *data, size_t nblocks)

            
            {

            
            	do {

            
            		md5_block(state, data);

            
            		data += MD5_BLOCK_SIZE;

            
            	} while (--nblocks);

            
            }


            void md5_init(struct md5_ctx *ctx)

            
            {

            
            	ctx->state = md5_iv;

            
            	ctx->bytecount = 0;

            
            }

            
            EXPORT_SYMBOL_GPL(md5_init);


            void md5_update(struct md5_ctx *ctx, const u8 *data, size_t len)

            
            {

            
            	size_t partial = ctx->bytecount % MD5_BLOCK_SIZE;


            	ctx->bytecount += len;


            	if (partial + len >= MD5_BLOCK_SIZE) {

            
            		size_t nblocks;


            		if (partial) {

            
            			size_t l = MD5_BLOCK_SIZE - partial;


            			memcpy(&ctx->buf[partial], data, l);

            
            			data += l;

            
            			len -= l;


            			md5_blocks(&ctx->state, ctx->buf, 1);

            
            		}


            		nblocks = len / MD5_BLOCK_SIZE;

            
            		len %= MD5_BLOCK_SIZE;


            		if (nblocks) {

            
            			md5_blocks(&ctx->state, data, nblocks);

            
            			data += nblocks * MD5_BLOCK_SIZE;

            
            		}

            
            		partial = 0;

            
            	}

            
            	if (len)

            
            		memcpy(&ctx->buf[partial], data, len);

            
            }

            
            EXPORT_SYMBOL_GPL(md5_update);


            static void __md5_final(struct md5_ctx *ctx, u8 out[MD5_DIGEST_SIZE])

            
            {

            
            	u64 bitcount = ctx->bytecount << 3;

            
            	size_t partial = ctx->bytecount % MD5_BLOCK_SIZE;


            	ctx->buf[partial++] = 0x80;

            
            	if (partial > MD5_BLOCK_SIZE - 8) {

            
            		memset(&ctx->buf[partial], 0, MD5_BLOCK_SIZE - partial);

            
            		md5_blocks(&ctx->state, ctx->buf, 1);

            
            		partial = 0;

            
            	}

            
            	memset(&ctx->buf[partial], 0, MD5_BLOCK_SIZE - 8 - partial);

            
            	*(__le64 *)&ctx->buf[MD5_BLOCK_SIZE - 8] = cpu_to_le64(bitcount);

            
            	md5_blocks(&ctx->state, ctx->buf, 1);


            	cpu_to_le32_array(ctx->state.h, ARRAY_SIZE(ctx->state.h));

            
            	memcpy(out, ctx->state.h, MD5_DIGEST_SIZE);

            
            }


            void md5_final(struct md5_ctx *ctx, u8 out[MD5_DIGEST_SIZE])

            
            {

            
            	__md5_final(ctx, out);

            
            	memzero_explicit(ctx, sizeof(*ctx));

            
            }

            
            EXPORT_SYMBOL_GPL(md5_final);


            void md5(const u8 *data, size_t len, u8 out[MD5_DIGEST_SIZE])

            
            {

            
            	struct md5_ctx ctx;


            	md5_init(&ctx);

            
            	md5_update(&ctx, data, len);

            
            	md5_final(&ctx, out);

            
            }

            
            EXPORT_SYMBOL_GPL(md5);


            static void __hmac_md5_preparekey(struct md5_block_state *istate,

            
            				  struct md5_block_state *ostate,

            
            				  const u8 *raw_key, size_t raw_key_len)

            
            {

            
            	union {

            
            		u8 b[MD5_BLOCK_SIZE];

            
            		unsigned long w[MD5_BLOCK_SIZE / sizeof(unsigned long)];

            
            	} derived_key = { 0 };


            	if (unlikely(raw_key_len > MD5_BLOCK_SIZE))

            
            		md5(raw_key, raw_key_len, derived_key.b);

            
            	else

            
            		memcpy(derived_key.b, raw_key, raw_key_len);


            	for (size_t i = 0; i < ARRAY_SIZE(derived_key.w); i++)

            
            		derived_key.w[i] ^= REPEAT_BYTE(HMAC_IPAD_VALUE);

            
            	*istate = md5_iv;

            
            	md5_blocks(istate, derived_key.b, 1);


            	for (size_t i = 0; i < ARRAY_SIZE(derived_key.w); i++)

            
            		derived_key.w[i] ^= REPEAT_BYTE(HMAC_OPAD_VALUE ^

            
            						HMAC_IPAD_VALUE);

            
            	*ostate = md5_iv;

            
            	md5_blocks(ostate, derived_key.b, 1);


            	memzero_explicit(&derived_key, sizeof(derived_key));

            
            }


            void hmac_md5_preparekey(struct hmac_md5_key *key,

            
            			 const u8 *raw_key, size_t raw_key_len)

            
            {

            
            	__hmac_md5_preparekey(&key->istate, &key->ostate, raw_key, raw_key_len);

            
            }

            
            EXPORT_SYMBOL_GPL(hmac_md5_preparekey);


            void hmac_md5_init(struct hmac_md5_ctx *ctx, const struct hmac_md5_key *key)

            
            {

            
            	ctx->hash_ctx.state = key->istate;

            
            	ctx->hash_ctx.bytecount = MD5_BLOCK_SIZE;

            
            	ctx->ostate = key->ostate;

            
            }

            
            EXPORT_SYMBOL_GPL(hmac_md5_init);


            void hmac_md5_init_usingrawkey(struct hmac_md5_ctx *ctx,

            
            			       const u8 *raw_key, size_t raw_key_len)

            
            {

            
            	__hmac_md5_preparekey(&ctx->hash_ctx.state, &ctx->ostate,

            
            			      raw_key, raw_key_len);

            
            	ctx->hash_ctx.bytecount = MD5_BLOCK_SIZE;

            
            }

            
            EXPORT_SYMBOL_GPL(hmac_md5_init_usingrawkey);


            void hmac_md5_final(struct hmac_md5_ctx *ctx, u8 out[MD5_DIGEST_SIZE])

            
            {

            
            	/* Generate the padded input for the outer hash in ctx->hash_ctx.buf. */

            
            	__md5_final(&ctx->hash_ctx, ctx->hash_ctx.buf);

            
            	memset(&ctx->hash_ctx.buf[MD5_DIGEST_SIZE], 0,

            
            	       MD5_BLOCK_SIZE - MD5_DIGEST_SIZE);

            
            	ctx->hash_ctx.buf[MD5_DIGEST_SIZE] = 0x80;

            
            	*(__le64 *)&ctx->hash_ctx.buf[MD5_BLOCK_SIZE - 8] =

            
            		cpu_to_le64(8 * (MD5_BLOCK_SIZE + MD5_DIGEST_SIZE));


            	/* Compute the outer hash, which gives the HMAC value. */

            
            	md5_blocks(&ctx->ostate, ctx->hash_ctx.buf, 1);

            
            	cpu_to_le32_array(ctx->ostate.h, ARRAY_SIZE(ctx->ostate.h));

            
            	memcpy(out, ctx->ostate.h, MD5_DIGEST_SIZE);


            	memzero_explicit(ctx, sizeof(*ctx));

            
            }

            
            EXPORT_SYMBOL_GPL(hmac_md5_final);


            void hmac_md5(const struct hmac_md5_key *key,

            
            	      const u8 *data, size_t data_len, u8 out[MD5_DIGEST_SIZE])

            
            {

            
            	struct hmac_md5_ctx ctx;


            	hmac_md5_init(&ctx, key);

            
            	hmac_md5_update(&ctx, data, data_len);

            
            	hmac_md5_final(&ctx, out);

            
            }

            
            EXPORT_SYMBOL_GPL(hmac_md5);


            void hmac_md5_usingrawkey(const u8 *raw_key, size_t raw_key_len,

            
            			  const u8 *data, size_t data_len,

            
            			  u8 out[MD5_DIGEST_SIZE])

            
            {

            
            	struct hmac_md5_ctx ctx;


            	hmac_md5_init_usingrawkey(&ctx, raw_key, raw_key_len);

            
            	hmac_md5_update(&ctx, data, data_len);

            
            	hmac_md5_final(&ctx, out);

            
            }

            
            EXPORT_SYMBOL_GPL(hmac_md5_usingrawkey);


            MODULE_DESCRIPTION("MD5 and HMAC-MD5 library functions");

            
            MODULE_LICENSE("GPL");
	// SPDX-License-Identifier: GPL-2.0-or-later
	/*
	* MD5 and HMAC-MD5 library functions
	*
	* md5_block() is derived from cryptoapi implementation, originally based on the
	* public domain implementation written by Colin Plumb in 1993.
	*
	* Copyright (c) Cryptoapi developers.
	* Copyright (c) 2002 James Morris <jmorris@intercode.com.au>
	* Copyright 2025 Google LLC
	*/

	#include <crypto/hmac.h>
	#include <crypto/md5.h>
	#include <linux/export.h>
	#include <linux/kernel.h>
	#include <linux/module.h>
	#include <linux/string.h>
	#include <linux/unaligned.h>
	#include <linux/wordpart.h>

	static const struct md5_block_state md5_iv = {
	.h = { MD5_H0, MD5_H1, MD5_H2, MD5_H3 },
	};

	#define F1(x, y, z) (z ^ (x & (y ^ z)))
	#define F2(x, y, z) F1(z, x, y)
	#define F3(x, y, z) (x ^ y ^ z)
	#define F4(x, y, z) (y ^ (x \| ~z))

	#define MD5STEP(f, w, x, y, z, in, s) \
	(w += f(x, y, z) + in, w = rol32(w, s) + x)

	static void md5_block(struct md5_block_state *state,
	const u8 data[MD5_BLOCK_SIZE])
	{
	u32 in[MD5_BLOCK_WORDS];
	u32 a, b, c, d;

	memcpy(in, data, MD5_BLOCK_SIZE);
	le32_to_cpu_array(in, ARRAY_SIZE(in));

	a = state->h[0];
	b = state->h[1];
	c = state->h[2];
	d = state->h[3];

	MD5STEP(F1, a, b, c, d, in[0] + 0xd76aa478, 7);
	MD5STEP(F1, d, a, b, c, in[1] + 0xe8c7b756, 12);
	MD5STEP(F1, c, d, a, b, in[2] + 0x242070db, 17);
	MD5STEP(F1, b, c, d, a, in[3] + 0xc1bdceee, 22);
	MD5STEP(F1, a, b, c, d, in[4] + 0xf57c0faf, 7);
	MD5STEP(F1, d, a, b, c, in[5] + 0x4787c62a, 12);
	MD5STEP(F1, c, d, a, b, in[6] + 0xa8304613, 17);
	MD5STEP(F1, b, c, d, a, in[7] + 0xfd469501, 22);
	MD5STEP(F1, a, b, c, d, in[8] + 0x698098d8, 7);
	MD5STEP(F1, d, a, b, c, in[9] + 0x8b44f7af, 12);
	MD5STEP(F1, c, d, a, b, in[10] + 0xffff5bb1, 17);
	MD5STEP(F1, b, c, d, a, in[11] + 0x895cd7be, 22);
	MD5STEP(F1, a, b, c, d, in[12] + 0x6b901122, 7);
	MD5STEP(F1, d, a, b, c, in[13] + 0xfd987193, 12);
	MD5STEP(F1, c, d, a, b, in[14] + 0xa679438e, 17);
	MD5STEP(F1, b, c, d, a, in[15] + 0x49b40821, 22);

	MD5STEP(F2, a, b, c, d, in[1] + 0xf61e2562, 5);
	MD5STEP(F2, d, a, b, c, in[6] + 0xc040b340, 9);
	MD5STEP(F2, c, d, a, b, in[11] + 0x265e5a51, 14);
	MD5STEP(F2, b, c, d, a, in[0] + 0xe9b6c7aa, 20);
	MD5STEP(F2, a, b, c, d, in[5] + 0xd62f105d, 5);
	MD5STEP(F2, d, a, b, c, in[10] + 0x02441453, 9);
	MD5STEP(F2, c, d, a, b, in[15] + 0xd8a1e681, 14);
	MD5STEP(F2, b, c, d, a, in[4] + 0xe7d3fbc8, 20);
	MD5STEP(F2, a, b, c, d, in[9] + 0x21e1cde6, 5);
	MD5STEP(F2, d, a, b, c, in[14] + 0xc33707d6, 9);
	MD5STEP(F2, c, d, a, b, in[3] + 0xf4d50d87, 14);
	MD5STEP(F2, b, c, d, a, in[8] + 0x455a14ed, 20);
	MD5STEP(F2, a, b, c, d, in[13] + 0xa9e3e905, 5);
	MD5STEP(F2, d, a, b, c, in[2] + 0xfcefa3f8, 9);
	MD5STEP(F2, c, d, a, b, in[7] + 0x676f02d9, 14);
	MD5STEP(F2, b, c, d, a, in[12] + 0x8d2a4c8a, 20);

	MD5STEP(F3, a, b, c, d, in[5] + 0xfffa3942, 4);
	MD5STEP(F3, d, a, b, c, in[8] + 0x8771f681, 11);
	MD5STEP(F3, c, d, a, b, in[11] + 0x6d9d6122, 16);
	MD5STEP(F3, b, c, d, a, in[14] + 0xfde5380c, 23);
	MD5STEP(F3, a, b, c, d, in[1] + 0xa4beea44, 4);
	MD5STEP(F3, d, a, b, c, in[4] + 0x4bdecfa9, 11);
	MD5STEP(F3, c, d, a, b, in[7] + 0xf6bb4b60, 16);
	MD5STEP(F3, b, c, d, a, in[10] + 0xbebfbc70, 23);
	MD5STEP(F3, a, b, c, d, in[13] + 0x289b7ec6, 4);
	MD5STEP(F3, d, a, b, c, in[0] + 0xeaa127fa, 11);
	MD5STEP(F3, c, d, a, b, in[3] + 0xd4ef3085, 16);
	MD5STEP(F3, b, c, d, a, in[6] + 0x04881d05, 23);
	MD5STEP(F3, a, b, c, d, in[9] + 0xd9d4d039, 4);
	MD5STEP(F3, d, a, b, c, in[12] + 0xe6db99e5, 11);
	MD5STEP(F3, c, d, a, b, in[15] + 0x1fa27cf8, 16);
	MD5STEP(F3, b, c, d, a, in[2] + 0xc4ac5665, 23);

	MD5STEP(F4, a, b, c, d, in[0] + 0xf4292244, 6);
	MD5STEP(F4, d, a, b, c, in[7] + 0x432aff97, 10);
	MD5STEP(F4, c, d, a, b, in[14] + 0xab9423a7, 15);
	MD5STEP(F4, b, c, d, a, in[5] + 0xfc93a039, 21);
	MD5STEP(F4, a, b, c, d, in[12] + 0x655b59c3, 6);
	MD5STEP(F4, d, a, b, c, in[3] + 0x8f0ccc92, 10);
	MD5STEP(F4, c, d, a, b, in[10] + 0xffeff47d, 15);
	MD5STEP(F4, b, c, d, a, in[1] + 0x85845dd1, 21);
	MD5STEP(F4, a, b, c, d, in[8] + 0x6fa87e4f, 6);
	MD5STEP(F4, d, a, b, c, in[15] + 0xfe2ce6e0, 10);
	MD5STEP(F4, c, d, a, b, in[6] + 0xa3014314, 15);
	MD5STEP(F4, b, c, d, a, in[13] + 0x4e0811a1, 21);
	MD5STEP(F4, a, b, c, d, in[4] + 0xf7537e82, 6);
	MD5STEP(F4, d, a, b, c, in[11] + 0xbd3af235, 10);
	MD5STEP(F4, c, d, a, b, in[2] + 0x2ad7d2bb, 15);
	MD5STEP(F4, b, c, d, a, in[9] + 0xeb86d391, 21);

	state->h[0] += a;
	state->h[1] += b;
	state->h[2] += c;
	state->h[3] += d;
	}

	static void md5_blocks(struct md5_block_state *state,
	const u8 *data, size_t nblocks)
	{
	do {
	md5_block(state, data);
	data += MD5_BLOCK_SIZE;
	} while (--nblocks);
	}

	void md5_init(struct md5_ctx *ctx)
	{
	ctx->state = md5_iv;
	ctx->bytecount = 0;
	}
	EXPORT_SYMBOL_GPL(md5_init);

	void md5_update(struct md5_ctx ctx, const u8 data, size_t len)
	{
	size_t partial = ctx->bytecount % MD5_BLOCK_SIZE;

	ctx->bytecount += len;

	if (partial + len >= MD5_BLOCK_SIZE) {
	size_t nblocks;

	if (partial) {
	size_t l = MD5_BLOCK_SIZE - partial;

	memcpy(&ctx->buf[partial], data, l);
	data += l;
	len -= l;

	md5_blocks(&ctx->state, ctx->buf, 1);
	}

	nblocks = len / MD5_BLOCK_SIZE;
	len %= MD5_BLOCK_SIZE;

	if (nblocks) {
	md5_blocks(&ctx->state, data, nblocks);
	data += nblocks * MD5_BLOCK_SIZE;
	}
	partial = 0;
	}
	if (len)
	memcpy(&ctx->buf[partial], data, len);
	}
	EXPORT_SYMBOL_GPL(md5_update);

	static void __md5_final(struct md5_ctx *ctx, u8 out[MD5_DIGEST_SIZE])
	{
	u64 bitcount = ctx->bytecount << 3;
	size_t partial = ctx->bytecount % MD5_BLOCK_SIZE;

	ctx->buf[partial++] = 0x80;
	if (partial > MD5_BLOCK_SIZE - 8) {
	memset(&ctx->buf[partial], 0, MD5_BLOCK_SIZE - partial);
	md5_blocks(&ctx->state, ctx->buf, 1);
	partial = 0;
	}
	memset(&ctx->buf[partial], 0, MD5_BLOCK_SIZE - 8 - partial);
	(__le64 )&ctx->buf[MD5_BLOCK_SIZE - 8] = cpu_to_le64(bitcount);
	md5_blocks(&ctx->state, ctx->buf, 1);

	cpu_to_le32_array(ctx->state.h, ARRAY_SIZE(ctx->state.h));
	memcpy(out, ctx->state.h, MD5_DIGEST_SIZE);
	}

	void md5_final(struct md5_ctx *ctx, u8 out[MD5_DIGEST_SIZE])
	{
	__md5_final(ctx, out);
	memzero_explicit(ctx, sizeof(*ctx));
	}
	EXPORT_SYMBOL_GPL(md5_final);

	void md5(const u8 *data, size_t len, u8 out[MD5_DIGEST_SIZE])
	{
	struct md5_ctx ctx;

	md5_init(&ctx);
	md5_update(&ctx, data, len);
	md5_final(&ctx, out);
	}
	EXPORT_SYMBOL_GPL(md5);

	static void __hmac_md5_preparekey(struct md5_block_state *istate,
	struct md5_block_state *ostate,
	const u8 *raw_key, size_t raw_key_len)
	{
	union {
	u8 b[MD5_BLOCK_SIZE];
	unsigned long w[MD5_BLOCK_SIZE / sizeof(unsigned long)];
	} derived_key = { 0 };

	if (unlikely(raw_key_len > MD5_BLOCK_SIZE))
	md5(raw_key, raw_key_len, derived_key.b);
	else
	memcpy(derived_key.b, raw_key, raw_key_len);

	for (size_t i = 0; i < ARRAY_SIZE(derived_key.w); i++)
	derived_key.w[i] ^= REPEAT_BYTE(HMAC_IPAD_VALUE);
	*istate = md5_iv;
	md5_blocks(istate, derived_key.b, 1);

	for (size_t i = 0; i < ARRAY_SIZE(derived_key.w); i++)
	derived_key.w[i] ^= REPEAT_BYTE(HMAC_OPAD_VALUE ^
	HMAC_IPAD_VALUE);
	*ostate = md5_iv;
	md5_blocks(ostate, derived_key.b, 1);

	memzero_explicit(&derived_key, sizeof(derived_key));
	}

	void hmac_md5_preparekey(struct hmac_md5_key *key,
	const u8 *raw_key, size_t raw_key_len)
	{
	__hmac_md5_preparekey(&key->istate, &key->ostate, raw_key, raw_key_len);
	}
	EXPORT_SYMBOL_GPL(hmac_md5_preparekey);

	void hmac_md5_init(struct hmac_md5_ctx ctx, const struct hmac_md5_key key)
	{
	ctx->hash_ctx.state = key->istate;
	ctx->hash_ctx.bytecount = MD5_BLOCK_SIZE;
	ctx->ostate = key->ostate;
	}
	EXPORT_SYMBOL_GPL(hmac_md5_init);

	void hmac_md5_init_usingrawkey(struct hmac_md5_ctx *ctx,
	const u8 *raw_key, size_t raw_key_len)
	{
	__hmac_md5_preparekey(&ctx->hash_ctx.state, &ctx->ostate,
	raw_key, raw_key_len);
	ctx->hash_ctx.bytecount = MD5_BLOCK_SIZE;
	}
	EXPORT_SYMBOL_GPL(hmac_md5_init_usingrawkey);

	void hmac_md5_final(struct hmac_md5_ctx *ctx, u8 out[MD5_DIGEST_SIZE])
	{
	/* Generate the padded input for the outer hash in ctx->hash_ctx.buf. */
	__md5_final(&ctx->hash_ctx, ctx->hash_ctx.buf);
	memset(&ctx->hash_ctx.buf[MD5_DIGEST_SIZE], 0,
	MD5_BLOCK_SIZE - MD5_DIGEST_SIZE);
	ctx->hash_ctx.buf[MD5_DIGEST_SIZE] = 0x80;
	(__le64 )&ctx->hash_ctx.buf[MD5_BLOCK_SIZE - 8] =
	cpu_to_le64(8 * (MD5_BLOCK_SIZE + MD5_DIGEST_SIZE));

	/* Compute the outer hash, which gives the HMAC value. */
	md5_blocks(&ctx->ostate, ctx->hash_ctx.buf, 1);
	cpu_to_le32_array(ctx->ostate.h, ARRAY_SIZE(ctx->ostate.h));
	memcpy(out, ctx->ostate.h, MD5_DIGEST_SIZE);

	memzero_explicit(ctx, sizeof(*ctx));
	}
	EXPORT_SYMBOL_GPL(hmac_md5_final);

	void hmac_md5(const struct hmac_md5_key *key,
	const u8 *data, size_t data_len, u8 out[MD5_DIGEST_SIZE])
	{
	struct hmac_md5_ctx ctx;

	hmac_md5_init(&ctx, key);
	hmac_md5_update(&ctx, data, data_len);
	hmac_md5_final(&ctx, out);
	}
	EXPORT_SYMBOL_GPL(hmac_md5);

	void hmac_md5_usingrawkey(const u8 *raw_key, size_t raw_key_len,
	const u8 *data, size_t data_len,
	u8 out[MD5_DIGEST_SIZE])
	{
	struct hmac_md5_ctx ctx;

	hmac_md5_init_usingrawkey(&ctx, raw_key, raw_key_len);
	hmac_md5_update(&ctx, data, data_len);
	hmac_md5_final(&ctx, out);
	}
	EXPORT_SYMBOL_GPL(hmac_md5_usingrawkey);

	MODULE_DESCRIPTION("MD5 and HMAC-MD5 library functions");
	MODULE_LICENSE("GPL");