diff options
Diffstat (limited to 'md5crypt.c')
| -rw-r--r-- | md5crypt.c | 165 |
1 files changed, 165 insertions, 0 deletions
diff --git a/md5crypt.c b/md5crypt.c new file mode 100644 index 0000000..52cf295 --- /dev/null +++ b/md5crypt.c @@ -0,0 +1,165 @@ +/* + * ---------------------------------------------------------------------------- + * "THE BEER-WARE LICENSE" (Revision 42): + * <phk@login.dknet.dk> wrote this file. As long as you retain this + * notice you can do whatever you want with this stuff. If we meet some + * day, and you think this stuff is worth it, you can buy me a beer in + * return. Poul-Henning Kamp + * ---------------------------------------------------------------------------- + */ + +#include "includes.h" + +#if defined(HAVE_MD5_PASSWORDS) && !defined(HAVE_MD5_CRYPT) +#include <sys/types.h> + +#include <string.h> + +#include <openssl/md5.h> + +/* 0 ... 63 => ascii - 64 */ +static unsigned char itoa64[] = + "./0123456789ABCDEFGHIJKLMNOPQRSTUVWXYZabcdefghijklmnopqrstuvwxyz"; + +static char *magic = "$1$"; + +static char * +to64(unsigned long v, int n) +{ + static char buf[5]; + char *s = buf; + + if (n > 4) + return (NULL); + + memset(buf, '\0', sizeof(buf)); + while (--n >= 0) { + *s++ = itoa64[v&0x3f]; + v >>= 6; + } + + return (buf); +} + +int +is_md5_salt(const char *salt) +{ + return (strncmp(salt, magic, strlen(magic)) == 0); +} + +char * +md5_crypt(const char *pw, const char *salt) +{ + static char passwd[120], salt_copy[9]; + static const char *sp, *ep; + unsigned char final[16]; + int sl, pl, i, j; + MD5_CTX ctx, ctx1; + unsigned long l; + + /* Refine the Salt first */ + sp = salt; + + /* If it starts with the magic string, then skip that */ + if(strncmp(sp, magic, strlen(magic)) == 0) + sp += strlen(magic); + + /* It stops at the first '$', max 8 chars */ + for (ep = sp; *ep != '$'; ep++) { + if (*ep == '\0' || ep >= (sp + 8)) + return (NULL); + } + + /* get the length of the true salt */ + sl = ep - sp; + + /* Stash the salt */ + memcpy(salt_copy, sp, sl); + salt_copy[sl] = '\0'; + + MD5_Init(&ctx); + + /* The password first, since that is what is most unknown */ + MD5_Update(&ctx, pw, strlen(pw)); + + /* Then our magic string */ + MD5_Update(&ctx, magic, strlen(magic)); + + /* Then the raw salt */ + MD5_Update(&ctx, sp, sl); + + /* Then just as many characters of the MD5(pw, salt, pw) */ + MD5_Init(&ctx1); + MD5_Update(&ctx1, pw, strlen(pw)); + MD5_Update(&ctx1, sp, sl); + MD5_Update(&ctx1, pw, strlen(pw)); + MD5_Final(final, &ctx1); + + for(pl = strlen(pw); pl > 0; pl -= 16) + MD5_Update(&ctx, final, pl > 16 ? 16 : pl); + + /* Don't leave anything around in vm they could use. */ + memset(final, '\0', sizeof final); + + /* Then something really weird... */ + for (j = 0, i = strlen(pw); i != 0; i >>= 1) + if (i & 1) + MD5_Update(&ctx, final + j, 1); + else + MD5_Update(&ctx, pw + j, 1); + + /* Now make the output string */ + snprintf(passwd, sizeof(passwd), "%s%s$", magic, salt_copy); + + MD5_Final(final, &ctx); + + /* + * and now, just to make sure things don't run too fast + * On a 60 Mhz Pentium this takes 34 msec, so you would + * need 30 seconds to build a 1000 entry dictionary... + */ + for(i = 0; i < 1000; i++) { + MD5_Init(&ctx1); + if (i & 1) + MD5_Update(&ctx1, pw, strlen(pw)); + else + MD5_Update(&ctx1, final, 16); + + if (i % 3) + MD5_Update(&ctx1, sp, sl); + + if (i % 7) + MD5_Update(&ctx1, pw, strlen(pw)); + + if (i & 1) + MD5_Update(&ctx1, final, 16); + else + MD5_Update(&ctx1, pw, strlen(pw)); + + MD5_Final(final, &ctx1); + } + + l = (final[ 0]<<16) | (final[ 6]<<8) | final[12]; + strlcat(passwd, to64(l, 4), sizeof(passwd)); + l = (final[ 1]<<16) | (final[ 7]<<8) | final[13]; + strlcat(passwd, to64(l, 4), sizeof(passwd)); + l = (final[ 2]<<16) | (final[ 8]<<8) | final[14]; + strlcat(passwd, to64(l, 4), sizeof(passwd)); + l = (final[ 3]<<16) | (final[ 9]<<8) | final[15]; + strlcat(passwd, to64(l, 4), sizeof(passwd)); + l = (final[ 4]<<16) | (final[10]<<8) | final[ 5]; + strlcat(passwd, to64(l, 4), sizeof(passwd)); + l = final[11] ; + strlcat(passwd, to64(l, 2), sizeof(passwd)); + + /* Don't leave anything around in vm they could use. */ + memset(final, 0, sizeof(final)); + memset(salt_copy, 0, sizeof(salt_copy)); + memset(&ctx, 0, sizeof(ctx)); + memset(&ctx1, 0, sizeof(ctx1)); + (void)to64(0, 4); + + return (passwd); +} + +#endif /* defined(HAVE_MD5_PASSWORDS) && !defined(HAVE_MD5_CRYPT) */ |