// 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");