| // SPDX-License-Identifier: GPL-2.0-or-later |
| /* |
| * MD5 and HMAC-MD5 library functions |
| * |
| * md5_block_generic() 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 = (w << s | w >> (32 - s)) + x) |
| |
| static void md5_block_generic(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 __maybe_unused md5_blocks_generic(struct md5_block_state *state, |
| const u8 *data, size_t nblocks) |
| { |
| do { |
| md5_block_generic(state, data); |
| data += MD5_BLOCK_SIZE; |
| } while (--nblocks); |
| } |
| |
| #ifdef CONFIG_CRYPTO_LIB_MD5_ARCH |
| #include "md5.h" /* $(SRCARCH)/md5.h */ |
| #else |
| #define md5_blocks md5_blocks_generic |
| #endif |
| |
| 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); |
| |
| #ifdef md5_mod_init_arch |
| static int __init md5_mod_init(void) |
| { |
| md5_mod_init_arch(); |
| return 0; |
| } |
| subsys_initcall(md5_mod_init); |
| |
| static void __exit md5_mod_exit(void) |
| { |
| } |
| module_exit(md5_mod_exit); |
| #endif |
| |
| MODULE_DESCRIPTION("MD5 and HMAC-MD5 library functions"); |
| MODULE_LICENSE("GPL"); |